PlayerTag.java

package com.denizenscript.denizen.objects;

import com.denizenscript.denizen.Denizen;
import com.denizenscript.denizen.nms.NMSHandler;
import com.denizenscript.denizen.nms.NMSVersion;
import com.denizenscript.denizen.nms.abstracts.ImprovedOfflinePlayer;
import com.denizenscript.denizen.nms.abstracts.Sidebar;
import com.denizenscript.denizen.nms.interfaces.AdvancementHelper;
import com.denizenscript.denizen.objects.properties.entity.EntityHealth;
import com.denizenscript.denizen.scripts.commands.player.DisguiseCommand;
import com.denizenscript.denizen.scripts.commands.player.ExperienceCommand;
import com.denizenscript.denizen.scripts.commands.player.SidebarCommand;
import com.denizenscript.denizen.scripts.commands.server.BossBarCommand;
import com.denizenscript.denizen.tags.core.PlayerTagBase;
import com.denizenscript.denizen.utilities.*;
import com.denizenscript.denizen.utilities.blocks.FakeBlock;
import com.denizenscript.denizen.utilities.depends.Depends;
import com.denizenscript.denizen.utilities.entity.BossBarHelper;
import com.denizenscript.denizen.utilities.entity.FakeEntity;
import com.denizenscript.denizen.utilities.entity.HideEntitiesHelper;
import com.denizenscript.denizen.utilities.flags.PlayerFlagHandler;
import com.denizenscript.denizen.utilities.packets.DenizenPacketHandler;
import com.denizenscript.denizen.utilities.packets.HideParticles;
import com.denizenscript.denizen.utilities.packets.ItemChangeMessage;
import com.denizenscript.denizen.utilities.packets.NetworkInterceptHelper;
import com.denizenscript.denizencore.DenizenCore;
import com.denizenscript.denizencore.flags.AbstractFlagTracker;
import com.denizenscript.denizencore.flags.FlaggableObject;
import com.denizenscript.denizencore.objects.*;
import com.denizenscript.denizencore.objects.core.*;
import com.denizenscript.denizencore.tags.Attribute;
import com.denizenscript.denizencore.tags.ObjectTagProcessor;
import com.denizenscript.denizencore.tags.TagContext;
import com.denizenscript.denizencore.tags.TagRunnable;
import com.denizenscript.denizencore.utilities.CoreUtilities;
import com.denizenscript.denizencore.utilities.Deprecations;
import com.denizenscript.denizencore.utilities.debugging.Debug;
import net.citizensnpcs.api.CitizensAPI;
import net.citizensnpcs.api.npc.NPC;
import net.citizensnpcs.npc.NPCSelector;
import org.bukkit.*;
import org.bukkit.advancement.Advancement;
import org.bukkit.advancement.AdvancementProgress;
import org.bukkit.block.BlockState;
import org.bukkit.block.Sign;
import org.bukkit.block.banner.Pattern;
import org.bukkit.block.banner.PatternType;
import org.bukkit.boss.BossBar;
import org.bukkit.command.PluginCommand;
import org.bukkit.entity.*;
import org.bukkit.event.inventory.InventoryType;
import org.bukkit.inventory.*;
import org.bukkit.map.MapView;
import org.bukkit.scoreboard.Scoreboard;
import org.bukkit.scoreboard.Team;
import org.bukkit.util.RayTraceResult;

import java.util.*;

public class PlayerTag implements ObjectTag, Adjustable, EntityFormObject, FlaggableObject {

    // <--[ObjectType]
    // @name PlayerTag
    // @prefix p
    // @base EntityTag
    // @implements FlaggableObject
    // @ExampleTagBase player
    // @ExampleValues <player>
    // @ExampleForReturns
    // - kill %VALUE%
    // @ExampleForReturns
    // - heal %VALUE%
    // @ExampleForReturns
    // - narrate "hello there!" targets:%VALUE%
    // @format
    // The identity format for players is the UUID of the relevant player.
    //
    // @description
    // A PlayerTag represents a player in the game.
    //
    // This object type is flaggable.
    // Flags on this object type will be stored in the file "plugins/Denizen/player_flags/(UUID).dat",
    // with automatic loading only when the player is online and caching for interacting with offline player flags.
    //
    // -->

    /////////////////////
    //   STATIC METHODS
    /////////////////

    public static PlayerTag mirrorBukkitPlayer(OfflinePlayer player) {
        if (player == null) {
            return null;
        }
        else {
            return new PlayerTag(player);
        }
    }

    static Map<String, UUID> playerNames = new HashMap<>();

    /**
     * Notes that the player exists, for easy PlayerTag valueOf handling.
     */
    public static void notePlayer(OfflinePlayer player) {
        if (player.getName() == null) {
            Debug.echoError("Null named player " + player + " - may be file corruption, or player data imported from non-bukkit server?");
            return;
        }
        if (!playerNames.containsKey(CoreUtilities.toLowerCase(player.getName()))) {
            playerNames.put(CoreUtilities.toLowerCase(player.getName()), player.getUniqueId());
        }
    }

    public static boolean isNoted(OfflinePlayer player) {
        return playerNames.containsValue(player.getUniqueId());
    }

    public static Map<String, UUID> getAllPlayers() {
        return playerNames;
    }

    /////////////////////
    //   OBJECT FETCHER
    /////////////////

    @Fetchable("p")
    public static PlayerTag valueOf(String string, TagContext context) {
        return valueOfInternal(string, context, true);
    }

    public static String playerByNameMessage = BukkitImplDeprecations.playerByNameWarning.message;

    public static PlayerTag valueOfInternal(String string, TagContext context, boolean defaultAnnounce) {
        if (string == null) {
            return null;
        }
        boolean announce = context == null ? defaultAnnounce : context.showErrors();
        string = CoreUtilities.toLowerCase(string);
        if (string.startsWith("p@")) {
            string = string.substring("p@".length());
        }
        if (string.length() == 36 && string.indexOf('-') >= 0) {
            try {
                UUID uuid = UUID.fromString(string);
                if (uuid != null) {
                    OfflinePlayer player = Bukkit.getOfflinePlayer(uuid);
                    if (player != null) {
                        return new PlayerTag(player);
                    }
                }
            }
            catch (IllegalArgumentException e) {
                // Nothing
            }
        }
        // Match as a player name
        if (string.length() <= 16 && playerNames.containsKey(string)) {
            OfflinePlayer player = Bukkit.getOfflinePlayer(playerNames.get(string));
            if (announce && (context == null || context.script != null)) { // 'script != null' check is to allow ex command usage silently
                BukkitImplDeprecations.playerByNameWarning.message = playerByNameMessage + " Player named '" + player.getName() + "' has UUID: " + player.getUniqueId();
                BukkitImplDeprecations.playerByNameWarning.warn(context);
            }
            return new PlayerTag(player);
        }
        if (announce) {
            Debug.log("Minor: Invalid Player! '" + string + "' could not be found.");
        }
        return null;
    }

    public static boolean matches(String arg) {
        if (arg == null) {
            return false;
        }
        arg = CoreUtilities.toLowerCase(arg);
        if (arg.startsWith("p@")) {
            return true;
        }
        if (arg.length() == 36 && arg.indexOf('-') >= 0) {
            try {
                UUID uuid = UUID.fromString(arg);
                if (uuid != null) {
                    OfflinePlayer player = Bukkit.getOfflinePlayer(uuid);
                    if (player != null && (player.isOnline() || player.hasPlayedBefore())) {
                        return true;
                    }
                }
            }
            catch (IllegalArgumentException e) {
                // Nothing
            }
        }
        return false;
    }

    public static boolean playerNameIsValid(String name) {
        return playerNames.containsKey(CoreUtilities.toLowerCase(name));
    }

    /////////////////////
    //   CONSTRUCTORS
    /////////////////

    public PlayerTag(OfflinePlayer player) {
        this(player.getUniqueId());
    }

    public PlayerTag(UUID uuid) {
        this.uuid = uuid;
    }

    public PlayerTag(Player player) {
        this((OfflinePlayer) player);
        if (EntityTag.isNPC(player)) {
            throw new IllegalStateException("NPCs are not allowed as PlayerTag objects!");
        }
    }

    /////////////////////
    //   INSTANCE FIELDS/METHODS
    /////////////////

    @Override
    public AbstractFlagTracker getFlagTracker() {
        return PlayerFlagHandler.getTrackerFor(getUUID());
    }

    @Override
    public void reapplyTracker(AbstractFlagTracker tracker) {
        // Nothing to do.
    }

    UUID uuid;

    public boolean isValid() {
        OfflinePlayer pl = getOfflinePlayer();
        if (pl != null && pl.hasPlayedBefore()) {
            return true;
        }
        return getPlayerEntity() != null;
    }

    public Player getPlayerEntity() {
        return Bukkit.getPlayer(uuid);
    }

    public UUID getUUID() {
        return uuid;
    }

    public OfflinePlayer getOfflinePlayer() {
        return Bukkit.getOfflinePlayer(uuid);
    }

    public ImprovedOfflinePlayer getNBTEditor() {
        ImprovedOfflinePlayer result = ImprovedOfflinePlayer.offlinePlayers.get(uuid);
        if (result == null || (!result.modified && result.timeLastLoaded + Settings.worldPlayerDataMaxCacheTicks < DenizenCore.currentTimeMonotonicMillis)) {
            result = NMSHandler.playerHelper.getOfflineData(uuid);
            if (result != null) {
                ImprovedOfflinePlayer.offlinePlayers.put(uuid, result);
            }
        }
        return result;
    }

    @Override
    public EntityTag getDenizenEntity() {
        return new EntityTag(getPlayerEntity());
    }

    public NPCTag getSelectedNPC() {
        if (Depends.citizens != null && CitizensAPI.hasImplementation()) {
            NPC npc = CitizensAPI.getDefaultNPCSelector().getSelected(getPlayerEntity());
            if (npc != null) {
                return new NPCTag(npc);
            }
        }
        return null;
    }

    public String getName() {
        return getOfflinePlayer().getName();
    }

    @Override
    public LocationTag getLocation() {
        if (isOnline()) {
            return new LocationTag(getPlayerEntity().getLocation());
        }
        else {
            return new LocationTag(getNBTEditor().getLocation());
        }
    }

    public int getRemainingAir() {
        if (isOnline()) {
            return getPlayerEntity().getRemainingAir();
        }
        else {
            return getNBTEditor().getRemainingAir();
        }
    }

    public int getMaximumAir() {
        if (isOnline()) {
            return getPlayerEntity().getMaximumAir();
        }
        else {
            return 300;
        }
    }

    public double getHealth() {
        if (isOnline()) {
            return getPlayerEntity().getHealth();
        }
        else {
            return getNBTEditor().getHealthFloat();
        }
    }

    public double getMaxHealth() {
        if (isOnline()) {
            return getPlayerEntity().getMaxHealth();
        }
        else {
            return getNBTEditor().getMaxHealth();
        }
    }

    public int getFoodLevel() {
        if (isOnline()) {
            return getPlayerEntity().getFoodLevel();
        }
        else {
            return getNBTEditor().getFoodLevel();
        }
    }

    public LocationTag getEyeLocation() {
        if (isOnline()) {
            return new LocationTag(getPlayerEntity().getEyeLocation());
        }
        else {
            return null;
        }
    }

    public InventoryTag getInventory() {
        if (isOnline()) {
            return InventoryTag.mirrorBukkitInventory(getPlayerEntity().getInventory());
        }
        else {
            return new InventoryTag(getNBTEditor());
        }
    }

    public CraftingInventory getBukkitWorkbench() {
        if (isOnline()) {
            if (getPlayerEntity().getOpenInventory().getType() == InventoryType.WORKBENCH
                    || getPlayerEntity().getOpenInventory().getType() == InventoryType.CRAFTING) {
                return (CraftingInventory) getPlayerEntity().getOpenInventory().getTopInventory();
            }
        }
        return null;
    }

    public InventoryTag getWorkbench() {
        if (isOnline()) {
            CraftingInventory workbench = getBukkitWorkbench();
            if (workbench != null) {
                return new InventoryTag(workbench, getPlayerEntity());
            }
        }
        return null;
    }

    public InventoryTag getEnderChest() {
        if (isOnline()) {
            return new InventoryTag(getPlayerEntity().getEnderChest(), getPlayerEntity());
        }
        else {
            return new InventoryTag(getNBTEditor(), true);
        }
    }

    public WorldTag getWorldTag() {
        if (isOnline()) {
            return new WorldTag(getPlayerEntity().getWorld());
        }
        else {
            return new WorldTag(getLocation().getWorldName());
        }
    }

    public World getWorld() {
        if (isOnline()) {
            return getPlayerEntity().getWorld();
        }
        else {
            return getLocation().getWorld();
        }
    }

    public ItemTag getHeldItem() {
        return new ItemTag(getPlayerEntity().getEquipment().getItemInMainHand());
    }

    public ItemTag getOffhandItem() {
        return new ItemTag(getPlayerEntity().getEquipment().getItemInOffHand());
    }

    public void decrementStatistic(Statistic statistic, int amount) {
        getOfflinePlayer().decrementStatistic(statistic, amount);
    }

    public void decrementStatistic(Statistic statistic, EntityType entity, int amount) {
        if (statistic.getType() == Statistic.Type.ENTITY) {
            getOfflinePlayer().decrementStatistic(statistic, entity, amount);
        }
    }

    public void decrementStatistic(Statistic statistic, Material material, int amount) {
        if (statistic.getType() == Statistic.Type.BLOCK || statistic.getType() == Statistic.Type.ITEM) {
            getOfflinePlayer().decrementStatistic(statistic, material, amount);
        }
    }

    public void incrementStatistic(Statistic statistic, int amount) {
        getOfflinePlayer().incrementStatistic(statistic, amount);
    }

    public void incrementStatistic(Statistic statistic, EntityType entity, int amount) {
        if (statistic.getType() == Statistic.Type.ENTITY) {
            getOfflinePlayer().incrementStatistic(statistic, entity, amount);
        }
    }

    public void incrementStatistic(Statistic statistic, Material material, int amount) {
        if (statistic.getType() == Statistic.Type.BLOCK  || statistic.getType() == Statistic.Type.ITEM) {
            getOfflinePlayer().incrementStatistic(statistic, material, amount);
        }
    }

    public void setStatistic(Statistic statistic, int amount) {
        getOfflinePlayer().setStatistic(statistic, amount);
    }

    public void setStatistic(Statistic statistic, EntityType entity, int amount) {
        if (statistic.getType() == Statistic.Type.ENTITY) {
            getOfflinePlayer().setStatistic(statistic, entity, amount);
        }
    }

    public void setStatistic(Statistic statistic, Material material, int amount) {
        if (statistic.getType() == Statistic.Type.BLOCK || statistic.getType() == Statistic.Type.ITEM) {
            getOfflinePlayer().setStatistic(statistic, material, amount);
        }
    }

    public boolean isOnline() {
        return getPlayerEntity() != null;
    }

    public void setBedSpawnLocation(Location location) {
        if (isOnline()) {
            getPlayerEntity().setBedSpawnLocation(location);
        }
        else {
            getNBTEditor().setBedSpawnLocation(location);
        }
    }

    public void setLocation(Location location) {
        if (isOnline()) {
            getPlayerEntity().teleport(location);
        }
        else {
            getNBTEditor().setLocation(location);
        }
    }

    public void setMaximumAir(int air) {
        if (isOnline()) {
            getPlayerEntity().setMaximumAir(air);
        }
        else {
            Debug.echoError("Cannot set the maximum air of an offline player!");
        }
    }

    public void setRemainingAir(int air) {
        if (isOnline()) {
            getPlayerEntity().setRemainingAir(air);
        }
        else {
            getNBTEditor().setRemainingAir(air);
        }
    }

    public void setHealth(double health) {
        if (isOnline()) {
            getPlayerEntity().setHealth(health);
        }
        else {
            getNBTEditor().setHealthFloat((float) health);
        }
    }

    public void setMaxHealth(double maxHealth) {
        if (isOnline()) {
            getPlayerEntity().setMaxHealth(maxHealth);
        }
        else {
            getNBTEditor().setMaxHealth(maxHealth);
        }
    }

    public void setFoodLevel(int foodLevel) {
        if (isOnline()) {
            getPlayerEntity().setFoodLevel(foodLevel);
        }
        else {
            getNBTEditor().setFoodLevel(foodLevel);
        }
    }

    public float getExp() {
        if (isOnline()) {
            return getPlayerEntity().getExp();
        }
        else {
            return getNBTEditor().getExp();
        }
    }

    public void setExp(float xp) {
        if (isOnline()) {
            getPlayerEntity().setExp(xp);
        }
        else {
            getNBTEditor().setExp(xp);
        }
    }

    public int getTotalExperience() {
        if (isOnline()) {
            return getPlayerEntity().getTotalExperience();
        }
        else {
            return getNBTEditor().getTotalExperience();
        }
    }

    public void setTotalExperience(int xp) {
        if (isOnline()) {
            getPlayerEntity().setTotalExperience(xp);
        }
        else {
            getNBTEditor().setTotalExperience(xp);
        }
    }

    public int getLevel() {
        if (isOnline()) {
            return getPlayerEntity().getLevel();
        }
        else {
            return getNBTEditor().getLevel();
        }
    }

    public void setLevel(int level) {
        if (isOnline()) {
            getPlayerEntity().setLevel(level);
        }
        else {
            getNBTEditor().setLevel(level);
        }
    }

    public void setGameMode(GameMode mode) {
        if (isOnline()) {
            getPlayerEntity().setGameMode(mode);
        }
        else {
            getNBTEditor().setGameMode(mode);
        }
    }

    public boolean hasChunkLoaded(Chunk chunk) {
        return NMSHandler.playerHelper.hasChunkLoaded(getPlayerEntity(), chunk);
    }

    /////////////////////
    //   ObjectTag Methods
    /////////////////

    private String prefix = "Player";

    @Override
    public String getPrefix() {
        return prefix;
    }

    @Override
    public PlayerTag setPrefix(String prefix) {
        this.prefix = prefix;
        return this;
    }

    @Override
    public String debuggable() {
        return "<LG>p@<Y>" + uuid + "<GR> (" + getOfflinePlayer().getName() + ")";
    }

    @Override
    public boolean isUnique() {
        return true;
    }

    @Override
    public String identify() {
        return "p@" + uuid;
    }

    @Override
    public String identifySimple() {
        return "p@" + getOfflinePlayer().getName();
    }

    @Override
    public String toString() {
        return identify();
    }

    @Override
    public Object getJavaObject() {
        return getOfflinePlayer();
    }

    @Override
    public int hashCode() {
        return getUUID().hashCode();
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof PlayerTag)) {
            return false;
        }
        return getUUID().equals(((PlayerTag) other).getUUID());
    }

    @Override
    public boolean isTruthy() {
        return isOnline();
    }

    public static void register() {

        AbstractFlagTracker.registerFlagHandlers(tagProcessor);

        /////////////////////
        //   OFFLINE ATTRIBUTES
        /////////////////

        // Defined in EntityTag
        tagProcessor.registerTag(ElementTag.class, "is_player", (attribute, object) -> {
            return new ElementTag(true);
        });

        /////////////////////
        //   DENIZEN ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.chat_history_list>
        // @returns ListTag
        // @description
        // Returns a list of the last 10 things the player has said, less if the player hasn't said all that much.
        // Works with offline players, if the player previously joined and typed in chat since the last server restart.
        // -->
        tagProcessor.registerTag(ListTag.class, "chat_history_list", (attribute, object) -> {
            List<String> history = PlayerTagBase.playerChatHistory.get(object.getUUID());
            return history == null ? new ListTag() : new ListTag(history, true);
        });

        // <--[tag]
        // @attribute <PlayerTag.chat_history[(<#>)]>
        // @returns ElementTag
        // @description
        // Returns the last thing the player said.
        // If a number is specified, returns an earlier thing the player said.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "chat_history", (attribute, object) -> {
            int x = 1;
            if (attribute.hasParam() && ArgumentHelper.matchesInteger(attribute.getParam())) {
                x = attribute.getIntParam();
            }
            List<String> messages = PlayerTagBase.playerChatHistory.get(object.getUUID());
            if (messages == null || messages.size() < x || x < 1) {
                return null;
            }
            return new ElementTag(messages.get(x - 1), true);
        });

        /////////////////////
        //   ECONOMY ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.formatted_money>
        // @returns ElementTag
        // @plugin Vault
        // @description
        // Returns the formatted form of the player's money balance in the registered Economy system.
        // -->
        tagProcessor.registerTag(ElementTag.class, "formatted_money", (attribute, object) -> {
            if (Depends.economy == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("No economy loaded! Have you installed Vault and a compatible economy plugin?");
                }
                return null;
            }
            return new ElementTag(Depends.economy.format(Depends.economy.getBalance(object.getOfflinePlayer())), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.money>
        // @returns ElementTag(Decimal)
        // @plugin Vault
        // @description
        // Returns the amount of money the player has with the registered Economy system.
        // May work offline depending on economy provider.
        // -->
        tagProcessor.registerTag(ElementTag.class, "money", (attribute, object) -> {
            if (Depends.economy == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("No economy loaded! Have you installed Vault and a compatible economy plugin?");
                }
                return null;
            }

            if (attribute.startsWith("formatted", 2)) {
                attribute.fulfill(1);
                BukkitImplDeprecations.playerMoneyFormatTag.warn(attribute.context);
                return new ElementTag(Depends.economy.format(Depends.economy.getBalance(object.getOfflinePlayer())));
            }

            if (attribute.startsWith("currency_singular", 2)) {
                attribute.fulfill(1);
                BukkitImplDeprecations.oldEconomyTags.warn(attribute.context);
                return new ElementTag(Depends.economy.currencyNameSingular());
            }

            if (attribute.startsWith("currency", 2)) {
                attribute.fulfill(1);
                BukkitImplDeprecations.oldEconomyTags.warn(attribute.context);
                return new ElementTag(Depends.economy.currencyNamePlural());
            }

            return new ElementTag(Depends.economy.getBalance(object.getOfflinePlayer()));

        });

        /////////////////////
        //   ENTITY LIST ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.target[(<matcher>)]>
        // @returns EntityTag
        // @description
        // Returns the entity that the player is looking at, within a maximum range of 50 blocks,
        // or null if the player is not looking at an entity.
        // Optionally, specify an entity type matcher to only count matches as possible targets.
        // -->
        registerOnlineOnlyTag(ObjectTag.class, "target", (attribute, object) -> {
            double range = 50;
            String matcher = attribute.hasParam() ? attribute.getParam() : null;

            // <--[tag]
            // @attribute <PlayerTag.target[(<matcher>)].within[(<#.#>)]>
            // @returns EntityTag
            // @description
            // Returns the living entity that the player is looking at within the specified range limit,
            // or null if the player is not looking at an entity.
            // Optionally, specify an entity type matcher to only count matches as possible targets.
            // -->
            if (attribute.startsWith("within", 2) && attribute.hasContext(2)) {
                range = attribute.getDoubleContext(2);
                attribute.fulfill(1);
            }
            Location eyeLoc = object.getEyeLocation();
            RayTraceResult result = eyeLoc.getWorld().rayTrace(eyeLoc, eyeLoc.getDirection(), range, FluidCollisionMode.NEVER, true, 0.01, (e) -> {
                if (e.getUniqueId().equals(object.getUUID())) {
                    return false;
                }
                if (matcher != null) {
                    return new EntityTag(e).tryAdvancedMatcher(matcher);
                }
                return true;
            });
            if (result == null || result.getHitEntity() == null) {
                return null;
            }
            return new EntityTag(result.getHitEntity()).getDenizenObject();
        });

        /////////////////////
        //   LOCATION ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.bed_spawn>
        // @returns LocationTag
        // @mechanism PlayerTag.bed_spawn_location
        // @description
        // Returns the location of the player's bed spawn location, or null if it doesn't exist.
        // Works with offline players.
        // -->
        registerOfflineTag(LocationTag.class, "bed_spawn", (attribute, object) -> {
            Location bedSpawn = object.isOnline() ? NMSHandler.playerHelper.getBedSpawnLocation(object.getPlayerEntity()) : object.getOfflinePlayer().getBedSpawnLocation();
            return bedSpawn != null ? new LocationTag(bedSpawn) : null;
        });

        // <--[tag]
        // @attribute <PlayerTag.calculated_bed_spawn>
        // @returns LocationTag
        // @description
        // Returns the player's calculated bed spawn location.
        // This is a location around their set spawn where they could actually spawn, such as a safe block next to a bed.
        // See <@link tag PlayerTag.bed_spawn> for the actual spawn location they have set.
        // -->
        registerOnlineOnlyTag(LocationTag.class, "calculated_bed_spawn", (attribute, object) -> {
            try {
                NMSHandler.chunkHelper.changeChunkServerThread(object.getWorld());
                Location calculatedBedSpawn = object.getPlayerEntity().getBedSpawnLocation();
                return calculatedBedSpawn != null ? new LocationTag(calculatedBedSpawn) : null;
            }
            finally {
                NMSHandler.chunkHelper.restoreServerThread(object.getWorld());
            }
        });

        registerOfflineTag(ObjectTag.class, "location", (attribute, object) -> {
            if (object.isOnline() && !object.getPlayerEntity().isDead()) {
                return new EntityTag(object.getPlayerEntity()).doLocationTag(attribute);
            }
            return object.getLocation();
        });

        registerOfflineTag(WorldTag.class, "world", (attribute, object) -> {
            return object.getWorldTag();
        });

        /////////////////////
        //   STATE ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.item_cooldown[<material>]>
        // @returns DurationTag
        // @description
        // Returns the cooldown duration remaining on player's material.
        // -->
        registerOnlineOnlyTag(DurationTag.class, "item_cooldown", (attribute, object) -> {
            MaterialTag mat = new ElementTag(attribute.getParam()).asType(MaterialTag.class, attribute.context);
            if (mat != null) {
                return new DurationTag((long) object.getPlayerEntity().getCooldown(mat.getMaterial()));
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.first_played_time>
        // @returns TimeTag
        // @description
        // Returns the time of when the player first logged on to this server.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(TimeTag.class, "first_played_time", (attribute, object) -> {
            return new TimeTag(object.getOfflinePlayer().getFirstPlayed());
        });
        tagProcessor.registerTag(DurationTag.class, "first_played", (attribute, object) -> {
            BukkitImplDeprecations.playerTimePlayedTags.warn(attribute.context);
            return new DurationTag(object.getOfflinePlayer().getFirstPlayed() / 50);
        });

        // <--[tag]
        // @attribute <PlayerTag.has_played_before>
        // @returns ElementTag(Boolean)
        // @description
        // Returns true if the player has played before, or is currently online. Returns false if this PlayerTag refers to a UUID that has never been on the server.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "has_played_before", (attribute, object) -> {
            return new ElementTag(object.isValid());
        });

        // <--[tag]
        // @attribute <PlayerTag.exhaustion>
        // @returns ElementTag(Decimal)
        // @mechanism PlayerTag.exhaustion
        // @description
        // Returns the player's exhaustion value. Exhaustion is increased in vanilla when a player sprints or jumps, and is used to reduce food saturation over time.
        // This can reach a maximum value of 40, and decreases by 4 every tick.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "exhaustion", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getExhaustion());
            }
            else {
                return new ElementTag(object.getNBTEditor().getExhaustion());
            }
        });

        // Handle EntityTag oxygen tags here to allow getting them when the player is offline
        registerOfflineTag(DurationTag.class, "max_oxygen", (attribute, object) -> {
            return new DurationTag((long) object.getMaximumAir());
        });

        registerOfflineTag(DurationTag.class, "oxygen", (attribute, object) -> {
            if (attribute.startsWith("max", 2)) {
                BukkitImplDeprecations.entityMaxOxygenTag.warn(attribute.context);
                attribute.fulfill(1);
                return new DurationTag((long) object.getMaximumAir());
            }
            return new DurationTag((long) object.getRemainingAir());
        });

        // <--[tag]
        // @attribute <PlayerTag.health_is_scaled>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player's health bar is currently being scaled.
        // -->
        registerOfflineTag(ElementTag.class, "health_is_scaled", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().isHealthScaled());
        });

        // <--[tag]
        // @attribute <PlayerTag.health_scale>
        // @returns ElementTag(Decimal)
        // @mechanism PlayerTag.health_scale
        // @description
        // Returns the current scale for the player's health bar.
        // -->
        registerOfflineTag(ElementTag.class, "health_scale", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getHealthScale());
        });

        // Handle EntityTag health tags here to allow getting them when the player is offline
        registerOfflineTag(ElementTag.class, "formatted_health", (attribute, object) -> {
            Double maxHealth = attribute.hasParam() ? attribute.getDoubleParam() : null;
            return EntityHealth.getHealthFormatted(new EntityTag(object.getPlayerEntity()), maxHealth);
        });

        registerOfflineTag(ElementTag.class, "health_percentage", (attribute, object) -> {
            double maxHealth = object.getPlayerEntity().getMaxHealth();
            if (attribute.hasParam()) {
                maxHealth = attribute.getIntParam();
            }
            return new ElementTag((object.getPlayerEntity().getHealth() / maxHealth) * 100);
        });

        registerOfflineTag(ElementTag.class, "health_max", (attribute, object) -> {
            return new ElementTag(object.getMaxHealth());
        });

        registerOfflineTag(ElementTag.class, "health", (attribute, object) -> {
            if (attribute.startsWith("is_scaled", 2)) {
                attribute.fulfill(1);
                BukkitImplDeprecations.entityHealthTags.warn(attribute.context);
                return new ElementTag(object.getPlayerEntity().isHealthScaled());
            }

            if (attribute.startsWith("scale", 2)) {
                attribute.fulfill(1);
                BukkitImplDeprecations.entityHealthTags.warn(attribute.context);
                return new ElementTag(object.getPlayerEntity().getHealthScale());
            }
            if (attribute.startsWith("formatted", 2)) {
                BukkitImplDeprecations.entityHealthTags.warn(attribute.context);
                Double maxHealth = attribute.hasContext(2) ? attribute.getDoubleContext(2) : null;
                attribute.fulfill(1);
                return EntityHealth.getHealthFormatted(new EntityTag(object.getPlayerEntity()), maxHealth);
            }
            if (attribute.startsWith("percentage", 2)) {
                BukkitImplDeprecations.entityHealthTags.warn(attribute.context);
                attribute.fulfill(1);
                double maxHealth = object.getPlayerEntity().getMaxHealth();
                if (attribute.hasParam()) {
                    maxHealth = attribute.getIntParam();
                }
                return new ElementTag((object.getPlayerEntity().getHealth() / maxHealth) * 100);
            }
            if (attribute.startsWith("max", 2)) {
                BukkitImplDeprecations.entityHealthTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getMaxHealth());
            }
            return new ElementTag(object.getHealth());
        });

        // <--[tag]
        // @attribute <PlayerTag.is_banned>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is banned.
        // -->
        tagProcessor.registerTag(ElementTag.class, "is_banned", (attribute, object) -> {
            if (object.getName() == null) {
                return new ElementTag(false);
            }
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null) {
                return new ElementTag(false);
            }
            else if (ban.getExpiration() == null) {
                return new ElementTag(true);
            }
            return new ElementTag(ban.getExpiration().after(new Date()));
        });

        // <--[tag]
        // @attribute <PlayerTag.is_online>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is currently online.
        // Works with offline players (returns false in that case).
        // -->
        tagProcessor.registerTag(ElementTag.class, "is_online", (attribute, object) -> {
            return new ElementTag(object.isOnline());
        });

        // <--[tag]
        // @attribute <PlayerTag.is_op>
        // @returns ElementTag(Boolean)
        // @mechanism PlayerTag.is_op
        // @description
        // Returns whether the player is a full server operator.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "is_op", (attribute, object) -> {
            return new ElementTag(object.getOfflinePlayer().isOp());
        });

        // <--[tag]
        // @attribute <PlayerTag.whitelisted>
        // @returns ElementTag(Boolean)
        // @mechanism PlayerTag.whitelisted
        // @description
        // Returns whether the player is whitelisted.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "whitelisted", (attribute, object) -> {
            return new ElementTag(object.getOfflinePlayer().isWhitelisted());
        }, "is_whitelisted");

        // <--[tag]
        // @attribute <PlayerTag.last_played_time>
        // @returns TimeTag
        // @description
        // Returns the time of when the player was last seen.
        // Works with offline players.
        // Not very useful for online players.
        // -->
        tagProcessor.registerTag(TimeTag.class, "last_played_time", (attribute, object) -> {
            if (object.isOnline()) {
                return TimeTag.now();
            }
            return new TimeTag(object.getOfflinePlayer().getLastPlayed());
        });
        tagProcessor.registerTag(DurationTag.class, "last_played", (attribute, object) -> {
            BukkitImplDeprecations.playerTimePlayedTags.warn(attribute.context);
            if (object.isOnline()) {
                return new DurationTag(System.currentTimeMillis() / 50);
            }
            return new DurationTag(object.getOfflinePlayer().getLastPlayed() / 50);
        });

        // <--[tag]
        // @attribute <PlayerTag.groups[(<world>)]>
        // @returns ListTag
        // @description
        // Returns a list of all groups the player is in.
        // May work with offline players, depending on permission plugin.
        // -->
        tagProcessor.registerTag(ListTag.class, "groups", (attribute, object) -> {
            if (Depends.permissions == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("No permission system loaded! Have you installed Vault and a compatible permissions plugin?");
                }
                return null;
            }
            ListTag list = new ListTag();
            WorldTag world = null;
            if (attribute.hasParam()) {
                world = attribute.paramAsType(WorldTag.class);
                if (world == null) {
                    Debug.echoError("Invalid world specified: " + attribute.getParam());
                    return null;
                }
            }
            for (String group : Depends.permissions.getGroups()) {
                if (Depends.permissions.playerInGroup(world != null ? world.getName() : null, object.getOfflinePlayer(), group)) {
                    list.addObject(new ElementTag(group, true));
                }
            }
            return list;
        });

        // <--[tag]
        // @attribute <PlayerTag.ban_expiration_time>
        // @returns TimeTag
        // @description
        // Returns the expiration of the player's ban, if they are banned.
        // Potentially can be null.
        // -->
        tagProcessor.registerTag(TimeTag.class, "ban_expiration_time", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || ban.getExpiration() == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new TimeTag(ban.getExpiration().getTime());
        });
        tagProcessor.registerTag(DurationTag.class, "ban_expiration", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BukkitImplDeprecations.playerTimePlayedTags.warn(attribute.context);
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || ban.getExpiration() == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new DurationTag(ban.getExpiration().getTime() / 50);
        });

        // <--[tag]
        // @attribute <PlayerTag.ban_reason>
        // @returns ElementTag
        // @description
        // Returns the reason for the player's ban, if they are banned.
        // -->
        tagProcessor.registerTag(ElementTag.class, "ban_reason", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new ElementTag(ban.getReason(), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.ban_created_time>
        // @returns TimeTag
        // @description
        // Returns when the player's ban was created, if they are banned.
        // -->
        tagProcessor.registerTag(TimeTag.class, "ban_created_time", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new TimeTag(ban.getCreated().getTime());
        });
        tagProcessor.registerTag(DurationTag.class, "ban_created", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            Deprecations.timeTagRewrite.warn(attribute.context);
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new DurationTag(ban.getCreated().getTime() / 50);
        });

        // <--[tag]
        // @attribute <PlayerTag.ban_source>
        // @returns ElementTag
        // @description
        // Returns the source of the player's ban, if they are banned.
        // -->
        tagProcessor.registerTag(ElementTag.class, "ban_source", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }
            return new ElementTag(ban.getSource(), true);
        });

        tagProcessor.registerTag(ObjectTag.class, "ban_info", (attribute, object) -> {
            if (object.getName() == null) {
                return null;
            }
            BukkitImplDeprecations.playerBanInfoTags.warn(attribute.context);
            BanEntry ban = Bukkit.getBanList(BanList.Type.NAME).getBanEntry(object.getName());
            if (ban == null || (ban.getExpiration() != null && ban.getExpiration().before(new Date()))) {
                return null;
            }

            if (attribute.startsWith("expiration", 2) && ban.getExpiration() != null) {
                attribute.fulfill(1);
                return new DurationTag(ban.getExpiration().getTime() / 50);
            }

            else if (attribute.startsWith("reason", 2)) {
                attribute.fulfill(1);
                return new ElementTag(ban.getReason());
            }

            else if (attribute.startsWith("created", 2)) {
                attribute.fulfill(1);
                return new DurationTag(ban.getCreated().getTime() / 50);
            }

            else if (attribute.startsWith("source", 2)) {
                attribute.fulfill(1);
                return new ElementTag(ban.getSource());
            }

            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.in_group[<group_name>]>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is in the specified group.
        // (May work with offline players, depending on your permissions system.)
        // -->
        tagProcessor.registerTag(ElementTag.class, "in_group", (attribute, object) -> {
            if (Depends.permissions == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("No permission system loaded! Have you installed Vault and a compatible permissions plugin?");
                }
                return null;
            }

            String group = attribute.getParam();

            // <--[tag]
            // @attribute <PlayerTag.in_group[<group_name>].global>
            // @returns ElementTag(Boolean)
            // @description
            // Returns whether the player has the group with no regard to the
            // player's current world.
            // (Works with offline players)
            // (Note: This may or may not be functional with your permissions system.)
            // -->

            // Non-world specific permission
            if (attribute.startsWith("global", 2)) {
                attribute.fulfill(1);
                return new ElementTag(Depends.permissions.playerInGroup(null, object.getOfflinePlayer(), group));
            }

            // <--[tag]
            // @attribute <PlayerTag.in_group[<group_name>].world[<world>]>
            // @returns ElementTag(Boolean)
            // @description
            // Returns whether the player has the group in regards to a specific world.
            // (Works with offline players)
            // (Note: This may or may not be functional with your permissions system.)
            // -->

            // Permission in certain world
            else if (attribute.startsWith("world", 2)) {
                WorldTag world = null;
                if (attribute.hasContext(2)) {
                    world = attribute.contextAsType(2, WorldTag.class);
                    if (world == null) {
                        Debug.echoError("Invalid world specified: " + attribute.getContext(2));
                        return null;
                    }
                }
                attribute.fulfill(1);
                return new ElementTag(Depends.permissions.playerInGroup(world != null ? world.getName() : null, object.getOfflinePlayer(), group));
            }

            // Permission in current world
            else if (object.isOnline()) {
                return new ElementTag(Depends.permissions.playerInGroup(object.getPlayerEntity(), group));
            }
            else if (Depends.permissions != null) {
                return new ElementTag(Depends.permissions.playerInGroup(null, object.getOfflinePlayer(), group));
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.has_permission[permission.node]>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player has the specified node.
        // (May work with offline players, depending on your permissions system.)
        // -->
        tagProcessor.registerTag(ElementTag.class, "has_permission", (attribute, object) -> {
            String permission = attribute.getParam();

            // <--[tag]
            // @attribute <PlayerTag.has_permission[permission.node].global>
            // @returns ElementTag(Boolean)
            // @description
            // Returns whether the player has the specified node, regardless of world.
            // (Works with offline players)
            // (Note: this may or may not be functional with your permissions system.)
            // -->

            // Non-world specific permission
            if (attribute.startsWith("global", 2)) {
                if (Depends.permissions == null) {
                    if (!attribute.hasAlternative()) {
                        Debug.echoError("No permission system loaded! Have you installed Vault and a compatible permissions plugin?");
                    }
                    return null;
                }

                attribute.fulfill(1);
                return new ElementTag(Depends.permissions.playerHas(null, object.getOfflinePlayer(), permission));
            }

            // <--[tag]
            // @attribute <PlayerTag.has_permission[permission.node].world[<world>]>
            // @returns ElementTag(Boolean)
            // @description
            // Returns whether the player has the specified node in regards to the
            // specified world.
            // (Works with offline players)
            // (Note: This may or may not be functional with your permissions system.)
            // -->

            // Permission in certain world
            else if (attribute.startsWith("world", 2)) {
                String world = attribute.getContext(2);
                if (Depends.permissions == null) {
                    if (!attribute.hasAlternative()) {
                        Debug.echoError("No permission system loaded! Have you installed Vault and a compatible permissions plugin?");
                    }
                    return null;
                }
                attribute.fulfill(1);
                if (world.startsWith("w@")) {
                    world = world.substring(2);
                }
                return new ElementTag(Depends.permissions.playerHas(world, object.getOfflinePlayer(), permission));
            }

            // Permission in current world
            else if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().hasPermission(permission));
            }
            else if (Depends.permissions != null) {
                return new ElementTag(Depends.permissions.playerHas(null, object.getOfflinePlayer(), permission));
            }
            return null;
        }, "permission");

        // <--[tag]
        // @attribute <PlayerTag.statistic[<statistic>]>
        // @returns ElementTag(Number)
        // @description
        // Returns the player's current value for the specified statistic.
        // Valid statistics: <@link url https://hub.spigotmc.org/javadocs/spigot/org/bukkit/Statistic.html>
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "statistic", (attribute, object) -> {
            if (!attribute.hasParam()) {
                return null;
            }
            Statistic statistic;
            try {
                statistic = Statistic.valueOf(attribute.getParam().toUpperCase());
            }
            catch (IllegalArgumentException ex) {
                attribute.echoError("Statistic '" + attribute.getParam() + "' does not exist: " + ex.getMessage());
                return null;
            }

            // <--[tag]
            // @attribute <PlayerTag.statistic[<statistic>].qualifier[<material>/<entity>]>
            // @returns ElementTag(Number)
            // @description
            // Returns the player's current value for the specified statistic, with the
            // specified qualifier, which can be either an entity or material.
            // Valid statistics: <@link url https://hub.spigotmc.org/javadocs/spigot/org/bukkit/Statistic.html>
            // To check a statistic type dynamically, refer to <@link tag server.statistic_type>.
            // -->
            if (attribute.startsWith("qualifier", 2)) {
                ObjectTag obj = ObjectFetcher.pickObjectFor(attribute.getContext(2), attribute.context);
                attribute.fulfill(1);
                try {
                    if (obj instanceof MaterialTag) {
                        return new ElementTag(object.getOfflinePlayer().getStatistic(statistic, ((MaterialTag) obj).getMaterial()));
                    }
                    else if (obj instanceof EntityTag) {
                        return new ElementTag(object.getOfflinePlayer().getStatistic(statistic, ((EntityTag) obj).getBukkitEntityType()));
                    }
                    else {
                        return null;
                    }
                }
                catch (Exception e) {
                    Debug.echoError("Invalid statistic: " + statistic + " for this player!");
                    return null;
                }
            }
            try {
                return new ElementTag(object.getOfflinePlayer().getStatistic(statistic));
            }
            catch (Exception e) {
                Debug.echoError("Invalid statistic: " + statistic + " for this player!");
                return null;
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.uuid>
        // @returns ElementTag
        // @description
        // Returns the UUID of the player.
        // Works with offline players.
        // -->
        tagProcessor.registerTag(ElementTag.class, "uuid", (attribute, object) -> {
            return new ElementTag(object.getUUID().toString());
        });

        // <--[tag]
        // @attribute <PlayerTag.list_name>
        // @returns ElementTag
        // @mechanism PlayerTag.player_list_name
        // @description
        // Returns the name of the player as shown in the player list.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "list_name", (attribute, object) -> {
            return new ElementTag(PaperAPITools.instance.getPlayerListName(object.getPlayerEntity()), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.display_name>
        // @returns ElementTag
        // @mechanism PlayerTag.display_name
        // @description
        // Returns the display name of the player, which may contain prefixes and suffixes, colors, etc.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "display_name", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getDisplayName(), true);
        });

        // Documented in EntityTag
        tagProcessor.registerTag(ElementTag.class, "name", (attribute, object) -> {
            if (attribute.startsWith("list", 2) && object.isOnline()) {
                BukkitImplDeprecations.playerNameTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getPlayerListName(), true);
            }
            if (attribute.startsWith("display", 2) && object.isOnline()) {
                BukkitImplDeprecations.playerNameTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getDisplayName(), true);
            }
            return new ElementTag(object.getName(), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.client_brand>
        // @returns ElementTag
        // @description
        // Returns the brand of the client, as sent via the "minecraft:brand" packet.
        // On normal clients, will say "vanilla". On broken clients, will say "unknown". Modded clients will identify themselves (though not guaranteed!).
        // -->
        registerOnlineOnlyTag(ElementTag.class, "client_brand", (attribute, object) -> {
            return new ElementTag(PaperAPITools.instance.getClientBrand(object.getPlayerEntity()), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.locale>
        // @returns ElementTag
        // @description
        // Returns the current locale of the player.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "locale", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getLocale(), true);
        });

        /////////////////////
        //   INVENTORY ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.inventory>
        // @returns InventoryTag
        // @description
        // Returns a InventoryTag of the player's current inventory.
        // Works with offline players.
        // -->
        registerOfflineTag(InventoryTag.class, "inventory", (attribute, object) -> {
            return object.getInventory();
        });

        // <--[tag]
        // @attribute <PlayerTag.enderchest>
        // @returns InventoryTag
        // @description
        // Gets the player's enderchest inventory.
        // Works with offline players.
        // -->
        registerOfflineTag(InventoryTag.class, "enderchest", (attribute, object) -> {
            return object.getEnderChest();
        });

        /////////////////////
        //   ONLINE ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.open_inventory>
        // @returns InventoryTag
        // @description
        // Gets the inventory the player currently has open. If the player has no open
        // inventory, this returns the player's inventory.
        // -->
        registerOnlineOnlyTag(InventoryTag.class, "open_inventory", (attribute, object) -> {
            return InventoryTag.mirrorBukkitInventory(object.getPlayerEntity().getOpenInventory().getTopInventory());
        });

        // <--[tag]
        // @attribute <PlayerTag.discovered_recipes>
        // @returns ListTag
        // @description
        // Returns a list of the recipes the player has discovered, in the Namespace:Key format, for example "minecraft:gold_nugget".
        // -->
        registerOnlineOnlyTag(ListTag.class, "discovered_recipes", (attribute, object) -> {
            ListTag result = new ListTag();
            for (NamespacedKey recipe : object.getPlayerEntity().getDiscoveredRecipes()) {
                result.addObject(new ElementTag(recipe.toString(), true));
            }
            return result;
        });

        // <--[tag]
        // @attribute <PlayerTag.selected_trade_index>
        // @returns ElementTag(Number)
        // @description
        // Returns the index of the trade the player is currently viewing, if any.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "selected_trade_index", (attribute, object) -> {
            if (object.getPlayerEntity().getOpenInventory().getTopInventory() instanceof MerchantInventory) {
                return new ElementTag(((MerchantInventory) object.getPlayerEntity().getOpenInventory().getTopInventory())
                        .getSelectedRecipeIndex() + 1);
            }
            return null;
        });

        // [tag]
        // @attribute <PlayerTag.selected_trade>
        // @returns TradeTag
        // @description
        // Returns the trade the player is currently viewing, if any.
        // This is almost completely broke and only works if the player has placed items in the trade slots.
        //
        registerOnlineOnlyTag(TradeTag.class, "selected_trade", (attribute, object) -> {
            Inventory playerInventory = object.getPlayerEntity().getOpenInventory().getTopInventory();
            if (playerInventory instanceof MerchantInventory && ((MerchantInventory) playerInventory).getSelectedRecipe() != null) {
                return new TradeTag(((MerchantInventory) playerInventory).getSelectedRecipe()).duplicate();
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.item_on_cursor>
        // @returns ItemTag
        // @mechanism PlayerTag.item_on_cursor
        // @description
        // Returns the item on the player's cursor, if any. This includes
        // chest interfaces, inventories, and hotbars, etc.
        // -->
        registerOnlineOnlyTag(ItemTag.class, "item_on_cursor", (attribute, object) -> {
            return new ItemTag(object.getPlayerEntity().getItemOnCursor());
        });

        // <--[tag]
        // @attribute <PlayerTag.held_item_slot>
        // @returns ElementTag(Number)
        // @description
        // Returns the slot location of the player's selected item.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "held_item_slot", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getInventory().getHeldItemSlot() + 1);
        });

        registerOnlineOnlyTag(ObjectTag.class, "item_in_hand", (attribute, object) -> {
            if (attribute.startsWith("slot", 2)) {
                BukkitImplDeprecations.playerItemInHandSlotTag.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getInventory().getHeldItemSlot() + 1);
            }
            return object.getHeldItem();
        });

        // <--[tag]
        // @attribute <PlayerTag.sidebar_lines>
        // @returns ListTag
        // @description
        // Returns the current lines set on the player's Sidebar via <@link command sidebar>.
        // -->
        registerOnlineOnlyTag(ListTag.class, "sidebar_lines", (attribute, object) -> {
            Sidebar sidebar = SidebarCommand.getSidebar(object);
            if (sidebar == null) {
                return null;
            }
            return new ListTag(sidebar.getLinesText(), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.sidebar_title>
        // @returns ElementTag
        // @description
        // Returns the current title set on the player's Sidebar via <@link command sidebar>.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "sidebar_title", (attribute, object) -> {
            Sidebar sidebar = SidebarCommand.getSidebar(object);
            if (sidebar == null) {
                return null;
            }
            return new ElementTag(sidebar.getTitle(), true);
        });

        // <--[tag]
        // @attribute <PlayerTag.sidebar_scores>
        // @returns ListTag
        // @description
        // Returns the current scores set on the player's Sidebar via <@link command sidebar>,
        // in the same order as <@link tag PlayerTag.sidebar_lines>.
        // -->
        registerOnlineOnlyTag(ListTag.class, "sidebar_scores", (attribute, object) -> {
            Sidebar sidebar = SidebarCommand.getSidebar(object);
            if (sidebar == null) {
                return null;
            }
            ListTag scores = new ListTag();
            for (int score : sidebar.getScores()) {
                scores.add(String.valueOf(score));
            }
            return scores;
        });

        registerOnlineOnlyTag(ObjectTag.class, "sidebar", (attribute, object) -> {
            BukkitImplDeprecations.playerSidebarTags.warn(attribute.context);
            if (attribute.startsWith("lines", 2)) {
                attribute.fulfill(1);
                Sidebar sidebar = SidebarCommand.getSidebar(object);
                if (sidebar == null) {
                    return null;
                }
                return new ListTag(sidebar.getLinesText());
            }
            if (attribute.startsWith("title", 2)) {
                attribute.fulfill(1);
                Sidebar sidebar = SidebarCommand.getSidebar(object);
                if (sidebar == null) {
                    return null;
                }
                return new ElementTag(sidebar.getTitle());
            }
            if (attribute.startsWith("scores", 2)) {
                attribute.fulfill(1);
                Sidebar sidebar = SidebarCommand.getSidebar(object);
                if (sidebar == null) {
                    return null;
                }
                ListTag scores = new ListTag();
                for (int score : sidebar.getScores()) {
                    scores.add(String.valueOf(score));
                }
                return scores;
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.skin_blob>
        // @returns ElementTag
        // @mechanism PlayerTag.skin_blob
        // @description
        // Returns the player's current skin blob.
        // In the format: "texture;signature" (two values separated by a semicolon).
        // See also <@link language Player Entity Skins (Skin Blobs)>.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "skin_blob", (attribute, object) -> {
            return new ElementTag(NMSHandler.instance.getProfileEditor().getPlayerSkinBlob(object.getPlayerEntity()));
        });

        // <--[tag]
        // @attribute <PlayerTag.skull_skin>
        // @returns ElementTag
        // @description
        // Returns the player's current skin blob, formatted for input to a Player Skull item.
        // In the format: "UUID|Texture|Name" (three values separated by pipes).
        // See also <@link language Player Entity Skins (Skin Blobs)>.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "skull_skin", (attribute, object) -> {
            String skin = NMSHandler.instance.getProfileEditor().getPlayerSkinBlob(object.getPlayerEntity());
            if (skin == null) {
                return null;
            }
            int semicolon = skin.indexOf(';');
            return new ElementTag(object.getPlayerEntity().getUniqueId() + "|" + skin.substring(0, semicolon) + "|" + object.getName());
        });

        // <--[tag]
        // @attribute <PlayerTag.skull_item>
        // @returns ItemTag
        // @description
        // Returns a Player_Head item with the skin of the player.
        // See also <@link language Player Entity Skins (Skin Blobs)>.
        // -->
        registerOnlineOnlyTag(ItemTag.class, "skull_item", (attribute, object) -> {
            ItemStack item = new ItemStack(Material.PLAYER_HEAD);
            item = NMSHandler.itemHelper.setSkullSkin(item, NMSHandler.instance.getPlayerProfile(object.getPlayerEntity()));
            return new ItemTag(item);
        });

        registerOnlineOnlyTag(ObjectTag.class, "attack_cooldown", (attribute, object) -> {
            BukkitImplDeprecations.playerAttackCooldownTags.warn(attribute.context);
            if (attribute.startsWith("duration", 2)) {
                attribute.fulfill(1);
                return new DurationTag((long) NMSHandler.playerHelper
                        .ticksPassedDuringCooldown(object.getPlayerEntity()));
            }
            else if (attribute.startsWith("max_duration", 2)) {
                attribute.fulfill(1);
                return new DurationTag((long) NMSHandler.playerHelper
                        .getMaxAttackCooldownTicks(object.getPlayerEntity()));
            }

            else if (attribute.startsWith("percent", 2)) {
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getAttackCooldown() * 100);
            }

            Debug.echoError("The tag 'player.attack_cooldown...' must be followed by a sub-tag.");

            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.main_hand>
        // @returns ElementTag
        // @description
        // Returns the player's main hand, either LEFT or RIGHT.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "main_hand", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getMainHand().toString());
        });

        /////////////////////
        //   CITIZENS ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.selected_npc>
        // @returns NPCTag
        // @mechanism PlayerTag.selected_npc
        // @description
        // Returns the NPCTag that the player currently has selected with '/npc select', null if no NPC selected.
        // -->
        registerOnlineOnlyTag(NPCTag.class, "selected_npc", (attribute, object) -> {
            if (object.getPlayerEntity().hasMetadata("selected")) {
                return object.getSelectedNPC();
            }
            return null;
        });

        /////////////////////
        //   CONVERSION ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.entity>
        // @returns EntityTag
        // @description
        // Returns the EntityTag object of the player.
        // (Note: This should never actually be needed. PlayerTags are considered valid EntityTags.)
        // -->
        registerOnlineOnlyTag(EntityTag.class, "entity", (attribute, object) -> {
            return new EntityTag(object.getPlayerEntity());
        });

        /////////////////////
        //   IDENTIFICATION ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.ip_address>
        // @returns ElementTag
        // @description
        // Returns the player's IP address, without port or hostname.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "ip_address", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getAddress().getAddress().toString());
        });

        // <--[tag]
        // @attribute <PlayerTag.ip>
        // @returns ElementTag
        // @description
        // Returns the player's IP address host name.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "ip", (attribute, object) -> {
            // <--[tag]
            // @attribute <PlayerTag.ip.address_only>
            // @returns ElementTag
            // @description
            // Returns the player's IP address with port (without triggering an rdns lookup).
            // -->
            if (attribute.startsWith("address_only", 2)) {
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getAddress().toString());
            }
            String host = object.getPlayerEntity().getAddress().getHostName();

            // <--[tag]
            // @attribute <PlayerTag.ip.address>
            // @returns ElementTag
            // @description
            // Returns the player's IP address with port (usually including an rdns host path).
            // -->
            if (attribute.startsWith("address", 2)) {
                attribute.fulfill(1);
                return new ElementTag(object.getPlayerEntity().getAddress().toString());
            }
            return new ElementTag(host);
        }, "host_name");

        // <--[tag]
        // @attribute <PlayerTag.nameplate>
        // @returns ElementTag
        // @description
        // Returns the displayed text in the nameplate of the player.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "nameplate", (attribute, object) -> {
            return new ElementTag(NMSHandler.instance.getProfileEditor().getPlayerName(object.getPlayerEntity()), true);
        });

        /////////////////////
        //   LOCATION ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.compass_target>
        // @returns LocationTag
        // @description
        // Returns the location of the player's compass target.
        // -->
        registerOnlineOnlyTag(LocationTag.class, "compass_target", (attribute, object) -> {
            Location target = object.getPlayerEntity().getCompassTarget();
            if (target != null) {
                return new LocationTag(target);
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.chunk_loaded[<chunk>]>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player has the chunk loaded on their client.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "chunk_loaded", (attribute, object) -> {
            if (!attribute.hasParam()) {
                return null;
            }
            ChunkTag chunk = attribute.paramAsType(ChunkTag.class);
            if (chunk == null) {
                return null;
            }
            return new ElementTag(chunk.isLoadedSafe() && object.hasChunkLoaded(chunk.getChunkForTag(attribute)));
        });

        /////////////////////
        //   STATE ATTRIBUTES
        /////////////////

        // <--[tag]
        // @attribute <PlayerTag.can_fly>
        // @returns ElementTag(Boolean)
        // @mechanism PlayerTag.can_fly
        // @description
        // Returns whether the player is allowed to fly.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "can_fly", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getAllowFlight());
            }
            else {
                return new ElementTag(object.getNBTEditor().getAllowFlight());
            }
        }, "allowed_flight");

        // <--[tag]
        // @attribute <PlayerTag.fly_speed>
        // @returns ElementTag(Decimal)
        // @mechanism PlayerTag.fly_speed
        // @description
        // Returns the speed the player can fly at.
        // Default value is '0.2'.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "fly_speed", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getFlySpeed());
            }
            else {
                return new ElementTag(object.getNBTEditor().getFlySpeed());
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.walk_speed>
        // @returns ElementTag(Decimal)
        // @mechanism PlayerTag.walk_speed
        // @description
        // Returns the speed the player can walk at.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "walk_speed", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getWalkSpeed());
            }
            else {
                return new ElementTag(object.getNBTEditor().getWalkSpeed());
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.saturation>
        // @returns ElementTag(Decimal)
        // @mechanism PlayerTag.saturation
        // @description
        // Returns the current food saturation of the player.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "saturation", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getSaturation());
            }
            else {
                return new ElementTag(object.getNBTEditor().getSaturation());
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.formatted_food_level[(<max>)]>
        // @returns ElementTag
        // @mechanism PlayerTag.food_level
        // @description
        // Returns a 'formatted' value of the player's current food level.
        // May be 'starving', 'famished', 'parched, 'hungry', or 'healthy'.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "formatted_food_level", (attribute, object) -> {
            double maxHunger = object.getPlayerEntity().getMaxHealth();
            if (attribute.hasParam()) {
                maxHunger = attribute.getIntParam();
            }
            attribute.fulfill(1);
            int foodLevel = object.getFoodLevel();
            if (foodLevel / maxHunger < .10) {
                return new ElementTag("starving");
            }
            else if (foodLevel / maxHunger < .40) {
                return new ElementTag("famished");
            }
            else if (foodLevel / maxHunger < .75) {
                return new ElementTag("parched");
            }
            else if (foodLevel / maxHunger < 1) {
                return new ElementTag("hungry");
            }
            else {
                return new ElementTag("healthy");
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.food_level>
        // @returns ElementTag(Number)
        // @mechanism PlayerTag.food_level
        // @description
        // Returns the current food level (aka hunger) of the player.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "food_level", (attribute, object) -> {
            if (attribute.startsWith("formatted", 2)) {
                BukkitImplDeprecations.playerFoodLevelFormatTag.warn(attribute.context);
                double maxHunger = object.getPlayerEntity().getMaxHealth();
                if (attribute.hasContext(2)) {
                    maxHunger = attribute.getIntContext(2);
                }
                attribute.fulfill(1);
                int foodLevel = object.getFoodLevel();
                if (foodLevel / maxHunger < .10) {
                    return new ElementTag("starving");
                }
                else if (foodLevel / maxHunger < .40) {
                    return new ElementTag("famished");
                }
                else if (foodLevel / maxHunger < .75) {
                    return new ElementTag("parched");
                }
                else if (foodLevel / maxHunger < 1) {
                    return new ElementTag("hungry");
                }
                else {
                    return new ElementTag("healthy");
                }
            }
            return new ElementTag(object.getFoodLevel());
        });

        // <--[tag]
        // @attribute <PlayerTag.gamemode>
        // @returns ElementTag
        // @mechanism PlayerTag.gamemode
        // @description
        // Returns the name of the gamemode the player is currently set to.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "gamemode", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(object.getPlayerEntity().getGameMode());
            }
            return new ElementTag(object.getNBTEditor().getGameMode());
        });

        // <--[tag]
        // @attribute <PlayerTag.is_blocking>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is currently blocking.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "is_blocking", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().isBlocking());
        });

        // <--[tag]
        // @attribute <PlayerTag.ping>
        // @returns ElementTag(Number)
        // @description
        // Returns the player's current ping.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "ping", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getPing());
        });

        // <--[tag]
        // @attribute <PlayerTag.is_flying>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is currently flying.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "is_flying", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().isFlying());
        });

        // <--[tag]
        // @attribute <PlayerTag.is_sneaking>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player is currently sneaking.
        // -->
        if (!Denizen.supportsPaper || NMSHandler.getVersion().isAtMost(NMSVersion.v1_18)) {
            registerOnlineOnlyTag(ElementTag.class, "is_sneaking", (attribute, object) -> {
                return new ElementTag(object.getPlayerEntity().isSneaking());
            });
        }

        // <--[tag]
        // @attribute <PlayerTag.is_sprinting>
        // @returns ElementTag(Boolean)
        // @mechanism PlayerTag.sprinting
        // @description
        // Returns whether the player is currently sprinting.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "is_sprinting", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().isSprinting());
        });

        // <--[tag]
        // @attribute <PlayerTag.has_advancement[<advancement>]>
        // @returns ElementTag(Boolean)
        // @description
        // Returns whether the player has completed the specified advancement.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "has_advancement", (attribute, object) -> {
            if (!attribute.hasParam()) {
                return null;
            }
            Advancement adv = AdvancementHelper.getAdvancement(attribute.getParam());
            if (adv == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("Advancement '" + attribute.getParam() + "' does not exist.");
                }
                return null;
            }
            AdvancementProgress progress = object.getPlayerEntity().getAdvancementProgress(adv);
            return new ElementTag(progress.isDone());
        });

        // <--[tag]
        // @attribute <PlayerTag.advancements>
        // @returns ListTag
        // @description
        // Returns a list of the names of all advancements the player has completed.
        // -->
        registerOnlineOnlyTag(ListTag.class, "advancements", (attribute, object) -> {
            ListTag list = new ListTag();
            Bukkit.advancementIterator().forEachRemaining((adv) -> {
                if (object.getPlayerEntity().getAdvancementProgress(adv).isDone()) {
                    list.add(adv.getKey().toString());
                }
            });
            return list;
        }, "list_advancements");

        // <--[tag]
        // @attribute <PlayerTag.time_asleep>
        // @returns DurationTag
        // @description
        // Returns the time the player has been asleep.
        // -->
        registerOnlineOnlyTag(DurationTag.class, "time_asleep", (attribute, object) -> {
            return new DurationTag((long) object.getPlayerEntity().getSleepTicks());
        });

        // <--[tag]
        // @attribute <PlayerTag.time>
        // @returns ElementTag(Number)
        // @description
        // Returns the time the player is currently experiencing.
        // This time could differ from the time that the rest of the world is currently experiencing if <@link command time> is being used on the player.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "time", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getPlayerTime());
        });

        // <--[tag]
        // @attribute <PlayerTag.weather>
        // @returns ElementTag
        // @description
        // Returns the type of weather the player is experiencing. This will be different
        // from the weather currently in the world that the player is residing in if
        // the weather is currently being forced onto the player.
        // Returns null if the player does not currently have any forced weather.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "weather", (attribute, object) -> {
            if (object.getPlayerEntity().getPlayerWeather() != null) {
                return new ElementTag(object.getPlayerEntity().getPlayerWeather());
            }
            else {
                return null;
            }
        });

        // <--[tag]
        // @attribute <PlayerTag.calculate_xp>
        // @returns ElementTag(Number)
        // @description
        // Returns the calculated total amount of XP the player has, based on the amount of experience needed per level, for each level the player has.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "calculate_xp", (attribute, object) -> {
            int level = object.getLevel();
            return new ElementTag(ExperienceCommand.TOTAL_XP_FOR_LEVEL(level) + (object.getExp() * ExperienceCommand.XP_FOR_NEXT_LEVEL(level)));
        });

        // <--[tag]
        // @attribute <PlayerTag.xp_level>
        // @returns ElementTag(Number)
        // @description
        // Returns the number of XP levels the player has.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "xp_level", (attribute, object) -> {
            return new ElementTag(object.getLevel());
        });

        // <--[tag]
        // @attribute <PlayerTag.xp_to_next_level>
        // @returns ElementTag(Number)
        // @description
        // Returns the amount of XP the player needs to get to the next level.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "xp_to_next_level", (attribute, object) -> {
            return new ElementTag(ExperienceCommand.XP_FOR_NEXT_LEVEL(object.getLevel()));
        });

        // <--[tag]
        // @attribute <PlayerTag.xp_total>
        // @returns ElementTag(Number)
        // @description
        // Returns the total amount of experience points the player has.
        // This is how much XP the player has ever received, not a current value.
        // To get the current total, use <@link tag PlayerTag.calculate_xp>.
        // Works with offline players.
        // -->
        registerOfflineTag(ElementTag.class, "xp_total", (attribute, object) -> {
            return new ElementTag(object.getTotalExperience());
        });

        // <--[tag]
        // @attribute <PlayerTag.xp>
        // @returns ElementTag(Decimal)
        // @description
        // Returns the percentage of experience points to the next level.
        // -->
        registerOfflineTag(ElementTag.class, "xp", (attribute, object) -> {
            if (attribute.startsWith("level", 2)) {
                BukkitImplDeprecations.playerXpTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getLevel());
            }
            if (attribute.startsWith("to_next_level", 2)) {
                BukkitImplDeprecations.playerXpTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(ExperienceCommand.XP_FOR_NEXT_LEVEL(object.getLevel()));
            }
            if (attribute.startsWith("total", 2)) {
                BukkitImplDeprecations.playerXpTags.warn(attribute.context);
                attribute.fulfill(1);
                return new ElementTag(object.getTotalExperience());
            }
            return new ElementTag(object.getExp() * 100);
        });

        // <--[tag]
        // @attribute <PlayerTag.chat_prefix>
        // @returns ElementTag
        // @plugin Vault
        // @mechanism PlayerTag.chat_prefix
        // @description
        // Returns the player's chat prefix.
        // NOTE: May work with offline players.
        // Requires a Vault-compatible chat plugin.
        // -->
        tagProcessor.registerTag(ElementTag.class, "chat_prefix", (attribute, object) -> {
            if (Depends.chat == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("'chat_prefix' tag unavailable: Vault and a chat plugin are required.");
                }
                return null;
            }
            String prefix = Depends.chat.getPlayerPrefix(object.getWorld().getName(), object.getOfflinePlayer());
            if (prefix == null) {
                return null;
            }
            return new ElementTag(prefix, true);
        });

        // <--[tag]
        // @attribute <PlayerTag.chat_suffix>
        // @returns ElementTag
        // @plugin Vault
        // @mechanism PlayerTag.chat_suffix
        // @description
        // Returns the player's chat suffix.
        // NOTE: May work with offline players.
        // Requires a Vault-compatible chat plugin.
        // -->
        tagProcessor.registerTag(ElementTag.class, "chat_suffix", (attribute, object) -> {
            if (Depends.chat == null) {
                if (!attribute.hasAlternative()) {
                    Debug.echoError("'chat_suffix' tag unavailable: Vault and a chat plugin are required.");
                }
                return null;
            }
            String suffix = Depends.chat.getPlayerSuffix(object.getWorld().getName(), object.getOfflinePlayer());
            if (suffix == null) {
                return null;
            }
            return new ElementTag(suffix, true);
        });

        // <--[tag]
        // @attribute <PlayerTag.fake_block_locations>
        // @returns ListTag(LocationTag)
        // @description
        // Returns a list of locations that the player will see a fake block at, as set by <@link command showfake> or connected commands.
        // -->
        tagProcessor.registerTag(ListTag.class, "fake_block_locations", (attribute, object) -> {
            ListTag list = new ListTag();
            FakeBlock.FakeBlockMap map = FakeBlock.blocks.get(object.getUUID());
            if (map != null) {
                for (LocationTag loc : map.byLocation.keySet()) {
                    list.addObject(loc.clone());
                }
            }
            return list;
        });

        // <--[tag]
        // @attribute <PlayerTag.fake_block[<location>]>
        // @returns MaterialTag
        // @description
        // Returns the fake material that the player will see at the input location, as set by <@link command showfake> or connected commands.
        // Works best alongside <@link tag PlayerTag.fake_block_locations>.
        // Returns null if the player doesn't have a fake block at the location.
        // -->
        tagProcessor.registerTag(MaterialTag.class, "fake_block", (attribute, object) -> {
            if (!attribute.hasParam()) {
                return null;
            }
            LocationTag input = attribute.paramAsType(LocationTag.class);
            FakeBlock.FakeBlockMap map = FakeBlock.blocks.get(object.getUUID());
            if (map != null) {
                FakeBlock block = map.byLocation.get(input);
                if (block != null) {
                    return block.material;
                }
            }
            return null;
        });

        // <--[tag]
        // @attribute <PlayerTag.skin_model>
        // @returns ElementTag
        // @description
        // Returns the player's skin model, either CLASSIC or SLIM.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "skin_model", (attribute, object) -> {
            return new ElementTag(object.getPlayerEntity().getPlayerProfile().getTextures().getSkinModel());
        });

        // <--[tag]
        // @attribute <PlayerTag.fake_entities>
        // @returns ListTag(EntityTag)
        // @description
        // Returns a list of fake entities the player can see, as set by <@link command fakespawn>.
        // Note that these entities are not being tracked by the server, so many operations may not be possible on them.
        // -->
        tagProcessor.registerTag(ListTag.class, "fake_entities", (attribute, object) -> {
            ListTag list = new ListTag();
            FakeEntity.FakeEntityMap map = FakeEntity.playersToEntities.get(object.getUUID());
            if (map != null) {
                for (Map.Entry<Integer, FakeEntity> entry : map.byId.entrySet()) {
                    list.addObject(entry.getValue().entity);
                }
            }
            return list;
        });

        // <--[tag]
        // @attribute <PlayerTag.disguise_to_self[(<player>)]>
        // @returns EntityTag
        // @group properties
        // @description
        // Returns the fake entity used to disguise the entity in the player's self-view (only relevant to players), either globally (if no context input given), or to the specified player.
        // Relates to <@link command disguise>.
        // -->
        tagProcessor.registerTag(EntityTag.class, "disguise_to_self", (attribute, object) -> {
            HashMap<UUID, DisguiseCommand.TrackedDisguise> map = DisguiseCommand.disguises.get(object.getUUID());
            if (map == null) {
                return null;
            }
            DisguiseCommand.TrackedDisguise disguise;
            if (attribute.hasParam()) {
                PlayerTag player = attribute.paramAsType(PlayerTag.class);
                if (player == null) {
                    attribute.echoError("Invalid player for is_disguised tag.");
                    return null;
                }
                disguise = map.get(player.getUUID());
                if (disguise == null) {
                    disguise = map.get(null);
                }
            }
            else {
                disguise = map.get(null);
            }
            if (disguise == null) {
                return null;
            }
            if (disguise.fakeToSelf == null) {
                return null;
            }
            return disguise.fakeToSelf.entity;
        });

        // <--[tag]
        // @attribute <PlayerTag.spectator_target>
        // @returns EntityTag
        // @mechanism PlayerTag.spectator_target
        // @description
        // Returns the entity that a spectator-mode player is currently spectating, if any.
        // -->
        registerOnlineOnlyTag(ObjectTag.class, "spectator_target", (attribute, object) -> {
            if (object.getPlayerEntity().getGameMode() != GameMode.SPECTATOR) {
                return null;
            }
            Entity target = object.getPlayerEntity().getSpectatorTarget();
            if (target == null) {
                return null;
            }
            return new EntityTag(target).getDenizenObject();
        });

        // <--[tag]
        // @attribute <PlayerTag.packets_sent>
        // @returns ElementTag(Number)
        // @description
        // Returns a total count of how many network packets have been sent to this player while they have been online.
        // It may be ideal to change setting "Packets.Auto init" in the Denizen config to "true" to guarantee this tag functions as expected.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "packets_sent", (attribute, object) -> {
            NetworkInterceptHelper.enable();
            return new ElementTag(NMSHandler.packetHelper.getPacketStats(object.getPlayerEntity(), true));
        });

        // <--[tag]
        // @attribute <PlayerTag.packets_received>
        // @returns ElementTag(Number)
        // @description
        // Returns a total count of how many network packets have been received from this player while they have been online.
        // It may be ideal to change setting "Packets.Auto init" in the Denizen config to "true" to guarantee this tag functions as expected.
        // -->
        registerOnlineOnlyTag(ElementTag.class, "packets_received", (attribute, object) -> {
            NetworkInterceptHelper.enable();
            return new ElementTag(NMSHandler.packetHelper.getPacketStats(object.getPlayerEntity(), false));
        });

        // <--[tag]
        // @attribute <PlayerTag.fish_hook>
        // @returns EntityTag
        // @description
        // Returns the fishing hook a player has cast (if any).
        // -->
        registerOnlineOnlyTag(EntityTag.class, "fish_hook", (attribute, object) -> {
            FishHook hook = NMSHandler.fishingHelper.getHookFrom(object.getPlayerEntity());
            if (hook == null) {
                return null;
            }
            return new EntityTag(hook);
        });

        // <--[tag]
        // @attribute <PlayerTag.spawn_forced>
        // @returns ElementTag(Boolean)
        // @mechanism PlayerTag.spawn_forced
        // @description
        // Returns whether the player's bed spawn location is forced (ie still valid even if a bed is missing).
        // -->
        registerOfflineTag(ElementTag.class, "spawn_forced", (attribute, object) -> {
            if (object.isOnline()) {
                return new ElementTag(NMSHandler.playerHelper.getSpawnForced(object.getPlayerEntity()));
            }
            return new ElementTag(object.getNBTEditor().isSpawnForced());
        });

        // <--[tag]
        // @attribute <PlayerTag.last_action_time>
        // @returns TimeTag
        // @description
        // Returns the time of the last direct input from the player. Internally used with <@link tag server.idle_timeout>.
        // -->
        registerOnlineOnlyTag(TimeTag.class, "last_action_time", (attribute, object) -> {
            // The internal time values use monotonic time - this converts to real time.
            long playerMilliTime = NMSHandler.playerHelper.getLastActionTime(object.getPlayerEntity());
            return new TimeTag(CoreUtilities.monotonicMillisToReal(playerMilliTime));
        });

        // <--[tag]
        // @attribute <PlayerTag.scoreboard_id>
        // @returns ElementTag
        // @description
        // Returns the ID of the scoreboard from <@link command scoreboard> that a player is currently viewing, if any.
        // -->
        tagProcessor.registerTag(ElementTag.class, "scoreboard_id", (attribute, object) -> {
            String id = ScoreboardHelper.viewerMap.get(object.getUUID());
            if (id == null) {
                return null;
            }
            return new ElementTag(id);
        });

        // <--[tag]
        // @attribute <PlayerTag.scoreboard_team_name[(<board>)]>
        // @returns ElementTag
        // @description
        // Returns the name of the team the player is in for a given scoreboard, if any.
        // If no scoreboard is specified, uses the default (main) board.
        // -->
        tagProcessor.registerTag(ElementTag.class, "scoreboard_team_name", (attribute, object) -> {
            Scoreboard board = attribute.hasParam() ? ScoreboardHelper.getScoreboard(attribute.getParam()) : ScoreboardHelper.getMain();
            Team team = board.getEntryTeam(object.getName());
            if (team == null) {
                return null;
            }
            return new ElementTag(team.getName());
        });

        // <--[tag]
        // @attribute <PlayerTag.bossbar_ids>
        // @returns ListTag
        // @description
        // Returns a list of all bossbars from <@link command bossbar> that this player can see.
        // Does not list bossbars created by any other source.
        // -->
        registerOnlineOnlyTag(ListTag.class, "bossbar_ids", (attribute, object) -> {
            ListTag result = new ListTag();
            for (Map.Entry<String, BossBar> bar : BossBarCommand.bossBarMap.entrySet()) {
                if (bar.getValue().getPlayers().contains(object.getPlayerEntity())) {
                    result.addObject(new ElementTag(bar.getKey(), true));
                }
            }
            return result;
        });

        // <--[tag]
        // @attribute <PlayerTag.tab_completions[<command>]>
        // @returns ListTag
        // @description
        // Returns a list of all tab completions for the given plaintext of a command.
        // Input is formatted equivalent to if it were typed into a chat bar, minus the '/' slash at the start.
        // Input must necessarily contain at least one space.
        // For example: "<player.tab_completions[npc ]>" will return all /NPC sub command names available to the player.
        // This is only compatible with commands registered in Spigot. Meaning in particular, vanilla commands are not recognized or supported.
        // -->
        registerOnlineOnlyTag(ListTag.class, "tab_completions", (attribute, object) -> {
            if (!attribute.hasParam()) {
                return null;
            }
            String cmdFull = attribute.getParam();
            int space = cmdFull.indexOf(' ');
            if (space == -1) {
                attribute.echoError("Invalid command input '" + cmdFull + "': must have at least one space");
                return null;
            }
            String cmdName = cmdFull.substring(0, space);
            PluginCommand actualCmd = Bukkit.getPluginCommand(cmdName);
            if (actualCmd == null) {
                attribute.echoError("Unknown command '" + cmdName + "'");
                return null;
            }
            String args = cmdFull.substring(space + 1);
            ListTag result = new ListTag();
            for (String str : actualCmd.tabComplete(object.getPlayerEntity(), cmdName, CoreUtilities.split(args, ' ').toArray(new String[0]))) {
                result.addObject(new ElementTag(str, true));
            }
            return result;
        });

        if (NMSHandler.getVersion().isAtLeast(NMSVersion.v1_19)) {

            // <--[tag]
            // @attribute <PlayerTag.last_death_location>
            // @returns LocationTag
            // @mechanism PlayerTag.last_death_location
            // @description
            // Returns the location where the player last died, if any.
            // Works with offline players.
            // -->
            registerOfflineTag(LocationTag.class, "last_death_location", (attribute, object) -> {
                Location deathLoc = object.getOfflinePlayer().getLastDeathLocation();
                return deathLoc != null ? new LocationTag(deathLoc) : null;
            });

            // <--[mechanism]
            // @object PlayerTag
            // @name last_death_location
            // @input LocationTag
            // @description
            // Sets the player's last death location, note that this only updates clientside when the player respawns.
            // Works with offline players.
            // See also <@link mechanism PlayerTag.refresh_player>.
            // @tags
            // <PlayerTag.last_death_location>
            // -->
            registerOfflineMechanism("last_death_location", LocationTag.class, (object, mechanism, input) -> {
                if (object.isOnline()) {
                    object.getPlayerEntity().setLastDeathLocation(input);
                }
                else {
                    object.getNBTEditor().setLastDeathLocation(input);
                }
            });
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name refresh_player
        // @input None
        // @description
        // Refreshes the player's client, resending some internal data.
        // -->
        registerOnlineOnlyMechanism("refresh_player", (object, mechanism) -> {
            NMSHandler.playerHelper.refreshPlayer(object.getPlayerEntity());
        });

        // <--[mechanism]
        // @object PlayerTag
        // @name whitelisted
        // @input ElementTag(Boolean)
        // @description
        // Sets whether the player is whitelisted.
        // Works with offline players.
        // @tags
        // <PlayerTag.whitelisted>
        // -->
        tagProcessor.registerMechanism("whitelisted", false, ElementTag.class, (object, mechanism, input) -> {
            if (mechanism.requireBoolean()) {
                object.getOfflinePlayer().setWhitelisted(input.asBoolean());
            }
        }, "is_whitelisted");



        // <--[mechanism]
        // @object PlayerTag
        // @name bed_spawn_location
        // @input LocationTag
        // @description
        // Sets the bed location that the player respawns at.
        // Provide no input to unset.
        // @tags
        // <PlayerTag.bed_spawn>
        // -->
        registerOfflineMechanism("bed_spawn_location", (object, mechanism) -> {
            if (!mechanism.hasValue()) {
                object.setBedSpawnLocation(null);
            }
            else if (mechanism.requireObject(LocationTag.class)) {
                object.setBedSpawnLocation(mechanism.valueAsType(LocationTag.class));
            }
        });

        // <--[mechanism]
        // @object PlayerTag
        // @name spawn_forced
        // @input ElementTag(Boolean)
        // @description
        // Sets whether the player's bed spawn location is forced (ie still valid even if a bed is missing).
        // @tags
        // <PlayerTag.spawn_forced>
        // -->
        registerOfflineMechanism("spawn_forced", ElementTag.class, (object, mechanism, input) -> {
            if (!mechanism.requireBoolean()) {
                return;
            }
            if (object.isOnline()) {
                NMSHandler.playerHelper.setSpawnForced(object.getPlayerEntity(), input.asBoolean());
            }
            else {
                object.getNBTEditor().setSpawnForced(input.asBoolean());
            }
        });
    }

    public static ObjectTagProcessor<PlayerTag> tagProcessor = new ObjectTagProcessor<>();

    /**
     * Needed for validation on tags that mess with 'getNBTEditor' or similar special calls for offline-player-compatibility logic.
     */
    public static <R extends ObjectTag> void registerOfflineTag(Class<R> returnType, String name, TagRunnable.ObjectInterface<PlayerTag, R> runnable, String... variants) {
        tagProcessor.registerTag(returnType, name, (attribute, object) -> {
            if (!object.isValid()) {
                if (!attribute.hasAlternative()) {
                    attribute.echoError("Player is not considered valid in tag '" + attribute.getAttributeWithoutParam(1) + "' for player: " + object.debuggable());
                }
                return null;
            }
            return runnable.run(attribute, object);
        }, variants);
    }

    public static <R extends ObjectTag> void registerOnlineOnlyTag(Class<R> returnType, String name, TagRunnable.ObjectInterface<PlayerTag, R> runnable, String... variants) {
        tagProcessor.registerTag(returnType, name, (attribute, object) -> {
            if (!object.isOnline()) {
                if (!attribute.hasAlternative()) {
                    attribute.echoError("Player is not online, but tag '" + attribute.getAttributeWithoutParam(1) + "' requires the player be online, for player: " + object.debuggable());
                }
                return null;
            }
            return runnable.run(attribute, object);
        }, variants);
    }

    public static void registerOnlineOnlyMechanism(String name, Mechanism.GenericMechRunnerInterface<PlayerTag> runnable) {
        tagProcessor.registerMechanism(name, false, (object, mechanism) -> {
            if (!object.isOnline()) {
                mechanism.echoError("Player is not online, but mechanism '" + name + "' requires the player be online, for player: " + object.debuggable());
                return;
            }
            runnable.run(object, mechanism);
        });
    }

    public static <P extends ObjectTag> void registerOnlineOnlyMechanism(String name, Class<P> paramType, Mechanism.ObjectInputMechRunnerInterface<PlayerTag, P> runnable) {
        tagProcessor.registerMechanism(name, false, paramType, (object, mechanism, input) -> {
            if (!object.isOnline()) {
                mechanism.echoError("Player is not online, but mechanism '" + name + "' requires the player be online, for player: " + object.debuggable());
                return;
            }
            runnable.run(object, mechanism, input);
        });
    }

    public static <P extends ObjectTag> void registerOfflineMechanism(String name, Class<P> paramType, Mechanism.ObjectInputMechRunnerInterface<PlayerTag, P> runnable, String... deprecatedVariants) {
        tagProcessor.registerMechanism(name, false, paramType, (object, mechanism, input) -> {
            if (!object.isValid()) {
                mechanism.echoError("Player is not considered valid in mechanism '" + name + "' for player: " + object.debuggable());
                return;
            }
            runnable.run(object, mechanism, input);
        }, deprecatedVariants);
    }

    public static void registerOfflineMechanism(String name, Mechanism.GenericMechRunnerInterface<PlayerTag> runnable, String... deprecatedVariants) {
        tagProcessor.registerMechanism(name, false, (object, mechanism) -> {
            if (!object.isValid()) {
                mechanism.echoError("Player is not considered valid in mechanism '" + name + "' for player: " + object.debuggable());
                return;
            }
            runnable.run(object, mechanism);
        }, deprecatedVariants);
    }

    @Override
    public ObjectTag getObjectAttribute(Attribute attribute) {
        return tagProcessor.getObjectAttribute(this, attribute);
    }

    @Override
    public ObjectTag getNextObjectTypeDown() {
        if (isOnline()) {
            return new EntityTag(getPlayerEntity());
        }
        return new ElementTag(identify());
    }

    public void applyProperty(Mechanism mechanism) {
        mechanism.echoError("Cannot apply properties to a player!");
    }

    @Override
    public void adjust(Mechanism mechanism) {

        // <--[mechanism]
        // @object PlayerTag
        // @name send_climbable_materials
        // @input ListTag(MaterialTag)
        // @description
        // Sends the player a list of climbable materials.
        // To climb a block, the player has to stand in it, which means only non-full blocks can be climbed.
        // Note that this gets reset once the player rejoins or once server resources are reloaded (see <@link event server resources reloaded>).
        // @tags
        // <server.vanilla_tagged_materials[<tag>]>
        // @example
        // # Lets the linked player climb iron_bars, while keeping other climbable materials climbable
        // - adjust <player> send_climbable_materials:<server.vanilla_tagged_materials[climbable].include[iron_bars]>
        // @example
        // # Lets the linked player climb only acacia_buttons, making all other materials non-climbable.
        // - adjust <player> send_climbable_materials:acacia_button
        // -->
        if (mechanism.matches("send_climbable_materials") && mechanism.requireObject(ListTag.class)) {
            List<MaterialTag> materialTags = mechanism.valueAsType(ListTag.class).filter(MaterialTag.class, mechanism.context);
            List<Material> materials = new ArrayList<>();
            for (MaterialTag materialTag : materialTags) {
                Material material = materialTag.getMaterial();
                if (!material.isBlock()) {
                    mechanism.echoError("Invalid material specified '" + material.name() + "': must be a block material.");
                    continue;
                }
                materials.add(material);
            }
            NMSHandler.playerHelper.sendClimbableMaterials(getPlayerEntity(), materials);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name noclip
        // @input ElementTag(Boolean)
        // @description
        // When true, causes the server to allow the player to noclip (ie, walk through blocks without being prevented).
        // This is purely serverside. The client will still not walk through blocks.
        // This is useful alongside <@link command showfake>.
        // Note that this may sometimes be imperfect / sometimes momentarily continue to clip block.
        // Note that this may also prevent other collisions (eg projectile impact) but is not guaranteed to.
        // -->
        if (mechanism.matches("noclip") && mechanism.hasValue()) {
            if (mechanism.getValue().asBoolean()) {
                DenizenPacketHandler.forceNoclip.add(getUUID());
            }
            else {
                DenizenPacketHandler.forceNoclip.remove(getUUID());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name respawn
        // @input None
        // @description
        // Forces the player to respawn if they are on the death screen.
        // -->
        if (mechanism.matches("respawn")) {
            NMSHandler.packetHelper.respawn(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name vision
        // @input ElementTag
        // @description
        // Changes the player's vision to the provided entity type. Valid types:
        // ENDERMAN, CAVE_SPIDER, SPIDER, CREEPER
        // Provide no value to reset the player's vision.
        // Note: This is powered by a bug in Minecraft that has been present for a long time, but may at some point be 'fixed' by Mojang.
        // -->
        if (mechanism.matches("vision")) {
            if (mechanism.hasValue() && mechanism.requireEnum(EntityType.class)) {
                NMSHandler.packetHelper.setVision(getPlayerEntity(), EntityType.valueOf(mechanism.getValue().asString().toUpperCase()));
            }
            else {
                NMSHandler.packetHelper.forceSpectate(getPlayerEntity(), getPlayerEntity());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name level
        // @input ElementTag(Number)
        // @description
        // Sets the level on the player. Does not affect the current progression of experience towards next level.
        // @tags
        // <PlayerTag.xp_level>
        // -->
        if (mechanism.matches("level") && mechanism.requireInteger()) {
            setLevel(mechanism.getValue().asInt());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name item_slot
        // @input ElementTag(Number)
        // @description
        // Sets the inventory slot that the player has selected.
        // Works with offline players.
        // @tags
        // <PlayerTag.held_item_slot>
        // -->
        if (mechanism.matches("item_slot") && mechanism.requireInteger()) {
            if (isOnline()) {
                getPlayerEntity().getInventory().setHeldItemSlot(mechanism.getValue().asInt() - 1);
            }
            else {
                getNBTEditor().setItemInHand(mechanism.getValue().asInt() - 1);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name window_property
        // @input ElementTag
        // @description
        // Sets various properties of a window the player has open, such as the open page in a lectern.
        // Input is of the form PROPERTY,VALUE where the value is a number.
        // Note that any adjusted window properties are entirely clientside.
        // Valid properties: <@link url https://hub.spigotmc.org/javadocs/spigot/org/bukkit/inventory/InventoryView.Property.html>
        // -->
        if (mechanism.matches("window_property")) {
            String[] split = mechanism.getValue().asString().split(",", 2);
            if (split.length != 2) {
                Debug.echoError("Invalid input! Must be in the form PROPERTY,VALUE");
            }
            else {
                try {
                    getPlayerEntity().setWindowProperty(InventoryView.Property.valueOf(split[0].toUpperCase()), Integer.parseInt(split[1]));
                }
                catch (NumberFormatException e) {
                    Debug.echoError("Input value must be a number!");
                }
                catch (IllegalArgumentException e) {
                    Debug.echoError("Must specify a valid window property!");
                }
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name item_on_cursor
        // @input ItemTag
        // @description
        // Sets the item on the player's cursor.
        // This includes chest interfaces, inventories, and hotbars, etc.
        // @tags
        // <PlayerTag.item_on_cursor>
        // -->
        if (mechanism.matches("item_on_cursor") && mechanism.requireObject(ItemTag.class)) {
            getPlayerEntity().setItemOnCursor(mechanism.valueAsType(ItemTag.class).getItemStack());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name award_advancement
        // @input ElementTag
        // @description
        // Awards an advancement to the player.
        // @tags
        // <PlayerTag.has_advancement[<name>]>
        // -->
        if (mechanism.matches("award_advancement")) {
            Advancement adv = AdvancementHelper.getAdvancement(mechanism.getValue().asString());
            if (adv == null) {
                if (mechanism.shouldDebug()) {
                    Debug.echoError("Advancement '" + mechanism.getValue().asString() + "' does not exist.");
                }
                return;
            }
            AdvancementProgress prog = getPlayerEntity().getAdvancementProgress(adv);
            for (String criteria : prog.getRemainingCriteria()) {
                prog.awardCriteria(criteria);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name revoke_advancement
        // @input ElementTag
        // @description
        // Un-awards an advancement from the player.
        // @tags
        // <PlayerTag.has_advancement[<name>]>
        // -->
        if (mechanism.matches("revoke_advancement")) {
            Advancement adv = AdvancementHelper.getAdvancement(mechanism.getValue().asString());
            if (adv == null) {
                if (mechanism.shouldDebug()) {
                    Debug.echoError("Advancement '" + mechanism.getValue().asString() + "' does not exist.");
                }
                return;
            }
            AdvancementProgress prog = getPlayerEntity().getAdvancementProgress(adv);
            for (String criteria : prog.getAwardedCriteria()) {
                prog.revokeCriteria(criteria);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_absorption_health
        // @input ElementTag(Decimal)
        // @description
        // Shows the player fake absorption health that persists on damage.
        // -->
        if (mechanism.matches("fake_absorption_health") && mechanism.requireFloat()) {
            NMSHandler.packetHelper.setFakeAbsorption(getPlayerEntity(), mechanism.getValue().asFloat());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name health_scale
        // @input ElementTag(Decimal)
        // @description
        // Sets the 'health scale' on the Player. Each heart equals '2'. The standard health scale is
        // 20, so for example, indicating a value of 40 will display double the amount of hearts
        // standard.
        // Player relogging will reset this mechanism.
        // @tags
        // <PlayerTag.health_scale>
        // -->
        if (mechanism.matches("health_scale") && mechanism.requireDouble()) {
            getPlayerEntity().setHealthScale(mechanism.getValue().asDouble());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name scale_health
        // @input ElementTag(Boolean)
        // @description
        // Enables or disables the health scale value. Disabling will result in the standard
        // amount of hearts being shown.
        // @tags
        // <PlayerTag.health_is_scaled>
        // -->
        if (mechanism.matches("scale_health") && mechanism.requireBoolean()) {
            getPlayerEntity().setHealthScaled(mechanism.getValue().asBoolean());
        }

        // Allow offline editing of health values
        if (mechanism.matches("max_health") && mechanism.requireDouble()) {
            setMaxHealth(mechanism.getValue().asDouble());
        }

        if (mechanism.matches("health") && mechanism.requireDouble()) {
            setHealth(mechanism.getValue().asDouble());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name resource_pack
        // @input ElementTag(|ElementTag)
        // @deprecated Use the "resourcepack" command instead of this old mechanism.
        // @description
        // Deprecated, use <@link command resourcepack>.
        // -->
        if (mechanism.matches("resource_pack") || mechanism.matches("texture_pack")) {
            BukkitImplDeprecations.playerResourcePackMech.warn(mechanism.context);
            String pack = mechanism.getValue().asString();
            int pipe = pack.indexOf('|');
            if (pipe > 0) {
                String hash = pack.substring(pipe + 1);
                pack = pack.substring(0, pipe);
                if (hash.length() != 40) {
                    Debug.echoError("Invalid resource_pack hash. Should be 40 characters of hexadecimal data.");
                    return;
                }
                byte[] hashData = new byte[20];
                for (int i = 0; i < 20; i++) {
                    hashData[i] = (byte) Integer.parseInt(hash.substring(i * 2, i * 2 + 2), 16);
                }
                getPlayerEntity().setResourcePack(pack, hashData);
            }
            else {
                getPlayerEntity().setResourcePack(pack);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name saturation
        // @input ElementTag(Decimal)
        // @description
        // Sets the current food saturation level of a player.
        // Works with offline players.
        // @tags
        // <PlayerTag.saturation>
        // -->
        if (mechanism.matches("saturation") && mechanism.requireFloat()) {
            if (isOnline()) {
                getPlayerEntity().setSaturation(mechanism.getValue().asFloat());
            }
            else {
                getNBTEditor().setSaturation(mechanism.getValue().asFloat());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name send_map
        // @input ElementTag(Number)
        // @description
        // Forces a player to receive the entirety of the specified map ID instantly.
        // This is mainly used as a way to correct bugs in map rendering.
        // -->
        if (mechanism.matches("send_map") && mechanism.requireInteger()) {
            MapView map = Bukkit.getServer().getMap((short) mechanism.getValue().asInt());
            if (map != null) {
                getPlayerEntity().sendMap(map);
            }
            else {
                Debug.echoError("No map found for ID " + mechanism.getValue().asInt() + "!");
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name food_level
        // @input ElementTag(Number)
        // @description
        // Sets the current food level of a player. Typically, '20' is full.
        // @tags
        // <PlayerTag.food_level>
        // -->
        if (mechanism.matches("food_level") && mechanism.requireInteger()) {
            setFoodLevel(mechanism.getValue().asInt());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name can_fly
        // @input ElementTag(Boolean)
        // @description
        // Sets whether the player is allowed to fly.
        // Works with offline players.
        // @tags
        // <PlayerTag.can_fly>
        // -->
        if (mechanism.matches("can_fly") && mechanism.requireBoolean()) {
            if (isOnline()) {
                getPlayerEntity().setAllowFlight(mechanism.getValue().asBoolean());
            }
            else {
                getNBTEditor().setAllowFlight(mechanism.getValue().asBoolean());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fly_speed
        // @input ElementTag(Decimal)
        // @description
        // Sets the fly speed of the player. Valid range is 0.0 to 1.0
        // Works with offline players.
        // @tags
        // <PlayerTag.fly_speed>
        // -->
        if (mechanism.matches("fly_speed") && mechanism.requireFloat()) {
            float val = mechanism.getValue().asFloat();
            if (val < -1 || val > 1) {
                mechanism.echoError("Invalid speed specified. Must be between -1 and 1.");
                return;
            }
            if (isOnline()) {
                getPlayerEntity().setFlySpeed(val);
            }
            else {
                getNBTEditor().setFlySpeed(val);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name flying
        // @input ElementTag(Boolean)
        // @description
        // Sets whether the player is flying.
        // @tags
        // <PlayerTag.is_flying>
        // -->
        if (mechanism.matches("flying") && mechanism.requireBoolean()) {
            boolean doFly = mechanism.getValue().asBoolean();
            if (doFly && !getPlayerEntity().getAllowFlight()) {
                Debug.echoError("Must adjust 'can_fly:true' before you can adjust 'flying:true'");
                return;
            }
            getPlayerEntity().setFlying(doFly);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name sprinting
        // @input ElementTag(Boolean)
        // @description
        // Sets whether the player is sprinting.
        // @tags
        // <PlayerTag.is_sprinting>
        // -->
        if (mechanism.matches("sprinting") && mechanism.requireBoolean()) {
            getPlayerEntity().setSprinting(mechanism.getValue().asBoolean());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name gamemode
        // @input ElementTag
        // @description
        // Sets the game mode of the player.
        // Valid gamemodes are survival, creative, adventure, and spectator.
        // Works with offline players.
        // @tags
        // <PlayerTag.gamemode>
        // -->
        if (mechanism.matches("gamemode") && mechanism.requireEnum(GameMode.class)) {
            setGameMode(GameMode.valueOf(mechanism.getValue().asString().toUpperCase()));
        }

        if (mechanism.matches("kick")) {
            BukkitImplDeprecations.oldKickMech.warn(mechanism.context);
            getPlayerEntity().kickPlayer(mechanism.getValue().asString());
        }

        if (mechanism.matches("weather") && mechanism.requireEnum(WeatherType.class)) {
            BukkitImplDeprecations.oldWeatherMech.warn(mechanism.context);
            getPlayerEntity().setPlayerWeather(WeatherType.valueOf(mechanism.getValue().asString().toUpperCase()));
        }

        if (mechanism.matches("reset_weather")) {
            BukkitImplDeprecations.oldWeatherMech.warn(mechanism.context);
            getPlayerEntity().resetPlayerWeather();
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name player_list_name
        // @input ElementTag
        // @description
        // Sets the entry that is shown in the 'player list' that is shown when pressing tab.
        // @tags
        // <PlayerTag.list_name>
        // -->
        if (mechanism.matches("player_list_name")) {
            PaperAPITools.instance.setPlayerListName(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name display_name
        // @input ElementTag
        // @description
        // Sets the name displayed for the player when chatting.
        // This only applies if there's a chat plugin using it.
        // @tags
        // <PlayerTag.display_name>
        // -->
        if (mechanism.matches("display_name")) {
            getPlayerEntity().setDisplayName(mechanism.getValue().asString());
            return;
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name show_workbench
        // @input LocationTag
        // @description
        // Shows the player a workbench GUI corresponding to a given location.
        // -->
        if (mechanism.matches("show_workbench") && mechanism.requireObject(LocationTag.class)) {
            getPlayerEntity().openWorkbench(mechanism.valueAsType(LocationTag.class), true);
            return;
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name location
        // @input LocationTag
        // @description
        // If the player is online, teleports the player to a given location.
        // Otherwise, sets the player's next spawn location.
        // @tags
        // <PlayerTag.location>
        // -->
        if (mechanism.matches("location") && mechanism.requireObject(LocationTag.class)) {
            setLocation(mechanism.valueAsType(LocationTag.class));
        }

        if (mechanism.matches("time") && mechanism.requireInteger()) {
            BukkitImplDeprecations.oldTimeMech.warn(mechanism.context);
            getPlayerEntity().setPlayerTime(mechanism.getValue().asInt(), true);
        }

        if (mechanism.matches("freeze_time")) {
            BukkitImplDeprecations.oldTimeMech.warn(mechanism.context);
            if (mechanism.requireInteger("Invalid integer specified. Assuming current world time.")) {
                getPlayerEntity().setPlayerTime(mechanism.getValue().asInt(), false);
            }
            else {
                getPlayerEntity().setPlayerTime(getPlayerEntity().getWorld().getTime(), false);
            }
        }

        if (mechanism.matches("reset_time")) {
            BukkitImplDeprecations.oldTimeMech.warn(mechanism.context);
            getPlayerEntity().resetPlayerTime();
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name walk_speed
        // @input ElementTag(Decimal)
        // @description
        // Sets the walk speed of the player. The standard value is '0.2'. Valid range is 0.0 to 1.0
        // Works with offline players.
        // @tags
        // <PlayerTag.walk_speed>
        // -->
        if (mechanism.matches("walk_speed") && mechanism.requireFloat()) {
            float val = mechanism.getValue().asFloat();
            if (val < -1 || val > 1) {
                mechanism.echoError("Invalid speed specified. Must be between -1 and 1.");
                return;
            }
            if (isOnline()) {
                getPlayerEntity().setWalkSpeed(val);
            }
            else {
                getNBTEditor().setWalkSpeed(val);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name exhaustion
        // @input ElementTag(Decimal)
        // @description
        // Sets the exhaustion level of a player.
        // Works with offline players.
        // @tags
        // <PlayerTag.exhaustion>
        // -->
        if (mechanism.matches("exhaustion") && mechanism.requireFloat()) {
            if (isOnline()) {
                getPlayerEntity().setExhaustion(mechanism.getValue().asFloat());
            }
            else {
                getNBTEditor().setExhaustion(mechanism.getValue().asFloat());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name show_entity
        // @input EntityTag
        // @description
        // Shows the player a previously hidden entity.
        // To show for everyone, use <@link mechanism EntityTag.show_to_players>.
        // See also <@link mechanism PlayerTag.hide_entity>.
        // -->
        if (mechanism.matches("show_entity") && mechanism.requireObject(EntityTag.class)) {
            HideEntitiesHelper.unhideEntity(getPlayerEntity(), mechanism.valueAsType(EntityTag.class).getBukkitEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name hide_entity
        // @input EntityTag
        // @description
        // Hides an entity from the player.
        // To hide from everyone, use <@link mechanism EntityTag.hide_from_players>.
        // See also <@link mechanism PlayerTag.show_entity>.
        // -->
        if (mechanism.matches("hide_entity")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                ListTag split = mechanism.valueAsType(ListTag.class);
                if (split.size() > 0 && new ElementTag(split.get(0)).matchesType(EntityTag.class)) {
                    EntityTag entity = EntityTag.valueOf(split.get(0), mechanism.context);
                    if (!entity.isSpawnedOrValidForTag()) {
                        Debug.echoError("Can't hide the unspawned entity '" + split.get(0) + "'!");
                    }
                    else {
                        HideEntitiesHelper.hideEntity(getPlayerEntity(), entity.getBukkitEntity());
                    }
                }
                else {
                    Debug.echoError("'" + split.get(0) + "' is not a valid entity!");
                }
            }
            else {
                Debug.echoError("Must specify an entity to hide!");
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name hide_entities
        // @input ElementTag
        // @description
        // Hides a matchable type of entity from the player. Can use any advanced entity matchers per <@link language Advanced Object Matching>.
        // To hide a specific entity from the player, use <@link mechanism PlayerTag.hide_entity>.
        // To remove hide sets, use <@link mechanism PlayerTag.unhide_entities>.
        // Note that dynamic matchables like 'entity_flagged' will behave in unexpected ways when dynamically changing.
        // -->
        if (mechanism.matches("hide_entities") && mechanism.hasValue()) {
            HideEntitiesHelper.PlayerHideMap map = HideEntitiesHelper.getPlayerMapFor(getUUID());
            String hideMe = mechanism.getValue().asString();
            map.matchersHidden.add(hideMe);
            if (isOnline()) {
                for (Entity ent : getPlayerEntity().getWorld().getEntities()) {
                    if (new EntityTag(ent).tryAdvancedMatcher(hideMe) && map.shouldHide(ent)) {
                        NMSHandler.entityHelper.sendHidePacket(getPlayerEntity(), ent);
                    }
                }
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name unhide_entities
        // @input ElementTag
        // @description
        // Removes any entity hides added by <@link mechanism PlayerTag.hide_entities>. Input must exactly match the input given to the hide mechanism.
        // -->
        if (mechanism.matches("unhide_entities") && mechanism.hasValue()) {
            HideEntitiesHelper.PlayerHideMap map = HideEntitiesHelper.getPlayerMapFor(getUUID());
            String unhideMe = mechanism.getValue().asString();
            map.matchersHidden.remove(unhideMe);
            if (map.matchersHidden.isEmpty() && map.entitiesHidden.isEmpty() && map.overridinglyShow.isEmpty()) {
                HideEntitiesHelper.playerHides.remove(getUUID());
            }
            if (isOnline()) {
                for (Entity ent : getPlayerEntity().getWorld().getEntities()) {
                    if (new EntityTag(ent).tryAdvancedMatcher(unhideMe) && !map.shouldHide(ent)) {
                        NMSHandler.entityHelper.sendShowPacket(getPlayerEntity(), ent);
                    }
                }
            }
        }

        if (mechanism.matches("show_boss_bar")) {
            BukkitImplDeprecations.oldBossBarMech.warn(mechanism.context);
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 2);
                if (split.length == 2 && new ElementTag(split[0]).isDouble()) {
                    BossBarHelper.showSimpleBossBar(getPlayerEntity(), split[1], new ElementTag(split[0]).asDouble() * (1.0 / 200.0));
                }
                else {
                    BossBarHelper.showSimpleBossBar(getPlayerEntity(), split[0], 1.0);
                }
            }
            else {
                BossBarHelper.removeSimpleBossBar(getPlayerEntity());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_experience
        // @input ElementTag(Decimal)(|ElementTag(Number))
        // @description
        // Shows the player a fake experience bar, with a number between 0.0 and 1.0 to specify how far along the bar is.
        // Use with no input value to reset to the player's normal experience.
        // Optionally, you can specify a fake experience level.
        // For example: - adjust <player> fake_experience:0.5|5
        // -->
        if (mechanism.matches("fake_experience")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 2);
                if (split.length > 0 && new ElementTag(split[0]).isFloat()) {
                    if (split.length > 1 && new ElementTag(split[1]).isInt()) {
                        getPlayerEntity().sendExperienceChange(new ElementTag(split[0]).asFloat(), new ElementTag(split[1]).asInt());
                    }
                    else {
                        getPlayerEntity().sendExperienceChange(new ElementTag(split[0]).asFloat());
                    }
                }
                else {
                    mechanism.echoError("'" + split[0] + "' is not a valid decimal number!");
                }
            }
            else {
                getPlayerEntity().sendExperienceChange(getPlayerEntity().getExp(), getPlayerEntity().getLevel());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_health
        // @input ElementTag(Decimal)(|ElementTag(Number)(|ElementTag(Decimal)))
        // @description
        // Shows the player a fake health bar, with a number between 0 and 20, where 1 is half of a heart.
        // Use with no input value to reset to the player's normal health.
        // Optionally, you can specify a fake food level, between 0 and 20.
        // You can also optionally specify a food saturation level between 0 and 10.
        // For example:
        // - adjust <player> fake_health:1
        // - adjust <player> fake_health:10|15
        // - adjust <player> fake_health:<player.health>|3|0
        // -->
        if (mechanism.matches("fake_health")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 3);
                if (split.length > 0 && new ElementTag(split[0]).isFloat()) {
                    if (split.length > 1 && new ElementTag(split[1]).isInt()) {
                        if (split.length > 2 && new ElementTag(split[2]).isFloat()) {
                            NMSHandler.packetHelper.showHealth(getPlayerEntity(), new ElementTag(split[0]).asFloat(),
                                    new ElementTag(split[1]).asInt(), new ElementTag(split[2]).asFloat());
                        }
                        else {
                            NMSHandler.packetHelper.showHealth(getPlayerEntity(), new ElementTag(split[0]).asFloat(),
                                    new ElementTag(split[1]).asInt(), getPlayerEntity().getSaturation());
                        }
                    }
                    else {
                        NMSHandler.packetHelper.showHealth(getPlayerEntity(), new ElementTag(split[0]).asFloat(),
                                getPlayerEntity().getFoodLevel(), getPlayerEntity().getSaturation());
                    }
                }
                else {
                    Debug.echoError("'" + split[0] + "' is not a valid decimal number!");
                }
            }
            else {
                NMSHandler.packetHelper.resetHealth(getPlayerEntity());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_mount_health
        // @input ElementTag(Decimal)|ElementTag(Decimal)
        // @description
        // Shows the player a fake health bar for their mounted. Specify both the current and maximum health values.
        // Use with no input value to reset to the real health value.
        // Using a health of '0' will make your mount look dead but continue to function.
        // For example:
        // - adjust <player> fake_mount_health:10|15
        // -->
        if (mechanism.matches("fake_mount_health")) {
            if (!isOnline() || !getPlayerEntity().isInsideVehicle()) {
                mechanism.echoError("Cannot run fake_mount_health - player is offline or unmounted.");
                return;
            }
            Entity vehicle = getPlayerEntity().getVehicle();
            if (!(vehicle instanceof LivingEntity)) {
                mechanism.echoError("Cannot run fake_mount_health - vehicle is not a living entity.");
                return;
            }
            LivingEntity liveVehicle = (LivingEntity) vehicle;
            double current, maximum;
            if (mechanism.hasValue()) {
                ListTag input = mechanism.valueAsType(ListTag.class);
                if (input.size() != 2) {
                    mechanism.echoError("Cannot run fake_mount_health - improper input.");
                    return;
                }
                current = new ElementTag(input.get(0)).asDouble();
                maximum = new ElementTag(input.get(1)).asDouble();
            }
            else {
                current = liveVehicle.getHealth();
                maximum = liveVehicle.getMaxHealth();
            }
            NMSHandler.packetHelper.showMobHealth(getPlayerEntity(), liveVehicle, current, maximum);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_entity_health
        // @input MapTag
        // @description
        // Shows the player a fake health number for a given entity.
        // Input is a map with 'entity' as the target entity, and 'health' as the health amount.
        // Optionally add 'max' to set the max health too.
        // Using health of '0' can cause an entity to look dead.
        // For example:
        // - adjust <player> fake_entity_health:[entity=<player.target>;health=0]
        // -->
        if (mechanism.matches("fake_entity_health") && mechanism.requireObject(MapTag.class)) {
            if (!isOnline()) {
                mechanism.echoError("Cannot run fake_entity_health - player is offline.");
                return;
            }
            MapTag map = mechanism.valueAsType(MapTag.class);
            EntityTag entity = map.getObjectAs("entity", EntityTag.class, mechanism.context);
            ElementTag healthObject = map.getElement("health");
            ElementTag maxObject = map.getElement("max");
            if (healthObject == null) {
                mechanism.echoError("Cannot run fake_entity_health - input map is missing 'health' key.");
                return;
            }
            double health = healthObject.asDouble();
            if (entity == null || !entity.isLivingEntity()) {
                mechanism.echoError("Cannot run fake_entity_health - entity is invalid or not living.");
                return;
            }
            double max = maxObject == null ? entity.getLivingEntity().getMaxHealth() : maxObject.asDouble();
            NMSHandler.packetHelper.showMobHealth(getPlayerEntity(), entity.getLivingEntity(), health, max);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fake_equipment
        // @input EntityTag(|ElementTag|ItemTag)
        // @description
        // Shows the player fake equipment on the specified living entity, which has no real non-visual effects.
        // Input is in the form Entity|Slot|Item, where the slot can be one of the following: HAND, OFF_HAND, BOOTS, LEGS, CHEST, HEAD
        // Optionally, exclude the slot and item to stop showing the fake equipment, if any, on the specified entity.
        // For example:
        // - adjust <player> fake_equipment:<[some_entity]>|chest|diamond_chestplate
        // - adjust <player> fake_equipment:<player>|head|jack_o_lantern
        // Consider instead using <@link command fakeequip>.
        // -->
        if (mechanism.matches("fake_equipment")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 3);
                if (split.length > 0 && new ElementTag(split[0]).matchesType(EntityTag.class)) {
                    String slot = split.length > 1 ? split[1].toUpperCase() : null;
                    if (split.length > 1 && (new ElementTag(slot).matchesEnum(EquipmentSlot.class)
                            || slot.equals("MAIN_HAND") || slot.equals("BOOTS"))) {
                        if (split.length > 2 && new ElementTag(split[2]).matchesType(ItemTag.class)) {
                            if (slot.equals("MAIN_HAND")) {
                                slot = "HAND";
                            }
                            else if (slot.equals("BOOTS")) {
                                slot = "FEET";
                            }
                            NMSHandler.packetHelper.showEquipment(getPlayerEntity(),
                                    new ElementTag(split[0]).asType(EntityTag.class, mechanism.context).getLivingEntity(),
                                    EquipmentSlot.valueOf(slot),
                                    new ElementTag(split[2]).asType(ItemTag.class, mechanism.context).getItemStack());
                        }
                        else if (split.length > 2) {
                            Debug.echoError("'" + split[2] + "' is not a valid ItemTag!");
                        }
                    }
                    else if (split.length > 1) {
                        Debug.echoError("'" + split[1] + "' is not a valid slot; must be HAND, OFF_HAND, BOOTS, LEGS, CHEST, or HEAD!");
                    }
                    else {
                        NMSHandler.packetHelper.resetEquipment(getPlayerEntity(),
                                new ElementTag(split[0]).asType(EntityTag.class, mechanism.context).getLivingEntity());
                    }
                }
                else {
                    Debug.echoError("'" + split[0] + "' is not a valid EntityTag!");
                }
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name fov_multiplier
        // @input ElementTag(Decimal)
        // @description
        // Sets the player's field of view multiplier.
        // Leave input empty to reset.
        // Note: Values outside a (-1, 1) range will have little effect on the player's fov.
        // -->
        if (mechanism.matches("fov_multiplier")) {
            if (mechanism.hasValue() && mechanism.requireFloat()) {
                NMSHandler.packetHelper.setFieldOfView(getPlayerEntity(), mechanism.getValue().asFloat());
            }
            else {
                NMSHandler.packetHelper.setFieldOfView(getPlayerEntity(), Float.NaN);
            }
        }

        if (mechanism.matches("item_message")) {
            BukkitImplDeprecations.itemMessage.warn(mechanism.context);
            ItemChangeMessage.sendMessage(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name show_endcredits
        // @input None
        // @description
        // Shows the player the end credits.
        // -->
        if (mechanism.matches("show_endcredits")) {
            NMSHandler.playerHelper.showEndCredits(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name show_demo
        // @input None
        // @description
        // Shows the player the demo screen.
        // -->
        if (mechanism.matches("show_demo")) {
            NMSHandler.packetHelper.showDemoScreen(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name spectator_target
        // @input EntityTag
        // @description
        // Switches the player to spectator mode and causes them to immediately start spectating an entity.
        // To instead fake this effect, use <@link mechanism PlayerTag.spectate>
        // Give no input to detach the player from any target.
        // @tags
        // <PlayerTag.spectator_target>
        // -->
        if (mechanism.matches("spectator_target")) {
            if (mechanism.hasValue()) {
                getPlayerEntity().setGameMode(GameMode.SPECTATOR);
                getPlayerEntity().setSpectatorTarget(mechanism.valueAsType(EntityTag.class).getBukkitEntity());
            }
            else if (getPlayerEntity().getGameMode() == GameMode.SPECTATOR) {
                getPlayerEntity().setSpectatorTarget(null);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name spectate
        // @input EntityTag
        // @description
        // Forces the player to spectate from the entity's point of view, using a packet (meaning, the player starts spectating clientside, but not serverside).
        // The player will not move from their existing location serverside.
        // To cause real spectator mode spectating, use <@link mechanism PlayerTag.spectator_target>
        // Note that in some cases you may want to force the player into the spectate gamemode prior to using this mechanism.
        // Note: They cannot cancel the spectating without a re-log -- you must make them spectate themselves to cancel the effect.
        // Like: - adjust <player> spectate:<player>
        // -->
        if (mechanism.matches("spectate") && mechanism.requireObject(EntityTag.class)) {
            NMSHandler.packetHelper.forceSpectate(getPlayerEntity(), mechanism.valueAsType(EntityTag.class).getBukkitEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name open_book
        // @input None
        // @description
        // Forces the player to open the written book in their hand.
        // The book can safely be removed from the player's hand without the player closing the book.
        // -->
        if (mechanism.matches("open_book")) {
            ItemStack book = getPlayerEntity().getEquipment().getItemInMainHand();
            if (book.getType() == Material.WRITTEN_BOOK) {
                getPlayerEntity().openBook(book);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name open_offhand_book
        // @input None
        // @description
        // Forces the player to open the written book in their offhand.
        // The book can safely be removed from the player's offhand without the player closing the book.
        // -->
        if (mechanism.matches("open_offhand_book")) {
            ItemStack book = getPlayerEntity().getEquipment().getItemInOffHand();
            if (book.getType() == Material.WRITTEN_BOOK) {
                getPlayerEntity().openBook(book);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name show_book
        // @input ItemTag
        // @description
        // Displays a book to a player. Must be a WRITTEN_BOOK item.
        // For simple usage, consider specifying a book script name as the input.
        // -->
        if (mechanism.matches("show_book")
                && mechanism.requireObject(ItemTag.class)) {
            ItemTag book = mechanism.valueAsType(ItemTag.class);
            if (book.getBukkitMaterial() != Material.WRITTEN_BOOK) {
                mechanism.echoError("show_book mechanism must have a written book as input.");
                return;
            }
            getPlayerEntity().openBook(book.getItemStack());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name resend_recipes
        // @input None
        // @description
        // Sends the player a list of the full details of all recipes on the server.
        // This is useful when reloading new item scripts with custom recipes.
        // This will automatically resend discovered recipes at the same time (otherwise the player will seemingly have no recipes unlocked).
        // -->
        if (mechanism.matches("resend_recipes")) {
            NMSHandler.playerHelper.resendRecipeDetails(getPlayerEntity());
            NMSHandler.playerHelper.resendDiscoveredRecipes(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name resend_discovered_recipes
        // @input None
        // @description
        // Sends the player the full list of recipes they have discovered over again.
        // This is useful when used alongside <@link mechanism PlayerTag.quietly_discover_recipe>.
        // -->
        if (mechanism.matches("resend_discovered_recipes")) {
            NMSHandler.playerHelper.resendDiscoveredRecipes(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name quietly_discover_recipe
        // @input ListTag
        // @description
        // Causes the player to discover a recipe, or list of recipes, without being notified or updated about this happening.
        // Generally helpful to follow this with <@link mechanism PlayerTag.resend_discovered_recipes>.
        // Input is in the Namespace:Key format, for example "minecraft:gold_nugget".
        // -->
        if (mechanism.matches("quietly_discover_recipe")) {
            for (String keyText : mechanism.valueAsType(ListTag.class)) {
                NamespacedKey key = Utilities.parseNamespacedKey(keyText);
                NMSHandler.playerHelper.quietlyAddRecipe(getPlayerEntity(), key);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name discover_recipe
        // @input ListTag
        // @description
        // Causes the player to discover a recipe, or list of recipes. Input is in the Namespace:Key format, for example "minecraft:gold_nugget".
        // -->
        if (mechanism.matches("discover_recipe")) {
            List<NamespacedKey> keys = new ArrayList<>();
            for (String key : mechanism.valueAsType(ListTag.class)) {
                keys.add(Utilities.parseNamespacedKey(key));
            }
            getPlayerEntity().discoverRecipes(keys);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name forget_recipe
        // @input ListTag
        // @description
        // Causes the player to forget ('undiscover') a recipe, or list of recipes. Input is in the Namespace:Key format, for example "minecraft:gold_nugget".
        // -->
        if (mechanism.matches("forget_recipe")) {
            List<NamespacedKey> keys = new ArrayList<>();
            for (String key : mechanism.valueAsType(ListTag.class)) {
                keys.add(Utilities.parseNamespacedKey(key));
            }
            getPlayerEntity().undiscoverRecipes(keys);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name edit_sign
        // @input LocationTag
        // @description
        // Allows the player to edit an existing sign. To create a sign, see <@link command Sign>.
        // Give no input to make a fake edit interface.
        // -->
        if (mechanism.matches("edit_sign")) {
            if (mechanism.hasValue() && mechanism.requireObject(LocationTag.class)) {
                BlockState state = mechanism.valueAsType(LocationTag.class).getBlockState();
                if (!(state instanceof Sign)) {
                    mechanism.echoError("Invalid location specified: must be a sign.");
                    return;
                }
                if (!NMSHandler.getVersion().isAtLeast(NMSVersion.v1_18)) {
                    NMSHandler.packetHelper.showSignEditor(getPlayerEntity(), state.getLocation());
                    return;
                }
                getPlayerEntity().openSign((Sign) state);
            }
            else {
                NMSHandler.packetHelper.showSignEditor(getPlayerEntity(), null);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name tab_list_info
        // @input ElementTag
        // @description
        // Show the player some text in the header and footer area in their tab list.
        // - adjust <player> tab_list_info:<header>|<footer>
        // -->
        if (mechanism.matches("tab_list_info")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 2);
                if (split.length > 0) {
                    String header = split[0];
                    String footer = split.length > 1 ? split[1] : "";
                    NMSHandler.packetHelper.showTabListHeaderFooter(getPlayerEntity(), header, footer);
                }
                else {
                    mechanism.echoError("Must specify a header and footer to show!");
                }
            }
            else {
                getPlayerEntity().setPlayerListHeaderFooter(null, null);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name sign_update
        // @input ElementTag
        // @description
        // Shows the player fake lines on a sign, with input in the format of LocationTag|ListTag.
        // -->
        if (mechanism.matches("sign_update")) {
            if (!mechanism.getValue().asString().isEmpty()) {
                String[] split = mechanism.getValue().asString().split("\\|", 2);
                if (LocationTag.matches(split[0]) && split.length > 1) {
                    ListTag lines = ListTag.valueOf(split[1], mechanism.context);
                    LocationTag location = LocationTag.valueOf(split[0], mechanism.context);
                    PaperAPITools.instance.sendSignUpdate(getPlayerEntity(), location, lines.toArray(new String[4]));
                }
                else {
                    Debug.echoError("Must specify a valid location and at least one sign line!");
                }
            }
            else {
                Debug.echoError("Must specify a valid location and at least one sign line!");
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name banner_update
        // @input ElementTag
        // @description
        // Shows the player fake patterns on a banner. Input must be in the form: "LOCATION|COLOR/PATTERN|..."
        // As of Minecraft 1.13, the base color is unique material types, and so <@link command showfake> must be used for base color changes.
        // For the list of possible patterns, see <@link url https://hub.spigotmc.org/javadocs/spigot/org/bukkit/block/banner/PatternType.html>.
        // -->
        if (mechanism.matches("banner_update")) {
            if (mechanism.getValue().asString().length() > 0) {
                String[] split = mechanism.getValue().asString().split("\\|");
                List<Pattern> patterns = new ArrayList<>();
                if (LocationTag.matches(split[0]) && split.length > 1) {
                    List<String> splitList;
                    for (int i = 1; i < split.length; i++) {
                        String string = split[i];
                        if (i == 1 && !string.contains("/")) {
                            continue; // Comapt with old input format that had base_color
                        }
                        try {
                            splitList = CoreUtilities.split(string, '/', 2);
                            patterns.add(new Pattern(DyeColor.valueOf(splitList.get(0).toUpperCase()),
                                    PatternType.valueOf(splitList.get(1).toUpperCase())));
                        }
                        catch (Exception e) {
                            Debug.echoError("Could not apply pattern to banner: " + string);
                        }
                    }
                    LocationTag location = LocationTag.valueOf(split[0], mechanism.context);
                    NMSHandler.packetHelper.showBannerUpdate(getPlayerEntity(), location, patterns);
                }
                else {
                    Debug.echoError("Must specify a valid location and pattern list!");
                }
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name stop_sound
        // @input ElementTag
        // @description
        // Stops all sounds of the specified type for the player.
        // Valid types are AMBIENT, BLOCKS, HOSTILE, MASTER, MUSIC, NEUTRAL, PLAYERS, RECORDS, VOICE, and WEATHER
        // Instead of a type, you can specify a full sound key, which usually has the 'minecraft:' prefix.
        // If no sound type is specified, all types will be stopped.
        // -->
        if (mechanism.matches("stop_sound")) {
            SoundCategory category = null;
            String key = null;
            if (mechanism.hasValue()) {
                if (mechanism.getValue().matchesEnum(SoundCategory.class)) {
                    category = mechanism.getValue().asEnum(SoundCategory.class);
                    if (NMSHandler.getVersion().isAtLeast(NMSVersion.v1_19)) {
                        getPlayerEntity().stopSound(category);
                        return;
                    }
                }
                else {
                    key = mechanism.getValue().asString();
                }
            }
            NMSHandler.playerHelper.stopSound(getPlayerEntity(), key, category);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name update_advancements
        // @input None
        // @description
        // Updates the player's client-side advancements to match their server data.
        // -->
        if (mechanism.matches("update_advancements")) {
            NMSHandler.advancementHelper.update(getPlayerEntity());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name name
        // @input ElementTag
        // @description
        // Changes the name on this player's nameplate.
        // @tags
        // <PlayerTag.name>
        // -->
        if (mechanism.matches("name") && mechanism.hasValue()) {
            String name = mechanism.getValue().asString();
            if (name.length() > 16) {
                Debug.echoError("Must specify a name with no more than 16 characters.");
            }
            else {
                NMSHandler.instance.getProfileEditor().setPlayerName(getPlayerEntity(), mechanism.getValue().asString());
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name skin
        // @input ElementTag
        // @description
        // Changes the skin of the player to the skin of the given player name.
        // See also <@link language Player Entity Skins (Skin Blobs)>.
        // -->
        if (mechanism.matches("skin") && mechanism.hasValue()) {
            String name = mechanism.getValue().asString();
            if (name.length() > 16) {
                mechanism.echoError("Must specify a name with no more than 16 characters.");
                return;
            }
            PaperAPITools.instance.setSkin(getPlayerEntity(), name);
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name skin_blob
        // @input ElementTag
        // @description
        // Changes the skin of the player to the specified blob.
        // In the format: "texture;signature" (two values separated by a semicolon).
        // See also <@link language Player Entity Skins (Skin Blobs)>.
        // @tags
        // <PlayerTag.skin_blob>
        // -->
        if (mechanism.matches("skin_blob") && mechanism.hasValue()) {
            PaperAPITools.instance.setSkinBlob(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name is_op
        // @input ElementTag(Boolean)
        // @description
        // Changes whether the player is a server operator or not.
        // @tags
        // <PlayerTag.is_op>
        // -->
        if (mechanism.matches("is_op") && mechanism.requireBoolean()) {
            ImprovedOfflinePlayer.invalidateNow(getUUID());
            getOfflinePlayer().setOp(mechanism.getValue().asBoolean());
        }

        if (mechanism.matches("money") && mechanism.requireDouble() && Depends.economy != null) {
            BukkitImplDeprecations.oldMoneyMech.warn(mechanism.context);
            double bal = Depends.economy.getBalance(getOfflinePlayer());
            double goal = mechanism.getValue().asDouble();
            if (goal > bal) {
                Depends.economy.depositPlayer(getOfflinePlayer(), goal - bal);
            }
            else if (bal > goal) {
                Depends.economy.withdrawPlayer(getOfflinePlayer(), bal - goal);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name chat_prefix
        // @input ElementTag
        // @plugin Vault
        // @description
        // Set the player's chat prefix.
        // Requires a Vault-compatible chat plugin.
        // @tags
        // <PlayerTag.chat_prefix>
        // -->
        if (mechanism.matches("chat_prefix")) {
            if (Depends.chat == null) {
                Debug.echoError("Chat_Prefix mechanism invalid: No linked Chat plugin.");
                return;
            }
            Depends.chat.setPlayerPrefix(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name chat_suffix
        // @input ElementTag
        // @plugin Vault
        // @description
        // Set the player's chat suffix.
        // Requires a Vault-compatible chat plugin.
        // @tags
        // <PlayerTag.chat_suffix>
        // -->
        if (mechanism.matches("chat_suffix")) {
            if (Depends.chat == null) {
                Debug.echoError("Chat_Suffix mechanism invalid: No linked Chat plugin.");
                return;
            }
            Depends.chat.setPlayerSuffix(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name selected_npc
        // @input NPCTag
        // @description
        // Sets the NPC that the player has selected.
        // @tags
        // <PlayerTag.selected_npc>
        // -->
        if (mechanism.matches("selected_npc") && Depends.citizens != null && mechanism.requireObject(NPCTag.class)) {
            ((NPCSelector) CitizensAPI.getDefaultNPCSelector()).select(getPlayerEntity(), mechanism.valueAsType(NPCTag.class).getCitizen());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name hide_particles
        // @input ElementTag
        // @description
        // Hides a certain type of particle from the player.
        // Input is the particle type name - refer to <@link tag server.particle_types>.
        // Give no input to remove all hides from a player.
        // Hides will persist through players reconnecting, but not through servers restarting.
        // -->
        if (mechanism.matches("hide_particles")) {
            if (!mechanism.hasValue()) {
                HideParticles.hidden.remove(getUUID());
            }
            else {
                NetworkInterceptHelper.enable();
                HashSet<Particle> particles = HideParticles.hidden.computeIfAbsent(getUUID(), k -> new HashSet<>());
                Particle particle = Particle.valueOf(mechanism.getValue().asString().toUpperCase());
                particles.add(particle);
            }
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name send_to
        // @input ElementTag
        // @plugin BungeeCord
        // @description
        // Sends the player to the specified Bungee server.
        // This also works with other Bungee-Messaging compatible proxy systems, such as Velocity.
        // -->
        if (mechanism.matches("send_to") && mechanism.hasValue()) {
            if (!isOnline()) {
                Debug.echoError("Cannot use send_to on offline player.");
                return;
            }
            Depends.bungeeSendPlayer(getPlayerEntity(), mechanism.getValue().asString());
        }

        // <--[mechanism]
        // @object PlayerTag
        // @name send_server_brand
        // @input ElementTag
        // @description
        // Sends the player a fake server brand, that will be displayed in the F3 Debug screen.
        // -->
        if (mechanism.matches("send_server_brand") && mechanism.hasValue()) {
            if (!isOnline()) {
                Debug.echoError("Cannot use send_server_brand on offline player.");
                return;
            }
            NMSHandler.packetHelper.sendBrand(getPlayerEntity(), mechanism.getValue().asString());
        }

        tagProcessor.processMechanism(this, mechanism);

        // Pass along to EntityTag mechanism handler if not already handled.
        if (!mechanism.fulfilled()) {
            if (isOnline()) {
                new EntityTag(getPlayerEntity()).adjust(mechanism);
            }
            else {
                if (mechanism.matches("show_to_players")) {
                    HideEntitiesHelper.removeHide(null, getUUID());
                }
                if (mechanism.matches("hide_from_players")) {
                    HideEntitiesHelper.addHide(null, getUUID());
                }
            }
        }
    }

    @Override
    public boolean advancedMatches(String matcher) {
        return isOnline() && getDenizenEntity().tryAdvancedMatcher(matcher);
    }

    /**
     * Return an appropriate error-header output for this object, if any.
     */
    @Override
    public String getErrorHeaderContext() {
        return " with player '<A>" + getName() + "<LR>'";
    }
}