Add support for saved items.

Introduces the concept of a _saved item_; an in-game item that has been
captured in a YAML file via Bukkit's item serialization mechanism. These
items can be referenced in the config-file in all places that any other
normal item can be used, assuming the ThingManager is in charge of the
parsing. This should help bridge the gap between class chests and the
config-file by allowing any Bukkit serializable item stack to be stored
and referenced as if MobArena's item syntax directly supported it.

Three new setup commands are introduced to help manage the items, such
that they can be created, deleted, and loaded (for "editing" purposes).
The commands are somewhat rough around the edges and may need a little
bit of polish going forward.

Together with the new inventory referencing Things, this functionality
should help provide most of the flexibility people have been missing
from the item syntax for about a decade... Hell, it's about time.

Closes #212

src/main/java/com/garbagemule/MobArena/MobArena.java

@@ -8,6 +8,7 @@
 import com.garbagemule.MobArena.formula.FormulaManager;
 import com.garbagemule.MobArena.framework.Arena;
 import com.garbagemule.MobArena.framework.ArenaMaster;
+import com.garbagemule.MobArena.items.SavedItemsManager;
 import com.garbagemule.MobArena.listeners.MAGlobalListener;
 import com.garbagemule.MobArena.metrics.ArenaCountChart;
 import com.garbagemule.MobArena.metrics.ClassChestsChart;
@@ -67,6 +68,8 @@ public class MobArena extends JavaPlugin
     private FormulaManager formman;
     private FormulaMacros macros;
 
+    private SavedItemsManager itemman;
+
     private SignListeners signListeners;
 
     @Override
@@ -106,6 +109,7 @@ private void setup() {
         try {
             createDataFolder();
             setupFormulaMacros();
+            setupSavedItemsManager();
             setupArenaMaster();
             setupCommandHandler();
 
@@ -134,6 +138,10 @@ private void setupFormulaMacros() {
         macros = FormulaMacros.create(this);
     }
 
+    private void setupSavedItemsManager() {
+        itemman = new SavedItemsManager(this);
+    }
+
     private void setupArenaMaster() {
         arenaMaster = new ArenaMasterImpl(this);
     }
@@ -190,6 +198,7 @@ public void reload() {
             reloadConfig();
             reloadGlobalMessenger();
             reloadFormulaMacros();
+            reloadSavedItemsManager();
             reloadArenaMaster();
             reloadAnnouncementsFile();
             reloadSigns();
@@ -226,6 +235,10 @@ private void reloadFormulaMacros() {
         }
     }
 
+    private void reloadSavedItemsManager() {
+        itemman.reload();
+    }
+
     private void reloadArenaMaster() {
         arenaMaster.getArenas().forEach(Arena::forceEnd);
         arenaMaster.initialize();
@@ -317,4 +330,8 @@ public FormulaManager getFormulaManager() {
     public FormulaMacros getFormulaMacros() {
         return macros;
     }
+
+    public SavedItemsManager getSavedItemsManager() {
+        return itemman;
+    }
 }

src/main/java/com/garbagemule/MobArena/commands/CommandHandler.java

@@ -15,12 +15,15 @@
 import com.garbagemule.MobArena.commands.setup.CheckDataCommand;
 import com.garbagemule.MobArena.commands.setup.CheckSpawnsCommand;
 import com.garbagemule.MobArena.commands.setup.ClassChestCommand;
+import com.garbagemule.MobArena.commands.setup.DeleteItemCommand;
 import com.garbagemule.MobArena.commands.setup.EditArenaCommand;
 import com.garbagemule.MobArena.commands.setup.ListClassesCommand;
+import com.garbagemule.MobArena.commands.setup.LoadItemCommand;
 import com.garbagemule.MobArena.commands.setup.RemoveArenaCommand;
 import com.garbagemule.MobArena.commands.setup.RemoveContainerCommand;
 import com.garbagemule.MobArena.commands.setup.RemoveLeaderboardCommand;
 import com.garbagemule.MobArena.commands.setup.RemoveSpawnpointCommand;
+import com.garbagemule.MobArena.commands.setup.SaveItemCommand;
 import com.garbagemule.MobArena.commands.setup.SettingCommand;
 import com.garbagemule.MobArena.commands.setup.SetupCommand;
 import com.garbagemule.MobArena.commands.user.ArenaListCommand;
@@ -340,6 +343,10 @@ private void registerCommands() {
 
         register(RemoveLeaderboardCommand.class);
         register(AutoGenerateCommand.class);
+
+        register(SaveItemCommand.class);
+        register(DeleteItemCommand.class);
+        register(LoadItemCommand.class);
     }
 
     /**

src/main/java/com/garbagemule/MobArena/commands/setup/DeleteItemCommand.java

@@ -0,0 +1,60 @@
+package com.garbagemule.MobArena.commands.setup;
+
+import com.garbagemule.MobArena.commands.Command;
+import com.garbagemule.MobArena.commands.CommandInfo;
+import com.garbagemule.MobArena.framework.ArenaMaster;
+import com.garbagemule.MobArena.items.SavedItemsManager;
+import org.bukkit.ChatColor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@CommandInfo(
+    name    = "deleteitem",
+    pattern = "deleteitem",
+    usage   = "/ma deleteitem <identifier>",
+    desc    = "delete the item with the given identifier",
+    permission = "mobarena.setup.deleteitem"
+)
+public class DeleteItemCommand implements Command {
+
+    @Override
+    public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
+        if (args.length != 1) {
+            return false;
+        }
+
+        String key = args[0];
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        try {
+            items.deleteItem(key);
+        } catch (Exception e) {
+            am.getGlobalMessenger().tell(sender, "Couldn't delete " + ChatColor.YELLOW + key + ChatColor.RESET + ", because: " + ChatColor.RED + e.getMessage());
+            return true;
+        }
+
+        am.getGlobalMessenger().tell(sender, "Saved item " + ChatColor.YELLOW + key + ChatColor.RESET + " deleted.");
+        return true;
+    }
+
+    @Override
+    public List<String> tab(ArenaMaster am, Player player, String... args) {
+        if (args.length > 1) {
+            return Collections.emptyList();
+        }
+
+        String prefix = args[0].toLowerCase();
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        List<String> keys = items.getKeys();
+
+        return keys.stream()
+            .filter(key -> key.startsWith(prefix))
+            .collect(Collectors.toList());
+    }
+
+}

src/main/java/com/garbagemule/MobArena/commands/setup/LoadItemCommand.java

@@ -0,0 +1,70 @@
+package com.garbagemule.MobArena.commands.setup;
+
+import com.garbagemule.MobArena.Msg;
+import com.garbagemule.MobArena.commands.Command;
+import com.garbagemule.MobArena.commands.CommandInfo;
+import com.garbagemule.MobArena.commands.Commands;
+import com.garbagemule.MobArena.framework.ArenaMaster;
+import com.garbagemule.MobArena.items.SavedItemsManager;
+import org.bukkit.ChatColor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@CommandInfo(
+    name    = "loaditem",
+    pattern = "loaditem",
+    usage   = "/ma loaditem <identifier>",
+    desc    = "load the item saved by the given identifier into your hand",
+    permission = "mobarena.setup.loaditem"
+)
+public class LoadItemCommand implements Command {
+
+    @Override
+    public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
+        if (!Commands.isPlayer(sender)) {
+            am.getGlobalMessenger().tell(sender, Msg.MISC_NOT_FROM_CONSOLE);
+            return true;
+        }
+
+        if (args.length != 1) {
+            return false;
+        }
+
+        String key = args[0];
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        ItemStack stack = items.getItem(key);
+        if (stack == null) {
+            am.getGlobalMessenger().tell(sender, "No saved item with identifier " + ChatColor.YELLOW + key + ChatColor.RESET + " found.");
+            return true;
+        }
+
+        Player player = Commands.unwrap(sender);
+        player.getInventory().setItemInMainHand(stack);
+
+        am.getGlobalMessenger().tell(sender, "Saved item " + ChatColor.YELLOW + key + ChatColor.RESET + " loaded.");
+        return true;
+    }
+
+    @Override
+    public List<String> tab(ArenaMaster am, Player player, String... args) {
+        if (args.length > 1) {
+            return Collections.emptyList();
+        }
+
+        String prefix = args[0].toLowerCase();
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        List<String> keys = items.getKeys();
+
+        return keys.stream()
+            .filter(key -> key.startsWith(prefix))
+            .collect(Collectors.toList());
+    }
+
+}

src/main/java/com/garbagemule/MobArena/commands/setup/SaveItemCommand.java

@@ -0,0 +1,88 @@
+package com.garbagemule.MobArena.commands.setup;
+
+import com.garbagemule.MobArena.Msg;
+import com.garbagemule.MobArena.commands.Command;
+import com.garbagemule.MobArena.commands.CommandInfo;
+import com.garbagemule.MobArena.commands.Commands;
+import com.garbagemule.MobArena.framework.ArenaMaster;
+import com.garbagemule.MobArena.items.SavedItemsManager;
+import org.bukkit.ChatColor;
+import org.bukkit.Material;
+import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@CommandInfo(
+    name    = "saveitem",
+    pattern = "saveitem",
+    usage   = "/ma saveitem <identifier>",
+    desc    = "save the currently held item for use in the config-file",
+    permission = "mobarena.setup.saveitem"
+)
+public class SaveItemCommand implements Command {
+
+    @Override
+    public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
+        if (!Commands.isPlayer(sender)) {
+            am.getGlobalMessenger().tell(sender, Msg.MISC_NOT_FROM_CONSOLE);
+            return true;
+        }
+
+        if (args.length != 1) {
+            return false;
+        }
+
+        String key = args[0];
+        if (key.contains(":")) {
+            am.getGlobalMessenger().tell(sender, "The identifier cannot contain a colon (:).");
+            return true;
+        }
+        if (key.contains("/")) {
+            am.getGlobalMessenger().tell(sender, "The identifier cannot contain a slash (/).");
+            return true;
+        }
+        if (key.contains("\\")) {
+            am.getGlobalMessenger().tell(sender, "The identifier cannot contain a backslash (\\).");
+            return true;
+        }
+
+        Player player = Commands.unwrap(sender);
+        ItemStack stack = player.getInventory().getItemInMainHand();
+        if (stack.getType() == Material.AIR) {
+            am.getGlobalMessenger().tell(sender, "You must be holding an item.");
+            return true;
+        }
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        try {
+            items.saveItem(key, stack);
+        } catch (Exception e) {
+            am.getGlobalMessenger().tell(sender, "Couldn't save " + ChatColor.YELLOW + key + ChatColor.RESET + ", because: " + ChatColor.RED + e.getMessage());
+            return true;
+        }
+
+        am.getGlobalMessenger().tell(sender, "Item saved as " + ChatColor.YELLOW + key + ChatColor.RESET + ".");
+        return true;
+    }
+
+    @Override
+    public List<String> tab(ArenaMaster am, Player player, String... args) {
+        if (args.length > 1) {
+            return Collections.emptyList();
+        }
+
+        String prefix = args[0].toLowerCase();
+
+        SavedItemsManager items = am.getPlugin().getSavedItemsManager();
+        List<String> keys = items.getKeys();
+
+        return keys.stream()
+            .filter(key -> key.startsWith(prefix))
+            .collect(Collectors.toList());
+    }
+
+}