reorganize events to event handler class

src/main/java/org/mcmonkey/sentinel/SentinelEventHandler.java

@@ -4,11 +4,18 @@
 import net.citizensnpcs.api.npc.NPC;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Entity;
+import org.bukkit.entity.Projectile;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
 import org.bukkit.event.entity.EntityDamageByEntityEvent;
+import org.bukkit.event.entity.EntityDeathEvent;
 import org.bukkit.event.player.AsyncPlayerChatEvent;
+import org.bukkit.event.player.PlayerMoveEvent;
+import org.bukkit.event.player.PlayerTeleportEvent;
+import org.bukkit.projectiles.ProjectileSource;
+
+import java.util.UUID;
 
 public class SentinelEventHandler implements Listener {
 
@@ -26,18 +33,145 @@ public void run() {
                 if (!event.getPlayer().isOnline()) {
                     return;
                 }
-                for (NPC npc : CitizensAPI.getNPCRegistry()) {
-                    if (npc.hasTrait(SentinelTrait.class)) {
-                        SentinelTrait sentinel = npc.getTrait(SentinelTrait.class);
-                        if (sentinel.allTargets.isEventTarget(event)) {
-                            sentinel.targetingHelper.addTarget(event.getPlayer().getUniqueId());
-                        }
-                        if (sentinel.allAvoids.isEventTarget(event)) {
-                            sentinel.targetingHelper.addAvoid(event.getPlayer().getUniqueId());
-                        }
+                for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+                    if (sentinel.allTargets.isEventTarget(event)) {
+                        sentinel.targetingHelper.addTarget(event.getPlayer().getUniqueId());
+                    }
+                    if (sentinel.allAvoids.isEventTarget(event)) {
+                        sentinel.targetingHelper.addAvoid(event.getPlayer().getUniqueId());
                     }
                 }
             }
         });
     }
+
+    /**
+     * Tries to get a Sentinel from an entity. Returns null if it is not a Sentinel.
+     */
+    public SentinelTrait tryGetSentinel(Entity entity) {
+        if (CitizensAPI.getNPCRegistry().isNPC(entity)) {
+            NPC npc = CitizensAPI.getNPCRegistry().getNPC(entity);
+            if (npc.hasTrait(SentinelTrait.class)) {
+                return npc.getTrait(SentinelTrait.class);
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Called when combat occurs in the world (and has not yet been processed by other plugins),
+     * to handle things like cancelling invalid damage to/from a Sentinel NPC,
+     * changing damage values given to or received from an NPC,
+     * and if relevant handling config options that require overriding damage events.
+     */
+    @EventHandler(priority = EventPriority.LOW)
+    public void whenAttacksAreHappening(EntityDamageByEntityEvent event) {
+        if (event.isCancelled()) {
+            return;
+        }
+        UUID victimUuid = event.getEntity().getUniqueId();
+        for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+            sentinel.whenSomethingMightDie(victimUuid);
+        }
+        SentinelTrait victim = tryGetSentinel(event.getEntity());
+        if (victim != null) {
+            victim.whenAttacksAreHappeningToMe(event);
+        }
+        SentinelTrait attacker = tryGetSentinel(event.getDamager());
+        if (attacker != null) {
+            attacker.whenAttacksAreHappeningFromMe(event);
+        }
+        if (event.getDamager() instanceof Projectile) {
+            ProjectileSource source = ((Projectile) event.getDamager()).getShooter();
+            if (source instanceof Entity) {
+                SentinelTrait shooter = tryGetSentinel((Entity) source);
+                if (shooter != null) {
+                    shooter.whenAttacksAreHappeningFromMyArrow(event);
+                }
+            }
+        }
+    }
+
+    /**
+     * Called when combat has occurred in the world (and has been processed by all other plugins), to handle things like cancelling invalid damage to/from a Sentinel NPC,
+     * adding targets (if combat occurs near an NPC), and if relevant handling config options that require overriding damage events.
+     */
+    @EventHandler(priority = EventPriority.LOWEST)
+    public void whenAttacksHappened(EntityDamageByEntityEvent event) {
+        if (event.isCancelled()) {
+            return;
+        }
+        SentinelTrait victim = tryGetSentinel(event.getEntity());
+        if (victim != null) {
+            victim.whenAttacksHappened(event);
+        }
+        SentinelTrait attacker = tryGetSentinel(event.getDamager());
+        if (attacker != null) {
+            attacker.whenAttacksHappened(event);
+        }
+        if (event.getDamager() instanceof Projectile) {
+            ProjectileSource source = ((Projectile) event.getDamager()).getShooter();
+            if (source instanceof Entity) {
+                SentinelTrait shooter = tryGetSentinel((Entity) source);
+                if (shooter != null) {
+                    shooter.whenAttacksHappened(event);
+                }
+            }
+        }
+        for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+            UUID guarding = sentinel.getGuarding();
+            if (guarding != null) {
+                if (event.getEntity().getUniqueId().equals(guarding)) {
+                    sentinel.whenAttacksHappened(event);
+                }
+            }
+        }
+    }
+
+    /**
+     * Called when any entity dies, to process drops handling and targeting updates.
+     */
+    @EventHandler
+    public void whenAnEnemyDies(EntityDeathEvent event) {
+        UUID dead = event.getEntity().getUniqueId();
+        for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+            sentinel.whenAnEnemyDies(dead);
+            sentinel.whenSomethingDies(event);
+            if (sentinel.getLivingEntity().getUniqueId().equals(dead)) {
+                sentinel.whenWeDie(event);
+            }
+        }
+    }
+
+    /**
+     * Called when a player teleports, to handle NPC guard updates.
+     */
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onPlayerTeleports(final PlayerTeleportEvent event) {
+        if (event.isCancelled()) {
+            return;
+        }
+        UUID uuid = event.getPlayer().getUniqueId();
+        for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+            if (sentinel.getGuarding() != null && sentinel.getGuarding().equals(uuid)) {
+                sentinel.onPlayerTeleports(event);
+            }
+        }
+    }
+
+    /**
+     * Called every time a player moves at all, for use with monitoring if players move into range of an NPC.
+     */
+    @EventHandler
+    public void onPlayerMovesInRange(PlayerMoveEvent event) {
+        if (event.isCancelled()) {
+            return;
+        }
+        if (event.getTo().toVector().equals(event.getFrom().toVector())) {
+            return;
+        }
+        for (SentinelTrait sentinel : SentinelPlugin.instance.currentSentinelNPCs) {
+            sentinel.onPlayerMovesInRange(event);
+        }
+    }
 }

src/main/java/org/mcmonkey/sentinel/SentinelPlugin.java

@@ -59,6 +59,11 @@ public class SentinelPlugin extends JavaPlugin implements Listener {
      */
     public static SentinelPlugin instance;
 
+    /**
+     * A list of all currently spawned Sentinel NPCs.
+     */
+    public ArrayList<SentinelTrait> currentSentinelNPCs = new ArrayList<>();
+
     /**
      * Permissions handler.
      */