Add tiers wave reward section.

This commit introduces a new optional wave rewards section, `tiers`,
which allows server owners to configure rewards that "upgrade" over
time. This makes it possible to create reward configurations where
(some of) the rewards don't stack as the waves progress, but instead
change into different rewards. The most obvious use case is wanting to
grant an armor set for beating a specific wave, but a _better_ set for
beating a later wave, without granting both sets.

Turns out this was a lot easier than I thought it would be. We didn't
even need a rework of anything, and the Things API didn't even need to
adapt in any way. As an added bonus, we managed to get the associated
GitHub issue wrapped up before it turned 8 years old. Neat!

Closes #346

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

@@ -124,7 +124,7 @@ public class ArenaImpl implements Arena
     private WaveManager   waveManager;
     private MASpawnThread spawnThread;
     private SheepBouncer  sheepBouncer;
-    private Map<Integer, ThingPicker> everyWaveMap, afterWaveMap;
+    private Map<Integer, ThingPicker> everyWaveMap, afterWaveMap, waveTiersMap;
 
     // Misc
     private ArenaListener eventListener;
@@ -208,6 +208,7 @@ public class ArenaImpl implements Arena
         this.waveManager  = new WaveManager(this, section.getConfigurationSection("waves"));
         this.everyWaveMap = MAUtils.getArenaRewardMap(plugin, section, name, "every");
         this.afterWaveMap = MAUtils.getArenaRewardMap(plugin, section, name, "after");
+        this.waveTiersMap = MAUtils.getArenaRewardMap(plugin, section, name, "tiers");
 
         // Misc
         this.eventListener = new ArenaListener(this, plugin);
@@ -351,6 +352,11 @@ public class ArenaImpl implements Arena
         return afterWaveMap.get(wave);
     }
 
+    @Override
+    public ThingPicker getWaveTierReward(int wave) {
+        return waveTiersMap.get(wave);
+    }
+
     @Override
     public Set<Player> getPlayersInArena() {
         return Collections.unmodifiableSet(arenaPlayers);

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

@@ -366,6 +366,11 @@ public class MASpawnThread implements Runnable
         if (after != null) {
             addReward(after);
         }
+
+        ThingPicker tier = arena.getWaveTierReward(wave);
+        if (tier != null) {
+            setRewardTier(tier);
+        }
     }
 
     private void updateStats(int wave) {
@@ -400,4 +405,14 @@ public class MASpawnThread implements Runnable
             }
         }
     }
+
+    private void setRewardTier(ThingPicker picker) {
+        for (Player p : arena.getPlayersInArena()) {
+            Thing reward = picker.pick();
+            if (reward != null) {
+                rewardManager.setTieredReward(p, reward);
+                arena.getMessenger().tell(p, Msg.WAVE_TIER_REWARD, reward.toString());
+            }
+        }
+    }
 }

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

@@ -78,6 +78,7 @@ public enum Msg {
     WAVE_BOSS_KILLED("&a%&r killed the boss!"),
     WAVE_BOSS_REWARD_EARNED("You earned: &e%"),
     WAVE_REWARD("You just earned a reward: &e%&r"),
+    WAVE_TIER_REWARD("You just unlocked a new reward tier: &e%&r"),
     MISC_REWARD_ADDED("You were just given a reward: &e%&r"),
     MISC_LIST_PLAYERS("Live players: &a%&r"),
     MISC_LIST_ARENAS("Available arenas: %"),

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

@@ -14,15 +14,18 @@ import java.util.Set;
 public class RewardManager
 {
     private Map<Player,List<Thing>> players;
+    private Map<Player,Thing> tiered;
     private Set<Player> rewarded;
 
     public RewardManager(Arena arena) {
         this.players  = new HashMap<>();
+        this.tiered  = new HashMap<>();
         this.rewarded = new HashSet<>();
     }
 
     public void reset() {
         players.clear();
+        tiered.clear();
         rewarded.clear();
     }
 
@@ -33,7 +36,17 @@ public class RewardManager
         players.get(p).add(thing);
     }
 
+    public void setTieredReward(Player p, Thing thing) {
+        tiered.put(p, thing);
+    }
+
     public void grantRewards(Player p) {
+        grantNormalRewards(p);
+        grantTieredRewards(p);
+        rewarded.add(p);
+    }
+
+    private void grantNormalRewards(Player p) {
         if (rewarded.contains(p)) return;
 
         List<Thing> rewards = players.get(p);
@@ -45,6 +58,14 @@ public class RewardManager
             }
             reward.giveTo(p);
         }
-        rewarded.add(p);
+    }
+
+    private void grantTieredRewards(Player p) {
+        if (rewarded.contains(p)) return;
+
+        Thing reward = tiered.get(p);
+        if (reward == null) return;
+
+        reward.giveTo(p);
     }
 }

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

@@ -70,6 +70,8 @@ public interface Arena
 
     ThingPicker getAfterWaveReward(int wave);
 
+    ThingPicker getWaveTierReward(int wave);
+
     Set<Player> getPlayersInArena();
 
     Set<Player> getPlayersInLobby();

src/main/resources/res/rewards.yml

@@ -7,3 +7,7 @@ waves:
         '7': minecart, chest_minecart, furnace_minecart
         '13': iron_sword, iron_pickaxe, iron_shovel
         '16': diamond_sword
+    tiers:
+        '4': diamond
+        '11': diamond:10
+        '17': diamond:25