Add 7 new placeholders for Challenges Addon.

- `[gamemode]_challenge_total_completion_count` returns number of sum of challenge completions for user.
- `[gamemode]_challenge_completed_count` returns number of completed challenges (at least once) for user.
- `[gamemode]_challenge_uncompleted_count` returns number of uncompleted challenges for user.
- `[gamemode]_challenge_completed_level_count` returns number of completed levels for user.
- `[gamemode]_challenge_uncompleted_level_count` returns number of uncompleted levels for user.
- `[gamemode]_challenge_unlocked_level_count` returns number of unlocked levels for user.
- `[gamemode]_challenge_locked_level_count` returns number of locked levels for user.

Fixes #224

src/main/java/world/bentobox/challenges/ChallengesAddon.java

@@ -7,6 +7,7 @@ import java.util.Optional;
 
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
+import org.bukkit.World;
 
 import world.bentobox.bentobox.api.addons.Addon;
 import world.bentobox.bentobox.api.addons.GameModeAddon;
@@ -156,11 +157,8 @@ public class ChallengesAddon extends Addon {
         List<GameModeAddon> hookedGameModes = new ArrayList<>();
 
         this.getPlugin().getAddonsManager().getGameModeAddons().forEach(gameModeAddon -> {
-        	if (!this.settings
-        	        .getDisabledGameModes()
-        	        .contains(gameModeAddon
-        	                .getDescription()
-        	                .getName()))
+        	if (!this.settings.getDisabledGameModes().contains(
+        	    gameModeAddon.getDescription().getName()))
 			{
 				if (gameModeAddon.getPlayerCommand().isPresent())
 				{
@@ -178,6 +176,8 @@ public class ChallengesAddon extends Addon {
 
 				CHALLENGES_WORLD_PROTECTION.addGameModeAddon(gameModeAddon);
 				CHALLENGES_ISLAND_PROTECTION.addGameModeAddon(gameModeAddon);
+
+				this.registerPlaceholders(gameModeAddon);
 			}
 		});
 
@@ -314,6 +314,56 @@ public class ChallengesAddon extends Addon {
     }
 
 
+    /**
+     * This method registers placeholders into GameMode addon.
+     * @param gameModeAddon GameMode addon where placeholders must be hooked in.
+     */
+    private void registerPlaceholders(GameModeAddon gameModeAddon)
+    {
+        final String gameMode = gameModeAddon.getDescription().getName().toLowerCase();
+        final World world = gameModeAddon.getOverWorld();
+
+        // Number of completions for all challenges placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_total_completion_count",
+            user -> String.valueOf(this.challengesManager.getTotalChallengeCompletionCount(user, world)));
+
+        // Completed challenge count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_completed_count",
+            user -> String.valueOf(this.challengesManager.getCompletedChallengeCount(user, world)));
+
+        // Uncompleted challenge count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_uncompleted_count",
+            user -> String.valueOf(this.challengesManager.getChallengeCount(world) -
+                this.challengesManager.getCompletedChallengeCount(user, world)));
+
+        // Completed challenge level count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_completed_level_count",
+            user -> String.valueOf(this.challengesManager.getCompletedLevelCount(user, world)));
+
+        // Uncompleted challenge level count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_uncompleted_level_count",
+            user -> String.valueOf(this.challengesManager.getLevelCount(world) -
+                this.challengesManager.getCompletedLevelCount(user, world)));
+
+        // Unlocked challenge level count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_unlocked_level_count",
+            user -> String.valueOf(this.challengesManager.getLevelCount(world) -
+                this.challengesManager.getUnlockedLevelCount(user, world)));
+
+        // Locked challenge level count placeholder
+        this.getPlugin().getPlaceholdersManager().registerPlaceholder(this,
+            gameMode + "_challenge_locked_level_count",
+            user -> String.valueOf(this.challengesManager.getLevelCount(world) -
+                this.challengesManager.getUnlockedLevelCount(user, world)));
+    }
+
+
 // ---------------------------------------------------------------------
 // Section: Getters
 // ---------------------------------------------------------------------

src/main/java/world/bentobox/challenges/ChallengesManager.java

@@ -1507,7 +1507,7 @@ public class ChallengesManager
     public List<LevelStatus> getAllChallengeLevelStatus(User user, World world)
     {
         return this.islandWorldManager.getAddon(world).map(gameMode ->
-        this.getAllChallengeLevelStatus(
+            this.getAllChallengeLevelStatus(
                 this.getDataUniqueID(user, Util.getWorld(world)),
                 gameMode.getDescription().getName())).
                 orElse(Collections.emptyList());
@@ -1546,11 +1546,11 @@ public class ChallengesManager
     public List<Challenge> getAllChallenges(@NonNull World world)
     {
         return this.islandWorldManager.getAddon(world).map(gameMode ->
-        this.challengeCacheData.values().stream().
-        filter(challenge -> challenge.matchGameMode(gameMode.getDescription().getName())).
-        sorted(this.challengeComparator).
-        collect(Collectors.toList())).
-                orElse(Collections.emptyList());
+            this.challengeCacheData.values().stream().
+                filter(challenge -> challenge.matchGameMode(gameMode.getDescription().getName())).
+                sorted(this.challengeComparator).
+                collect(Collectors.toList())).
+            orElse(Collections.emptyList());
     }
 
 
@@ -1692,6 +1692,45 @@ public class ChallengesManager
     }
 
 
+    /**
+     * This method returns number of challenges in given world.
+     * @param world World where challenge count must be returned.
+     * @return Number of challenges in given world.
+     */
+    public int getChallengeCount(World world)
+    {
+        return this.getAllChallenges(world).size();
+    }
+
+
+    /**
+     * This method returns number of completed challenges in given world.
+     * @param user User which completed challenge count must be returned.
+     * @param world World where challenge count must be returned.
+     * @return Number of completed challenges by given user in given world.
+     */
+    public long getCompletedChallengeCount(User user, World world)
+    {
+        return this.getAllChallenges(world).stream().
+            filter(challenge -> this.getChallengeTimes(user, world, challenge) > 0).
+            count();
+    }
+
+
+    /**
+     * This method returns total number of all completion times for all challenges in given world.
+     * @param user User which total completion count must be returned.
+     * @param world World where challenge count must be returned.
+     * @return Sum of completion count for all challenges by given user in given world.
+     */
+    public long getTotalChallengeCompletionCount(User user, World world)
+    {
+        return this.getAllChallenges(world).stream().
+            mapToLong(challenge -> this.getChallengeTimes(user, world, challenge)).
+            sum();
+    }
+
+
     // ---------------------------------------------------------------------
     // Section: Level related methods
     // ---------------------------------------------------------------------
@@ -1962,4 +2001,43 @@ public class ChallengesManager
                 this.levelDatabase.loadObjects().stream().anyMatch(
                         level -> level.matchGameMode(gameMode));
     }
+
+
+    /**
+     * This method returns number of levels in given world.
+     * @param world World where level count must be returned.
+     * @return Number of levels in given world.
+     */
+    public int getLevelCount(World world)
+    {
+        return this.getLevels(world).size();
+    }
+
+
+    /**
+     * This method returns number of completed levels in given world.
+     * @param user User which completed level count must be returned.
+     * @param world World where level count must be returned.
+     * @return Number of completed levels by given user in given world.
+     */
+    public long getCompletedLevelCount(User user, World world)
+    {
+        return this.getAllChallengeLevelStatus(user, world).stream().
+            filter(LevelStatus::isComplete).
+            count();
+    }
+
+
+    /**
+     * This method returns number of unlocked levels in given world.
+     * @param user User which unlocked level count must be returned.
+     * @param world World where level count must be returned.
+     * @return Number of unlocked levels by given user in given world.
+     */
+    public long getUnlockedLevelCount(User user, World world)
+    {
+        return this.getAllChallengeLevelStatus(user, world).stream().
+            filter(LevelStatus::isUnlocked).
+            count();
+    }
 }