Pre-instantiate commands.

This commit makes use of the `register(Command)` method in MobArena's
command handler to pre-instantiate the command classes and inject the
main plugin instance in their constructors. This allows us to get rid of
the horrible Singleton anti-pattern.

Closes #6

src/main/java/org/mobarena/stats/MobArenaStatsPlugin.java

@@ -37,12 +37,6 @@ import java.util.logging.Level;
 
 public class MobArenaStatsPlugin extends JavaPlugin implements MobArenaStats {
 
-    // The sad state of affairs is that MobArena's command framework has no
-    // support for registering commands by instance, but only by class, which
-    // means that we can't properly inject dependencies and have to resort to
-    // the Singleton Pattern.
-    private static MobArenaStats instance;
-
     private StatsStoreRegistry statsStoreRegistry;
 
     private Executor syncExecutor;
@@ -78,8 +72,6 @@ public class MobArenaStatsPlugin extends JavaPlugin implements MobArenaStats {
 
     private void setup() {
         try {
-            instance = this;
-
             createDataFolder();
             createConfigFile();
             setupExecutors();
@@ -128,14 +120,14 @@ public class MobArenaStatsPlugin extends JavaPlugin implements MobArenaStats {
         CommandHandler handler = (CommandHandler) command.getExecutor();
 
         // User commands
-        handler.register(ArenaStatsCommand.class);
+        handler.register(new ArenaStatsCommand(this));
-        handler.register(GlobalStatsCommand.class);
+        handler.register(new GlobalStatsCommand(this));
-        handler.register(PlayerStatsCommand.class);
+        handler.register(new PlayerStatsCommand(this));
 
         // Admin commands
-        handler.register(DeleteSessionStatsCommand.class);
+        handler.register(new DeleteSessionStatsCommand(this));
-        handler.register(ExportCommand.class);
+        handler.register(new ExportCommand(this));
-        handler.register(ImportCommand.class);
+        handler.register(new ImportCommand(this));
     }
 
     private void setupMetrics() {
@@ -207,8 +199,4 @@ public class MobArenaStatsPlugin extends JavaPlugin implements MobArenaStats {
         return statsStore;
     }
 
-    public static MobArenaStats getInstance() {
-        return instance;
-    }
-
 }

src/main/java/org/mobarena/stats/command/ArenaStatsCommand.java

@@ -8,7 +8,6 @@ import com.garbagemule.MobArena.util.Slugs;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.ArenaStats;
 import org.mobarena.stats.store.StatsStore;
 
@@ -29,11 +28,14 @@ import static org.bukkit.ChatColor.YELLOW;
 )
 public class ArenaStatsCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public ArenaStatsCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         if (args.length < 1) {
             return false;
         }

src/main/java/org/mobarena/stats/command/DeleteSessionStatsCommand.java

@@ -8,7 +8,6 @@ import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.StatsStore;
 
 import java.util.List;
@@ -23,11 +22,14 @@ import java.util.UUID;
 )
 public class DeleteSessionStatsCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public DeleteSessionStatsCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         // TODO: check args, handle non-UUID input error
         UUID sessionId = UUID.fromString(args[0]);
 

src/main/java/org/mobarena/stats/command/ExportCommand.java

@@ -7,7 +7,6 @@ import com.garbagemule.MobArena.framework.ArenaMaster;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.StatsExport;
 import org.mobarena.stats.store.StatsStore;
 import org.mobarena.stats.store.StatsStoreRegistry;
@@ -21,11 +20,14 @@ import org.mobarena.stats.store.StatsStoreRegistry;
 )
 public class ExportCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public ExportCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         StatsStore store = plugin.getStatsStore();
         StatsStoreRegistry registry = plugin.getStatsStoreRegistry();
 

src/main/java/org/mobarena/stats/command/GlobalStatsCommand.java

@@ -6,7 +6,6 @@ import com.garbagemule.MobArena.commands.CommandInfo;
 import com.garbagemule.MobArena.framework.ArenaMaster;
 import org.bukkit.command.CommandSender;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.GlobalStats;
 import org.mobarena.stats.store.StatsStore;
 
@@ -27,11 +26,14 @@ import static org.bukkit.ChatColor.YELLOW;
 )
 public class GlobalStatsCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public GlobalStatsCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         Messenger messenger = am.getGlobalMessenger();
         plugin.getAsyncExecutor().execute(() -> {
             StatsStore store = plugin.getStatsStore();

src/main/java/org/mobarena/stats/command/ImportCommand.java

@@ -8,7 +8,6 @@ import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.StatsExport;
 import org.mobarena.stats.store.StatsImport;
 import org.mobarena.stats.store.StatsStore;
@@ -30,15 +29,18 @@ import java.util.stream.Collectors;
 )
 public class ImportCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public ImportCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
         if (args.length < 1) {
             return false;
         }
 
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         Path data = plugin.getDataFolder().toPath();
         Path file = data.resolve(args[0]);
         if (!Files.exists(file)) {
@@ -110,9 +112,6 @@ public class ImportCommand implements Command {
             return Collections.emptyList();
         }
 
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         String[] files = plugin.getDataFolder().list();
         if (files == null || files.length == 0) {
             return Collections.emptyList();

src/main/java/org/mobarena/stats/command/PlayerStatsCommand.java

@@ -7,7 +7,6 @@ import com.garbagemule.MobArena.framework.ArenaMaster;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.mobarena.stats.MobArenaStats;
-import org.mobarena.stats.MobArenaStatsPlugin;
 import org.mobarena.stats.store.PlayerStats;
 import org.mobarena.stats.store.StatsStore;
 
@@ -28,11 +27,14 @@ import static org.bukkit.ChatColor.YELLOW;
 )
 public class PlayerStatsCommand implements Command {
 
+    private final MobArenaStats plugin;
+
+    public PlayerStatsCommand(MobArenaStats plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean execute(ArenaMaster am, CommandSender sender, String... args) {
-        // :(
-        MobArenaStats plugin = MobArenaStatsPlugin.getInstance();
-
         String name;
         if (args.length == 0) {
             if (!(sender instanceof Player)) {