Implement a configurable races whitelist

src/main/java/com/minelittlepony/unicopia/UConfig.java

@@ -0,0 +1,74 @@
+package com.minelittlepony.unicopia;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.util.List;
+
+import com.google.common.collect.Lists;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.annotations.Expose;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+public class UConfig {
+
+    private static UConfig instance;
+
+    private static final Gson gson = new GsonBuilder()
+            .excludeFieldsWithoutExposeAnnotation()
+            .setPrettyPrinting()
+            .create();
+
+    public static UConfig getInstance() {
+        return instance;
+    }
+
+    static void init(File directory) {
+        File file = new File(directory, "unicopia.json");
+
+        try {
+            if (!file.exists()) {
+                file.createNewFile();
+            }
+
+            try(JsonReader reader = new JsonReader(new InputStreamReader(new FileInputStream(file)));) {
+                instance = gson.fromJson(reader, UConfig.class);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            if (instance == null) {
+                instance = new UConfig();
+            }
+        }
+
+        instance.file = file;
+
+    }
+
+    private File file;
+
+    @Expose
+    private final List<Race> speciesWhiteList = Lists.newArrayList();
+
+    public List<Race> getSpeciesWhiteList() {
+        return speciesWhiteList;
+    }
+
+    public void save() {
+        if (file.exists()) {
+            file.delete();
+        }
+
+        try (JsonWriter writer = new JsonWriter(new OutputStreamWriter(new FileOutputStream(file)))) {
+            gson.toJson(this, UConfig.class, writer);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

src/main/java/com/minelittlepony/unicopia/Unicopia.java

@@ -101,6 +101,8 @@ public class Unicopia implements IGuiHandler {
 
     @EventHandler
     public void preInit(FMLPreInitializationEvent event) {
+        UConfig.init(event.getModConfigurationDirectory());
+
         if (UClient.isClientSide()) {
             UEntities.preInit();
         }

src/main/java/com/minelittlepony/unicopia/command/CommandRacelist.java

@@ -0,0 +1,78 @@
+package com.minelittlepony.unicopia.command;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.minelittlepony.unicopia.Race;
+import com.minelittlepony.unicopia.player.PlayerSpeciesList;
+
+import net.minecraft.command.CommandBase;
+import net.minecraft.command.CommandException;
+import net.minecraft.command.ICommandSender;
+import net.minecraft.command.WrongUsageException;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.text.TextComponentTranslation;
+
+class CommandRacelist extends CommandBase {
+
+	public String getName() {
+		return "racelist";
+	}
+
+    public int getRequiredPermissionLevel() {
+        return 4;
+    }
+
+	public String getUsage(ICommandSender sender) {
+		return "commands.racelist.usage";
+	}
+
+	public void execute(MinecraftServer server, ICommandSender sender, String[] args) throws CommandException {
+        if (args.length < 2) {
+            throw new WrongUsageException(getUsage(sender));
+        }
+
+        EntityPlayer player = getCommandSenderAsPlayer(sender);
+
+        Race race = Race.fromName(args[1], Race.HUMAN);
+
+        TextComponentTranslation formattedName = new TextComponentTranslation(race.name().toLowerCase());
+
+        if (race == Race.HUMAN) {
+            player.sendMessage(new TextComponentTranslation("commands.racelist.illegal", formattedName));
+        } else if (args[0].contentEquals("allow")) {
+            PlayerSpeciesList.instance().whiteListRace(race);
+
+            player.sendMessage(new TextComponentTranslation("commands.racelist.allowed", formattedName));
+        } else if (args[0].contentEquals("disallow")) {
+            PlayerSpeciesList.instance().unwhiteListRace(race);
+
+            player.sendMessage(new TextComponentTranslation("commands.racelist.disallowed", formattedName));
+        } else {
+            throw new WrongUsageException(getUsage(sender));
+        }
+	}
+
+    /**
+     * Adds the strings available in this command to the given list of tab completion options.
+     */
+    public List<String> getTabCompletions(MinecraftServer server, ICommandSender sender, String[] args, BlockPos pos) {
+        if (args.length == 1) {
+            return getListOfStringsMatchingLastWord(args, "allow", "disallow");
+        }
+
+        if (args.length == 2) {
+            ArrayList<String> names = new ArrayList<String>();
+
+            for (Race i : Race.values()) {
+                names.add(i.name().toLowerCase());
+            }
+
+            return getListOfStringsMatchingLastWord(args, names.stream().toArray(String[]::new));
+        }
+
+        return null;
+    }
+}

src/main/java/com/minelittlepony/unicopia/command/CommandSpecies.java

@@ -158,7 +158,7 @@ class CommandSpecies extends CommandBase {
     			}
     		}
 
-			return getListOfStringsMatchingLastWord(args, names.toArray(new String[names.size()]));
+			return getListOfStringsMatchingLastWord(args, names.stream().toArray(String[]::new));
     	}
 
     	if ((args.length == 3 && args[0].contentEquals("set")) || (args[0].contentEquals("get") && args.length == 2)) {

src/main/java/com/minelittlepony/unicopia/command/Commands.java

@@ -7,6 +7,7 @@ public class Commands {
     public static void init(FMLServerStartingEvent event) {
         event.registerServerCommand(new CommandOverrideGameMode());
         event.registerServerCommand(new CommandSpecies());
+        event.registerServerCommand(new CommandRacelist());
 
         event.getServer().setAllowFlight(true);
     }

src/main/java/com/minelittlepony/unicopia/player/PlayerSpeciesList.java

@@ -1,10 +1,9 @@
 package com.minelittlepony.unicopia.player;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.UUID;
 
 import com.minelittlepony.unicopia.Race;
+import com.minelittlepony.unicopia.UConfig;
 import com.minelittlepony.unicopia.forgebullshit.FBS;
 
 import net.minecraft.entity.Entity;
@@ -19,14 +18,28 @@ public class PlayerSpeciesList {
         return instance;
     }
 
-    private List<Race> serverPermittedRaces = new ArrayList<>();
+    public boolean whiteListRace(Race race) {
+        boolean result = UConfig.getInstance().getSpeciesWhiteList().add(race);
+
+        UConfig.getInstance().save();
+
+        return result;
+    }
+
+    public boolean unwhiteListRace(Race race) {
+        boolean result = UConfig.getInstance().getSpeciesWhiteList().remove(race);
+
+        UConfig.getInstance().save();
+
+        return result;
+    }
 
     public boolean speciesPermitted(Race race, EntityPlayer sender) {
         if (race == Race.ALICORN && (sender == null || !sender.capabilities.isCreativeMode)) {
             return false;
         }
 
-        return race.isDefault() || serverPermittedRaces.isEmpty() || serverPermittedRaces.contains(race);
+        return race.isDefault() || UConfig.getInstance().getSpeciesWhiteList().isEmpty() || UConfig.getInstance().getSpeciesWhiteList().contains(race);
     }
 
     public IRaceContainer<?> emptyContainer(Entity entity) {