Intial i18n messages support

Send different languages of messages based on player's client setting

src/main/java/fr/xephi/authme/message/AbstractMessageFileHandler.java

@@ -14,6 +14,7 @@ import org.bukkit.configuration.file.YamlConfiguration;
 import javax.annotation.PostConstruct;
 import javax.inject.Inject;
 import java.io.File;
+import java.util.concurrent.ConcurrentHashMap;
 
 import static fr.xephi.authme.message.MessagePathHelper.DEFAULT_LANGUAGE;
 
@@ -33,6 +34,7 @@ public abstract class AbstractMessageFileHandler implements Reloadable {
 
     private String filename;
     private FileConfiguration configuration;
+    private ConcurrentHashMap<String, FileConfiguration> i18nConfiguration;
     private final String defaultFile;
 
     protected AbstractMessageFileHandler() {
@@ -46,6 +48,7 @@ public abstract class AbstractMessageFileHandler implements Reloadable {
         filename = createFilePath(language);
         File messagesFile = initializeFile(filename);
         configuration = YamlConfiguration.loadConfiguration(messagesFile);
+        i18nConfiguration = null;
     }
 
     protected String getLanguage() {
@@ -83,6 +86,24 @@ public abstract class AbstractMessageFileHandler implements Reloadable {
             : message;
     }
 
+    /**
+     * Returns the i18n message for the given key and given locale.
+     *
+     * @param key the key to retrieve the message for
+     * @param locale the locale that player client setting uses
+     * @return the message
+     */
+    public String getMessageByLocale(String key, String locale) {
+        if (locale == null || !settings.getProperty(PluginSettings.I18N_MESSAGES)) {
+            return getMessage(key);
+        }
+
+        String message = getI18nConfiguration(locale).getString(key);
+        return message == null
+            ? "Error retrieving message '" + key + "'"
+            : message;
+    }
+
     /**
      * Returns the message for the given key only if it exists,
      * i.e. without falling back to the default file.
@@ -94,6 +115,25 @@ public abstract class AbstractMessageFileHandler implements Reloadable {
         return configuration.getString(key);
     }
 
+    public FileConfiguration getI18nConfiguration(String locale) {
+        if (i18nConfiguration == null) {
+            i18nConfiguration = new ConcurrentHashMap<>();
+        }
+
+        if (i18nConfiguration.containsKey(locale)) {
+            return i18nConfiguration.get(locale);
+        } else {
+            // Sync with reload();
+            String i18nFilename = createFilePath(locale);
+            File i18nMessagesFile = initializeFile(i18nFilename);
+            FileConfiguration config = YamlConfiguration.loadConfiguration(i18nMessagesFile);
+
+            i18nConfiguration.put(locale, config);
+
+            return config;
+        }
+    }
+
     /**
      * Creates the path to the messages file for the given language code.
      *

src/main/java/fr/xephi/authme/message/Messages.java

@@ -4,6 +4,7 @@ import com.google.common.collect.ImmutableMap;
 import fr.xephi.authme.ConsoleLogger;
 import fr.xephi.authme.mail.EmailService;
 import fr.xephi.authme.output.ConsoleLoggerFactory;
+import fr.xephi.authme.util.PlayerUtils;
 import fr.xephi.authme.util.expiring.Duration;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
@@ -120,7 +121,8 @@ public class Messages {
      * @return The message from the file
      */
     private String retrieveMessage(MessageKey key, CommandSender sender) {
-        String message = messagesFileHandler.getMessage(key.getKey());
+        String locale = PlayerUtils.getLocale(sender);
+        String message = messagesFileHandler.getMessageByLocale(key.getKey(), locale);
         String displayName = sender.getName();
         if (sender instanceof Player) {
             displayName = ((Player) sender).getDisplayName();

src/main/java/fr/xephi/authme/settings/properties/PluginSettings.java

@@ -16,6 +16,13 @@ public final class PluginSettings implements SettingsHolder {
     public static final Property<Boolean> MENU_UNREGISTER_COMPATIBILITY =
         newProperty("3rdPartyFeature.compatibility.menuPlugins", false);
 
+    @Comment({
+        "Send i18n messages to player based on their client settings, this option will override `settings.messagesLanguage`",
+        "This will not affect language of authme help command."
+    })
+    public static final Property<Boolean> I18N_MESSAGES =
+        newProperty("3rdPartyFeature.features.i18nMessages.enabled", false);
+
     @Comment({
         "Do you want to enable the session feature?",
         "If enabled, when a player authenticates successfully,",

src/main/java/fr/xephi/authme/util/PlayerUtils.java

@@ -1,7 +1,10 @@
 package fr.xephi.authme.util;
 
+import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 
+import java.lang.reflect.Method;
+
 /**
  * Player utilities.
  */
@@ -36,4 +39,30 @@ public final class PlayerUtils {
         }
     }
 
+    /**
+     * Returns the locale that player uses.
+     *
+     * @param sender The player
+     */
+    public static String getLocale(CommandSender sender) {
+        String locale = null;
+
+        if (sender instanceof Player) {
+            Player player = (Player) sender;
+            if (Utils.majorVersion >= 12) {
+                locale = player.getLocale();
+            } else {
+                try {
+                    Method spigotMethod = player.getClass().getMethod("spigot");
+                    Object spigot = spigotMethod.invoke(player);
+
+                    Method spigotGetLocaleMethod = spigot.getClass().getMethod("getLocale");
+                    locale = (String) spigotGetLocaleMethod.invoke(spigot);
+                } catch (Exception ignored) {
+                }
+            }
+        }
+
+        return locale;
+    }
 }

src/main/java/fr/xephi/authme/util/Utils.java

@@ -2,6 +2,7 @@ package fr.xephi.authme.util;
 
 import fr.xephi.authme.ConsoleLogger;
 import fr.xephi.authme.output.ConsoleLoggerFactory;
+import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.ConsoleCommandSender;
@@ -107,4 +108,12 @@ public final class Utils {
     public static boolean isEmailEmpty(String email) {
         return StringUtils.isBlank(email) || "your@email.com".equalsIgnoreCase(email);
     }
+
+    private final static String[] serverVersion = Bukkit.getServer().getBukkitVersion()
+        .substring(0, Bukkit.getServer().getBukkitVersion().indexOf("-"))
+        .split("\\.");
+
+    private final static int mcFirstVersion = Integer.parseInt(serverVersion[0]);
+    public final static int majorVersion = Integer.parseInt(serverVersion[1]);
+    public final static int minorVersion = Integer.parseInt(serverVersion[2]);
 }