Detect and replace default language setting in config files during initialization

core/src/main/java/com/xujiayao/discord_mc_chat/utils/config/ConfigManager.java

@@ -1,6 +1,7 @@
 package com.xujiayao.discord_mc_chat.utils.config;
 
 import com.fasterxml.jackson.databind.JsonNode;
+import com.xujiayao.discord_mc_chat.utils.StringUtils;
 import com.xujiayao.discord_mc_chat.utils.YamlUtils;
 import com.xujiayao.discord_mc_chat.utils.i18n.I18nManager;
 
@@ -10,7 +11,6 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.nio.file.StandardCopyOption;
 import java.util.function.Function;
 
 import static com.xujiayao.discord_mc_chat.Constants.LOGGER;
@@ -43,16 +43,24 @@ public class ConfigManager {
 			// If config.yml does not exist or is empty, create it from the appropriate template.
 			if (!Files.exists(CONFIG_FILE_PATH) || Files.size(CONFIG_FILE_PATH) == 0) {
 				LOGGER.warn(I18nManager.getDmccTranslation("utils.config.config.not_found"));
-				LOGGER.warn(I18nManager.getDmccTranslation("utils.config.config.creating", CONFIG_FILE_PATH));
-				LOGGER.warn(I18nManager.getDmccTranslation("utils.config.config.edit_prompt", CONFIG_FILE_PATH));
+				LOGGER.info(I18nManager.getDmccTranslation("utils.config.config.creating", CONFIG_FILE_PATH));
+				LOGGER.info(I18nManager.getDmccTranslation("utils.config.config.replacing_lang", I18nManager.getLanguage()));
+				LOGGER.info(I18nManager.getDmccTranslation("utils.config.config.edit_prompt", CONFIG_FILE_PATH));
 
 				try (InputStream inputStream = ConfigManager.class.getResourceAsStream(configTemplatePath)) {
 					if (inputStream == null) {
 						throw new IOException("Default config template not found: " + configTemplatePath);
 					}
 
-					// Copy the template config file as is
-					Files.copy(inputStream, CONFIG_FILE_PATH, StandardCopyOption.REPLACE_EXISTING);
+					// Read the template content
+					String template = new String(inputStream.readAllBytes(), StandardCharsets.UTF_8);
+
+					// Replace the default language with the detected system language.
+					// This ensures the generated config file uses the user's system language if supported.
+					template = template.replace("\nlanguage: \"to_be_auto_replaced\"\n", StringUtils.format("\nlanguage: \"{}\"\n", I18nManager.getLanguage()));
+
+					// Write the config file with the replaced language setting
+					Files.writeString(CONFIG_FILE_PATH, template, StandardCharsets.UTF_8);
 				}
 
 				return false;

core/src/main/java/com/xujiayao/discord_mc_chat/utils/i18n/I18nManager.java

@@ -13,6 +13,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 import static com.xujiayao.discord_mc_chat.Constants.LOGGER;
@@ -30,9 +31,34 @@ public class I18nManager {
 	private static final Path CUSTOM_MESSAGES_DIR = Paths.get("./config/discord_mc_chat/custom_messages");
 	private static final Path CACHE_DIR = Paths.get("./config/discord_mc_chat/cache/lang");
 	private static final Map<String, String> minecraftTranslations = new HashMap<>();
-	private static String language = "en_us";
+	private static String language = detectLanguage();
 	private static JsonNode customMessages;
 
+	/**
+	 * Gets the currently selected language code.
+	 *
+	 * @return The language code (e.g., "en_us").
+	 */
+	public static String getLanguage() {
+		return language;
+	}
+
+	/**
+	 * Detects the system language and checks if it is supported by DMCC.
+	 *
+	 * @return The detected language code (e.g., "zh_cn") if supported, otherwise "en_us".
+	 */
+	public static String detectLanguage() {
+		String code = Locale.getDefault().toString().toLowerCase();
+
+		// Check if the internal translation file exists for the detected language
+		if (I18nManager.class.getResource("/lang/" + code + ".yml") != null) {
+			return code;
+		}
+
+		return "en_us";
+	}
+
 	/**
 	 * Loads only DMCC's internal translations from resources.
 	 *

core/src/main/resources/config/config_single_server.yml

@@ -12,7 +12,7 @@ mode: single_server
 # ==================================================
 
 # 语言设置
-language: "en_us"
+language: "to_be_auto_replaced"
 
 # Discord 设置
 discord:

core/src/main/resources/config/config_standalone.yml

@@ -12,7 +12,7 @@ mode: standalone
 # ==================================================
 
 # 语言设置
-language: "en_us"
+language: "to_be_auto_replaced"
 
 # 多服务器功能
 multi_server:

core/src/main/resources/lang/en_us.yml

@@ -75,6 +75,7 @@ utils:
     config:
       not_found: "Configuration file not found or is empty."
       creating: "Creating a default one at \"{}\"."
+      replacing_lang: "Replacing language setting in config file to \"{}\"."
       edit_prompt: "Please edit \"{}\" before reloading DMCC."
       mode_mismatch: "Mode mismatch detected."
       mode_mismatch_detail: "The expected mode is \"{}\" (from mode.yml or environment), but config.yml is for \"{}\"."

core/src/main/resources/lang/zh_cn.yml

@@ -75,6 +75,7 @@ utils:
     config:
       not_found: "配置文件未找到或为空。"
       creating: "正在于 \"{}\" 创建默认文件。"
+      replacing_lang: "正在将配置文件中的语言设置替换为 \"{}\"。"
       edit_prompt: "请在重新加载 DMCC 之前编辑 \"{}\"。"
       mode_mismatch: "检测到模式不匹配。"
       mode_mismatch_detail: "期望的模式是 \"{}\"（来自 mode.yml 或环境），但 config.yml 是针对 \"{}\" 的。"