import type { LanguageConfig } from "../types";
import { LANGUAGE_CONFIGS, getLanguageConfig } from "../config/languages";

/**
 * 语言管理器
 * 负责管理支持的编程语言，从配置文件读取
 */
export class LanguageManager {
  private languages: Map<string, LanguageConfig> = new Map();
  private currentLanguage: LanguageConfig;

  constructor(defaultLanguage: string = "javascript") {
    // 从配置加载所有语言
    LANGUAGE_CONFIGS.forEach((config) => {
      this.languages.set(config.id, config);
    });

    // 设置默认语言
    const lang = this.languages.get(defaultLanguage);
    if (!lang) {
      throw new Error(`Language "${defaultLanguage}" not found in config`);
    }
    this.currentLanguage = lang;
  }

  /**
   * 获取指定语言配置
   */
  getLanguage(id: string): LanguageConfig | undefined {
    return this.languages.get(id);
  }

  /**
   * 获取所有语言
   */
  getAllLanguages(): LanguageConfig[] {
    return Array.from(this.languages.values());
  }

  /**
   * 切换语言
   */
  switchLanguage(languageId: string): LanguageConfig {
    const lang = this.languages.get(languageId);
    if (!lang) {
      throw new Error(`Language "${languageId}" not supported`);
    }
    this.currentLanguage = lang;
    return this.currentLanguage;
  }

  /**
   * 获取当前语言
   */
  getCurrentLanguage(): LanguageConfig {
    return this.currentLanguage;
  }

  /**
   * 检查语言是否支持
   */
  isSupported(languageId: string): boolean {
    return this.languages.has(languageId);
  }

  /**
   * 获取可运行的语言列表
   */
  getRunnableLanguages(): LanguageConfig[] {
    return Array.from(this.languages.values()).filter((lang) => lang.canRun);
  }

  /**
   * 获取语言的代码模板（支持外部配置）
   * 优先级: languageTemplates > questionConfig > fallbackTemplate > 空字符串
   */
  getTemplate(
    languageId: string,
    questionConfig?: import("../types/question").QuestionConfig,
    languageTemplates?: import("../types/question").LanguageTemplates,
  ): string {
    // 优先级 1: 直接传入的 languageTemplates
    if (
      languageTemplates &&
      languageTemplates[languageId] !== undefined &&
      languageTemplates[languageId] !== null
    ) {
      return languageTemplates[languageId];
    }

    // 优先级 2: questionConfig 中的模板
    if (
      questionConfig?.languageTemplates?.[languageId] !== undefined &&
      questionConfig?.languageTemplates?.[languageId] !== null
    ) {
      return questionConfig.languageTemplates[languageId];
    }

    // 优先级 3: 语言的 fallbackTemplate
    const langConfig = this.languages.get(languageId);
    if (langConfig && (langConfig as any).fallbackTemplate) {
      return (langConfig as any).fallbackTemplate;
    }

    // 优先级 4: 空字符串（允许用户从空白开始）
    return "";
  }
}