/**
 * AI服务类
 * 处理与AI模型的通信和响应
 */
class AIService {
  constructor() {
    this.apiEndpoint = CONFIG.AI_API.ENDPOINT;
    this.model = CONFIG.AI_API.MODEL;
    this.context = [];
    // 使用默认API密钥
    this.apiKey = CONFIG.AI_API.DEFAULT_API_KEY;
    this.controller = null; // 用于中断请求的 AbortController
  }

  /**
   * 初始化AI服务
   */
  async init() {
    try {
      // 尝试从storage中获取用户设置的API密钥
      const result = await Utils.getStorageData("apiKey");
      if (result?.apiKey) {
        this.apiKey = result.apiKey;
      }
      console.log("AI Service initialized");
    } catch (error) {
      console.error("Failed to initialize AI service:", error);
    }
  }

  /**
   * 设置API密钥
   * @param {string} apiKey
   */
  async setApiKey(apiKey) {
    this.apiKey = apiKey;
    await Utils.setStorageData("apiKey", { apiKey });
  }

  /**
   * 发送消息到DeepSeek API
   * @param {string} message 用户消息
   * @returns {Promise<string>} AI响应
   */
  async sendMessage(message) {
    try {
      // 创建新的 AbortController
      this.controller = new AbortController();

      const response = await fetch(this.apiEndpoint, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          Authorization: `Bearer ${this.apiKey}`,
        },
        body: JSON.stringify({
          model: this.model,
          messages: this.formatMessages(message),
          max_tokens: CONFIG.AI_API.MAX_TOKENS,
          temperature: CONFIG.AI_API.TEMPERATURE,
        }),
        signal: this.controller.signal,
      });

      if (!response.ok) {
        throw new Error(`API request failed: ${response.status}`);
      }

      const data = await response.json();
      const aiResponse = data.choices[0]?.message?.content;

      if (!aiResponse) {
        throw new Error("无效的API响应");
      }

      return aiResponse;
    } catch (error) {
      if (error.name === "AbortError") {
        throw new Error("REQUEST_ABORTED");
      }
      console.error("API call failed:", error);
      throw error;
    } finally {
      this.controller = null;
    }
  }

  /**
   * 格式化消息历史
   * @param {string} currentMessage 当前消息
   * @returns {Array} 格式化后的消息数组
   */
  formatMessages(currentMessage) {
    const messages = this.context.map((msg) => ({
      role: msg.role,
      content: msg.content,
    }));

    messages.push({
      role: "user",
      content: currentMessage,
    });

    return messages;
  }

  /**
   * 更新对话上下文
   * @param {string} message 新消息
   * @param {string} role 消息角色（user/assistant）
   */
  updateContext(message, role) {
    this.context.push({
      role,
      content: message,
      timestamp: new Date().toISOString(),
    });

    // 保持上下文长度在合理范围内
    if (this.context.length > 10) {
      this.context = this.context.slice(-10);
    }
  }

  /**
   * 清除对话上下文
   */
  clearContext() {
    this.context = [];
  }

  /**
   * 获取当前对话上下文
   * @returns {Array} 对话上下文数组
   */
  getContext() {
    return this.context;
  }

  // 添加中断方法
  abortRequest() {
    if (this.controller) {
      this.controller.abort();
      this.controller = null;
    }
  }
}

// 确保在DOM加载完成后再创建实例
document.addEventListener("DOMContentLoaded", () => {
  // 只有在实例不存在时才创建
  if (!window.aiService) {
    window.aiService = new AIService();
  }
});