// src/views/AgentChat/hooks/useAgentChat.ts
// 消息处理 Hook - 发送消息、处理响应、错误处理

import { useState, useCallback } from 'react';
import type { Dispatch, SetStateAction, KeyboardEvent } from 'react';
import axios from 'axios';
import { MessageTypes, type Message } from '../constants/messageTypes';
import type { UploadedFile } from './useFileUpload';
import type { User } from './useAgentSessions';

/**
 * Toast 通知函数类型（来自 Chakra UI）
 */
export interface ToastFunction {
  (options: {
    title: string;
    description?: string;
    status: 'success' | 'error' | 'warning' | 'info';
    duration?: number;
    isClosable?: boolean;
  }): void;
}

/**
 * useAgentChat Hook 参数
 */
export interface UseAgentChatParams {
  /** 当前用户信息 */
  user: User | null;
  /** 当前会话 ID */
  currentSessionId: string | null;
  /** 设置当前会话 ID */
  setCurrentSessionId: Dispatch<SetStateAction<string | null>>;
  /** 选中的 AI 模型 */
  selectedModel: string;
  /** 选中的工具列表 */
  selectedTools: string[];
  /** 已上传文件列表 */
  uploadedFiles: UploadedFile[];
  /** 清空已上传文件 */
  clearFiles: () => void;
  /** Toast 通知函数 */
  toast: ToastFunction;
  /** 重新加载会话列表（发送消息成功后调用） */
  loadSessions: () => Promise<void>;
}

/**
 * useAgentChat Hook 返回值
 */
export interface UseAgentChatReturn {
  /** 消息列表 */
  messages: Message[];
  /** 设置消息列表 */
  setMessages: Dispatch<SetStateAction<Message[]>>;
  /** 输入框内容 */
  inputValue: string;
  /** 设置输入框内容 */
  setInputValue: Dispatch<SetStateAction<string>>;
  /** 是否正在处理消息 */
  isProcessing: boolean;
  /** 发送消息 */
  handleSendMessage: () => Promise<void>;
  /** 键盘事件处理（Enter 发送） */
  handleKeyPress: (e: KeyboardEvent<HTMLInputElement>) => void;
  /** 添加消息到列表 */
  addMessage: (message: Partial<Message>) => void;
}

/**
 * useAgentChat Hook
 *
 * 处理消息发送、AI 响应、错误处理逻辑
 *
 * @param params - UseAgentChatParams
 * @returns UseAgentChatReturn
 *
 * @example
 * ```tsx
 * const {
 *   messages,
 *   inputValue,
 *   setInputValue,
 *   isProcessing,
 *   handleSendMessage,
 *   handleKeyPress,
 * } = useAgentChat({
 *   user,
 *   currentSessionId,
 *   setCurrentSessionId,
 *   selectedModel,
 *   selectedTools,
 *   uploadedFiles,
 *   clearFiles,
 *   toast,
 *   loadSessions,
 * });
 * ```
 */
export const useAgentChat = ({
  user,
  currentSessionId,
  setCurrentSessionId,
  selectedModel,
  selectedTools,
  uploadedFiles,
  clearFiles,
  toast,
  loadSessions,
}: UseAgentChatParams): UseAgentChatReturn => {
  const [messages, setMessages] = useState<Message[]>([]);
  const [inputValue, setInputValue] = useState('');
  const [isProcessing, setIsProcessing] = useState(false);

  /**
   * 添加消息到列表
   */
  const addMessage = useCallback((message: Partial<Message>) => {
    setMessages((prev) => [
      ...prev,
      {
        id: Date.now() + Math.random(),
        timestamp: new Date().toISOString(),
        ...message,
      } as Message,
    ]);
  }, []);

  /**
   * 发送消息到后端 API
   */
  const handleSendMessage = useCallback(async () => {
    if (!inputValue.trim() || isProcessing) return;

    // 创建用户消息
    const userMessage: Partial<Message> = {
      type: MessageTypes.USER,
      content: inputValue,
      timestamp: new Date().toISOString(),
      files: uploadedFiles.length > 0 ? uploadedFiles : undefined,
    };

    addMessage(userMessage);
    const userInput = inputValue;

    // 清空输入框和文件
    setInputValue('');
    clearFiles();
    setIsProcessing(true);

    try {
      // 显示 "思考中" 状态
      addMessage({
        type: MessageTypes.AGENT_THINKING,
        content: '正在分析你的问题...',
      });

      // 调用后端 API
      const response = await axios.post('/mcp/agent/chat', {
        message: userInput,
        conversation_history: messages
          .filter((m) => m.type === MessageTypes.USER || m.type === MessageTypes.AGENT_RESPONSE)
          .map((m) => ({
            isUser: m.type === MessageTypes.USER,
            content: m.content,
          })),
        user_id: user?.id ? String(user.id) : 'anonymous',
        user_nickname: user?.nickname || '匿名用户',
        user_avatar: user?.avatar || '',
        subscription_type: user?.subscription_type || 'free',
        session_id: currentSessionId,
        model: selectedModel,
        tools: selectedTools,
        files: uploadedFiles.length > 0 ? uploadedFiles : undefined,
      });

      // 移除 "思考中" 消息
      setMessages((prev) => prev.filter((m) => m.type !== MessageTypes.AGENT_THINKING));

      if (response.data.success) {
        const data = response.data;

        // 更新会话 ID（如果是新会话）
        if (data.session_id && !currentSessionId) {
          setCurrentSessionId(data.session_id);
        }

        // 显示执行计划（如果有）
        if (data.plan) {
          addMessage({
            type: MessageTypes.AGENT_PLAN,
            content: '已制定执行计划',
            plan: data.plan,
          });
        }

        // 显示执行步骤（如果有）
        if (data.steps && data.steps.length > 0) {
          addMessage({
            type: MessageTypes.AGENT_EXECUTING,
            content: '正在执行步骤...',
            plan: data.plan,
            stepResults: data.steps,
          });
        }

        // 移除 "执行中" 消息
        setMessages((prev) => prev.filter((m) => m.type !== MessageTypes.AGENT_EXECUTING));

        // 显示最终回复
        addMessage({
          type: MessageTypes.AGENT_RESPONSE,
          content: data.final_answer || data.message || '处理完成',
          plan: data.plan,
          stepResults: data.steps,
          metadata: data.metadata,
        });

        // 重新加载会话列表
        loadSessions();
      }
    } catch (error: any) {
      console.error('Agent chat error:', error);

      // 移除 "思考中" 和 "执行中" 消息
      setMessages((prev) =>
        prev.filter(
          (m) => m.type !== MessageTypes.AGENT_THINKING && m.type !== MessageTypes.AGENT_EXECUTING
        )
      );

      // 显示错误消息
      const errorMessage = error.response?.data?.error || error.message || '处理失败';
      addMessage({
        type: MessageTypes.ERROR,
        content: `处理失败：${errorMessage}`,
      });

      // 显示 Toast 通知
      toast({
        title: '处理失败',
        description: errorMessage,
        status: 'error',
        duration: 5000,
      });
    } finally {
      setIsProcessing(false);
    }
  }, [
    inputValue,
    isProcessing,
    uploadedFiles,
    messages,
    user,
    currentSessionId,
    selectedModel,
    selectedTools,
    addMessage,
    clearFiles,
    setCurrentSessionId,
    loadSessions,
    toast,
  ]);

  /**
   * 键盘事件处理（Enter 发送，Shift+Enter 换行）
   */
  const handleKeyPress = useCallback(
    (e: KeyboardEvent<HTMLInputElement>) => {
      if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        handleSendMessage();
      }
    },
    [handleSendMessage]
  );

  return {
    messages,
    setMessages,
    inputValue,
    setInputValue,
    isProcessing,
    handleSendMessage,
    handleKeyPress,
    addMessage,
  };
};