/**
 * 消息模块 React Hooks
 * 
 * 提供React组件与消息状态管理的集成
 * 所有hooks都基于zustand store和订阅机制
 * 确保组件能实时获取状态更新
 * 
 * 重构说明：直接使用 zustand store，移除了对 messageManager 的直接依赖
 */

import { useState, useEffect, useCallback, useRef } from 'react';
import { ConversationResponse, MessageResponse, MessageSegment } from '../../types/dto';
import { useMessageStore, subscriptionManager, normalizeConversationId } from './store';
import type { MessageEvent, MessageSubscriber } from './types';

// ==================== useConversations - 获取会话列表 ====================

interface UseConversationsReturn {
  conversations: ConversationResponse[];
  isLoading: boolean;
  refresh: () => Promise<void>;
  loadMore: () => Promise<void>;
  hasMore: boolean;
}

/**
 * 获取会话列表
 * 用于 MessageListScreen 等需要显示会话列表的组件
 */
export function useConversations(
  fetchConversations: (forceRefresh: boolean, source: string) => Promise<void>,
  loadMoreConversations: () => Promise<void>,
  canLoadMore: () => boolean,
  initialize: () => Promise<void>
): UseConversationsReturn {
  const store = useMessageStore();
  const [conversations, setConversations] = useState<ConversationResponse[]>(() => store.getConversations());
  const [isLoading, setIsLoading] = useState(() => store.isLoading());
  const [hasMore, setHasMore] = useState(() => canLoadMore());

  useEffect(() => {
    // 订阅事件
    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      switch (event.type) {
        case 'conversations_updated':
          setConversations(store.getConversations());
          setHasMore(canLoadMore());
          break;
        case 'conversations_loading':
          setIsLoading(!!event.payload?.loading);
          break;
        case 'connection_changed':
          // 连接状态变化时可能需要刷新
          break;
      }
    });

    // 初始化
    initialize().catch(error => {
      console.error('[useConversations] 初始化失败:', error);
    });

    // 冷启动兜底：延迟做一次强制刷新
    const coldStartSyncTimer = setTimeout(() => {
      fetchConversations(true, 'hooks-initial-refresh').catch(error => {
        console.error('[useConversations] 冷启动强制刷新失败:', error);
      });
    }, 1200);

    return () => {
      clearTimeout(coldStartSyncTimer);
      unsubscribe();
    };
  }, []);

  const refresh = useCallback(async () => {
    await fetchConversations(true, 'hooks-manual-refresh');
  }, [fetchConversations]);

  const loadMore = useCallback(async () => {
    await loadMoreConversations();
  }, [loadMoreConversations]);

  return {
    conversations,
    isLoading,
    refresh,
    loadMore,
    hasMore,
  };
}

// ==================== useMessages - 获取指定会话的消息 ====================

interface UseMessagesReturn {
  messages: MessageResponse[];
  isLoading: boolean;
  hasMore: boolean;
  loadMore: () => Promise<void>;
  refresh: () => Promise<void>;
}

/**
 * 获取指定会话的消息
 */
export function useMessages(
  conversationId: string,
  fetchMessages: (conversationId: string) => Promise<void>,
  loadMoreMessages: (conversationId: string, beforeSeq: number, limit?: number) => Promise<MessageResponse[]>
): UseMessagesReturn {
  const store = useMessageStore();
  const normalizedConversationId = normalizeConversationId(conversationId);
  
  const [messages, setMessages] = useState<MessageResponse[]>(() => 
    store.getMessages(normalizedConversationId)
  );
  const [isLoading, setIsLoading] = useState(() => 
    store.isLoadingMessages(normalizedConversationId)
  );
  const [hasMore, setHasMore] = useState(true);

  useEffect(() => {
    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'messages_updated' && event.payload.conversationId === normalizedConversationId) {
        setMessages(event.payload.messages);
      }
    });

    // 激活会话
    fetchMessages(normalizedConversationId).catch(error => {
      console.error('[useMessages] 激活会话失败:', error);
    });

    return () => {
      // 清理活动会话
      if (store.getActiveConversation() === normalizedConversationId) {
        store.setCurrentConversation(null);
      }
      unsubscribe();
    };
  }, [normalizedConversationId]);

  const loadMore = useCallback(async () => {
    const currentMessages = store.getMessages(conversationId);
    if (currentMessages.length === 0) return;

    // 消息数组在 store 内保持 seq 升序，首项即最早消息
    const minSeq = currentMessages[0]?.seq;
    if (minSeq === undefined) return;

    const loadedMessages = await loadMoreMessages(conversationId, minSeq, 20);
    setHasMore(loadedMessages.length > 0);
  }, [conversationId, loadMoreMessages]);

  const refresh = useCallback(async () => {
    await fetchMessages(conversationId);
    setMessages(store.getMessages(conversationId));
  }, [conversationId, fetchMessages]);

  return {
    messages,
    isLoading,
    hasMore,
    loadMore,
    refresh,
  };
}

// ==================== useSendMessage - 发送消息 ====================

interface UseSendMessageReturn {
  sendMessage: (segments: MessageSegment[], options?: { replyToId?: string }) => Promise<MessageResponse | null>;
  isSending: boolean;
}

/**
 * 发送消息
 */
export function useSendMessage(
  conversationId: string,
  sendMessageService: (conversationId: string, segments: MessageSegment[], options?: { replyToId?: string }) => Promise<MessageResponse | null>
): UseSendMessageReturn {
  const [isSending, setIsSending] = useState(false);

  const sendMessage = useCallback(async (segments: MessageSegment[], options?: { replyToId?: string }) => {
    setIsSending(true);
    try {
      const message = await sendMessageService(conversationId, segments, options);
      return message;
    } catch (error) {
      console.error('[useSendMessage] 发送消息失败:', error);
      return null;
    } finally {
      setIsSending(false);
    }
  }, [conversationId, sendMessageService]);

  return {
    sendMessage,
    isSending,
  };
}

// ==================== useMarkAsRead - 标记已读 ====================

interface UseMarkAsReadReturn {
  markAsRead: (seq: number) => Promise<void>;
  markAllAsRead: () => Promise<void>;
}

/**
 * 标记已读
 */
export function useMarkAsRead(
  conversationId: string,
  markAsReadService: (conversationId: string, seq: number) => Promise<void>,
  markAllAsReadService: () => Promise<void>
): UseMarkAsReadReturn {
  const markAsRead = useCallback(async (seq: number) => {
    await markAsReadService(conversationId, seq);
  }, [conversationId, markAsReadService]);

  const markAllAsRead = useCallback(async () => {
    await markAllAsReadService();
  }, [markAllAsReadService]);

  return {
    markAsRead,
    markAllAsRead,
  };
}

// ==================== useUnreadCount - 获取未读数 ====================

interface UseUnreadCountReturn {
  totalUnreadCount: number;
  systemUnreadCount: number;
  refresh: () => Promise<void>;
}

/**
 * 获取未读数
 */
export function useUnreadCount(fetchUnreadCount: () => Promise<void>): UseUnreadCountReturn {
  const store = useMessageStore();
  const [counts, setCounts] = useState(() => store.getUnreadCount());

  useEffect(() => {
    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'unread_count_updated') {
        setCounts(store.getUnreadCount());
      }
    });

    // 初始获取
    fetchUnreadCount();

    return unsubscribe;
  }, []);

  const refresh = useCallback(async () => {
    await fetchUnreadCount();
  }, [fetchUnreadCount]);

  return {
    totalUnreadCount: counts.total,
    systemUnreadCount: counts.system,
    refresh,
  };
}

// ==================== useSystemUnreadCount - 获取系统消息未读数 ====================

interface UseSystemUnreadCountReturn {
  systemUnreadCount: number;
  setSystemUnreadCount: (count: number) => void;
  incrementSystemUnreadCount: () => void;
  decrementSystemUnreadCount: (count?: number) => void;
}

/**
 * 获取系统消息未读数
 */
export function useSystemUnreadCount(
  setSystemUnreadCountService: (count: number) => void,
  incrementSystemUnreadCountService: () => void,
  decrementSystemUnreadCountService: (count?: number) => void
): UseSystemUnreadCountReturn {
  const store = useMessageStore();
  const [systemUnreadCount, setSystemUnreadCountState] = useState(() => 
    store.getUnreadCount().system
  );

  useEffect(() => {
    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'unread_count_updated') {
        setSystemUnreadCountState(store.getUnreadCount().system);
      }
    });

    return unsubscribe;
  }, []);

  const setSystemUnreadCount = useCallback((count: number) => {
    setSystemUnreadCountService(count);
  }, [setSystemUnreadCountService]);

  const incrementSystemUnreadCount = useCallback(() => {
    incrementSystemUnreadCountService();
  }, [incrementSystemUnreadCountService]);

  const decrementSystemUnreadCount = useCallback((count = 1) => {
    decrementSystemUnreadCountService(count);
  }, [decrementSystemUnreadCountService]);

  return {
    systemUnreadCount,
    setSystemUnreadCount,
    incrementSystemUnreadCount,
    decrementSystemUnreadCount,
  };
}

// ==================== useConversation - 获取单个会话 ====================

interface UseConversationReturn {
  conversation: ConversationResponse | null;
  refresh: () => Promise<void>;
}

/**
 * 获取单个会话
 */
export function useConversation(
  conversationId: string,
  fetchConversationDetail: (conversationId: string) => Promise<ConversationResponse | null>
): UseConversationReturn {
  const store = useMessageStore();
  const [conversation, setConversation] = useState<ConversationResponse | null>(() => 
    store.getConversation(conversationId)
  );

  useEffect(() => {
    setConversation(store.getConversation(conversationId));

    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'conversations_updated') {
        const updated = store.getConversation(conversationId);
        setConversation(updated);
      }
    });

    return unsubscribe;
  }, [conversationId]);

  const refresh = useCallback(async () => {
    await fetchConversationDetail(conversationId);
    setConversation(store.getConversation(conversationId));
  }, [conversationId, fetchConversationDetail]);

  return {
    conversation,
    refresh,
  };
}

// ==================== useMessageManager - 通用订阅 ====================

interface UseMessageManagerReturn {
  isConnected: boolean;
  subscribe: (subscriber: MessageSubscriber) => () => void;
}

/**
 * 通用消息订阅
 */
export function useMessageManager(initialize: () => Promise<void>): UseMessageManagerReturn {
  const store = useMessageStore();
  const [isConnected, setIsConnected] = useState(() => store.isConnected());

  useEffect(() => {
    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'connection_changed') {
        setIsConnected(event.payload.connected);
      }
    });

    initialize().then(() => {
      setIsConnected(store.isConnected());
    }).catch(error => {
      console.error('[useMessageManager] 初始化失败:', error);
    });

    return unsubscribe;
  }, []);

  const subscribe = useCallback((subscriber: MessageSubscriber) => {
    return subscriptionManager.subscribe(subscriber);
  }, []);

  return {
    isConnected,
    subscribe,
  };
}

// ==================== useCreateConversation - 创建会话 ====================

interface UseCreateConversationReturn {
  createConversation: (userId: string) => Promise<ConversationResponse | null>;
  isCreating: boolean;
}

/**
 * 创建会话
 */
export function useCreateConversation(
  createConversationService: (userId: string) => Promise<ConversationResponse | null>
): UseCreateConversationReturn {
  const [isCreating, setIsCreating] = useState(false);

  const createConversation = useCallback(async (userId: string) => {
    setIsCreating(true);
    try {
      const conversation = await createConversationService(userId);
      return conversation;
    } catch (error) {
      console.error('[useCreateConversation] 创建会话失败:', error);
      return null;
    } finally {
      setIsCreating(false);
    }
  }, [createConversationService]);

  return {
    createConversation,
    isCreating,
  };
}

// ==================== useUpdateConversation - 更新会话 ====================

interface UseUpdateConversationReturn {
  updateConversation: (conversationId: string, updates: Partial<ConversationResponse>) => void;
}

/**
 * 更新会话
 */
export function useUpdateConversation(
  updateConversationService: (conversationId: string, updates: Partial<ConversationResponse>) => void
): UseUpdateConversationReturn {
  const updateConversation = useCallback((conversationId: string, updates: Partial<ConversationResponse>) => {
    updateConversationService(conversationId, updates);
  }, [updateConversationService]);

  return {
    updateConversation,
  };
}

// ==================== useGroupTyping - 群聊输入状态 ====================

interface UseGroupTypingReturn {
  typingUsers: string[];
}

/**
 * 获取群聊输入状态
 */
export function useGroupTyping(groupId: string): UseGroupTypingReturn {
  const store = useMessageStore();
  const [typingUsers, setTypingUsers] = useState<string[]>(() => 
    store.getTypingUsers(groupId)
  );

  useEffect(() => {
    setTypingUsers(store.getTypingUsers(groupId));

    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'typing_status' && event.payload.groupId === groupId) {
        setTypingUsers(event.payload.typingUsers);
      }
    });

    return unsubscribe;
  }, [groupId]);

  return {
    typingUsers,
  };
}

// ==================== useGroupMuted - 群聊禁言状态 ====================

interface UseGroupMutedReturn {
  isMuted: boolean;
  setMutedStatus: (muted: boolean) => void;
}

/**
 * 获取群聊禁言状态
 */
export function useGroupMuted(groupId: string): UseGroupMutedReturn {
  const store = useMessageStore();
  const [isMuted, setIsMuted] = useState(() => store.isMuted(groupId));

  useEffect(() => {
    setIsMuted(store.isMuted(groupId));

    const unsubscribe = subscriptionManager.subscribe((event: MessageEvent) => {
      if (event.type === 'group_notice' && event.payload.groupId === groupId) {
        if (event.payload.noticeType === 'muted' || event.payload.noticeType === 'unmuted') {
          setIsMuted(event.payload.noticeType === 'muted');
        }
      }
    });

    return unsubscribe;
  }, [groupId]);

  const setMutedStatus = useCallback((muted: boolean) => {
    store.setMutedStatus(groupId, muted);
  }, [groupId]);

  return {
    isMuted,
    setMutedStatus,
  };
}

// ==================== useActiveConversation - 活动会话 ====================

interface UseActiveConversationReturn {
  activeConversationId: string | null;
  setActiveConversation: (conversationId: string | null) => void;
}

/**
 * 获取/设置活动会话
 */
export function useActiveConversation(): UseActiveConversationReturn {
  const store = useMessageStore();
  const [activeConversationId, setActiveConversationId] = useState<string | null>(() => 
    store.getActiveConversation()
  );

  const setActiveConversation = useCallback((conversationId: string | null) => {
    store.setCurrentConversation(conversationId);
    setActiveConversationId(conversationId);
  }, []);

  return {
    activeConversationId,
    setActiveConversation,
  };
}