import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { App } from 'antd';
import apiClient from '../utils/apiClient';
import { buildApiUrl, API_ENDPOINTS } from '../config/api';

const AUTO_REFRESH_INTERVAL = 30;

export default function useAdminDashboardPage() {
  const { message, modal } = App.useApp();
  const inFlightRef = useRef(false);
  const mountedRef = useRef(true);

  const [stats, setStats] = useState(null);
  const [onlineUsers, setOnlineUsers] = useState([]);
  const [usersList, setUsersList] = useState([]);
  const [tasks, setTasks] = useState([]);
  const [resources, setResources] = useState(null);
  const [loading, setLoading] = useState(true);
  const [taskLoading, setTaskLoading] = useState(false);
  const [lastUpdatedAt, setLastUpdatedAt] = useState(null);

  const [taskType, setTaskType] = useState('all');
  const [taskStatus, setTaskStatus] = useState('all');
  const [autoRefresh, setAutoRefresh] = useState(true);
  const [countdown, setCountdown] = useState(AUTO_REFRESH_INTERVAL);

  const [showMeetingModal, setShowMeetingModal] = useState(false);
  const [meetingDetails, setMeetingDetails] = useState(null);
  const [meetingLoading, setMeetingLoading] = useState(false);

  useEffect(() => {
    mountedRef.current = true;
    return () => {
      mountedRef.current = false;
    };
  }, []);

  const fetchStats = useCallback(async () => {
    const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.ADMIN.DASHBOARD_STATS));
    if (response.code === '200') {
      setStats(response.data);
    }
  }, []);

  const fetchOnlineUsers = useCallback(async () => {
    const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.ADMIN.ONLINE_USERS));
    if (response.code === '200') {
      setOnlineUsers(response.data.users || []);
    }
  }, []);

  const fetchUsersList = useCallback(async () => {
    const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.ADMIN.USER_STATS));
    if (response.code === '200') {
      setUsersList(response.data.users || []);
    }
  }, []);

  const fetchTasks = useCallback(async () => {
    try {
      setTaskLoading(true);
      const params = new URLSearchParams();
      if (taskType !== 'all') params.append('task_type', taskType);
      if (taskStatus !== 'all') params.append('status', taskStatus);
      params.append('limit', '20');

      const response = await apiClient.get(buildApiUrl(`${API_ENDPOINTS.ADMIN.TASKS_MONITOR}?${params.toString()}`));
      if (response.code === '200') {
        setTasks(response.data.tasks || []);
      }
    } finally {
      setTaskLoading(false);
    }
  }, [taskStatus, taskType]);

  const fetchResources = useCallback(async () => {
    const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.ADMIN.SYSTEM_RESOURCES));
    if (response.code === '200') {
      setResources(response.data);
    }
  }, []);

  const fetchAllData = useCallback(async ({ silent = false } = {}) => {
    if (inFlightRef.current) {
      return;
    }
    inFlightRef.current = true;

    try {
      if (!silent && mountedRef.current) {
        setLoading(true);
      }
      await Promise.all([fetchStats(), fetchOnlineUsers(), fetchUsersList(), fetchTasks(), fetchResources()]);
      if (mountedRef.current) {
        setLastUpdatedAt(new Date());
        setCountdown(AUTO_REFRESH_INTERVAL);
      }
    } catch (error) {
      console.error('获取数据失败:', error);
      if (mountedRef.current && !silent) {
        message.error('加载数据失败，请稍后重试');
      }
    } finally {
      inFlightRef.current = false;
      if (mountedRef.current && !silent) {
        setLoading(false);
      }
    }
  }, [fetchOnlineUsers, fetchResources, fetchStats, fetchTasks, fetchUsersList, message]);

  useEffect(() => {
    fetchAllData();
  }, [fetchAllData]);

  useEffect(() => {
    if (!autoRefresh || showMeetingModal) {
      return undefined;
    }

    const timer = setInterval(() => {
      setCountdown((prev) => {
        if (prev <= 1) {
          fetchAllData({ silent: true });
          return AUTO_REFRESH_INTERVAL;
        }
        return prev - 1;
      });
    }, 1000);

    return () => clearInterval(timer);
  }, [autoRefresh, fetchAllData, showMeetingModal]);

  useEffect(() => {
    fetchTasks();
  }, [fetchTasks]);

  const handleKickUser = (user) => {
    modal.confirm({
      title: '踢出用户',
      content: `确定要踢出用户"${user.caption}"吗？该用户将被强制下线。`,
      okText: '确定',
      okType: 'danger',
      cancelText: '取消',
      onOk: async () => {
        try {
          const response = await apiClient.post(buildApiUrl(API_ENDPOINTS.ADMIN.KICK_USER(user.user_id)));
          if (response.code === '200') {
            message.success('用户已被踢出');
            fetchOnlineUsers();
          }
        } catch {
          message.error('踢出用户失败');
        }
      },
    });
  };

  const handleViewMeeting = async (meetingId) => {
    setMeetingLoading(true);
    setShowMeetingModal(true);
    try {
      const response = await apiClient.get(buildApiUrl(API_ENDPOINTS.MEETINGS.DETAIL(meetingId)));
      if (response.code === '200') {
        setMeetingDetails(response.data);
      }
    } catch {
      message.error('获取会议详情失败');
    } finally {
      setMeetingLoading(false);
    }
  };

  const handleDownloadTranscript = async (meetingId) => {
    try {
      const response = await apiClient.get(buildApiUrl(`/api/meetings/${meetingId}/transcript`));
      if (response.code === '200') {
        const dataStr = JSON.stringify(response.data, null, 2);
        const blob = new Blob([dataStr], { type: 'application/json' });
        const url = URL.createObjectURL(blob);
        const link = document.createElement('a');
        link.href = url;
        link.download = `transcript_${meetingId}.json`;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
      }
    } catch {
      message.error('下载失败');
    }
  };

  const closeMeetingModal = () => {
    setShowMeetingModal(false);
    setMeetingDetails(null);
  };

  const taskCompletionRate = useMemo(() => {
    const all = tasks.length || 1;
    const completed = tasks.filter((item) => item.status === 'completed').length;
    return Math.round((completed / all) * 100);
  }, [tasks]);

  return {
    stats,
    onlineUsers,
    usersList,
    tasks,
    resources,
    loading,
    taskLoading,
    lastUpdatedAt,
    taskType,
    setTaskType,
    taskStatus,
    setTaskStatus,
    autoRefresh,
    setAutoRefresh,
    countdown,
    showMeetingModal,
    meetingDetails,
    meetingLoading,
    fetchAllData,
    fetchOnlineUsers,
    handleKickUser,
    handleViewMeeting,
    handleDownloadTranscript,
    closeMeetingModal,
    taskCompletionRate,
  };
}