import { useState, useEffect, useRef } from 'react'
import { useNavigate, useLocation } from 'react-router-dom'
import { useTranslation } from 'react-i18next'
import { List, Card, Tag, Tabs, PullToRefresh, InfiniteScroll } from 'antd-mobile'
import {
  ClockCircleOutline,
  CheckCircleOutline,
  CloseCircleOutline,
  ExclamationCircleOutline,
} from 'antd-mobile-icons'
import { approvalApi } from '../../services/api'
import styles from './list.module.css'

// 状态映射
const statusConfig: Record<string, { color: string; icon: React.ReactNode; text: string }> = {
  draft: { color: 'default', icon: <ClockCircleOutline />, text: '草稿' },
  pending: { color: 'warning', icon: <ExclamationCircleOutline />, text: '审批中' },
  approved: { color: 'success', icon: <CheckCircleOutline />, text: '已通过' },
  rejected: { color: 'danger', icon: <CloseCircleOutline />, text: '已拒绝' },
  cancelled: { color: 'default', icon: <CloseCircleOutline />, text: '已撤销' },
}

interface ApprovalItem {
  id: number
  title: string
  business_type: string
  status: string
  created_at: string
  applicant?: {
    name: string
  }
  flow?: {
    name: string
  }
}

// 业务类型映射
const businessTypeConfig: Record<string, string> = {
  business_trip: '出差申请',
  expense: '费用报销',
  leave: '请假申请',
  purchase: '采购申请',
}

export default function ApprovalList() {
  const { t } = useTranslation()
  const navigate = useNavigate()
  const location = useLocation()

  // 优先从 sessionStorage 恢复 tab，其次从 location.state，最后默认为 'my'
  const savedTab = sessionStorage.getItem('approval-tab') as string
  const stateTab = ((location.state as any)?.fromTab as string) || undefined
  const initialTab = (savedTab && ['my', 'pending', 'approved', 'cc'].includes(savedTab)) ? savedTab : (stateTab || 'my')
  const [activeTab, setActiveTab] = useState<'my' | 'pending' | 'approved' | 'cc'>(initialTab)
  const [list, setList] = useState<ApprovalItem[]>([])
  const [loading, setLoading] = useState(false)
  const [hasMore, setHasMore] = useState(false)
  const [page, setPage] = useState(1)

  const requestIdRef = useRef<string>('')

  // 加载数据 - 接收 tab 参数
  const loadData = async (pageNum: number = 1, isRefresh: boolean = false, tab?: string) => {
    // 生成新的请求 ID
    const requestId = `${tab || activeTab}-${pageNum}-${Date.now()}-${Math.random()}`
    requestIdRef.current = requestId

    const currentTab = tab || activeTab

    console.log('🔍 Loading approval list START:', {
      requestId,
      currentTab,
      activeTab,
      tab,
      pageNum,
      isRefresh,
      requestIdRefNow: requestIdRef.current
    })

    setLoading(true)

    try {
      const result = await approvalApi.getList({
        type: currentTab,
        page: pageNum,
        page_size: 20,
      })

      console.log('📦 API response received:', {
        requestId,
        currentTab,
        requestIdRefNow: requestIdRef.current,
        count: result?.list?.length
      })

      // 检查是否是最新的请求
      if (requestIdRef.current !== requestId) {
        console.log('⏭️ Skipping outdated response:', {
          requestId,
          latestRequestId: requestIdRef.current
        })
        return
      }

      const newList = result?.list || []

      // 直接更新数据
      console.log('✅ Updating list for tab:', currentTab, 'items:', newList.length)
      setList(newList)
      setHasMore(newList.length >= 20)
      setPage(pageNum)
    } catch (error: any) {
      console.error('❌ Failed to load approvals:', error)
    } finally {
      setLoading(false)
    }
  }

  // 切换标签
  const handleTabChange = (key: string) => {
    console.log('🔄 Tab changing from', activeTab, 'to', key)
    setActiveTab(key as 'my' | 'pending' | 'approved' | 'cc')
    // 保存 tab 到 sessionStorage
    sessionStorage.setItem('approval-tab', key)
    setList([])
    setHasMore(false)
    setPage(1)
    // 直接传入新的 tab 值
    loadData(1, true, key)
  }

  // 刷新
  const handleRefresh = async () => {
    await loadData(1, true, activeTab)
  }

  // 加载更多
  const handleLoadMore = async () => {
    await loadData(page + 1, false, activeTab)
  }

  // 初始加载
  useEffect(() => {
    console.log('🚀 Initial load effect')
    loadData(1, true)

    return () => {
      console.log('🧹 Cleanup function called')
    }
  }, [])

  // 查看详情
  const handleViewDetail = (id: number) => {
    navigate(`/approval/${id}`, { state: { fromTab: activeTab } })
  }

  // 格式化日期
  const formatDate = (dateStr: string) => {
    const date = new Date(dateStr)
    return `${date.getMonth() + 1}/${date.getDate()}`
  }

  // 格式化时间
  const formatTime = (dateStr: string) => {
    const date = new Date(dateStr)
    const now = new Date()
    const diff = now.getTime() - date.getTime()
    const days = Math.floor(diff / (1000 * 60 * 60 * 24))

    if (days === 0) {
      const hours = Math.floor(diff / (1000 * 60 * 60))
      if (hours === 0) {
        const minutes = Math.floor(diff / (1000 * 60))
        return minutes < 1 ? '刚刚' : `${minutes}分钟前`
      }
      return `${hours}小时前`
    }
    if (days === 1) return '昨天'
    if (days < 7) return `${days}天前`
    return formatDate(dateStr)
  }

  return (
    <div className={styles.list}>
      <Tabs activeKey={activeTab} onChange={handleTabChange}>
        <Tabs.Tab title="我发起的" key="my" />
        <Tabs.Tab title="待我审批" key="pending" />
        <Tabs.Tab title="我已审批" key="approved" />
        <Tabs.Tab title="抄送我的" key="cc" />
      </Tabs>

      <PullToRefresh onRefresh={handleRefresh}>
        <List>
          {list.map((item) => {
            const config = statusConfig[item.status] || statusConfig.draft

            return (
              <List.Item
                key={item.id}
                onClick={() => handleViewDetail(item.id)}
                className={styles.item}
              >
                <Card className={styles.card}>
                  <div className={styles.header}>
                    <span className={styles.title}>{item.title}</span>
                    <Tag color={config.color} className={styles.tag}>
                      {config.icon}
                      {config.text}
                    </Tag>
                  </div>
                  <div className={styles.content}>
                    <div className={styles.info}>
                      <span className={styles.businessType}>
                        {businessTypeConfig[item.business_type] || item.business_type}
                      </span>
                      <span className={styles.flow}>{item.flow?.name}</span>
                    </div>
                    <div className={styles.time}>{formatTime(item.created_at)}</div>
                    {item.applicant && activeTab !== 'my' && (
                      <div className={styles.applicant}>申请人: {item.applicant.name}</div>
                    )}
                  </div>
                </Card>
              </List.Item>
            )
          })}
        </List>
      </PullToRefresh>

      {list.length === 0 && !loading && (
        <div className={styles.empty}>
          <ExclamationCircleOutline fontSize={48} color="#cccccc" />
          <p>暂无审批记录</p>
        </div>
      )}

      <InfiniteScroll loadMore={handleLoadMore} hasMore={hasMore} />
    </div>
  )
}