import React, { useState } from 'react'
import { View, Text } from '@tarojs/components'
import { Card, Button, Tag } from '@nutui/nutui-react-taro'
import { Scan, Success, Failure, ArrowLeft } from '@nutui/icons-react-taro'
import Taro from '@tarojs/taro'
import { confirmWechatQRLogin, parseQRContent } from '@/api/passport/qr-login'

enum ScanType {
  LOGIN = 'login',
  UNKNOWN = 'unknown',
}

interface ScanRecord {
  id: number
  time: string
  success: boolean
  type: ScanType
  message: string
  raw?: string
}

const UnifiedQRPage: React.FC = () => {
  const [loading, setLoading] = useState(false)
  const [lastRecord, setLastRecord] = useState<ScanRecord | null>(null)
  const [scanHistory, setScanHistory] = useState<ScanRecord[]>([])

  const pushHistory = (record: ScanRecord) => {
    setLastRecord(record)
    setScanHistory((prev) => [record, ...prev.slice(0, 4)])
  }

  const handleGoBack = () => {
    Taro.navigateBack()
  }

  const buildRecord = (success: boolean, type: ScanType, message: string, raw?: string): ScanRecord => ({
    id: Date.now(),
    time: new Date().toLocaleString(),
    success,
    type,
    message,
    raw,
  })

  const handleLoginScan = async (raw: string) => {
    const token = parseQRContent(raw)
    const userId = Number(Taro.getStorageSync('UserId') || 0)

    if (!token) {
      throw new Error('未识别到可登录的二维码内容')
    }
    if (!userId) {
      throw new Error('请先登录小程序账号后再扫码')
    }

    const result = await confirmWechatQRLogin(token, userId)
    if (result?.status !== 'confirmed') {
      throw new Error(result?.message || '二维码登录确认失败')
    }

    return '登录确认成功'
  }

  const handleStartScan = async () => {
    if (loading) return

    try {
      setLoading(true)
      const res = await Taro.scanCode({ scanType: ['qrCode'] })
      const raw = (res.result || '').trim()

      if (!raw) {
        throw new Error('扫码结果为空')
      }

      const token = parseQRContent(raw)
      if (token) {
        const message = await handleLoginScan(raw)
        pushHistory(buildRecord(true, ScanType.LOGIN, message, raw))
        Taro.showToast({ title: message, icon: 'success' })
        return
      }

      const unsupportedMessage = '当前版本仅支持登录二维码，核销能力待补充'
      pushHistory(buildRecord(false, ScanType.UNKNOWN, unsupportedMessage, raw))
      Taro.showToast({ title: unsupportedMessage, icon: 'none' })
    } catch (error: any) {
      const message =
        error?.errMsg?.includes('cancel')
          ? '已取消扫码'
          : error?.message || '扫码失败'

      pushHistory(buildRecord(false, ScanType.UNKNOWN, message))
      if (message !== '已取消扫码') {
        Taro.showToast({ title: message, icon: 'none' })
      }
    } finally {
      setLoading(false)
    }
  }

  const getTypeTag = (type: ScanType) => {
    if (type === ScanType.LOGIN) {
      return <Tag type='success'>登录</Tag>
    }
    return <Tag type='primary'>其他</Tag>
  }

  return (
    <View className='unified-qr-page min-h-screen bg-gray-50'>
      <View className='bg-white px-4 py-3 border-b border-gray-100 flex items-center'>
        <ArrowLeft className='text-gray-600 mr-3' size='20' onClick={handleGoBack} />
        <View className='flex-1'>
          <Text className='text-lg font-bold'>统一扫码</Text>
          <Text className='text-sm text-gray-600 block'>先恢复登录扫码，后续再补齐核销流程</Text>
        </View>
      </View>

      <Card className='m-4'>
        <View className='text-center py-6'>
          <Scan className='text-blue-500 mx-auto mb-4' size='48' />
          <Text className='text-lg font-medium text-gray-800 mb-2 block'>扫码入口</Text>
          <Text className='text-gray-600 mb-6 block'>当前可识别网页登录二维码，其他码先给出明确提示</Text>
          <Button
            type='primary'
            size='large'
            loading={loading}
            disabled={loading}
            onClick={handleStartScan}
            className='w-full'
          >
            {loading ? '扫码中...' : '开始扫码'}
          </Button>
        </View>
      </Card>

      {lastRecord && (
        <Card className='mx-4 mb-4'>
          <View className='flex items-start'>
            <View className='mr-3 mt-1'>
              {lastRecord.success ? (
                <Success className='text-green-500' size='18' />
              ) : (
                <Failure className='text-red-500' size='18' />
              )}
            </View>
            <View className='flex-1'>
              <View className='flex items-center justify-between mb-2'>
                <Text className='font-medium'>最近一次结果</Text>
                {getTypeTag(lastRecord.type)}
              </View>
              <Text className='text-sm text-gray-800 block mb-1'>{lastRecord.message}</Text>
              <Text className='text-xs text-gray-500 block'>{lastRecord.time}</Text>
            </View>
          </View>
        </Card>
      )}

      {scanHistory.length > 0 && (
        <Card className='mx-4 mb-4'>
          <Text className='font-medium block mb-3'>扫码记录</Text>
          {scanHistory.map((item) => (
            <View key={item.id} className='py-2 border-b border-gray-100' style={item === scanHistory[scanHistory.length - 1] ? { borderBottom: 'none' } : undefined}>
              <View className='flex items-center justify-between mb-1'>
                <Text className='text-sm text-gray-800'>{item.message}</Text>
                {getTypeTag(item.type)}
              </View>
              <Text className='text-xs text-gray-500 block'>{item.time}</Text>
            </View>
          ))}
        </Card>
      )}
    </View>
  )
}

export default UnifiedQRPage