import { ElMessage } from 'element-plus'
import { selectRegion as selectRegionAPI } from '@/api/play'

export function useQrCode() {
  
  const validateQrCodeUrl = async (url) => {
    try {
      console.log('开始验证二维码URL:', url)
      
      if (!url || typeof url !== 'string') {
        console.error('无效的二维码URL:', url)
        return false
      }
      
      if (process.env.NODE_ENV === 'production') {
        console.log('生产环境跳过URL验证')
        return true
      }
      
      const controller = new AbortController()
      const timeoutId = setTimeout(() => {
        controller.abort()
        console.log('URL验证超时')
      }, 3000)
      
      const response = await fetch(url, { 
        method: 'HEAD',
        signal: controller.signal,
        mode: 'no-cors'
      })
      
      clearTimeout(timeoutId)
      console.log('URL验证响应:', response.status)
      return true
    } catch (error) {
      console.warn('二维码URL验证失败:', error.name, error.message)
      return true
    }
  }

  const fetchQrCodeAfterDelay = async (state, countdown, mecmachineId, qrCreatedAt, qrExpireAt, retryCount = 0) => {
    try {
      const qrCodeUrl = `https://uzi1.cn/image/${mecmachineId}/二维码.png?t=${Date.now()}`
      console.log(`尝试获取二维码 (第${retryCount + 1}次):`, qrCodeUrl)
      
      const isUrlValid = await validateQrCodeUrl(qrCodeUrl)
      console.log('URL验证结果:', isUrlValid)
      
      if (!isUrlValid) {
        throw new Error('二维码URL无法访问')
      }
      
      console.log('设置二维码信息:', { qrCodeUrl, qrCreatedAt, qrExpireAt })
      state.qrInfo = {
        url: qrCodeUrl,
        createdAt: qrCreatedAt,
        expireAt: qrExpireAt
      }
      
      const now = Date.now()
      const expireTime = new Date(qrExpireAt).getTime()
      countdown.value = Math.max(0, Math.floor((expireTime - now) / 1000))
      
      state.qrRetryCount = 0
      state.isWaitingQr = false
      
      console.log('二维码设置完成，countdown:', countdown.value)
      ElMessage.success('二维码已准备就绪，请扫码登录')
      
    } catch (error) {
      console.error(`二维码获取失败 (第${retryCount + 1}次):`, error.message || error)
      
      if (retryCount < state.maxQrRetries) {
        state.qrRetryCount = retryCount + 1
        const delay = state.qrRetryDelay * Math.pow(2, retryCount)
        
        console.log(`${delay}ms后进行第${retryCount + 2}次重试`)
        ElMessage.warning(`二维码获取失败，${delay/1000}秒后重试...`)
        
        setTimeout(() => {
          fetchQrCodeAfterDelay(state, countdown, mecmachineId, qrCreatedAt, qrExpireAt, retryCount + 1)
        }, delay)
      } else {
        console.error('二维码获取重试次数用完，显示错误状态')
        state.qrRetryCount = 0
        state.isWaitingQr = false
        state.qrError = `二维码获取失败，已重试${state.maxQrRetries}次。可能是网络问题或服务器繁忙，请稍后重试。`
        ElMessage.error('二维码获取失败，请点击重新获取按钮')
      }
    }
  }

  const retrySelectRegion = async (state, code, region) => {
    try {
      console.log('重试选择区域:', region)
      const response = await selectRegionAPI({ code, region })
      const data = response.data
      
      console.log('retrySelectRegion 响应数据:', data)
      return data
      
    } catch (error) {
      console.error('重试选择区域失败:', error)
      ElMessage.error('重新请求二维码失败，请手动刷新页面')
      throw error
    }
  }

  const processSelectRegionResponse = async (state, countdown, data, startCountdown, startLoginPolling, updateStateFromResponse) => {
    if (data.qrDelaySeconds && data.qrDelaySeconds > 0 && data.mecmachineId) {
      console.log('进入延迟分支')
      await updateStateFromResponse(data, true)
      
      state.qrDelaySeconds = data.qrDelaySeconds
      state.isWaitingQr = true
      console.log('设置状态:', { status: state.status, isWaitingQr: state.isWaitingQr })
      ElMessage.info(`正在准备二维码，请等待 ${data.qrDelaySeconds} 秒...`)
      
      setTimeout(async () => {
        state.isWaitingQr = false
        
        await fetchQrCodeAfterDelay(state, countdown, data.mecmachineId, data.qrCreatedAt, data.qrExpireAt)
        
        if (state.status === 'USING') {
          startCountdown()
          startLoginPolling()
        }
      }, data.qrDelaySeconds * 1000)
    } else {
      console.log('进入立即处理分支')
      await updateStateFromResponse(data)
      state.isWaitingQr = false
      console.log('设置状态:', { status: state.status, isWaitingQr: state.isWaitingQr, qrInfo: !!state.qrInfo })
      
      if (state.qrInfo && state.qrInfo.url) {
        const isUrlValid = await validateQrCodeUrl(state.qrInfo.url)
        if (!isUrlValid) {
          console.warn('立即获取的二维码URL无法访问，尝试重试')
          state.qrInfo = null
          await fetchQrCodeAfterDelay(state, countdown, data.mecmachineId, data.qrCreatedAt, data.qrExpireAt)
        }
      }
      
      if (state.status === 'USING') {
        startCountdown()
        startLoginPolling()
      }
    }
  }

  const handleQrImageError = (state, event) => {
    console.error('二维码图片加载失败:', event)
    state.qrError = '二维码图片加载失败，可能是网络问题'
    ElMessage.error('二维码图片加载失败')
  }

  const retryGetQrCode = async (state, selectRegion) => {
    if (state.submitting) return
    
    state.submitting = true
    state.qrError = null
    state.isWaitingQr = true
    state.qrRetryCount = 0
    
    try {
      if (state.region) {
        await selectRegion(state.region)
      }
    } catch (error) {
      console.error('重新获取二维码失败:', error)
      state.qrError = '重新获取失败，请刷新页面重试'
    } finally {
      state.submitting = false
    }
  }

  return {
    validateQrCodeUrl,
    fetchQrCodeAfterDelay,
    retrySelectRegion,
    processSelectRegionResponse,
    handleQrImageError,
    retryGetQrCode
  }
}