'use client'

import React, { useEffect, useState } from 'react'
import { Result, Button, Spin, Card } from 'antd'
import { CheckCircleOutlined, CloseCircleOutlined, LoadingOutlined } from '@ant-design/icons'
import { useRouter, useSearchParams } from 'next/navigation'
import { getCheckoutSessionStatus, PaymentStatusResponse } from '@/lib/stripe'

/**
 * 支付状态枚举
 */
enum PaymentStatus {
  LOADING = 'loading',
  SUCCESS = 'success',
  FAILED = 'failed'
}

/**
 * 支付回调页面组件
 * 处理Stripe Checkout支付完成后的状态展示和用户操作
 */
export default function PayCallbackPage() {
  const router = useRouter()
  const searchParams = useSearchParams()
  const [paymentStatus, setPaymentStatus] = useState<PaymentStatus>(PaymentStatus.LOADING)
  const [paymentInfo, setPaymentInfo] = useState<any>(null)
  const callBackUrl = localStorage.getItem('callBackUrl') || '/'

  /**
   * 获取Stripe Checkout Session支付状态
   */
  const fetchPaymentStatus = async () => {
    try {
      // 从URL参数获取session_id和user_id
      const sessionId = searchParams.get('session_id')
      const userId = searchParams.get('user_id')

      if (!sessionId || !userId) {
        throw new Error('缺少必要的参数: session_id 或 user_id')
      }

      // 调用真实的Stripe API获取支付状态
      const response = await getCheckoutSessionStatus(sessionId, userId)

      if (response.successful && response.data) {
        const { payment_status, biz_order_no, pay_time, subscription } = response.data

        if (payment_status === 'success') {
          setPaymentStatus(PaymentStatus.SUCCESS)
          setPaymentInfo({
            orderId: biz_order_no,
            sessionId,
            paymentTime: pay_time,
            subscription: subscription ? {
              planName: subscription.plan_name,
              planDisplayName: subscription.plan_display_name,
              status: subscription.status,
              currentPeriodEnd: subscription.current_period_end
            } : null
          })
        } else if (payment_status === 'fail') {
          setPaymentStatus(PaymentStatus.FAILED)
          setPaymentInfo({
            orderId: biz_order_no,
            sessionId,
            errorMessage: '支付处理失败，请重试'
          })
        } else {
          // pending状态，继续等待
          setTimeout(fetchPaymentStatus, 2000)
        }
      } else {
        throw new Error(response.message || '获取支付状态失败')
      }
    } catch (error) {
      console.error('获取支付状态失败:', error)
      setPaymentStatus(PaymentStatus.FAILED)
      setPaymentInfo({
        errorMessage: error instanceof Error ? error.message : '网络错误，无法获取支付状态'
      })
    }
  }

  /**
   * 返回上一页的函数
   */
  const handleGoBack = () => {
    router.push(callBackUrl)
  }

  /**
   * 重新支付的函数
   */
  const handleRetryPayment = () => {
    router.push('/pricing')
  }

  useEffect(() => {
    fetchPaymentStatus()
  }, [])

  // 加载状态
  if (paymentStatus === PaymentStatus.LOADING) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-black">
        <div className="w-96 text-center bg-black border border-white/20 rounded-lg p-8">
          <Spin
            indicator={<LoadingOutlined style={{ fontSize: 48, color: 'white' }} spin />}
            size="large"
          />
          <div className="mt-6 text-lg text-white">正在获取支付状态...</div>
          <div className="mt-2 text-sm text-white/70">请稍候，我们正在处理您的支付信息</div>
        </div>
      </div>
    )
  }

  // 支付成功状态
  if (paymentStatus === PaymentStatus.SUCCESS) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-black">
        <div className="w-[32rem] text-center bg-black border border-white/20 rounded-lg p-8">
          <div className="mb-6">
            <CheckCircleOutlined className="text-white text-6xl mb-4" />
            <h1 className="text-white text-2xl font-bold mb-2">支付成功！</h1>
            <p className="text-white/70 text-base">{`订单号: ${paymentInfo?.orderId || 'N/A'}`}</p>
          </div>

          <div className="text-center text-white/70 mb-8 space-y-2">
            {paymentInfo?.subscription && (
              <>
                <p>订阅计划: {paymentInfo.subscription.planDisplayName}</p>
                <p>订阅状态: {paymentInfo.subscription.status}</p>
                {paymentInfo.subscription.currentPeriodEnd && (
                  <p>到期时间: {new Date(paymentInfo.subscription.currentPeriodEnd).toLocaleString()}</p>
                )}
              </>
            )}
            {paymentInfo?.paymentTime && (
              <p>支付时间: {new Date(paymentInfo.paymentTime).toLocaleString()}</p>
            )}
            <p>感谢您的购买！</p>
          </div>

          <Button
            type="primary"
            size="large"
            onClick={handleGoBack}
            data-alt="back-to-previous-page-button"
            className="w-full h-12 bg-white text-black hover:bg-white/90 border border-white/20"
          >
            返回上一页
          </Button>
        </div>
      </div>
    )
  }

  // 支付失败状态
  return (
    <div className="min-h-screen flex items-center justify-center bg-black">
      <div className="w-[32rem] text-center bg-black border border-white/20 rounded-lg p-8">
        <div className="mb-6">
          <CloseCircleOutlined className="text-white text-6xl mb-4" />
          <h1 className="text-white text-2xl font-bold mb-2">支付失败</h1>
          <p className="text-white/70 text-base">{paymentInfo?.errorMessage || '支付处理过程中发生错误'}</p>
        </div>

        <div className="text-center text-white/70 mb-8 space-y-2">
          <p>订单号: {paymentInfo?.orderId || 'N/A'}</p>
          <p>如果问题持续存在，请联系客服</p>
        </div>

        <div className="space-y-3">
          <Button
            type="primary"
            size="large"
            onClick={handleRetryPayment}
            data-alt="retry-payment-button"
            className="w-full h-12 bg-white text-black hover:bg-white/90 border border-white/20"
          >
            重新支付
          </Button>

          <Button
            size="large"
            onClick={handleGoBack}
            data-alt="back-to-previous-page-button"
            className="w-full h-12 bg-black text-white hover:bg-white hover:text-black border border-white/20"
          >
            返回上一页
          </Button>
        </div>
      </div>
    </div>
  )
}