import React, { useEffect, useState } from 'react';
import { useParams, useNavigate, useLocation } from 'react-router-dom';
import { Button, message, Result, Spin } from 'antd';
import { WechatOutlined, AlipayCircleOutlined, CheckCircleOutlined } from '@ant-design/icons';
import { QRCodeSVG } from 'qrcode.react';
import { getOrder, initiatePayment, confirmPayment, nativePay, queryOrderStatus } from '../api';
import './Payment.css';

const Payment = () => {
  const { orderId: initialOrderId } = useParams();
  const navigate = useNavigate();
  const location = useLocation();
  const [currentOrderId, setCurrentOrderId] = useState(location.state?.order_id || initialOrderId);
  const [order, setOrder] = useState(location.state?.orderInfo || null);
  const [codeUrl, setCodeUrl] = useState(location.state?.codeUrl || null);
  const [loading, setLoading] = useState(!location.state?.orderInfo && !location.state?.codeUrl);
  const [paying, setPaying] = useState(!!location.state?.codeUrl);
  const [paySuccess, setPaySuccess] = useState(false);
  const [paymentMethod, setPaymentMethod] = useState('wechat');

  useEffect(() => {
    if (codeUrl && !paying) {
      setPaying(true);
    }
  }, [codeUrl]);

  useEffect(() => {
    console.log('Payment page state:', { currentOrderId, order, codeUrl, paying });
    if (!order && !codeUrl) {
      fetchOrder();
    }
  }, [currentOrderId]);

  useEffect(() => {
    if (paying && !codeUrl && order) {
      handlePay();
    }
  }, [paying, codeUrl, order]);

  // 轮询订单状态
  useEffect(() => {
    let timer;
    if (paying && !paySuccess) {
      timer = setInterval(async () => {
        try {
          const response = await queryOrderStatus(currentOrderId);
          if (response.data.status === 'paid') {
            setPaySuccess(true);
            setPaying(false);
            clearInterval(timer);
          }
        } catch (error) {
          console.error('Check payment status failed:', error);
        }
      }, 3000);
    }
    return () => clearInterval(timer);
  }, [paying, paySuccess, currentOrderId]);

  const fetchOrder = async () => {
    try {
      const response = await getOrder(currentOrderId);
      setOrder(response.data);
    } catch (error) {
      console.error('Failed to fetch order:', error);
      // Fallback if getOrder API fails (404/405), we might show basic info or error
      // Assuming for now it works or we handle it
      message.error('无法获取订单信息，请重试');
    } finally {
      setLoading(false);
    }
  };

  const handlePay = async () => {
    if (paymentMethod === 'alipay') {
        message.info('暂未开通支付宝支付，请使用微信支付');
        return;
    }

    if (codeUrl) {
      setPaying(true);
      return;
    }

    if (!order) {
      message.error('正在加载订单信息，请稍后...');
      return;
    }

    setPaying(true);
    try {
      const orderData = {
        goodid: order.config || order.goodid,
        quantity: order.quantity,
        customer_name: order.customer_name,
        phone_number: order.phone_number,
        shipping_address: order.shipping_address,
        ref_code: order.ref_code
      };
      
      const response = await nativePay(orderData);
      setCodeUrl(response.data.code_url);
      if (response.data.order_id) {
        setCurrentOrderId(response.data.order_id);
      }
      message.success('支付二维码已生成');
    } catch (error) {
      console.error(error);
      message.error('生成支付二维码失败，请重试');
      setPaying(false);
    }
  };

  if (loading) return <div style={{ padding: 50, textAlign: 'center' }}><Spin size="large" /><div style={{ marginTop: 20 }}>正在加载订单信息...</div></div>;

  if (paySuccess) {
    return (
      <div className="payment-container" style={{ borderColor: '#00b96b' }}>
        <Result
          status="success"
          icon={<CheckCircleOutlined style={{ color: '#00b96b' }} />}
          title={<span style={{ color: '#fff' }}>支付成功</span>}
          subTitle={<span style={{ color: '#888' }}>订单 {currentOrderId} 已完成支付，我们将尽快为您发货。</span>}
          extra={[
            <Button type="primary" key="home" onClick={() => navigate('/')}>
              返回首页
            </Button>,
          ]}
        />
      </div>
    );
  }

  return (
    <div className="payment-container">
      <div className="payment-title">收银台</div>
      
      {order ? (
        <>
          <div className="payment-amount">¥{order.total_price}</div>
          <div className="payment-info">
            <p><strong>订单编号：</strong> {order.id}</p>
            <p><strong>商品名称：</strong> {order.config_name || 'AI 硬件设备'}</p>
            <p><strong>收货人：</strong> {order.customer_name}</p>
          </div>
        </>
      ) : (
        <div className="payment-info">
           <p>订单 ID: {currentOrderId}</p>
           <p>无法加载详情，但您可以尝试支付。</p>
        </div>
      )}

      <div style={{ color: '#fff', marginBottom: 15, textAlign: 'left' }}>选择支付方式：</div>
      <div className="payment-method">
        <div 
          className={`payment-method-item ${paymentMethod === 'wechat' ? 'active' : ''}`}
          onClick={() => setPaymentMethod('wechat')}
        >
          <WechatOutlined style={{ color: '#09BB07', fontSize: 24, verticalAlign: 'middle', marginRight: 8 }} />
          微信支付
        </div>
        <div 
          className={`payment-method-item ${paymentMethod === 'alipay' ? 'active' : ''}`}
          onClick={() => setPaymentMethod('alipay')}
        >
          <AlipayCircleOutlined style={{ color: '#1677FF', fontSize: 24, verticalAlign: 'middle', marginRight: 8 }} />
          支付宝
        </div>
      </div>

      {paying && (
        <div style={{ margin: '20px 0', padding: 20, background: '#fff', borderRadius: 8, display: 'inline-block', minWidth: 240, minHeight: 280 }}>
           {codeUrl ? (
              <>
                <div style={{ background: '#fff', padding: '10px', borderRadius: '4px', display: 'inline-block' }}>
                  <QRCodeSVG value={codeUrl} size={200} />
                </div>
                <p style={{ color: '#000', marginTop: 15, fontWeight: 'bold', fontSize: 18 }}>请使用微信扫码支付</p>
                <p style={{ color: '#666', fontSize: 14 }}>支付完成后将自动跳转</p>
              </>
            ) : (
             <div style={{ padding: '40px 0', textAlign: 'center' }}>
               <Spin />
               <div style={{ marginTop: 10 }}>正在生成支付二维码...</div>
             </div>
           )}
        </div>
      )}

      {!paying && (
        <Button 
          type="primary" 
          size="large" 
          block 
          onClick={handlePay} 
          style={{ height: 50, fontSize: 18, background: paymentMethod === 'wechat' ? '#09BB07' : '#1677FF' }}
        >
          立即支付
        </Button>
      )}
    </div>
  );
};

export default Payment;