package com.xuekairui.payment.service;

import cn.hutool.core.util.IdUtil;
import com.alipay.api.AlipayClient;
import com.alipay.api.domain.AlipayTradeRefundModel;
import com.alipay.api.request.AlipayTradeRefundRequest;
import com.alipay.api.response.AlipayTradeRefundResponse;
import com.github.binarywang.wxpay.bean.request.WxPayRefundV3Request;
import com.github.binarywang.wxpay.bean.result.WxPayRefundV3Result;
import com.github.binarywang.wxpay.service.WxPayService;
import com.xuekairui.common.BusinessException;
import com.xuekairui.common.ErrorCode;
import com.xuekairui.payment.config.PaymentProperties;
import com.xuekairui.payment.enums.PaymentChannel;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;

/**
 * 支付退款服务
 *
 * <p>封装微信支付和支付宝的原路退款逻辑。
 * 用于重复支付场景：同一订单多渠道支付成功后，对第二笔及之后的支付自动发起退款。
 */
@Slf4j
@Service
@RequiredArgsConstructor
public class PaymentRefundService {

    private final PaymentProperties paymentProperties;
    @Qualifier("alipayClient")
    private final ObjectProvider<AlipayClient> alipayClientProvider;
    private final ObjectProvider<WxPayService> wxPayServiceProvider;

    /**
     * 发起原路退款
     *
     * @param channel 支付渠道：WECHAT/ALIPAY
     * @param orderNo  商户订单号
     * @param tradeNo  第三方交易号（微信 transaction_id / 支付宝 trade_no）
     * @param amount   退款金额（元）
     * @return 退款交易号（第三方退款单号）
     */
    public String refund(String channel, String orderNo, String tradeNo, BigDecimal amount) {
        String refundNo = "RF" + IdUtil.getSnowflake(1, 1).nextIdStr();

        if (paymentProperties.isMock()) {
            log.info("【模拟】重复支付退款成功: orderNo={}, tradeNo={}, refundNo={}, amount={}元",
                    orderNo, tradeNo, refundNo, amount);
            return refundNo;
        }

        PaymentChannel ch = PaymentChannel.fromCode(channel);
        if (ch == null) {
            throw new BusinessException(ErrorCode.PAY_CHANNEL_NOT_SUPPORT, "不支持的退款渠道: " + channel);
        }

        return switch (ch) {
            case WECHAT -> wechatRefund(orderNo, tradeNo, amount, refundNo);
            case ALIPAY -> alipayRefund(orderNo, tradeNo, amount, refundNo);
        };
    }

    /**
     * 微信支付退款（API v3）
     *
     * <p>调用微信支付 v3 退款接口，按原交易号原路退回。
     * 需要商户已配置退款证书（apiclient_key.pem + apiclient_cert.pem）。
     */
    private String wechatRefund(String orderNo, String tradeNo, BigDecimal amount, String refundNo) {
        WxPayService wxPayService = wxPayServiceProvider.getIfAvailable();
        if (wxPayService == null) {
            throw new BusinessException(ErrorCode.PAY_CHANNEL_NOT_CONFIGURED, "WxPayService未初始化，无法退款");
        }

        try {
            WxPayRefundV3Request request = new WxPayRefundV3Request();
            request.setOutTradeNo(orderNo);
            request.setOutRefundNo(refundNo);
            request.setReason("重复支付自动退款");

            int totalCents = amount.movePointRight(2).intValue();
            WxPayRefundV3Request.Amount amountObj = new WxPayRefundV3Request.Amount();
            amountObj.setRefund(totalCents);
            amountObj.setTotal(totalCents);
            amountObj.setCurrency("CNY");
            request.setAmount(amountObj);

            WxPayRefundV3Result result = wxPayService.refundV3(request);
            log.info("微信退款成功: orderNo={}, tradeNo={}, refundNo={}, refundId={}",
                    orderNo, tradeNo, refundNo, result.getRefundId());
            return result.getRefundId();
        } catch (Exception e) {
            log.error("微信退款失败: orderNo={}, tradeNo={}, refundNo={}", orderNo, tradeNo, refundNo, e);
            throw new BusinessException(ErrorCode.REFUND_FAILED, "微信退款失败: " + e.getMessage());
        }
    }

    /**
     * 支付宝退款（alipay.trade.refund）
     *
     * <p>调用支付宝统一收单交易退款接口，按原交易号原路退回。
     */
    private String alipayRefund(String orderNo, String tradeNo, BigDecimal amount, String refundNo) {
        AlipayClient alipayClient = alipayClientProvider.getIfAvailable();
        if (alipayClient == null) {
            throw new BusinessException(ErrorCode.PAY_CHANNEL_NOT_CONFIGURED, "AlipayClient未初始化，无法退款");
        }

        try {
            AlipayTradeRefundRequest request = new AlipayTradeRefundRequest();
            AlipayTradeRefundModel model = new AlipayTradeRefundModel();
            model.setOutTradeNo(orderNo);
            model.setTradeNo(tradeNo);
            model.setRefundAmount(amount.toPlainString());
            model.setOutRequestNo(refundNo);
            model.setRefundReason("重复支付自动退款");
            request.setBizModel(model);

            boolean publicKeyMode = paymentProperties.getAlipay().getAlipayPublicKey() != null
                    && !paymentProperties.getAlipay().getAlipayPublicKey().isBlank();
            AlipayTradeRefundResponse response = publicKeyMode
                    ? alipayClient.execute(request)
                    : alipayClient.certificateExecute(request);

            if (!response.isSuccess()) {
                log.error("支付宝退款失败: orderNo={}, tradeNo={}, refundNo={}, code={}, subCode={}, subMsg={}",
                        orderNo, tradeNo, refundNo, response.getCode(), response.getSubCode(), response.getSubMsg());
                throw new BusinessException(ErrorCode.REFUND_FAILED,
                        "支付宝退款失败: " + response.getSubMsg());
            }

            log.info("支付宝退款成功: orderNo={}, tradeNo={}, refundNo={}, tradeNo={}",
                    orderNo, tradeNo, refundNo, response.getTradeNo());
            return response.getTradeNo();
        } catch (BusinessException e) {
            throw e;
        } catch (Exception e) {
            log.error("支付宝退款异常: orderNo={}, tradeNo={}, refundNo={}", orderNo, tradeNo, refundNo, e);
            throw new BusinessException(ErrorCode.REFUND_FAILED, "支付宝退款异常: " + e.getMessage());
        }
    }
}