package wechat

import (
	"context"
	"fmt"
	"time"

	"github.com/ArtisanCloud/PowerWeChat/v3/src/payment/refund/request"
)

// RefundOrder 调用微信支付 v3 退款接口（全额退款）
// orderSn: 商户订单号；transactionID: 微信支付单号（二选一，有则优先用 transactionID）；totalCents: 订单金额（分）；reason: 退款原因
func RefundOrder(ctx context.Context, orderSn, transactionID string, totalCents int, reason string) error {
	if paymentApp == nil || paymentApp.Refund == nil {
		return fmt.Errorf("支付/退款未初始化")
	}
	if totalCents <= 0 {
		return fmt.Errorf("退款金额必须大于 0")
	}
	outRefundNo := fmt.Sprintf("RF%s%06d", time.Now().Format("20060102150405"), time.Now().UnixNano()%1000000)
	if reason == "" {
		reason = "用户申请退款"
	}
	req := &request.RequestRefund{
		OutRefundNo: outRefundNo,
		Reason:      reason,
		Amount: &request.RefundAmount{
			Refund:   totalCents,
			Total:    totalCents,
			Currency: "CNY",
			From:     []*request.RefundAmountFrom{},
		},
	}
	if transactionID != "" {
		req.TransactionID = transactionID
	} else {
		req.OutTradeNo = orderSn
	}
	_, err := paymentApp.Refund.Refund(ctx, req)
	return err
}