package payment

import (
	"context"
	"crypto/subtle"
	"fmt"
	"net/http"
	"time"

	"git.apinb.com/heqiapp/platforms/backend/api/internal/config"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/impl"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/models"
	"github.com/gin-gonic/gin"
	"github.com/smartwalle/alipay/v3"
)

// CloseExpired 批量关闭已过期的渠道支付单；单笔失败留待下一轮安全重试。
func CloseExpired(ctx context.Context, limit int) (int, error) {
	var orders []models.PaymentOrder
	if err := impl.DBService.Where("payment_status = ? AND expires_at <= ?", StatusPending, time.Now()).Order("expires_at asc").Limit(limit).Find(&orders).Error; err != nil {
		return 0, err
	}
	closed := 0
	for _, order := range orders {
		if err := closeChannelOrder(ctx, order); err != nil {
			continue
		}
		now := time.Now()
		result := impl.DBService.Model(&models.PaymentOrder{}).Where("id = ? AND payment_status = ?", order.ID, StatusPending).Updates(map[string]any{"payment_status": StatusClosed, "closed_at": &now})
		if result.Error == nil && result.RowsAffected == 1 {
			closed++
		}
	}
	return closed, nil
}

func closeChannelOrder(ctx context.Context, order models.PaymentOrder) error {
	if order.Channel == "alipay" {
		client, err := alipayClient()
		if err != nil {
			return err
		}
		_, err = client.TradeClose(ctx, alipay.TradeClose{OutTradeNo: order.PaymentNo})
		return err
	}
	if order.Channel == "wechat" {
		client, err := wechatClient(ctx)
		if err != nil {
			return err
		}
		_, err = client.Post(ctx, fmt.Sprintf("https://api.mch.weixin.qq.com/v3/pay/transactions/out-trade-no/%s/close", order.PaymentNo), map[string]string{"mchid": config.Spec.Payment.Wechat.MerchantID})
		return err
	}
	return nil
}

// CloseExpiredHandler 只接受 Worker 共享凭证，不暴露为平台用户动作。
func CloseExpiredHandler(ctx *gin.Context) {
	expected := config.Spec.Payment.InternalServiceToken
	actual := ctx.GetHeader("X-Heqi-Worker-Token")
	if expected == "" || len(actual) != len(expected) || subtle.ConstantTimeCompare([]byte(actual), []byte(expected)) != 1 {
		ctx.AbortWithStatus(http.StatusUnauthorized)
		return
	}
	count, err := CloseExpired(ctx, 100)
	if err != nil {
		ctx.JSON(http.StatusInternalServerError, gin.H{"error": "close expired payments failed"})
		return
	}
	ctx.JSON(http.StatusOK, gin.H{"closed": count})
}