package activityclient

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"time"

	"91porn-server/app/appg"
	"91porn-server/common"
	"91porn-server/common/httputil"
	"91porn-server/common/log"
)

// 抵扣券状态回调(与 activity-public-server /api/app/deduct/coupon/notify 约定一致)。
// 券状态流转由本服双回调驱动：建单成功->used、支付成功->verified。
const (
	DeductCouponStatusUsed     = "used"     // 建单成功: 券 active -> used(下单占用/已使用)，需携 deductAmount
	DeductCouponStatusVerified = "verified" // 支付成功: 券 used -> verified(已核销)，usedCount++
	DeductCouponStatusFailed   = "failed"   // 支付失败: 券 used -> active(释放)
	DeductCouponStatusClosed   = "closed"   // 订单关闭/超时: 券 used -> active(释放)
)

const deductCouponNotifyPath = "/api/app/deduct/coupon/notify"

// deductCouponNotifyReq 支付结果回调请求体
type deductCouponNotifyReq struct {
	CouponID     string `json:"couponId"`               // 下单时收到的券号，原样回传
	OrderID      string `json:"orderId,omitempty"`      // 本服订单号，活动服存档对账用
	Status       string `json:"status"`                 // paid/failed/closed
	DeductAmount int64  `json:"deductAmount,omitempty"` // 实际抵扣金额(分)，对账用
}

// NotifyDeductCoupon 向活动服回调抵扣券支付结果。
// 鉴权走方向B(X-Svc-*)，密钥用 secretKey 原始字节(BuildSvcHeaders 已按此实现)。
// 单次调用；活动服对 couponId 幂等，重复回调安全。
// 返回 nil 表示活动服已受理(HTTP 200 且 body.code==200)。
func NotifyDeductCoupon(ctx context.Context, couponID, orderID, status string, deductAmount int64) error {
	conf := appg.Conf.ActivityServer
	if conf.ApiUrl == "" || conf.AppId == "" {
		return fmt.Errorf("活动服配置缺失(apiUrl/appId)")
	}
	if couponID == "" {
		return fmt.Errorf("couponId 为空")
	}

	body, err := json.Marshal(deductCouponNotifyReq{
		CouponID:     couponID,
		OrderID:      orderID,
		Status:       status,
		DeductAmount: deductAmount,
	})
	if err != nil {
		return fmt.Errorf("marshal notify body failed: %w", err)
	}

	// 签名针对下面实际发送的 body 字节；httputil 对 []byte 原样透传，两者一致
	headers := BuildSvcHeaders(conf.AppId, conf.SecretKey, "POST", deductCouponNotifyPath, "", body)
	if headers == nil {
		return fmt.Errorf("生成服务间签名头失败")
	}
	headers["Content-Type"] = "application/json"

	resp, err := httputil.DefaultClientPostWithCtx(ctx, conf.ApiUrl+deductCouponNotifyPath, headers, body)
	if err != nil {
		return fmt.Errorf("请求活动服失败: %w", err)
	}
	defer resp.Body.Close()
	respBody, _ := io.ReadAll(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("活动服回调HTTP状态异常: %d, body: %s", resp.StatusCode, string(respBody))
	}
	var out struct {
		Code int    `json:"code"`
		Msg  string `json:"msg"`
	}
	if err := json.Unmarshal(respBody, &out); err != nil {
		return fmt.Errorf("解析活动服回调响应失败: %w, body: %s", err, string(respBody))
	}
	if out.Code != 200 {
		return fmt.Errorf("活动服回调返回非成功: code=%d, msg=%s", out.Code, out.Msg)
	}
	return nil
}

// NotifyDeductCouponAsync 异步回调抵扣券状态，失败按 1s/3s/5s/10s 退避重试。
// 独立 goroutine 执行，不阻塞下单/支付主流程；最终仍失败仅记录错误——
// 活动服会在 used 券超 30 分钟未核销时由定时任务兜底释放回 active，不会丢一致性。
func NotifyDeductCouponAsync(couponID, orderID, status string, deductAmount int64) {
	if couponID == "" {
		return
	}
	common.Go(func() {
		backoffs := []time.Duration{0, time.Second, 3 * time.Second, 5 * time.Second, 10 * time.Second}
		var lastErr error
		for i, d := range backoffs {
			if d > 0 {
				time.Sleep(d)
			}
			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
			lastErr = NotifyDeductCoupon(ctx, couponID, orderID, status, deductAmount)
			cancel()
			if lastErr == nil {
				if i > 0 {
					log.Info("活动服-抵扣券回调重试成功",
						log.Any("couponId", couponID), log.Any("status", status), log.Any("attempt", i+1))
				}
				return
			}
			log.Warn("活动服-抵扣券回调失败,待重试",
				log.Any("couponId", couponID), log.Any("orderId", orderID),
				log.Any("status", status), log.Any("attempt", i+1), log.E(lastErr))
		}
		log.Error("活动服-抵扣券回调最终失败(依赖活动服到期兜底释放)",
			log.Any("couponId", couponID), log.Any("orderId", orderID),
			log.Any("status", status), log.Any("deductAmount", deductAmount), log.E(lastErr))
	})
}