package kills

import (
	"context"
	"encoding/base64"
	"fmt"
	"github.com/gin-gonic/gin"
	"log"
	"math/rand"
	"net/http"
	"time"
	"toutoukan/init/redisInit"
	"toutoukan/model/usermodel/userOrder"
	"toutoukan/services/order/killOrder/orderMq/mqproducer"
	"toutoukan/utill/luaScripts"
)

func GenerateOrderID() string {
	timestamp := time.Now().Format("20060102150405")

	randomBytes := make([]byte, 8)
	_, err := rand.Read(randomBytes)
	if err != nil {
		return fmt.Sprintf("ORD%s%011d", timestamp, time.Now().UnixNano()%100000000000)
	}

	randomStr := base64.URLEncoding.EncodeToString(randomBytes)[:11]
	return fmt.Sprintf("ORD%s%s", timestamp, randomStr)
}

func Userkill(c *gin.Context) {
	var req userOrder.UserRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数错误", "detail": err.Error()})
		return
	}
	fmt.Printf("用户%d请求购买%s", req.UserID, req.Order)

	OrderID := GenerateOrderID()

	// 1. Redis扣减库存（不变）
	result, err := redisInit.RedisClient.Eval(context.Background(), luaScripts.Luascript_forkill, []string{req.Order, "mayiming"}, 1, OrderID).Int()
	if err != nil {
		log.Printf("Redis 脚本执行错误: %v", err)
		c.JSON(500, gin.H{"error": "库存操作失败", "detail": err.Error()})
		return
	}
	if result != 1 {
		c.JSON(200, gin.H{"result": "库存不足，扣减失败"})
		return
	}

	// 2. 发送MQ消息（关键：发送失败需回滚Redis）
	msgSent := false
	defer func() {
		// 若消息未发送成功，回滚Redis库存
		if !msgSent {
			log.Printf("消息发送失败，回滚Redis库存，商品: %s，用户: %d", req.Order, req.UserID)
			// 回滚Redis：库存+1，同时移除可能的订单记录（根据Lua脚本逻辑调整）
			redisInit.RedisClient.Incr(context.Background(), req.Order)
			// 若Lua脚本中记录了订单ID（如存到set中），也需删除
			//redisInit.RedisClient.SRem(context.Background(), req.Order, OrderID)
		}
	}()

	// 发送消息（同步发送，确保拿到发送结果）
	sendErr := mqproducer.SendNormalMessage(OrderID, req.Order, req.UserID)
	if sendErr != nil {
		log.Printf("MQ消息发送失败: %v", sendErr)
		c.JSON(500, gin.H{"error": "消息发送失败", "detail": sendErr.Error()})
		return
	}

	// 消息发送成功，标记为已发送（避免defer回滚）
	msgSent = true
	c.JSON(200, gin.H{"result": "库存扣减成功"})
}