package luckygift

import (
	"chatapp3-golang/internal/utils"
	"context"
	"net/http"
	"strings"
	"time"

	"github.com/redis/go-redis/v9"
)

// LuckyGiftRewardDispatchEvent 是发送给 Java 房间侧统计消费者的中奖事件。
type LuckyGiftRewardDispatchEvent struct {
	EventID     string                          `json:"eventId"`
	BusinessID  string                          `json:"businessId"`
	SysOrigin   string                          `json:"sysOrigin"`
	RoomID      int64                           `json:"roomId"`
	SendUserID  int64                           `json:"sendUserId"`
	GiftID      int64                           `json:"giftId"`
	GiftPrice   int64                           `json:"giftPrice"`
	GiftNum     int64                           `json:"giftNum"`
	RewardTotal int64                           `json:"rewardTotal"`
	Results     []LuckyGiftRewardDispatchResult `json:"results"`
	PublishedAt int64                           `json:"publishedAt"`
}

// LuckyGiftRewardDispatchResult 是单个中奖子单的房间侧结算载体。
type LuckyGiftRewardDispatchResult struct {
	OrderSeed    string `json:"orderSeed"`
	AcceptUserID int64  `json:"acceptUserId"`
	RewardNum    int64  `json:"rewardNum"`
}

func (s *LuckyGiftService) publishRewardEvent(
	ctx context.Context,
	req LuckyGiftDrawRequest,
	results []LuckyGiftDrawResult,
	rewardTotal int64,
) error {
	if rewardTotal <= 0 {
		return nil
	}

	streamKey := strings.TrimSpace(s.cfg.LuckyGift.RewardStreamKey)
	if streamKey == "" {
		return NewAppError(http.StatusInternalServerError, "lucky_gift_reward_stream_not_configured", "lucky gift reward stream is not configured")
	}

	winResults := make([]LuckyGiftRewardDispatchResult, 0, len(results))
	for _, item := range results {
		if item.RewardNum <= 0 {
			continue
		}
		winResults = append(winResults, LuckyGiftRewardDispatchResult{
			OrderSeed:    item.ID,
			AcceptUserID: item.AcceptUserID,
			RewardNum:    item.RewardNum,
		})
	}
	if len(winResults) == 0 {
		return nil
	}

	event := LuckyGiftRewardDispatchEvent{
		EventID:     luckyGiftRewardEventID(req.BusinessID),
		BusinessID:  req.BusinessID,
		SysOrigin:   req.SysOrigin,
		RoomID:      req.RoomID,
		SendUserID:  req.SendUserID,
		GiftID:      req.GiftID,
		GiftPrice:   req.GiftPrice,
		GiftNum:     req.GiftNum,
		RewardTotal: rewardTotal,
		Results:     winResults,
		PublishedAt: time.Now().UnixMilli(),
	}

	_, err := s.repo.Redis.XAdd(ctx, &redis.XAddArgs{
		Stream: streamKey,
		Values: map[string]any{
			"eventId":     event.EventID,
			"businessId":  event.BusinessID,
			"payload":     utils.MustJSONString(event, "{}"),
			"publishedAt": event.PublishedAt,
		},
	}).Result()
	if err != nil {
		return NewAppError(http.StatusBadGateway, "lucky_gift_reward_stream_publish_failed", err.Error())
	}
	return nil
}

func luckyGiftRewardEventID(businessID string) string {
	return "LUCKY_GIFT_REWARD:" + strings.TrimSpace(businessID)
}