hd/services/red_envelope/red_envelop.go

package red_envelope_service

import (
	"errors"
	"hudongzhuanjia/models"
	"hudongzhuanjia/utils"
	"hudongzhuanjia/utils/define"
	"math/rand"
	"time"

	"github.com/ouxuanserver/osmanthuswine/src/core"
)

func GetCurrentRB(aid, uid, rid int, archId int) (map[string]interface{}, error) {
	// 信息 一轮只能有一个
	rule := new(models.ShakeRedEnvelopeRule)
	exist, err := rule.GetCurrent(aid)
	if err != nil {
		return nil, err
	}
	if exist {
		shakeUser := new(models.ShakeRedEnvelopeUser)
		exist, err := shakeUser.Exist(uid, rule.Id, archId, rid)
		if err != nil {
			return nil, err
		}
		if !exist {
			shakeUser.UserId = uid
			shakeUser.ArchId = archId
			shakeUser.ShakeRedEnvelopeActivityId = rule.ShakeRedEnvelopeActivityId
			shakeUser.ShakeRedEnvelopeRuleId = rule.Id
			shakeUser.RehearsalId = rid
			shakeUser.CreatedAt = time.Now()
			shakeUser.UpdateAt = time.Now()
			shakeUser.IsDelete = 0
			_, err = models.Add(shakeUser)
			if err != nil {
				return nil, err
			}
		}
		return map[string]interface{}{
			"rule": rule,
		}, nil
	}
	return nil, errors.New("尚未开启轮次")
	// 记录一下参与人数
}

const (
	MinRedPackAmount = 100   // 1块钱
	MaxRedPackAmount = 20000 // 200块钱
)

func GenRedPack(amount, num int) []int {
	sumMoney := 0
	redPacks := make([]int, 0)
	maxMoney := MaxRedPackAmount
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for i := 0; i < num; i++ {
		maxMoney = (amount - sumMoney) / (num - i)
		if maxMoney > MaxRedPackAmount {
			maxMoney = MaxRedPackAmount
		}
		money := r.Int()
		if money < MinRedPackAmount {
			money = MinRedPackAmount
		} else if money > MaxRedPackAmount {
			money = MaxRedPackAmount
		}

		// 剩余红包的限制
		rate := (amount - sumMoney - money) / (num - i)
		if rate <= MinRedPackAmount {
			money = MinRedPackAmount
		} else if rate >= MaxRedPackAmount {
			money = MaxRedPackAmount
		}

		if num-i == 1 { // 最后一个
			money = amount - sumMoney
		}
		sumMoney += money
		redPacks = append(redPacks, money)
	}
	return redPacks
}

// 提前生成红包
func GenRedEnvelope(aid int, name string, rid int, rule *models.ShakeRedEnvelopeRule, archId int) error {
	// 判断红包是否存在
	// 根据算法提前生成红包
	r := rand.New(rand.NewSource(time.Now().Unix()))
	if rule.Model == define.SHAKERB_RULE_RANDOM { // 随机红包
		// 检测红包是否存在
		randSum := int(rule.RandSum * 100)
		sumMoney := 0
		maxMoney := MaxRedPackAmount
		if randSum/rule.RedEnvelopeNum <= MinRedPackAmount && randSum/rule.RedEnvelopeNum >= MaxRedPackAmount {
			return errors.New("每个红包的平均金额必须在1.00元到200.00元之间")
		}
		for i := 0; i < rule.RedEnvelopeNum; i++ {
			// 前置判断每次循环是否存在最小值
			//最大可领金额 = 剩余金额的平均值x2 = (剩余金额 / 剩余数量) * 2
			maxMoney = (randSum - sumMoney) / (rule.RedEnvelopeNum - i)
			if maxMoney > MaxRedPackAmount {
				maxMoney = MaxRedPackAmount
			}
			money := r.Intn(maxMoney)
			if money < MinRedPackAmount { // 随机的金额可能小于1块钱
				money = MinRedPackAmount
			} else if money > MaxRedPackAmount {
				money = MaxRedPackAmount
			}

			// 提前预判剩余红包和红包的金额比例 ==> money/num <= 0.01
			rate := (randSum - sumMoney - money) / (rule.RedEnvelopeNum - i)
			if rate <= MinRedPackAmount {
				money = MinRedPackAmount
			} else if rate >= MaxRedPackAmount {
				money = MaxRedPackAmount
			}

			if rule.RedEnvelopeNum-i == 1 {
				money = randSum - sumMoney
			}
			record := new(models.ShakeRedEnvelopeRecord)
			record.ActivityId = aid
			record.Name = name
			record.RehearsalId = rid
			record.ShakeRedEnvelopeActivityId = rule.ShakeRedEnvelopeActivityId
			record.ShakeRedEnvelopeRuleId = rule.Id
			record.Amount = utils.Float64CusDecimal(float64(money)/float64(100), 2)
			record.IsDraw = -1
			record.ArchId = archId

			if _, err := models.Add(record); err != nil {
				return err
			}
			sumMoney += money
		}
	} else if rule.Model == define.SHAKERB_RULE_COMMON { // 普通红包
		for i := 0; i < rule.RedEnvelopeNum; i++ {
			record := new(models.ShakeRedEnvelopeRecord)
			record.ActivityId = aid
			record.Name = name
			record.RehearsalId = rid
			record.ShakeRedEnvelopeActivityId = rule.ShakeRedEnvelopeActivityId
			record.ShakeRedEnvelopeRuleId = rule.Id
			record.Amount = rule.Single
			record.IsDraw = -1
			record.ArchId = archId
			if _, err := models.Add(record); err != nil {
				return err
			}
		}
	} else if rule.Model == define.SHAKERB_RULE_LADDER { // 阶梯红包
		ladders := make([]*models.ShakeRedEnvelopeRuleLadder, 0)
		err := core.GetXormAuto().Where("is_delete=0 and shake_red_envelope_rule_id=?", rule.Id).
			Desc("created_at").Find(&ladders)
		if err != nil {
			return err
		}
		for _, ladder := range ladders {
			for i := 0; i < int(ladder.RedEnvelopeNum); i++ {
				record := new(models.ShakeRedEnvelopeRecord)
				record.ActivityId = aid
				record.Name = name
				record.RehearsalId = rid
				record.ShakeRedEnvelopeActivityId = rule.ShakeRedEnvelopeActivityId
				record.ShakeRedEnvelopeRuleId = rule.Id
				record.Amount = ladder.Single
				record.IsDraw = -1
				record.ArchId = archId
				if _, err := models.Add(record); err != nil {
					return err
				}
			}
		}
	}
	return nil
}