package model

import (
	"errors"
	"fmt"
	"github.com/codinl/go-logger"
	"github.com/jinzhu/gorm"
	"time"
)

const (
	//VmEventExchangeGoods = "exchange_goods"
	VmEventBuyGoods             = "buy_goods"              // 购买商品积分抵扣
	VmEventBuyGoodsReject       = "buy_goods_reject"       // 购买商品积分抵扣取消
	VmEventOpenMember           = "open_member"            // 开通租卡会员奖励
	VmEventRenewMember          = "renew_member"           // 续费租卡会员奖励
	VmEventUpgradeMember        = "upgrade_member"         // 升级租卡会员奖励
	VmEventInvite1Member        = "invite_1_member"        // 邀请会员奖励
	VmEventInvite2Member        = "invite_2_member"        // 邀请会员奖励
	VmEventAttendance           = "attendance"             // 签到获取积分
	VmEventErpOrderSale         = "erp_order_sale"         // 零售销售获得积分
	VmEventErpOrderReject       = "erp_order_reject"       // 零售退货扣除积分
	VmEventOpenPrivilegeMember  = "open_privilege_member"  // 开通尊享会员奖励
	VmEventRenewPrivilegeMember = "renew_privilege_member" // 续费尊享会员奖励
)

// 用户积分
// gen:qs
//
//go:generate goqueryset -in user_vm.go
type UserVm struct {
	Model

	Uid uint32 `json:"uid" gorm:"column:uid;unique_index"`
	Vm  uint32 `json:"vm"`
}

// 用户积分-变动记录
// gen:qs
type UserVmRecord struct {
	Model

	Uid        uint32     `json:"uid" gorm:"column:uid;index"`
	BeforeVm   uint32     `json:"before_vm"`                      // 变动前
	AfterVm    uint32     `json:"after_vm"`                       // 变动后
	Alter      int        `json:"alter"`                          // 数值
	Event      string     `json:"event" gorm:"type:varchar(100)"` // 事件
	Describe   string     `json:"describe" gorm:"type:text"`      // 描述
	ErpOrderId uint32     `json:"erp_order_id" gorm:"index"`      // 零售订单id
	BillSn     string     `json:"bill_sn"`                        // 零售订单编号
	ExpiryDate *time.Time `json:"expiry_date"`                    // 积分过期时间
	UsedVm     int        `json:"used_vm"`                        // 已使用积分
	ExpiryVm   int        `json:"expiry_vm"  gorm:"-"`            // 即将过期的积分
}

func UserVmUpdate(uid uint32, amount int, event, describe string) error {
	var userVm UserVm
	err := NewUserVmQuerySet(DB).UidEq(uid).One(&userVm)
	if err != nil && err != RecordNotFound {
		logger.Error("err:", err)
		return err
	}
	begin := DB.Begin()
	if err == RecordNotFound {
		if amount < 0 {
			begin.Rollback()
			logger.Error("amount lt 0")
			return errors.New("amount lt 0")
		}
		userVm = UserVm{
			Uid: uid,
			Vm:  uint32(amount),
		}
		err = begin.Create(&userVm).Error
		if err != nil {
			begin.Rollback()
			logger.Error("err:", err)
			return err
		}
	} else {
		// 如果用户积分不够抵扣，则扣到0为止
		if int(userVm.Vm)+amount <= 0 {
			sql := fmt.Sprintf("UPDATE user_vm SET vm = ? WHERE uid=?")
			err = begin.Exec(sql, 0, uid).Error
		} else {
			sql := fmt.Sprintf("UPDATE user_vm SET vm = vm+? WHERE uid=?")
			err = begin.Exec(sql, amount, uid).Error
		}
		if err != nil {
			begin.Rollback()
			logger.Error("err:", err)
			return err
		}
	}

	vmRecord := &UserVmRecord{
		Uid:      uid,
		BeforeVm: uint32(userVm.Vm),
		AfterVm:  uint32(int(userVm.Vm) + amount),
		Alter:    amount,
		Event:    event,
		Describe: describe,
	}

	if newValue := int(userVm.Vm) + amount; newValue > 0 {
		vmRecord.AfterVm = uint32(newValue)
	}

	// 如果是正积分，则记录该订单对应积分的有效时间
	if amount > 0 {
		expireTime := time.Now().AddDate(1, 0, 0)
		vmRecord.ExpiryDate = &expireTime
		if event == VmEventBuyGoodsReject { // 使用积分购买商品后取消
			err = RefundPoints(begin, uid, amount)
			if err != nil {
				begin.Rollback()
				logger.Error("err:", err)
				return err
			}
		}
	} else { // 如果是负积分，则记录积分使用情况；优先扣除最早获得的积分
		if event == VmEventBuyGoods || event == VmEventErpOrderReject { // 使用积分购买商品，或者零售退货扣除积分
			err = UsePoints(begin, uid, -amount)
			if err != nil {
				begin.Rollback()
				logger.Error("err:", err)
				return err
			}
		}
	}

	err = begin.Create(vmRecord).Error
	if err != nil {
		begin.Rollback()
		logger.Error("err:", err)
		return err
	}

	err = begin.Commit().Error
	if err != nil {
		begin.Rollback()
		logger.Error("err:", err)
		return err
	}
	return nil
}

// GetUserAvailablePointsRecords 查找用户的所有可用积分记录，按时间排序
func GetUserAvailablePointsRecords(uid uint32) []UserVmRecord {
	var userVmRecord []UserVmRecord
	err := NewUserVmRecordQuerySet(DB).UidEq(uid).OrderDescByCreatedAt().
		EventIn(VmEventOpenMember, VmEventInvite1Member, VmEventInvite2Member, VmEventRenewMember, VmEventUpgradeMember,
			VmEventAttendance, VmEventErpOrderSale).All(&userVmRecord)
	if err != nil {
		logger.Error("get user_vm_record err:", err)
		return []UserVmRecord{}
	}

	return userVmRecord
}

func UsePoints(gdb *gorm.DB, uid uint32, points int) error {
	// 1. 查找用户的所有可用积分记录，按时间排序
	records := GetUserAvailablePointsRecords(uid)

	remaining := points

	for _, record := range records {
		if record.ExpiryDate != nil && record.ExpiryDate.IsZero() {
			record.ExpiryDate = nil
		}
		available := record.Alter - record.UsedVm // 计算该订单剩余可用积分
		if available >= remaining {
			// 该订单的剩余积分足够
			record.UsedVm += remaining
			// 更新积分记录
			err := gdb.Model(&record).Where("id = ?", record.ID).Updates(record).Error
			if err != nil {
				logger.Error("update user_vm_record err:", err)
				return err
			}
			break
		} else {
			// 该订单的剩余积分不足，全部使用，继续扣减下一条记录
			record.UsedVm = record.Alter
			remaining -= available
			// 更新积分记录
			err := gdb.Model(&record).Where("id = ?", record.ID).Updates(record).Error
			if err != nil {
				logger.Error("update user_vm_record err:", err)
				return err
			}
		}
	}

	return nil
}

// GetUserUsedPointsRecords 查找用户的已使用积分记录，按使用时间倒序排序
func GetUserUsedPointsRecords(uid uint32) []UserVmRecord {
	var userVmRecord []UserVmRecord
	err := NewUserVmRecordQuerySet(DB).UidEq(uid).OrderDescByCreatedAt().
		EventIn(VmEventOpenMember, VmEventInvite1Member, VmEventInvite2Member, VmEventRenewMember, VmEventUpgradeMember,
			VmEventAttendance, VmEventErpOrderSale).UsedVmNe(0).All(&userVmRecord)
	if err != nil {
		logger.Error("get user_vm_record err:", err)
		return []UserVmRecord{}
	}

	return userVmRecord
}

// RefundPoints 查找用户的已使用积分记录，按使用时间倒序排序
func RefundPoints(gdb *gorm.DB, uid uint32, points int) error {
	// 1. 查找用户的已使用积分记录，按使用时间倒序排序
	usedRecords := GetUserUsedPointsRecords(uid)

	remaining := points

	for _, record := range usedRecords {
		used := record.UsedVm // 获取该订单已使用的积分

		if used >= remaining {
			// 该订单已使用的积分足够返还
			record.UsedVm -= remaining
			// 更新积分记录
			err := gdb.Model(&record).Where("id = ?", record.ID).Updates(record).Error
			if err != nil {
				logger.Error("RefundPoints update user_vm_record err:", err)
				return err
			}
			break
		} else {
			// 该订单已使用的积分不足以完全返还，全部返还后继续处理下一条记录
			record.UsedVm = 0
			remaining -= used
			// 更新积分记录
			err := gdb.Model(&record).Where("id = ?", record.ID).Updates(record).Error
			//err := gdb.Omit("created_at").Save(record).Error
			if err != nil {
				logger.Error("RefundPoints update user_vm_record err:", err)
				return err
			}
		}
	}

	return nil
}