package model

import (
	"errors"
	"fmt"
	"gorm.io/gorm"
	"one-api/common"
	"one-api/constant"
	"strconv"
	"strings"
)

type Token struct {
	Id                 int            `json:"id"`
	UserId             int            `json:"user_id" gorm:"index"`
	Key                string         `json:"key" gorm:"type:char(48);uniqueIndex"`
	Status             int            `json:"status" gorm:"default:1"`
	Name               string         `json:"name" gorm:"index" `
	CreatedTime        int64          `json:"created_time" gorm:"bigint"`
	AccessedTime       int64          `json:"accessed_time" gorm:"bigint"`
	ExpiredTime        int64          `json:"expired_time" gorm:"bigint;default:-1"` // -1 means never expired
	RemainQuota        int            `json:"remain_quota" gorm:"default:0"`
	UnlimitedQuota     bool           `json:"unlimited_quota" gorm:"default:false"`
	ModelLimitsEnabled bool           `json:"model_limits_enabled" gorm:"default:false"`
	ModelLimits        string         `json:"model_limits" gorm:"type:varchar(1024);default:''"`
	UsedQuota          int            `json:"used_quota" gorm:"default:0"` // used quota
	DeletedAt          gorm.DeletedAt `gorm:"index"`
}

func GetAllUserTokens(userId int, startIdx int, num int) ([]*Token, error) {
	var tokens []*Token
	var err error
	err = DB.Where("user_id = ?", userId).Order("id desc").Limit(num).Offset(startIdx).Find(&tokens).Error
	return tokens, err
}

func SearchUserTokens(userId int, keyword string, token string) (tokens []*Token, err error) {
	if token != "" {
		token = strings.Trim(token, "sk-")
	}
	err = DB.Where("user_id = ?", userId).Where("name LIKE ?", "%"+keyword+"%").Where("`key` LIKE ?", "%"+token+"%").Find(&tokens).Error
	return tokens, err
}

func ValidateUserToken(key string) (token *Token, err error) {
	if key == "" {
		return nil, errors.New("未提供令牌")
	}
	token, err = CacheGetTokenByKey(key)
	if err == nil {
		if token.Status == common.TokenStatusExhausted {
			keyPrefix := key[:3]
			keySuffix := key[len(key)-3:]
			return nil, errors.New("该令牌额度已用尽 TokenStatusExhausted[sk-" + keyPrefix + "***" + keySuffix + "]")
		} else if token.Status == common.TokenStatusExpired {
			return nil, errors.New("该令牌已过期")
		}
		if token.Status != common.TokenStatusEnabled {
			return nil, errors.New("该令牌状态不可用")
		}
		if token.ExpiredTime != -1 && token.ExpiredTime < common.GetTimestamp() {
			if !common.RedisEnabled {
				token.Status = common.TokenStatusExpired
				err := token.SelectUpdate()
				if err != nil {
					common.SysError("failed to update token status" + err.Error())
				}
			}
			return nil, errors.New("该令牌已过期")
		}
		if !token.UnlimitedQuota && token.RemainQuota <= 0 {
			if !common.RedisEnabled {
				// in this case, we can make sure the token is exhausted
				token.Status = common.TokenStatusExhausted
				err := token.SelectUpdate()
				if err != nil {
					common.SysError("failed to update token status" + err.Error())
				}
			}
			keyPrefix := key[:3]
			keySuffix := key[len(key)-3:]
			return nil, errors.New(fmt.Sprintf("[sk-%s***%s] 该令牌额度已用尽 !token.UnlimitedQuota && token.RemainQuota = %d", keyPrefix, keySuffix, token.RemainQuota))
		}
		return token, nil
	}
	return nil, errors.New("无效的令牌")
}

func GetTokenByIds(id int, userId int) (*Token, error) {
	if id == 0 || userId == 0 {
		return nil, errors.New("id 或 userId 为空！")
	}
	token := Token{Id: id, UserId: userId}
	var err error = nil
	err = DB.First(&token, "id = ? and user_id = ?", id, userId).Error
	return &token, err
}

func GetTokenById(id int) (*Token, error) {
	if id == 0 {
		return nil, errors.New("id 为空！")
	}
	token := Token{Id: id}
	var err error = nil
	err = DB.First(&token, "id = ?", id).Error
	if err != nil {
		if common.RedisEnabled {
			go cacheSetToken(&token)
		}
	}
	return &token, err
}

func GetTokenByKey(key string) (*Token, error) {
	keyCol := "`key`"
	if common.UsingPostgreSQL {
		keyCol = `"key"`
	}
	var token Token
	err := DB.Where(keyCol+" = ?", key).First(&token).Error
	return &token, err
}

func (token *Token) Insert() error {
	var err error
	err = DB.Create(token).Error
	return err
}

// Update Make sure your token's fields is completed, because this will update non-zero values
func (token *Token) Update() error {
	var err error
	err = DB.Model(token).Select("name", "status", "expired_time", "remain_quota", "unlimited_quota", "model_limits_enabled", "model_limits").Updates(token).Error
	return err
}

func (token *Token) SelectUpdate() error {
	// This can update zero values
	return DB.Model(token).Select("accessed_time", "status").Updates(token).Error
}

func (token *Token) Delete() error {
	var err error
	err = DB.Delete(token).Error
	return err
}

func (token *Token) IsModelLimitsEnabled() bool {
	return token.ModelLimitsEnabled
}

func (token *Token) GetModelLimits() []string {
	if token.ModelLimits == "" {
		return []string{}
	}
	return strings.Split(token.ModelLimits, ",")
}

func (token *Token) GetModelLimitsMap() map[string]bool {
	limits := token.GetModelLimits()
	limitsMap := make(map[string]bool)
	for _, limit := range limits {
		limitsMap[limit] = true
	}
	return limitsMap
}

func DisableModelLimits(tokenId int) error {
	token, err := GetTokenById(tokenId)
	if err != nil {
		return err
	}
	token.ModelLimitsEnabled = false
	token.ModelLimits = ""
	return token.Update()
}

func DeleteTokenById(id int, userId int) (err error) {
	// Why we need userId here? In case user want to delete other's token.
	if id == 0 || userId == 0 {
		return errors.New("id 或 userId 为空！")
	}
	token := Token{Id: id, UserId: userId}
	err = DB.Where(token).First(&token).Error
	if err != nil {
		return err
	}
	return token.Delete()
}

func IncreaseTokenQuota(id int, quota int) (err error) {
	if quota < 0 {
		return errors.New("quota 不能为负数！")
	}
	if common.BatchUpdateEnabled {
		addNewRecord(BatchUpdateTypeTokenQuota, id, quota)
		return nil
	}
	return increaseTokenQuota(id, quota)
}

func increaseTokenQuota(id int, quota int) (err error) {
	err = DB.Model(&Token{}).Where("id = ?", id).Updates(
		map[string]interface{}{
			"remain_quota":  gorm.Expr("remain_quota + ?", quota),
			"used_quota":    gorm.Expr("used_quota - ?", quota),
			"accessed_time": common.GetTimestamp(),
		},
	).Error
	return err
}

func DecreaseTokenQuota(id int, quota int) (err error) {
	if quota < 0 {
		return errors.New("quota 不能为负数！")
	}
	if common.BatchUpdateEnabled {
		addNewRecord(BatchUpdateTypeTokenQuota, id, -quota)
		return nil
	}
	return decreaseTokenQuota(id, quota)
}

func decreaseTokenQuota(id int, quota int) (err error) {
	err = DB.Model(&Token{}).Where("id = ?", id).Updates(
		map[string]interface{}{
			"remain_quota":  gorm.Expr("remain_quota - ?", quota),
			"used_quota":    gorm.Expr("used_quota + ?", quota),
			"accessed_time": common.GetTimestamp(),
		},
	).Error
	return err
}

func PreConsumeTokenQuota(tokenId int, quota int) (userQuota int, err error) {
	if quota < 0 {
		return 0, errors.New("quota 不能为负数！")
	}
	token, err := GetTokenById(tokenId)
	if err != nil {
		return 0, err
	}
	if !token.UnlimitedQuota && token.RemainQuota < quota {
		return 0, errors.New("令牌额度不足")
	}
	userQuota, err = GetUserQuota(token.UserId)
	if err != nil {
		return 0, err
	}
	if userQuota < quota {
		return 0, errors.New(fmt.Sprintf("用户额度不足，剩余额度为 %d", userQuota))
	}
	if !token.UnlimitedQuota {
		err = DecreaseTokenQuota(tokenId, quota)
		if err != nil {
			return 0, err
		}
	}
	err = DecreaseUserQuota(token.UserId, quota)
	return userQuota - quota, err
}

func PostConsumeTokenQuota(tokenId int, userQuota int, quota int, preConsumedQuota int, sendEmail bool) (err error) {
	token, err := GetTokenById(tokenId)

	if quota > 0 {
		err = DecreaseUserQuota(token.UserId, quota)
	} else {
		err = IncreaseUserQuota(token.UserId, -quota)
	}
	if err != nil {
		return err
	}

	if !token.UnlimitedQuota {
		if quota > 0 {
			err = DecreaseTokenQuota(tokenId, quota)
		} else {
			err = IncreaseTokenQuota(tokenId, -quota)
		}
		if err != nil {
			return err
		}
	}

	if sendEmail {
		if (quota + preConsumedQuota) != 0 {
			quotaTooLow := userQuota >= common.QuotaRemindThreshold && userQuota-(quota+preConsumedQuota) < common.QuotaRemindThreshold
			noMoreQuota := userQuota-(quota+preConsumedQuota) <= 0
			if quotaTooLow || noMoreQuota {
				go func() {
					email, err := GetUserEmail(token.UserId)
					if err != nil {
						common.SysError("failed to fetch user email: " + err.Error())
					}
					prompt := "您的额度即将用尽"
					if noMoreQuota {
						prompt = "您的额度已用尽"
					}
					if email != "" {
						topUpLink := fmt.Sprintf("%s/topup", constant.ServerAddress)
						err = common.SendEmail(prompt, email,
							fmt.Sprintf("%s，当前剩余额度为 %d，为了不影响您的使用，请及时充值。<br/>充值链接：<a href='%s'>%s</a>", prompt, userQuota, topUpLink, topUpLink))
						if err != nil {
							common.SysError("failed to send email" + err.Error())
						}
						common.SysLog("user quota is low, consumed quota: " + strconv.Itoa(quota) + ", user quota: " + strconv.Itoa(userQuota))
					}
				}()
			}
		}
	}

	return nil
}