new-api/model/channel.go

package model

import (
	"database/sql/driver"
	"encoding/json"
	"errors"
	"math/rand"
	"one-api/common"
	"one-api/constant"
	"one-api/dto"
	"one-api/types"
	"strings"
	"sync"

	"gorm.io/gorm"
)

type Channel struct {
	Id                 int     `json:"id"`
	Type               int     `json:"type" gorm:"default:0"`
	Key                string  `json:"key" gorm:"not null"`
	OpenAIOrganization *string `json:"openai_organization"`
	TestModel          *string `json:"test_model"`
	Status             int     `json:"status" gorm:"default:1"`
	Name               string  `json:"name" gorm:"index"`
	Weight             *uint   `json:"weight" gorm:"default:0"`
	CreatedTime        int64   `json:"created_time" gorm:"bigint"`
	TestTime           int64   `json:"test_time" gorm:"bigint"`
	ResponseTime       int     `json:"response_time"` // in milliseconds
	BaseURL            *string `json:"base_url" gorm:"column:base_url;default:''"`
	Other              string  `json:"other"`
	Balance            float64 `json:"balance"` // in USD
	BalanceUpdatedTime int64   `json:"balance_updated_time" gorm:"bigint"`
	Models             string  `json:"models"`
	Group              string  `json:"group" gorm:"type:varchar(64);default:'default'"`
	UsedQuota          int64   `json:"used_quota" gorm:"bigint;default:0"`
	ModelMapping       *string `json:"model_mapping" gorm:"type:text"`
	//MaxInputTokens     *int    `json:"max_input_tokens" gorm:"default:0"`
	StatusCodeMapping *string `json:"status_code_mapping" gorm:"type:varchar(1024);default:''"`
	Priority          *int64  `json:"priority" gorm:"bigint;default:0"`
	AutoBan           *int    `json:"auto_ban" gorm:"default:1"`
	OtherInfo         string  `json:"other_info"`
	Tag               *string `json:"tag" gorm:"index"`
	Setting           *string `json:"setting" gorm:"type:text"` // 渠道额外设置
	ParamOverride     *string `json:"param_override" gorm:"type:text"`
	// add after v0.8.5
	ChannelInfo ChannelInfo `json:"channel_info" gorm:"type:json"`
}

type ChannelInfo struct {
	IsMultiKey           bool                  `json:"is_multi_key"`            // 是否多Key模式
	MultiKeySize         int                   `json:"multi_key_size"`          // 多Key模式下的Key数量
	MultiKeyStatusList   map[int]int           `json:"multi_key_status_list"`   // key状态列表，key index -> status
	MultiKeyPollingIndex int                   `json:"multi_key_polling_index"` // 多Key模式下轮询的key索引
	MultiKeyMode         constant.MultiKeyMode `json:"multi_key_mode"`
}

// Value implements driver.Valuer interface
func (c ChannelInfo) Value() (driver.Value, error) {
	return common.Marshal(&c)
}

// Scan implements sql.Scanner interface
func (c *ChannelInfo) Scan(value interface{}) error {
	bytesValue, _ := value.([]byte)
	return common.Unmarshal(bytesValue, c)
}

func (channel *Channel) getKeys() []string {
	if channel.Key == "" {
		return []string{}
	}
	// use \n to split keys
	keys := strings.Split(strings.Trim(channel.Key, "\n"), "\n")
	return keys
}

func (channel *Channel) GetNextEnabledKey() (string, *types.NewAPIError) {
	// If not in multi-key mode, return the original key string directly.
	if !channel.ChannelInfo.IsMultiKey {
		return channel.Key, nil
	}

	// Obtain all keys (split by \n)
	keys := channel.getKeys()
	if len(keys) == 0 {
		// No keys available, return error, should disable the channel
		return "", types.NewError(errors.New("no keys available"), types.ErrorCodeChannelNoAvailableKey)
	}

	statusList := channel.ChannelInfo.MultiKeyStatusList
	// helper to get key status, default to enabled when missing
	getStatus := func(idx int) int {
		if statusList == nil {
			return common.ChannelStatusEnabled
		}
		if status, ok := statusList[idx]; ok {
			return status
		}
		return common.ChannelStatusEnabled
	}

	// Collect indexes of enabled keys
	enabledIdx := make([]int, 0, len(keys))
	for i := range keys {
		if getStatus(i) == common.ChannelStatusEnabled {
			enabledIdx = append(enabledIdx, i)
		}
	}
	// If no specific status list or none enabled, fall back to first key
	if len(enabledIdx) == 0 {
		return keys[0], nil
	}

	switch channel.ChannelInfo.MultiKeyMode {
	case constant.MultiKeyModeRandom:
		// Randomly pick one enabled key
		return keys[enabledIdx[rand.Intn(len(enabledIdx))]], nil
	case constant.MultiKeyModePolling:
		// Use channel-specific lock to ensure thread-safe polling
		lock := getChannelPollingLock(channel.Id)
		lock.Lock()
		defer lock.Unlock()

		defer func() {
			if !common.MemoryCacheEnabled {
				_ = channel.Save()
			} else {
				// CacheUpdateChannel(channel)
			}
		}()
		// Start from the saved polling index and look for the next enabled key
		start := channel.ChannelInfo.MultiKeyPollingIndex
		if start < 0 || start >= len(keys) {
			start = 0
		}
		for i := 0; i < len(keys); i++ {
			idx := (start + i) % len(keys)
			if getStatus(idx) == common.ChannelStatusEnabled {
				// update polling index for next call (point to the next position)
				channel.ChannelInfo.MultiKeyPollingIndex = (idx + 1) % len(keys)
				return keys[idx], nil
			}
		}
		// Fallback – should not happen, but return first enabled key
		return keys[enabledIdx[0]], nil
	default:
		// Unknown mode, default to first enabled key (or original key string)
		return keys[enabledIdx[0]], nil
	}
}

func (channel *Channel) GetModels() []string {
	if channel.Models == "" {
		return []string{}
	}
	return strings.Split(strings.Trim(channel.Models, ","), ",")
}

func (channel *Channel) GetGroups() []string {
	if channel.Group == "" {
		return []string{}
	}
	groups := strings.Split(strings.Trim(channel.Group, ","), ",")
	for i, group := range groups {
		groups[i] = strings.TrimSpace(group)
	}
	return groups
}

func (channel *Channel) GetOtherInfo() map[string]interface{} {
	otherInfo := make(map[string]interface{})
	if channel.OtherInfo != "" {
		err := json.Unmarshal([]byte(channel.OtherInfo), &otherInfo)
		if err != nil {
			common.SysError("failed to unmarshal other info: " + err.Error())
		}
	}
	return otherInfo
}

func (channel *Channel) SetOtherInfo(otherInfo map[string]interface{}) {
	otherInfoBytes, err := json.Marshal(otherInfo)
	if err != nil {
		common.SysError("failed to marshal other info: " + err.Error())
		return
	}
	channel.OtherInfo = string(otherInfoBytes)
}

func (channel *Channel) GetTag() string {
	if channel.Tag == nil {
		return ""
	}
	return *channel.Tag
}

func (channel *Channel) SetTag(tag string) {
	channel.Tag = &tag
}

func (channel *Channel) GetAutoBan() bool {
	if channel.AutoBan == nil {
		return false
	}
	return *channel.AutoBan == 1
}

func (channel *Channel) Save() error {
	return DB.Save(channel).Error
}

func GetAllChannels(startIdx int, num int, selectAll bool, idSort bool) ([]*Channel, error) {
	var channels []*Channel
	var err error
	order := "priority desc"
	if idSort {
		order = "id desc"
	}
	if selectAll {
		err = DB.Order(order).Find(&channels).Error
	} else {
		err = DB.Order(order).Limit(num).Offset(startIdx).Omit("key").Find(&channels).Error
	}
	return channels, err
}

func GetChannelsByTag(tag string, idSort bool) ([]*Channel, error) {
	var channels []*Channel
	order := "priority desc"
	if idSort {
		order = "id desc"
	}
	err := DB.Where("tag = ?", tag).Order(order).Find(&channels).Error
	return channels, err
}

func SearchChannels(keyword string, group string, model string, idSort bool) ([]*Channel, error) {
	var channels []*Channel
	modelsCol := "`models`"

	// 如果是 PostgreSQL，使用双引号
	if common.UsingPostgreSQL {
		modelsCol = `"models"`
	}

	baseURLCol := "`base_url`"
	// 如果是 PostgreSQL，使用双引号
	if common.UsingPostgreSQL {
		baseURLCol = `"base_url"`
	}

	order := "priority desc"
	if idSort {
		order = "id desc"
	}

	// 构造基础查询
	baseQuery := DB.Model(&Channel{}).Omit("key")

	// 构造WHERE子句
	var whereClause string
	var args []interface{}
	if group != "" && group != "null" {
		var groupCondition string
		if common.UsingMySQL {
			groupCondition = `CONCAT(',', ` + commonGroupCol + `, ',') LIKE ?`
		} else {
			// sqlite, PostgreSQL
			groupCondition = `(',' || ` + commonGroupCol + ` || ',') LIKE ?`
		}
		whereClause = "(id = ? OR name LIKE ? OR " + commonKeyCol + " = ? OR " + baseURLCol + " LIKE ?) AND " + modelsCol + ` LIKE ? AND ` + groupCondition
		args = append(args, common.String2Int(keyword), "%"+keyword+"%", keyword, "%"+keyword+"%", "%"+model+"%", "%,"+group+",%")
	} else {
		whereClause = "(id = ? OR name LIKE ? OR " + commonKeyCol + " = ? OR " + baseURLCol + " LIKE ?) AND " + modelsCol + " LIKE ?"
		args = append(args, common.String2Int(keyword), "%"+keyword+"%", keyword, "%"+keyword+"%", "%"+model+"%")
	}

	// 执行查询
	err := baseQuery.Where(whereClause, args...).Order(order).Find(&channels).Error
	if err != nil {
		return nil, err
	}
	return channels, nil
}

func GetChannelById(id int, selectAll bool) (*Channel, error) {
	channel := &Channel{Id: id}
	var err error = nil
	if selectAll {
		err = DB.First(channel, "id = ?", id).Error
	} else {
		err = DB.Omit("key").First(channel, "id = ?", id).Error
	}
	if err != nil {
		return nil, err
	}
	if channel == nil {
		return nil, errors.New("channel not found")
	}
	return channel, nil
}

func BatchInsertChannels(channels []Channel) error {
	var err error
	err = DB.Create(&channels).Error
	if err != nil {
		return err
	}
	for _, channel_ := range channels {
		err = channel_.AddAbilities()
		if err != nil {
			return err
		}
	}
	return nil
}

func BatchDeleteChannels(ids []int) error {
	//使用事务 删除channel表和channel_ability表
	tx := DB.Begin()
	err := tx.Where("id in (?)", ids).Delete(&Channel{}).Error
	if err != nil {
		// 回滚事务
		tx.Rollback()
		return err
	}
	err = tx.Where("channel_id in (?)", ids).Delete(&Ability{}).Error
	if err != nil {
		// 回滚事务
		tx.Rollback()
		return err
	}
	// 提交事务
	tx.Commit()
	return err
}

func (channel *Channel) GetPriority() int64 {
	if channel.Priority == nil {
		return 0
	}
	return *channel.Priority
}

func (channel *Channel) GetWeight() int {
	if channel.Weight == nil {
		return 0
	}
	return int(*channel.Weight)
}

func (channel *Channel) GetBaseURL() string {
	if channel.BaseURL == nil {
		return ""
	}
	return *channel.BaseURL
}

func (channel *Channel) GetModelMapping() string {
	if channel.ModelMapping == nil {
		return ""
	}
	return *channel.ModelMapping
}

func (channel *Channel) GetStatusCodeMapping() string {
	if channel.StatusCodeMapping == nil {
		return ""
	}
	return *channel.StatusCodeMapping
}

func (channel *Channel) Insert() error {
	var err error
	err = DB.Create(channel).Error
	if err != nil {
		return err
	}
	err = channel.AddAbilities()
	return err
}

func (channel *Channel) Update() error {
	var err error
	err = DB.Model(channel).Updates(channel).Error
	if err != nil {
		return err
	}
	DB.Model(channel).First(channel, "id = ?", channel.Id)
	err = channel.UpdateAbilities(nil)
	return err
}

func (channel *Channel) UpdateResponseTime(responseTime int64) {
	err := DB.Model(channel).Select("response_time", "test_time").Updates(Channel{
		TestTime:     common.GetTimestamp(),
		ResponseTime: int(responseTime),
	}).Error
	if err != nil {
		common.SysError("failed to update response time: " + err.Error())
	}
}

func (channel *Channel) UpdateBalance(balance float64) {
	err := DB.Model(channel).Select("balance_updated_time", "balance").Updates(Channel{
		BalanceUpdatedTime: common.GetTimestamp(),
		Balance:            balance,
	}).Error
	if err != nil {
		common.SysError("failed to update balance: " + err.Error())
	}
}

func (channel *Channel) Delete() error {
	var err error
	err = DB.Delete(channel).Error
	if err != nil {
		return err
	}
	err = channel.DeleteAbilities()
	return err
}

var channelStatusLock sync.Mutex

// channelPollingLocks stores locks for each channel.id to ensure thread-safe polling
var channelPollingLocks sync.Map

// getChannelPollingLock returns or creates a mutex for the given channel ID
func getChannelPollingLock(channelId int) *sync.Mutex {
	if lock, exists := channelPollingLocks.Load(channelId); exists {
		return lock.(*sync.Mutex)
	}
	// Create new lock for this channel
	newLock := &sync.Mutex{}
	actual, _ := channelPollingLocks.LoadOrStore(channelId, newLock)
	return actual.(*sync.Mutex)
}

// CleanupChannelPollingLocks removes locks for channels that no longer exist
// This is optional and can be called periodically to prevent memory leaks
func CleanupChannelPollingLocks() {
	var activeChannelIds []int
	DB.Model(&Channel{}).Pluck("id", &activeChannelIds)

	activeChannelSet := make(map[int]bool)
	for _, id := range activeChannelIds {
		activeChannelSet[id] = true
	}

	channelPollingLocks.Range(func(key, value interface{}) bool {
		channelId := key.(int)
		if !activeChannelSet[channelId] {
			channelPollingLocks.Delete(channelId)
		}
		return true
	})
}

func handlerMultiKeyUpdate(channel *Channel, usingKey string, status int) {
	keys := channel.getKeys()
	if len(keys) == 0 {
		channel.Status = status
	} else {
		var keyIndex int
		for i, key := range keys {
			if key == usingKey {
				keyIndex = i
				break
			}
		}
		if channel.ChannelInfo.MultiKeyStatusList == nil {
			channel.ChannelInfo.MultiKeyStatusList = make(map[int]int)
		}
		if status == common.ChannelStatusEnabled {
			delete(channel.ChannelInfo.MultiKeyStatusList, keyIndex)
		} else {
			channel.ChannelInfo.MultiKeyStatusList[keyIndex] = status
		}
		if len(channel.ChannelInfo.MultiKeyStatusList) >= channel.ChannelInfo.MultiKeySize {
			channel.Status = common.ChannelStatusAutoDisabled
			info := channel.GetOtherInfo()
			info["status_reason"] = "All keys are disabled"
			info["status_time"] = common.GetTimestamp()
			channel.SetOtherInfo(info)
		}
	}
}

func UpdateChannelStatus(channelId int, usingKey string, status int, reason string) bool {
	if common.MemoryCacheEnabled {
		channelStatusLock.Lock()
		defer channelStatusLock.Unlock()

		channelCache, _ := CacheGetChannel(channelId)
		if channelCache == nil {
			return false
		}
		if channelCache.ChannelInfo.IsMultiKey {
			// 如果是多Key模式，更新缓存中的状态
			handlerMultiKeyUpdate(channelCache, usingKey, status)
			CacheUpdateChannel(channelCache)
			//return true
		} else {
			// 如果缓存渠道存在，且状态已是目标状态，直接返回
			if channelCache.Status == status {
				return false
			}
			// 如果缓存渠道不存在(说明已经被禁用)，且要设置的状态不为启用，直接返回
			if status != common.ChannelStatusEnabled {
				return false
			}
			CacheUpdateChannelStatus(channelId, status)
		}
	}

	shouldUpdateAbilities := false
	defer func() {
		if shouldUpdateAbilities {
			err := UpdateAbilityStatus(channelId, status == common.ChannelStatusEnabled)
			if err != nil {
				common.SysError("failed to update ability status: " + err.Error())
			}
		}
	}()
	channel, err := GetChannelById(channelId, true)
	if err != nil {
		return false
	} else {
		if channel.Status == status {
			return false
		}

		if channel.ChannelInfo.IsMultiKey {
			beforeStatus := channel.Status
			handlerMultiKeyUpdate(channel, usingKey, status)
			if beforeStatus != channel.Status {
				shouldUpdateAbilities = true
			}
		} else {
			info := channel.GetOtherInfo()
			info["status_reason"] = reason
			info["status_time"] = common.GetTimestamp()
			channel.SetOtherInfo(info)
			channel.Status = status
			shouldUpdateAbilities = true
		}
		err = channel.Save()
		if err != nil {
			common.SysError("failed to update channel status: " + err.Error())
			return false
		}
	}
	return true
}

func EnableChannelByTag(tag string) error {
	err := DB.Model(&Channel{}).Where("tag = ?", tag).Update("status", common.ChannelStatusEnabled).Error
	if err != nil {
		return err
	}
	err = UpdateAbilityStatusByTag(tag, true)
	return err
}

func DisableChannelByTag(tag string) error {
	err := DB.Model(&Channel{}).Where("tag = ?", tag).Update("status", common.ChannelStatusManuallyDisabled).Error
	if err != nil {
		return err
	}
	err = UpdateAbilityStatusByTag(tag, false)
	return err
}

func EditChannelByTag(tag string, newTag *string, modelMapping *string, models *string, group *string, priority *int64, weight *uint) error {
	updateData := Channel{}
	shouldReCreateAbilities := false
	updatedTag := tag
	// 如果 newTag 不为空且不等于 tag，则更新 tag
	if newTag != nil && *newTag != tag {
		updateData.Tag = newTag
		updatedTag = *newTag
	}
	if modelMapping != nil && *modelMapping != "" {
		updateData.ModelMapping = modelMapping
	}
	if models != nil && *models != "" {
		shouldReCreateAbilities = true
		updateData.Models = *models
	}
	if group != nil && *group != "" {
		shouldReCreateAbilities = true
		updateData.Group = *group
	}
	if priority != nil {
		updateData.Priority = priority
	}
	if weight != nil {
		updateData.Weight = weight
	}

	err := DB.Model(&Channel{}).Where("tag = ?", tag).Updates(updateData).Error
	if err != nil {
		return err
	}
	if shouldReCreateAbilities {
		channels, err := GetChannelsByTag(updatedTag, false)
		if err == nil {
			for _, channel := range channels {
				err = channel.UpdateAbilities(nil)
				if err != nil {
					common.SysError("failed to update abilities: " + err.Error())
				}
			}
		}
	} else {
		err := UpdateAbilityByTag(tag, newTag, priority, weight)
		if err != nil {
			return err
		}
	}
	return nil
}

func UpdateChannelUsedQuota(id int, quota int) {
	if common.BatchUpdateEnabled {
		addNewRecord(BatchUpdateTypeChannelUsedQuota, id, quota)
		return
	}
	updateChannelUsedQuota(id, quota)
}

func updateChannelUsedQuota(id int, quota int) {
	err := DB.Model(&Channel{}).Where("id = ?", id).Update("used_quota", gorm.Expr("used_quota + ?", quota)).Error
	if err != nil {
		common.SysError("failed to update channel used quota: " + err.Error())
	}
}

func DeleteChannelByStatus(status int64) (int64, error) {
	result := DB.Where("status = ?", status).Delete(&Channel{})
	return result.RowsAffected, result.Error
}

func DeleteDisabledChannel() (int64, error) {
	result := DB.Where("status = ? or status = ?", common.ChannelStatusAutoDisabled, common.ChannelStatusManuallyDisabled).Delete(&Channel{})
	return result.RowsAffected, result.Error
}

func GetPaginatedTags(offset int, limit int) ([]*string, error) {
	var tags []*string
	err := DB.Model(&Channel{}).Select("DISTINCT tag").Where("tag != ''").Offset(offset).Limit(limit).Find(&tags).Error
	return tags, err
}

func SearchTags(keyword string, group string, model string, idSort bool) ([]*string, error) {
	var tags []*string
	modelsCol := "`models`"

	// 如果是 PostgreSQL，使用双引号
	if common.UsingPostgreSQL {
		modelsCol = `"models"`
	}

	baseURLCol := "`base_url`"
	// 如果是 PostgreSQL，使用双引号
	if common.UsingPostgreSQL {
		baseURLCol = `"base_url"`
	}

	order := "priority desc"
	if idSort {
		order = "id desc"
	}

	// 构造基础查询
	baseQuery := DB.Model(&Channel{}).Omit("key")

	// 构造WHERE子句
	var whereClause string
	var args []interface{}
	if group != "" && group != "null" {
		var groupCondition string
		if common.UsingMySQL {
			groupCondition = `CONCAT(',', ` + commonGroupCol + `, ',') LIKE ?`
		} else {
			// sqlite, PostgreSQL
			groupCondition = `(',' || ` + commonGroupCol + ` || ',') LIKE ?`
		}
		whereClause = "(id = ? OR name LIKE ? OR " + commonKeyCol + " = ? OR " + baseURLCol + " LIKE ?) AND " + modelsCol + ` LIKE ? AND ` + groupCondition
		args = append(args, common.String2Int(keyword), "%"+keyword+"%", keyword, "%"+keyword+"%", "%"+model+"%", "%,"+group+",%")
	} else {
		whereClause = "(id = ? OR name LIKE ? OR " + commonKeyCol + " = ? OR " + baseURLCol + " LIKE ?) AND " + modelsCol + " LIKE ?"
		args = append(args, common.String2Int(keyword), "%"+keyword+"%", keyword, "%"+keyword+"%", "%"+model+"%")
	}

	subQuery := baseQuery.Where(whereClause, args...).
		Select("tag").
		Where("tag != ''").
		Order(order)

	err := DB.Table("(?) as sub", subQuery).
		Select("DISTINCT tag").
		Find(&tags).Error

	if err != nil {
		return nil, err
	}

	return tags, nil
}

func (channel *Channel) ValidateSettings() error {
	channelParams := &dto.ChannelSettings{}
	if channel.Setting != nil && *channel.Setting != "" {
		err := json.Unmarshal([]byte(*channel.Setting), channelParams)
		if err != nil {
			return err
		}
	}
	return nil
}

func (channel *Channel) GetSetting() dto.ChannelSettings {
	setting := dto.ChannelSettings{}
	if channel.Setting != nil && *channel.Setting != "" {
		err := json.Unmarshal([]byte(*channel.Setting), &setting)
		if err != nil {
			common.SysError("failed to unmarshal setting: " + err.Error())
			channel.Setting = nil // 清空设置以避免后续错误
			_ = channel.Save()    // 保存修改
		}
	}
	return setting
}

func (channel *Channel) SetSetting(setting dto.ChannelSettings) {
	settingBytes, err := json.Marshal(setting)
	if err != nil {
		common.SysError("failed to marshal setting: " + err.Error())
		return
	}
	channel.Setting = common.GetPointer[string](string(settingBytes))
}

func (channel *Channel) GetParamOverride() map[string]interface{} {
	paramOverride := make(map[string]interface{})
	if channel.ParamOverride != nil && *channel.ParamOverride != "" {
		err := json.Unmarshal([]byte(*channel.ParamOverride), &paramOverride)
		if err != nil {
			common.SysError("failed to unmarshal param override: " + err.Error())
		}
	}
	return paramOverride
}

func GetChannelsByIds(ids []int) ([]*Channel, error) {
	var channels []*Channel
	err := DB.Where("id in (?)", ids).Find(&channels).Error
	return channels, err
}

func BatchSetChannelTag(ids []int, tag *string) error {
	// 开启事务
	tx := DB.Begin()
	if tx.Error != nil {
		return tx.Error
	}

	// 更新标签
	err := tx.Model(&Channel{}).Where("id in (?)", ids).Update("tag", tag).Error
	if err != nil {
		tx.Rollback()
		return err
	}

	// update ability status
	channels, err := GetChannelsByIds(ids)
	if err != nil {
		tx.Rollback()
		return err
	}

	for _, channel := range channels {
		err = channel.UpdateAbilities(tx)
		if err != nil {
			tx.Rollback()
			return err
		}
	}

	// 提交事务
	return tx.Commit().Error
}

// CountAllChannels returns total channels in DB
func CountAllChannels() (int64, error) {
	var total int64
	err := DB.Model(&Channel{}).Count(&total).Error
	return total, err
}

// CountAllTags returns number of non-empty distinct tags
func CountAllTags() (int64, error) {
	var total int64
	err := DB.Model(&Channel{}).Where("tag is not null AND tag != ''").Distinct("tag").Count(&total).Error
	return total, err
}

// Get channels of specified type with pagination
func GetChannelsByType(startIdx int, num int, idSort bool, channelType int) ([]*Channel, error) {
	var channels []*Channel
	order := "priority desc"
	if idSort {
		order = "id desc"
	}
	err := DB.Where("type = ?", channelType).Order(order).Limit(num).Offset(startIdx).Omit("key").Find(&channels).Error
	return channels, err
}

// Count channels of specific type
func CountChannelsByType(channelType int) (int64, error) {
	var count int64
	err := DB.Model(&Channel{}).Where("type = ?", channelType).Count(&count).Error
	return count, err
}

// Return map[type]count for all channels
func CountChannelsGroupByType() (map[int64]int64, error) {
	type result struct {
		Type  int64 `gorm:"column:type"`
		Count int64 `gorm:"column:count"`
	}
	var results []result
	err := DB.Model(&Channel{}).Select("type, count(*) as count").Group("type").Find(&results).Error
	if err != nil {
		return nil, err
	}
	counts := make(map[int64]int64)
	for _, r := range results {
		counts[r.Type] = r.Count
	}
	return counts, nil
}