telegabber/telegram/commands.go

package telegram

import (
	"fmt"
	"github.com/pkg/errors"
	"sort"
	"strconv"
	"strings"
	"time"
	"unicode"

	"dev.narayana.im/narayana/telegabber/xmpp/gateway"

	log "github.com/sirupsen/logrus"
	"github.com/zelenin/go-tdlib/client"
)

const unknownCommand string = "Unknown command"
const notEnoughArguments string = "Not enough arguments"
const TelegramNotInitialized string = "Telegram connection is not initialized yet"
const TelegramAuthDone string = "Authorization is done already"
const notOnline string = "Not online"

var permissionsAdmin = client.ChatAdministratorRights{
	CanChangeInfo:      true,
	CanPostMessages:    true,
	CanEditMessages:    true,
	CanDeleteMessages:  true,
	CanInviteUsers:     true,
	CanRestrictMembers: true,
	CanPinMessages:     true,
	CanPromoteMembers:  false,
}
var permissionsMember = client.ChatPermissions{
	CanSendBasicMessages:  true,
	CanSendAudios:         true,
	CanSendDocuments:      true,
	CanSendPhotos:         true,
	CanSendVideos:         true,
	CanSendVideoNotes:     true,
	CanSendVoiceNotes:     true,
	CanSendPolls:          true,
	CanSendOtherMessages:  true,
	CanAddWebPagePreviews: true,
	CanChangeInfo:         true,
	CanInviteUsers:        true,
	CanPinMessages:        true,
	CanManageTopics:       true,
}
var permissionsReadonly = client.ChatPermissions{}

var transportCommands = map[string]command{
	"help":        command{0, []string{}, "help", nil},
	"login":       command{1, []string{"phone"}, "sign in", nil},
	"logout":      command{0, []string{}, "sign out", nil},
	"cancelauth":  command{0, []string{}, "quit the signin wizard", nil},
	"code":        command{1, []string{"xxxxx"}, "check one-time code", nil},
	"password":    command{1, []string{"********"}, "check 2fa password", nil},
	"setusername": command{0, []string{"@username"}, "update @username", nil},
	"setname":     command{1, []string{"first", "last"}, "update name", nil},
	"setbio":      command{0, []string{"Lorem ipsum"}, "update about", nil},
	"setpassword": command{0, []string{"old", "new"}, "set or remove password", nil},
	"config":      command{0, []string{"param", "value"}, "view or update configuration options", nil},
	"report":      command{2, []string{"chat", "comment"}, "report a chat by id or @username", nil},
	"add":         command{1, []string{"@username"}, "add @username to your chat list", nil},
	"join":        command{1, []string{"https://t.me/invite_link"}, "join to chat via invite link or @publicname", nil},
	"supergroup":  command{1, []string{"title", "description"}, "create new supergroup «title» with «description»", nil},
	"channel":     command{1, []string{"title", "description"}, "create new channel «title» with «description»", nil},
}

var notForGroups = []ChatType{ChatTypeBasicGroup, ChatTypeSupergroup, ChatTypeChannel}
var notForPM = []ChatType{ChatTypePrivate, ChatTypeSecret}
var notForPMAndBasic = []ChatType{ChatTypePrivate, ChatTypeSecret, ChatTypeBasicGroup}
var onlyForSecret = []ChatType{ChatTypePrivate, ChatTypeBasicGroup, ChatTypeSupergroup, ChatTypeChannel}

var chatCommands = map[string]command{
	"help":       command{0, []string{}, "help", nil},
	"d":          command{0, []string{"n"}, "delete your last message(s)", nil},
	"s":          command{1, []string{"edited message"}, "edit your last message", nil},
	"silent":     command{1, []string{"message"}, "send a message without sound", nil},
	"schedule":   command{2, []string{"{online | 2006-01-02T15:04:05 | 15:04:05}", "message"}, "schedules a message either to timestamp or to whenever the user goes online", nil},
	"forward":    command{2, []string{"message_id", "target_chat"}, "forwards a message", nil},
	"vcard":      command{0, []string{}, "print vCard as text", nil},
	"add":        command{1, []string{"@username"}, "add @username to your chat list", nil},
	"join":       command{1, []string{"https://t.me/invite_link"}, "join to chat via invite link or @publicname", nil},
	"group":      command{1, []string{"title"}, "create groupchat «title» with current user", &notForGroups},
	"supergroup": command{1, []string{"title", "description"}, "create new supergroup «title» with «description»", nil},
	"channel":    command{1, []string{"title", "description"}, "create new channel «title» with «description»", nil},
	"secret":     command{0, []string{}, "create secretchat with current user", &notForGroups},
	"search":     command{0, []string{"string", "[limit]"}, "search <string> in current chat", nil},
	"history":    command{0, []string{"limit"}, "get last [limit] messages from current chat", nil},
	"block":      command{0, []string{}, "blacklist current user", &notForGroups},
	"unblock":    command{0, []string{}, "unblacklist current user", &notForGroups},
	"invite":     command{1, []string{"id or @username"}, "add user to current chat", &notForPM},
	"link":       command{0, []string{}, "get invite link for current chat", &notForPM},
	"kick":       command{1, []string{"id or @username"}, "remove user from current chat", &notForPM},
	"mute":       command{1, []string{"id or @username", "hours"}, "mute user in current chat", &notForPMAndBasic},
	"unmute":     command{1, []string{"id or @username"}, "unrestrict user from current chat", &notForPMAndBasic},
	"ban":        command{1, []string{"id or @username", "hours"}, "restrict @username from current chat for [hours] or forever", &notForPM},
	"unban":      command{1, []string{"id or @username"}, "unbans @username in current chat (and devotes from admins)", &notForPM},
	"promote":    command{1, []string{"id or @username", "title"}, "promote user to admin in current chat", &notForPM},
	"leave":      command{0, []string{}, "leave current chat", &notForPM},
	"leave!":     command{0, []string{}, "leave current chat (for owners)", &notForPM},
	"ttl":        command{0, []string{"seconds"}, "set secret chat messages TTL before self-destroying", &onlyForSecret},
	"close":      command{0, []string{}, "close current secret chat", &onlyForSecret},
	"delete":     command{0, []string{}, "delete current chat from chat list", nil},
	"members":    command{0, []string{"query"}, "search members [by optional query] in current chat (requires admin rights)", nil},
}

var transportConfigurationOptions = map[string]configurationOption{
	"timezone":    configurationOption{"<timezone>", "adjust timezone for Telegram user statuses (example: +02:00)"},
	"keeponline":  configurationOption{"<bool>", "always keep telegram session online and rely on jabber offline messages (example: true)"},
	"rawmessages": configurationOption{"<bool>", "do not add additional info (message id, origin etc.) to incoming messages (example: true)"},
}

type command struct {
	RequiredArgs int
	Arguments    []string
	Description  string
	NotFor       *[]ChatType
}
type configurationOption struct {
	arguments   string
	description string
}

// CommandType disinguishes command sets by chat
type CommandType int

const (
	CommandTypeTransport CommandType = iota
	CommandTypeChat
)

// GetCommands exposes the set of commands
func GetCommands(typ CommandType) map[string]command {
	var commandMap map[string]command

	switch typ {
	case CommandTypeTransport:
		commandMap = transportCommands
	case CommandTypeChat:
		commandMap = chatCommands
	}

	return commandMap
}

// GetCommand obtains one command
func GetCommand(typ CommandType, cmd string) (command, bool) {
	commands := GetCommands(typ)
	command, ok := commands[cmd]
	return command, ok
}

// SortedCommandKeys sorts a slice with command keys
func SortedCommandKeys(commandMap map[string]command) []string {
	keys := make([]string, len(commandMap))

	i := 0
	for k := range commandMap {
		keys[i] = k
		i++
	}

	sort.Strings(keys)

	return keys
}

// CommandToHelpString builds a text description of a command
func CommandToHelpString(name string, cmd command) string {
	var str strings.Builder

	str.WriteString("/")
	str.WriteString(name)
	for i, arg := range cmd.Arguments {
		optional := i >= cmd.RequiredArgs
		str.WriteString(" ")
		if optional {
			str.WriteString("[")
		}
		str.WriteString(arg)
		if optional {
			str.WriteString("]")
		}
	}
	str.WriteString(" — ")
	str.WriteString(cmd.Description)

	return str.String()
}

// IsCommandFor checks the suitability of a command for a chat type
func IsCommandForChatType(cmd command, chatType ChatType) bool {
	if cmd.NotFor != nil {
		for _, typ := range *cmd.NotFor {
			if chatType == typ {
				return false
			}
		}
	}

	return true
}

func (c *Client) helpString(typ CommandType, chatId int64) string {
	var str strings.Builder

	commandMap := GetCommands(typ)
	chatType, chatTypeErr := c.GetChatType(chatId)

	str.WriteString("Available commands:\n")
	for _, name := range SortedCommandKeys(commandMap) {
		command := commandMap[name]
		if chatTypeErr == nil && !IsCommandForChatType(command, chatType) {
			continue
		}
		str.WriteString(CommandToHelpString(name, command))
		str.WriteString("\n")
	}

	if typ == CommandTypeTransport {
		str.WriteString("Configuration options\n")
		for name, option := range transportConfigurationOptions {
			str.WriteString(name)
			str.WriteString(" ")
			str.WriteString(option.arguments)
			str.WriteString(" — ")
			str.WriteString(option.description)
			str.WriteString("\n")
		}
	}
	str.WriteString("\nYou may use ! instead of / if it conflicts with internal commands of a client")

	return str.String()
}

func parseCommand(cmdline string) (string, []string) {
	bodyFields := strings.Fields(cmdline)
	return bodyFields[0][1:], bodyFields[1:]
}

func rawCmdArguments(cmdline string, start uint8) string {
	var state uint
	//  /cmd   ababa galamaga
	// 01   2  3    45
	startState := uint(3 + 2*start)
	for i, r := range cmdline {
		isOdd := state%2 == 1
		isSpace := unicode.IsSpace(r)
		if (!isOdd && !isSpace) || (isOdd && isSpace) {
			state += 1
		}
		if state == startState {
			return cmdline[i:]
		}
	}
	return ""
}

func keyValueString(key, value string) string {
	return fmt.Sprintf("%s: %s", key, value)
}

func (c *Client) unsubscribe(chatID int64) error {
	args := gateway.SimplePresence(chatID, "unsubscribed")
	return c.sendPresence(args...)
}

func (c *Client) sendMessagesReverse(chatID int64, messages []*client.Message) {
	for i := len(messages) - 1; i >= 0; i-- {
		message := messages[i]
		reply, _ := c.getMessageReply(message, false, true)

		gateway.SendMessage(
			c.jid,
			strconv.FormatInt(chatID, 10),
			c.formatMessage(0, 0, false, message),
			strconv.FormatInt(message.Id, 10),
			c.xmpp,
			reply,
			"",
			false,
			false,
		)
	}
}

func (c *Client) usernameOrIDToID(username string) (int64, error) {
	userID, err := strconv.ParseInt(username, 10, 64)
	// couldn't parse the id, try to lookup as a username
	if err != nil {
		chat, err := c.client.SearchPublicChat(&client.SearchPublicChatRequest{
			Username: username,
		})
		if err != nil {
			return 0, err
		}

		userID = chat.Id
		if userID <= 0 {
			return 0, errors.New("Not a user")
		}
	}

	return userID, nil
}

// ProcessTransportCommand executes a command sent directly to the component
// and returns a response
func (c *Client) ProcessTransportCommand(cmdline string, resource string) string {
	cmd, args := parseCommand(cmdline)
	command, ok := transportCommands[cmd]
	if !ok {
		return unknownCommand
	}
	if len(args) < command.RequiredArgs {
		return notEnoughArguments
	}

	switch cmd {
	case "login", "code", "password":
		if cmd == "login" && c.Session.Login != "" {
			return "Phone number already provided, use /cancelauth to start over"
		}

		if cmd == "login" {
			err := c.TryLogin(resource, args[0])
			if err != nil {
				return err.Error()
			}

			c.locks.authorizerWriteLock.Lock()
			defer c.locks.authorizerWriteLock.Unlock()

			c.authorizer.PhoneNumber <- args[0]
		} else {
			c.locks.authorizerWriteLock.Lock()
			defer c.locks.authorizerWriteLock.Unlock()

			if c.authorizer == nil {
				return TelegramNotInitialized
			}

			if c.authorizer.isClosed {
				return TelegramAuthDone
			}

			switch cmd {
			// check auth code
			case "code":
				c.authorizer.Code <- args[0]
			// check auth password
			case "password":
				c.authorizer.Password <- args[0]
			}
		}
	// sign out
	case "logout":
		if !c.Online() {
			return notOnline
		}

		for _, id := range c.cache.ChatsKeys() {
			c.unsubscribe(id)
		}

		_, err := c.client.LogOut()
		if err != nil {
			c.forceClose()
			return errors.Wrap(err, "Logout error").Error()
		}

		c.Session.Login = ""
	// cancel auth
	case "cancelauth":
		if c.Online() {
			return "Not allowed when online, use /logout instead"
		}
		c.cancelAuth()
		return "Cancelled"
	// set @username
	case "setusername":
		if !c.Online() {
			return notOnline
		}

		var username string
		if len(args) > 0 {
			username = args[0]
		}

		_, err := c.client.SetUsername(&client.SetUsernameRequest{
			Username: username,
		})
		if err != nil {
			return errors.Wrap(err, "Couldn't set username").Error()
		}
	// set My Name
	case "setname":
		firstname := args[0]
		var lastname string

		if firstname == "" {
			return "The name should contain at least one character"
		}
		if len(args) > 1 {
			lastname = rawCmdArguments(cmdline, 1)
		}

		c.locks.authorizerWriteLock.Lock()
		if c.authorizer != nil && !c.authorizer.isClosed {
			c.authorizer.FirstName <- firstname
			c.authorizer.LastName <- lastname
			c.locks.authorizerWriteLock.Unlock()
		} else {
			c.locks.authorizerWriteLock.Unlock()
			if !c.Online() {
				return notOnline
			}

			_, err := c.client.SetName(&client.SetNameRequest{
				FirstName: firstname,
				LastName:  lastname,
			})
			if err != nil {
				return errors.Wrap(err, "Couldn't set name").Error()
			}
		}
	// set About
	case "setbio":
		if !c.Online() {
			return notOnline
		}

		_, err := c.client.SetBio(&client.SetBioRequest{
			Bio: rawCmdArguments(cmdline, 0),
		})
		if err != nil {
			return errors.Wrap(err, "Couldn't set bio").Error()
		}
	// set password
	case "setpassword":
		if !c.Online() {
			return notOnline
		}

		var oldPassword string
		var newPassword string
		// 0 or 1 argument is ignored and the password is reset
		if len(args) > 1 {
			oldPassword = args[0]
			newPassword = args[1]
		}
		_, err := c.client.SetPassword(&client.SetPasswordRequest{
			OldPassword: oldPassword,
			NewPassword: newPassword,
		})
		if err != nil {
			return errors.Wrap(err, "Couldn't set password").Error()
		}
	case "config":
		if len(args) > 1 {
			var msg string
			if gateway.MessageOutgoingPermissionVersion == 0 && args[0] == "carbons" && args[1] == "true" {
				return "The server did not allow to enable carbons"
			}
			if !c.Session.RawMessages && args[0] == "nativeedits" && args[1] == "true" {
				return "nativeedits only works with rawmessages as of yet, enable it first"
			}
			if c.Session.NativeEdits && args[0] == "rawmessages" && args[1] == "false" {
				_, err := c.Session.Set("nativeedits", "false")
				if err != nil {
					return err.Error()
				}
				msg = "Automatically disabling nativeedits too...\n"
			}

			value, err := c.Session.Set(args[0], args[1])
			if err != nil {
				return err.Error()
			}
			gateway.DirtySessions = true

			return fmt.Sprintf("%s%s set to %s", msg, args[0], value)
		} else if len(args) > 0 {
			value, err := c.Session.Get(args[0])
			if err != nil {
				return err.Error()
			}

			return fmt.Sprintf("%s is set to %s", args[0], value)
		}

		var entries []string
		for key, value := range c.Session.ToMap() {
			entries = append(entries, fmt.Sprintf("%s is set to %s", key, value))
		}

		return strings.Join(entries, "\n")
	case "report":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error()
		}

		text := rawCmdArguments(cmdline, 1)
		_, err = c.client.ReportChat(&client.ReportChatRequest{
			ChatId: contact.Id,
			Reason: &client.ReportReasonCustom{},
			Text:   text,
		})
		if err != nil {
			return err.Error()
		} else {
			return "Reported"
		}
	case "add":
		return c.cmdAdd(args)
	case "join":
		return c.cmdJoin(args)
	case "supergroup":
		return c.cmdSupergroup(args, cmdline)
	case "channel":
		return c.cmdChannel(args, cmdline)
	case "help":
		return c.helpString(CommandTypeTransport, 0)
	}

	return ""
}

// ProcessChatCommand executes a command sent in a mapped chat
// and returns a response and the status of command support
func (c *Client) ProcessChatCommand(chatID int64, cmdline string) (string, bool) {
	if !c.Online() {
		return notOnline, true
	}

	cmd, args := parseCommand(cmdline)
	command, ok := chatCommands[cmd]
	if !ok {
		return unknownCommand, false
	}
	if len(args) < command.RequiredArgs {
		return notEnoughArguments, true
	}

	chatType, chatTypeErr := c.GetChatType(chatID)
	if chatTypeErr == nil && !IsCommandForChatType(command, chatType) {
		return "Not applicable for this chat type", true
	}

	switch cmd {
	// delete message
	case "d":
		if c.me == nil {
			return "@me is not initialized", true
		}

		var limit int32
		if len(args) > 0 {
			limit64, err := strconv.ParseInt(args[0], 10, 32)
			if err != nil {
				return err.Error(), true
			}
			limit = int32(limit64)
		} else {
			limit = 1
		}

		messages, err := c.getLastMessages(chatID, "", c.me.Id, limit)
		if err != nil {
			return err.Error(), true
		}
		log.Debugf("pre-deletion query: %#v %#v", messages, messages.Messages)

		var messageIds []int64
		for _, message := range messages.Messages {
			if message != nil {
				messageIds = append(messageIds, message.Id)
			}
		}

		_, err = c.client.DeleteMessages(&client.DeleteMessagesRequest{
			ChatId:     chatID,
			MessageIds: messageIds,
			Revoke:     true,
		})
		if err != nil {
			return err.Error(), true
		}
	// edit message
	case "s":
		if c.me == nil {
			return "@me is not initialized", true
		}

		messages, err := c.getLastMessages(chatID, "", c.me.Id, 1)
		if err != nil {
			return err.Error(), true
		}
		if len(messages.Messages) == 0 {
			return "No last message", true
		}

		message := messages.Messages[0]
		if message == nil {
			return "Last message is empty", true
		}

		content := c.PrepareOutgoingMessageContent(rawCmdArguments(cmdline, 0))

		if content != nil {
			_, err = c.client.EditMessageText(&client.EditMessageTextRequest{
				ChatId:              chatID,
				MessageId:           message.Id,
				InputMessageContent: content,
			})
			if err != nil {
				return "Message editing error", true
			}
		} else {
			return "Message processing error", true
		}
	// send without sound
	case "silent":
		content := c.PrepareOutgoingMessageContent(rawCmdArguments(cmdline, 0))

		if content != nil {
			_, err := c.client.SendMessage(&client.SendMessageRequest{
				ChatId:              chatID,
				InputMessageContent: content,
				Options: &client.MessageSendOptions{
					DisableNotification: true,
				},
			})
			if err != nil {
				return err.Error(), true
			}
		} else {
			return "Message processing error", true
		}
	// schedule a message to timestamp or to going online
	case "schedule":
		var state client.MessageSchedulingState
		var result string
		due := args[0]
		if due == "online" {
			state = &client.MessageSchedulingStateSendWhenOnline{}
			result = due
		} else {
			if c.Session.Timezone == "" {
				due += "Z"
			} else {
				due += c.Session.Timezone
			}

			switch 0 {
			default:
				// try bare time first
				timestamp, err := time.Parse("15:04:05Z07:00", due)
				if err == nil {
					now := time.Now().In(c.Session.TimezoneToLocation())
					// combine timestamp's time with today's date
					timestamp = time.Date(
						now.Year(),
						now.Month(),
						now.Day(),
						timestamp.Hour(),
						timestamp.Minute(),
						timestamp.Second(),
						0,
						timestamp.Location(),
					)
					diff := timestamp.Sub(now)
					if diff < 0 { // set to tomorrow
						timestamp = timestamp.AddDate(0, 0, 1)
					}
					state = &client.MessageSchedulingStateSendAtDate{
						SendDate: int32(timestamp.Unix()),
					}
					result = timestamp.Format(time.RFC3339)

					break
				}

				timestamp, err = time.Parse(time.RFC3339, due)
				if err == nil {
					// 2038 doomsday again
					state = &client.MessageSchedulingStateSendAtDate{
						SendDate: int32(timestamp.Unix()),
					}
					result = timestamp.Format(time.RFC3339)

					break
				}

				return "Invalid schedule time specifier", true
			}
		}

		content := c.PrepareOutgoingMessageContent(rawCmdArguments(cmdline, 1))

		if content != nil {
			_, err := c.client.SendMessage(&client.SendMessageRequest{
				ChatId:              chatID,
				InputMessageContent: content,
				Options: &client.MessageSendOptions{
					SchedulingState: state,
				},
			})
			if err != nil {
				return err.Error(), true
			}
			return "Scheduled to " + result, true
		} else {
			return "Message processing error", true
		}
	// forward a message to chat
	case "forward":
		messageId, err := strconv.ParseInt(args[0], 10, 64)
		if err != nil {
			return "Cannot parse message ID", true
		}

		targetChatParts := strings.Split(args[1], "@") // full JIDs are supported too
		targetChatId, err := strconv.ParseInt(targetChatParts[0], 10, 64)
		if err != nil {
			return "Cannot parse target chat ID", true
		}

		messages, err := c.client.ForwardMessages(&client.ForwardMessagesRequest{
			ChatId:     targetChatId,
			FromChatId: chatID,
			MessageIds: []int64{messageId},
		})
		if err != nil {
			return err.Error(), true
		}
		if messages != nil && messages.Messages != nil {
			for _, message := range messages.Messages {
				c.ProcessIncomingMessage(targetChatId, message)
			}
		}
	// print vCard
	case "vcard":
		info, err := c.GetVcardInfo(chatID)
		if err != nil {
			return err.Error(), true
		}
		_, link := c.PermastoreFile(info.Photo, true)
		entries := []string{
			keyValueString("Chat title", info.Fn),
			keyValueString("Photo", link),
			keyValueString("Usernames", c.usernamesToString(info.Nicknames)),
			keyValueString("Full name", info.Given+" "+info.Family),
			keyValueString("Phone number", info.Tel),
		}
		return strings.Join(entries, "\n"), true
	// add @contact
	case "add":
		return c.cmdAdd(args), true
	// join https://t.me/publichat or @publicchat
	case "join":
		return c.cmdJoin(args), true
	// create new supergroup
	case "supergroup":
		return c.cmdSupergroup(args, cmdline), true
	// create new channel
	case "channel":
		return c.cmdChannel(args, cmdline), true
	// create new secret chat with current user
	case "secret":
		_, err := c.client.CreateNewSecretChat(&client.CreateNewSecretChatRequest{
			UserId: chatID,
		})
		if err != nil {
			return err.Error(), true
		}
	// create group chat with current user
	case "group":
		_, err := c.client.CreateNewBasicGroupChat(&client.CreateNewBasicGroupChatRequest{
			UserIds: []int64{chatID},
			Title:   args[0],
		})
		if err != nil {
			return err.Error(), true
		}
	// blacklists current user
	case "block":
		_, err := c.client.SetMessageSenderBlockList(&client.SetMessageSenderBlockListRequest{
			SenderId:  &client.MessageSenderUser{UserId: chatID},
			BlockList: &client.BlockListMain{},
		})
		if err != nil {
			return err.Error(), true
		}
	// unblacklists current user
	case "unblock":
		_, err := c.client.SetMessageSenderBlockList(&client.SetMessageSenderBlockListRequest{
			SenderId:  &client.MessageSenderUser{UserId: chatID},
			BlockList: nil,
		})
		if err != nil {
			return err.Error(), true
		}
	// invite @username to current groupchat
	case "invite":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		_, err = c.client.AddChatMember(&client.AddChatMemberRequest{
			ChatId:       chatID,
			UserId:       contact.Id,
			ForwardLimit: 100,
		})
		if err != nil {
			return err.Error(), true
		}
	// get link to current chat
	case "link":
		link, err := c.client.CreateChatInviteLink(&client.CreateChatInviteLinkRequest{
			ChatId: chatID,
		})
		if err != nil {
			return err.Error(), true
		}
		return link.InviteLink, true
	// kick @username from current group chat
	case "kick":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status:   &client.ChatMemberStatusLeft{},
		})
		if err != nil {
			return err.Error(), true
		}
	// mute @username [n hours]
	case "mute":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		var hours int64
		if len(args) > 1 {
			hours, err = strconv.ParseInt(args[1], 10, 32)
			if err != nil {
				return "Invalid number of hours", true
			}
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status: &client.ChatMemberStatusRestricted{
				IsMember:            true,
				RestrictedUntilDate: c.formatBantime(hours),
				Permissions:         &permissionsReadonly,
			},
		})
		if err != nil {
			return err.Error(), true
		}
	// unmute @username
	case "unmute":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status: &client.ChatMemberStatusRestricted{
				IsMember:            true,
				RestrictedUntilDate: 0,
				Permissions:         &permissionsMember,
			},
		})
		if err != nil {
			return err.Error(), true
		}
	// ban @username from current chat [for N hours]
	case "ban":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		var hours int64
		if len(args) > 1 {
			hours, err = strconv.ParseInt(args[1], 10, 32)
			if err != nil {
				return "Invalid number of hours", true
			}
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status: &client.ChatMemberStatusBanned{
				BannedUntilDate: c.formatBantime(hours),
			},
		})
		if err != nil {
			return err.Error(), true
		}
	// unban @username
	case "unban":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status:   &client.ChatMemberStatusMember{},
		})
		if err != nil {
			return err.Error(), true
		}
	// promote @username to admin
	case "promote":
		contact, _, err := c.GetContactByUsername(args[0])
		if err != nil {
			return err.Error(), true
		}

		// clone the permissions
		status := client.ChatMemberStatusAdministrator{
			CanBeEdited: true,
			Rights:      &permissionsAdmin,
		}

		if len(args) > 1 {
			status.CustomTitle = args[1]
		}

		_, err = c.client.SetChatMemberStatus(&client.SetChatMemberStatusRequest{
			ChatId:   chatID,
			MemberId: &client.MessageSenderUser{UserId: contact.Id},
			Status:   &status,
		})
		if err != nil {
			return err.Error(), true
		}
	// leave current chat
	case "leave":
		_, err := c.client.LeaveChat(&client.LeaveChatRequest{
			ChatId: chatID,
		})
		if err != nil {
			return err.Error(), true
		}

		err = c.unsubscribe(chatID)
		if err != nil {
			return err.Error(), true
		}
	// leave current chat (for owners)
	case "leave!":
		_, err := c.client.DeleteChat(&client.DeleteChatRequest{
			ChatId: chatID,
		})
		if err != nil {
			return err.Error(), true
		}

		err = c.unsubscribe(chatID)
		if err != nil {
			return err.Error(), true
		}
	// set TTL
	case "ttl":
		var ttl int64
		var err error
		if len(args) > 0 {
			ttl, err = strconv.ParseInt(args[0], 10, 32)
			if err != nil {
				return "Invalid TTL", true
			}
		}
		_, err = c.client.SetChatMessageAutoDeleteTime(&client.SetChatMessageAutoDeleteTimeRequest{
			ChatId:                chatID,
			MessageAutoDeleteTime: int32(ttl),
		})

		if err != nil {
			return err.Error(), true
		}
	// close secret chat
	case "close":
		chat, _, err := c.GetContactByID(chatID, nil)
		if err != nil {
			return err.Error(), true
		}

		chatType := chat.Type.ChatTypeType()
		if chatType == client.TypeChatTypeSecret {
			chatTypeSecret, _ := chat.Type.(*client.ChatTypeSecret)
			_, err = c.client.CloseSecretChat(&client.CloseSecretChatRequest{
				SecretChatId: chatTypeSecret.SecretChatId,
			})
			if err != nil {
				return err.Error(), true
			}

			err = c.unsubscribe(chatID)
			if err != nil {
				return err.Error(), true
			}
		}
	// delete current chat
	case "delete":
		_, err := c.client.DeleteChatHistory(&client.DeleteChatHistoryRequest{
			ChatId:             chatID,
			RemoveFromChatList: true,
			Revoke:             true,
		})
		if err != nil {
			return err.Error(), true
		}

		err = c.unsubscribe(chatID)
		if err != nil {
			return err.Error(), true
		}
	// message search
	case "search":
		var limit int32 = 100
		if len(args) > 1 {
			newLimit, err := strconv.ParseInt(args[1], 10, 32)
			if err == nil {
				limit = int32(newLimit)
			}
		}

		var query string
		if len(args) > 0 {
			query = args[0]
		}

		messages, err := c.getLastMessages(chatID, query, 0, limit)
		if err != nil {
			return err.Error(), true
		}

		c.sendMessagesReverse(chatID, messages.Messages)
	// get latest entries from history
	case "history":
		var limit int32 = 10
		if len(args) > 0 {
			newLimit, err := strconv.ParseInt(args[0], 10, 32)
			if err == nil {
				limit = int32(newLimit)
			}
		}

		var newMessages *client.Messages
		var messages []*client.Message
		var err error
		var fromId int64
		for _ = range make([]struct{}, limit) { // safety limit
			if len(messages) > 0 {
				fromId = messages[len(messages)-1].Id
			}

			newMessages, err = c.client.GetChatHistory(&client.GetChatHistoryRequest{
				ChatId:        chatID,
				FromMessageId: fromId,
				Limit:         limit,
			})
			if err != nil {
				return err.Error(), true
			}

			messages = append(messages, newMessages.Messages...)

			if len(newMessages.Messages) == 0 || len(messages) >= int(limit) {
				break
			}
		}

		c.sendMessagesReverse(chatID, messages)
	// chat members
	case "members":
		var query string
		if len(args) > 0 {
			query = args[0]
		}

		members, err := c.GetChatMembers(chatID, false, query, MembersListMembers)
		if err != nil {
			return err.Error(), true
		}

		var entries []string
		for _, member := range members {
			senderId := c.GetSenderId(member.MemberId)
			entries = append(entries, fmt.Sprintf(
				"%v | role: %v",
				c.FormatContact(senderId),
				member.Status.ChatMemberStatusType(),
			))
		}

		return strings.Join(entries, "\n"), true
	case "help":
		return c.helpString(CommandTypeChat, chatID), true
	default:
		return "", false
	}

	return "", true
}

func (c *Client) cmdAdd(args []string) string {
	chat, err := c.client.SearchPublicChat(&client.SearchPublicChatRequest{
		Username: args[0],
	})
	if err != nil {
		return err.Error()
	}
	if chat == nil {
		return "No error, but chat is nil"
	}

	c.subscribeToID(chat.Id, chat)

	return ""
}

func (c *Client) cmdJoin(args []string) string {
	if strings.HasPrefix(args[0], "@") {
		chat, err := c.client.SearchPublicChat(&client.SearchPublicChatRequest{
			Username: args[0],
		})
		if err != nil {
			return err.Error()
		}
		if chat == nil {
			return "No error, but chat is nil"
		}
		_, err = c.client.JoinChat(&client.JoinChatRequest{
			ChatId: chat.Id,
		})
		if err != nil {
			return err.Error()
		}
	} else {
		_, err := c.client.JoinChatByInviteLink(&client.JoinChatByInviteLinkRequest{
			InviteLink: args[0],
		})
		if err != nil {
			return err.Error()
		}
	}

	return ""
}

func (c *Client) cmdSupergroup(args []string, cmdline string) string {
	_, err := c.client.CreateNewSupergroupChat(&client.CreateNewSupergroupChatRequest{
		Title:       args[0],
		Description: rawCmdArguments(cmdline, 1),
	})
	if err != nil {
		return err.Error()
	}

	return ""
}

func (c *Client) cmdChannel(args []string, cmdline string) string {
	_, err := c.client.CreateNewSupergroupChat(&client.CreateNewSupergroupChatRequest{
		Title:       args[0],
		Description: rawCmdArguments(cmdline, 1),
		IsChannel:   true,
	})
	if err != nil {
		return err.Error()
	}

	return ""
}