3 files changed, 859 insertions, 0 deletions
diff --git a/teleirc/matterbridge/bridge/telegram/handlers.go b/teleirc/matterbridge/bridge/telegram/handlers.go
new file mode 100644
index 0000000..a9d9bd6
--- /dev/null
+++ b/teleirc/matterbridge/bridge/telegram/handlers.go
@@ -0,0 +1,580 @@
+package btelegram
+
+import (
+	"fmt"
+	"html"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unicode/utf16"
+
+	"github.com/42wim/matterbridge/bridge/config"
+	"github.com/42wim/matterbridge/bridge/helper"
+	"github.com/davecgh/go-spew/spew"
+	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
+)
+
+func (b *Btelegram) handleUpdate(rmsg *config.Message, message, posted, edited *tgbotapi.Message) *tgbotapi.Message {
+	// handle channels
+	if posted != nil {
+		if posted.Text == "/chatId" {
+			chatID := strconv.FormatInt(posted.Chat.ID, 10)
+
+			_, err := b.Send(config.Message{
+				Channel: chatID,
+				Text:    fmt.Sprintf("ID of this chat: %s", chatID),
+			})
+			if err != nil {
+				b.Log.Warnf("Unable to send chatID to %s", chatID)
+			}
+		} else {
+			message = posted
+			rmsg.Text = message.Text
+		}
+	}
+
+	// edited channel message
+	if edited != nil && !b.GetBool("EditDisable") {
+		message = edited
+		rmsg.Text = rmsg.Text + message.Text + b.GetString("EditSuffix")
+	}
+	return message
+}
+
+// handleChannels checks if it's a channel message and if the message is a new or edited messages
+func (b *Btelegram) handleChannels(rmsg *config.Message, message *tgbotapi.Message, update tgbotapi.Update) *tgbotapi.Message {
+	return b.handleUpdate(rmsg, message, update.ChannelPost, update.EditedChannelPost)
+}
+
+// handleGroups checks if it's a group message and if the message is a new or edited messages
+func (b *Btelegram) handleGroups(rmsg *config.Message, message *tgbotapi.Message, update tgbotapi.Update) *tgbotapi.Message {
+	return b.handleUpdate(rmsg, message, update.Message, update.EditedMessage)
+}
+
+// handleForwarded handles forwarded messages
+func (b *Btelegram) handleForwarded(rmsg *config.Message, message *tgbotapi.Message) {
+	if message.ForwardDate == 0 {
+		return
+	}
+
+	if message.ForwardFromChat != nil && message.ForwardFrom == nil {
+		rmsg.Text = "Forwarded from " + message.ForwardFromChat.Title + ": " + rmsg.Text
+		return
+	}
+
+	if message.ForwardFrom == nil {
+		rmsg.Text = "Forwarded from " + unknownUser + ": " + rmsg.Text
+		return
+	}
+
+	usernameForward := ""
+	if b.GetBool("UseFirstName") {
+		usernameForward = message.ForwardFrom.FirstName
+	}
+	if b.GetBool("UseFullName") {
+		usernameForward = message.ForwardFrom.FirstName + " " + message.ForwardFrom.LastName
+	}
+
+	if usernameForward == "" {
+		usernameForward = message.ForwardFrom.UserName
+		if usernameForward == "" {
+			usernameForward = message.ForwardFrom.FirstName
+		}
+	}
+
+	if usernameForward == "" {
+		usernameForward = unknownUser
+	}
+
+	rmsg.Text = "Forwarded from " + usernameForward + ": " + rmsg.Text
+}
+
+// handleQuoting handles quoting of previous messages
+func (b *Btelegram) handleQuoting(rmsg *config.Message, message *tgbotapi.Message) {
+	if message.ReplyToMessage != nil {
+		usernameReply := ""
+		if message.ReplyToMessage.From != nil {
+			if b.GetBool("UseFirstName") {
+				usernameReply = message.ReplyToMessage.From.FirstName
+			}
+			if b.GetBool("UseFullName") {
+				usernameReply = message.ReplyToMessage.From.FirstName + " " + message.ReplyToMessage.From.LastName
+			}
+			if usernameReply == "" {
+				usernameReply = message.ReplyToMessage.From.UserName
+				if usernameReply == "" {
+					usernameReply = message.ReplyToMessage.From.FirstName
+				}
+			}
+		}
+		if usernameReply == "" {
+			usernameReply = unknownUser
+		}
+		if !b.GetBool("QuoteDisable") {
+			quote := message.ReplyToMessage.Text
+			if quote == "" {
+				quote = message.ReplyToMessage.Caption
+			}
+			rmsg.Text = b.handleQuote(rmsg.Text, usernameReply, quote)
+		}
+	}
+}
+
+// handleUsername handles the correct setting of the username
+func (b *Btelegram) handleUsername(rmsg *config.Message, message *tgbotapi.Message) {
+	if message.From != nil {
+		rmsg.UserID = strconv.FormatInt(message.From.ID, 10)
+		if b.GetBool("UseFirstName") {
+			rmsg.Username = message.From.FirstName
+		}
+		if b.GetBool("UseFullName") {
+			rmsg.Username = message.From.FirstName + " " + message.From.LastName
+		}
+		if rmsg.Username == "" {
+			rmsg.Username = message.From.UserName
+			if rmsg.Username == "" {
+				rmsg.Username = message.From.FirstName
+			}
+		}
+		// only download avatars if we have a place to upload them (configured mediaserver)
+		if b.General.MediaServerUpload != "" || (b.General.MediaServerDownload != "" && b.General.MediaDownloadPath != "") {
+			b.handleDownloadAvatar(message.From.ID, rmsg.Channel)
+		}
+	}
+
+	if message.SenderChat != nil { //nolint:nestif
+		rmsg.UserID = strconv.FormatInt(message.SenderChat.ID, 10)
+		if b.GetBool("UseFirstName") {
+			rmsg.Username = message.SenderChat.FirstName
+		}
+		if b.GetBool("UseFullName") {
+			rmsg.Username = message.SenderChat.FirstName + " " + message.SenderChat.LastName
+		}
+
+		if rmsg.Username == "" || rmsg.Username == "Channel_Bot" {
+			rmsg.Username = message.SenderChat.UserName
+
+			if rmsg.Username == "" || rmsg.Username == "Channel_Bot" {
+				rmsg.Username = message.SenderChat.FirstName
+			}
+		}
+		// only download avatars if we have a place to upload them (configured mediaserver)
+		if b.General.MediaServerUpload != "" || (b.General.MediaServerDownload != "" && b.General.MediaDownloadPath != "") {
+			b.handleDownloadAvatar(message.SenderChat.ID, rmsg.Channel)
+		}
+	}
+
+	// if we really didn't find a username, set it to unknown
+	if rmsg.Username == "" {
+		rmsg.Username = unknownUser
+	}
+}
+
+func (b *Btelegram) handleRecv(updates <-chan tgbotapi.Update) {
+	for update := range updates {
+		b.Log.Debugf("== Receiving event: %#v", update.Message)
+
+		if update.Message == nil && update.ChannelPost == nil &&
+			update.EditedMessage == nil && update.EditedChannelPost == nil {
+			b.Log.Info("Received event without messages, skipping.")
+			continue
+		}
+
+		if b.GetInt("debuglevel") == 1 {
+			spew.Dump(update.Message)
+		}
+
+		var message *tgbotapi.Message
+
+		rmsg := config.Message{Account: b.Account, Extra: make(map[string][]interface{})}
+
+		// handle channels
+		message = b.handleChannels(&rmsg, message, update)
+
+		// handle groups
+		message = b.handleGroups(&rmsg, message, update)
+
+		if message == nil {
+			b.Log.Error("message is nil, this shouldn't happen.")
+			continue
+		}
+
+		// set the ID's from the channel or group message
+		rmsg.ID = strconv.Itoa(message.MessageID)
+		rmsg.Channel = strconv.FormatInt(message.Chat.ID, 10)
+
+		// preserve threading from telegram reply
+		if message.ReplyToMessage != nil {
+			rmsg.ParentID = strconv.Itoa(message.ReplyToMessage.MessageID)
+		}
+
+		// handle entities (adding URLs)
+		b.handleEntities(&rmsg, message)
+
+		// handle username
+		b.handleUsername(&rmsg, message)
+
+		// handle any downloads
+		err := b.handleDownload(&rmsg, message)
+		if err != nil {
+			b.Log.Errorf("download failed: %s", err)
+		}
+
+		// handle forwarded messages
+		b.handleForwarded(&rmsg, message)
+
+		// quote the previous message
+		b.handleQuoting(&rmsg, message)
+
+		if rmsg.Text != "" || len(rmsg.Extra) > 0 {
+			// Comment the next line out due to avoid removing empty lines in Telegram
+			// rmsg.Text = helper.RemoveEmptyNewLines(rmsg.Text)
+			// channels don't have (always?) user information. see #410
+			if message.From != nil {
+				rmsg.Avatar = helper.GetAvatar(b.avatarMap, strconv.FormatInt(message.From.ID, 10), b.General)
+			}
+
+			b.Log.Debugf("<= Sending message from %s on %s to gateway", rmsg.Username, b.Account)
+			b.Log.Debugf("<= Message is %#v", rmsg)
+			b.Remote <- rmsg
+		}
+	}
+}
+
+// handleDownloadAvatar downloads the avatar of userid from channel
+// sends a EVENT_AVATAR_DOWNLOAD message to the gateway if successful.
+// logs an error message if it fails
+func (b *Btelegram) handleDownloadAvatar(userid int64, channel string) {
+	rmsg := config.Message{
+		Username: "system",
+		Text:     "avatar",
+		Channel:  channel,
+		Account:  b.Account,
+		UserID:   strconv.FormatInt(userid, 10),
+		Event:    config.EventAvatarDownload,
+		Extra:    make(map[string][]interface{}),
+	}
+
+	if _, ok := b.avatarMap[strconv.FormatInt(userid, 10)]; ok {
+		return
+	}
+
+	photos, err := b.c.GetUserProfilePhotos(tgbotapi.UserProfilePhotosConfig{UserID: userid, Limit: 1})
+	if err != nil {
+		b.Log.Errorf("Userprofile download failed for %#v %s", userid, err)
+	}
+
+	if len(photos.Photos) > 0 {
+		photo := photos.Photos[0][0]
+		url := b.getFileDirectURL(photo.FileID)
+		name := strconv.FormatInt(userid, 10) + ".png"
+		b.Log.Debugf("trying to download %#v fileid %#v with size %#v", name, photo.FileID, photo.FileSize)
+
+		err := helper.HandleDownloadSize(b.Log, &rmsg, name, int64(photo.FileSize), b.General)
+		if err != nil {
+			b.Log.Error(err)
+			return
+		}
+		data, err := helper.DownloadFile(url)
+		if err != nil {
+			b.Log.Errorf("download %s failed %#v", url, err)
+			return
+		}
+		helper.HandleDownloadData(b.Log, &rmsg, name, rmsg.Text, "", data, b.General)
+		b.Remote <- rmsg
+	}
+}
+
+func (b *Btelegram) maybeConvertTgs(name *string, data *[]byte) {
+	format := b.GetString("MediaConvertTgs")
+	if helper.SupportsFormat(format) {
+		b.Log.Debugf("Format supported by %s, converting %v", helper.LottieBackend(), name)
+	} else {
+		// Otherwise, no conversion was requested. Trying to run the usual webp
+		// converter would fail, because '.tgs.webp' is actually a gzipped JSON
+		// file, and has nothing to do with WebP.
+		return
+	}
+	err := helper.ConvertTgsToX(data, format, b.Log)
+	if err != nil {
+		b.Log.Errorf("conversion failed: %v", err)
+	} else {
+		*name = strings.Replace(*name, "tgs.webp", format, 1)
+	}
+}
+
+func (b *Btelegram) maybeConvertWebp(name *string, data *[]byte) {
+	if b.GetBool("MediaConvertWebPToPNG") {
+		b.Log.Debugf("WebP to PNG conversion enabled, converting %v", name)
+		err := helper.ConvertWebPToPNG(data)
+		if err != nil {
+			b.Log.Errorf("conversion failed: %v", err)
+		} else {
+			*name = strings.Replace(*name, ".webp", ".png", 1)
+		}
+	}
+}
+
+// handleDownloadFile handles file download
+func (b *Btelegram) handleDownload(rmsg *config.Message, message *tgbotapi.Message) error {
+	size := 0
+	var url, name, text string
+	switch {
+	case message.Sticker != nil:
+		text, name, url = b.getDownloadInfo(message.Sticker.FileID, ".webp", true)
+		size = message.Sticker.FileSize
+	case message.Voice != nil:
+		text, name, url = b.getDownloadInfo(message.Voice.FileID, ".ogg", true)
+		size = message.Voice.FileSize
+	case message.Video != nil:
+		text, name, url = b.getDownloadInfo(message.Video.FileID, "", true)
+		size = message.Video.FileSize
+	case message.Audio != nil:
+		text, name, url = b.getDownloadInfo(message.Audio.FileID, "", true)
+		size = message.Audio.FileSize
+	case message.Document != nil:
+		_, _, url = b.getDownloadInfo(message.Document.FileID, "", false)
+		size = message.Document.FileSize
+		name = message.Document.FileName
+		text = " " + message.Document.FileName + " : " + url
+	case message.Photo != nil:
+		photos := message.Photo
+		size = photos[len(photos)-1].FileSize
+		text, name, url = b.getDownloadInfo(photos[len(photos)-1].FileID, "", true)
+	}
+
+	// if name is empty we didn't match a thing to download
+	if name == "" {
+		return nil
+	}
+	// use the URL instead of native upload
+	if b.GetBool("UseInsecureURL") {
+		b.Log.Debugf("Setting message text to :%s", text)
+		rmsg.Text += text
+		return nil
+	}
+	// if we have a file attached, download it (in memory) and put a pointer to it in msg.Extra
+	err := helper.HandleDownloadSize(b.Log, rmsg, name, int64(size), b.General)
+	if err != nil {
+		return err
+	}
+	data, err := helper.DownloadFile(url)
+	if err != nil {
+		return err
+	}
+
+	if strings.HasSuffix(name, ".tgs.webp") {
+		b.maybeConvertTgs(&name, data)
+	} else if strings.HasSuffix(name, ".webp") {
+		b.maybeConvertWebp(&name, data)
+	}
+
+	// rename .oga to .ogg  https://github.com/42wim/matterbridge/issues/906#issuecomment-741793512
+	if strings.HasSuffix(name, ".oga") && message.Audio != nil {
+		name = strings.Replace(name, ".oga", ".ogg", 1)
+	}
+
+	helper.HandleDownloadData(b.Log, rmsg, name, message.Caption, "", data, b.General)
+	return nil
+}
+
+func (b *Btelegram) getDownloadInfo(id string, suffix string, urlpart bool) (string, string, string) {
+	url := b.getFileDirectURL(id)
+	name := ""
+	if urlpart {
+		urlPart := strings.Split(url, "/")
+		name = urlPart[len(urlPart)-1]
+	}
+	if suffix != "" && !strings.HasSuffix(name, suffix) && !strings.HasSuffix(name, ".webm") {
+		name += suffix
+	}
+	text := " " + url
+	return text, name, url
+}
+
+// handleDelete handles message deleting
+func (b *Btelegram) handleDelete(msg *config.Message, chatid int64) (string, error) {
+	if msg.ID == "" {
+		return "", nil
+	}
+
+	msgid, err := strconv.Atoi(msg.ID)
+	if err != nil {
+		return "", err
+	}
+
+	cfg := tgbotapi.NewDeleteMessage(chatid, msgid)
+	_, err = b.c.Request(cfg)
+
+	return "", err
+}
+
+// handleEdit handles message editing.
+func (b *Btelegram) handleEdit(msg *config.Message, chatid int64) (string, error) {
+	msgid, err := strconv.Atoi(msg.ID)
+	if err != nil {
+		return "", err
+	}
+	if strings.ToLower(b.GetString("MessageFormat")) == HTMLNick {
+		b.Log.Debug("Using mode HTML - nick only")
+		msg.Text = html.EscapeString(msg.Text)
+	}
+	m := tgbotapi.NewEditMessageText(chatid, msgid, msg.Username+msg.Text)
+	switch b.GetString("MessageFormat") {
+	case HTMLFormat:
+		b.Log.Debug("Using mode HTML")
+		m.ParseMode = tgbotapi.ModeHTML
+	case "Markdown":
+		b.Log.Debug("Using mode markdown")
+		m.ParseMode = tgbotapi.ModeMarkdown
+	case MarkdownV2:
+		b.Log.Debug("Using mode MarkdownV2")
+		m.ParseMode = MarkdownV2
+	}
+	if strings.ToLower(b.GetString("MessageFormat")) == HTMLNick {
+		b.Log.Debug("Using mode HTML - nick only")
+		m.ParseMode = tgbotapi.ModeHTML
+	}
+	_, err = b.c.Send(m)
+	if err != nil {
+		return "", err
+	}
+	return "", nil
+}
+
+// handleUploadFile handles native upload of files
+func (b *Btelegram) handleUploadFile(msg *config.Message, chatid int64, parentID int) (string, error) {
+	var media []interface{}
+	for _, f := range msg.Extra["file"] {
+		fi := f.(config.FileInfo)
+		file := tgbotapi.FileBytes{
+			Name:  fi.Name,
+			Bytes: *fi.Data,
+		}
+
+		if b.GetString("MessageFormat") == HTMLFormat {
+			fi.Comment = makeHTML(html.EscapeString(fi.Comment))
+		}
+
+		switch filepath.Ext(fi.Name) {
+		case ".jpg", ".jpe", ".png":
+			pc := tgbotapi.NewInputMediaPhoto(file)
+			if fi.Comment != "" {
+				pc.Caption, pc.ParseMode = TGGetParseMode(b, msg.Username, fi.Comment)
+			}
+			media = append(media, pc)
+		case ".mp4", ".m4v":
+			vc := tgbotapi.NewInputMediaVideo(file)
+			if fi.Comment != "" {
+				vc.Caption, vc.ParseMode = TGGetParseMode(b, msg.Username, fi.Comment)
+			}
+			media = append(media, vc)
+		case ".mp3", ".oga":
+			ac := tgbotapi.NewInputMediaAudio(file)
+			if fi.Comment != "" {
+				ac.Caption, ac.ParseMode = TGGetParseMode(b, msg.Username, fi.Comment)
+			}
+			media = append(media, ac)
+		case ".ogg":
+			voc := tgbotapi.NewVoice(chatid, file)
+			voc.Caption, voc.ParseMode = TGGetParseMode(b, msg.Username, fi.Comment)
+			voc.ReplyToMessageID = parentID
+			res, err := b.c.Send(voc)
+			if err != nil {
+				return "", err
+			}
+			return strconv.Itoa(res.MessageID), nil
+		default:
+			dc := tgbotapi.NewInputMediaDocument(file)
+			if fi.Comment != "" {
+				dc.Caption, dc.ParseMode = TGGetParseMode(b, msg.Username, fi.Comment)
+			}
+			media = append(media, dc)
+		}
+	}
+
+	return b.sendMediaFiles(msg, chatid, parentID, media)
+}
+
+func (b *Btelegram) handleQuote(message, quoteNick, quoteMessage string) string {
+	format := b.GetString("quoteformat")
+	if format == "" {
+		format = "{MESSAGE} (re @{QUOTENICK}: {QUOTEMESSAGE})"
+	}
+	quoteMessagelength := len([]rune(quoteMessage))
+	if b.GetInt("QuoteLengthLimit") != 0 && quoteMessagelength >= b.GetInt("QuoteLengthLimit") {
+		runes := []rune(quoteMessage)
+		quoteMessage = string(runes[0:b.GetInt("QuoteLengthLimit")])
+		if quoteMessagelength > b.GetInt("QuoteLengthLimit") {
+			quoteMessage += "..."
+		}
+	}
+	format = strings.Replace(format, "{MESSAGE}", message, -1)
+	format = strings.Replace(format, "{QUOTENICK}", quoteNick, -1)
+	format = strings.Replace(format, "{QUOTEMESSAGE}", quoteMessage, -1)
+	return format
+}
+
+// handleEntities handles messageEntities
+func (b *Btelegram) handleEntities(rmsg *config.Message, message *tgbotapi.Message) {
+	if message.Entities == nil {
+		return
+	}
+
+	indexMovedBy := 0
+	prevLinkOffset := -1
+
+	for _, e := range message.Entities {
+
+		asRunes := utf16.Encode([]rune(rmsg.Text))
+
+		if e.Type == "text_link" {
+			offset := e.Offset + indexMovedBy
+			url, err := e.ParseURL()
+			if err != nil {
+				b.Log.Errorf("entity text_link url parse failed: %s", err)
+				continue
+			}
+			utfEncodedString := utf16.Encode([]rune(rmsg.Text))
+			if offset+e.Length > len(utfEncodedString) {
+				b.Log.Errorf("entity length is too long %d > %d", offset+e.Length, len(utfEncodedString))
+				continue
+			}
+			rmsg.Text = string(utf16.Decode(asRunes[:offset+e.Length])) + " ( " + url.String() + " ) " + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += len(url.String()) + 3
+			prevLinkOffset = e.Offset
+		}
+
+		if e.Offset == prevLinkOffset {
+			continue
+		}
+
+		if e.Type == "code" {
+			offset := e.Offset + indexMovedBy
+			rmsg.Text = string(utf16.Decode(asRunes[:offset])) + "`" + string(utf16.Decode(asRunes[offset:offset+e.Length])) + "`" + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += 2
+		}
+
+		if e.Type == "pre" {
+			offset := e.Offset + indexMovedBy
+			rmsg.Text = string(utf16.Decode(asRunes[:offset])) + "```\n" + string(utf16.Decode(asRunes[offset:offset+e.Length])) + "```\n" + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += 8
+		}
+
+		if e.Type == "bold" {
+			offset := e.Offset + indexMovedBy
+			rmsg.Text = string(utf16.Decode(asRunes[:offset])) + "*" + string(utf16.Decode(asRunes[offset:offset+e.Length])) + "*" + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += 2
+		}
+		if e.Type == "italic" {
+			offset := e.Offset + indexMovedBy
+			rmsg.Text = string(utf16.Decode(asRunes[:offset])) + "_" + string(utf16.Decode(asRunes[offset:offset+e.Length])) + "_" + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += 2
+		}
+		if e.Type == "strike" {
+			offset := e.Offset + indexMovedBy
+			rmsg.Text = string(utf16.Decode(asRunes[:offset])) + "~" + string(utf16.Decode(asRunes[offset:offset+e.Length])) + "~" + string(utf16.Decode(asRunes[offset+e.Length:]))
+			indexMovedBy += 2
+		}
+	}
+}
diff --git a/teleirc/matterbridge/bridge/telegram/html.go b/teleirc/matterbridge/bridge/telegram/html.go
new file mode 100644
index 0000000..4aa9fd3
--- /dev/null
+++ b/teleirc/matterbridge/bridge/telegram/html.go
@@ -0,0 +1,74 @@
+package btelegram
+
+import (
+	"bytes"
+
+	"github.com/russross/blackfriday"
+)
+
+type customHTML struct {
+	blackfriday.Renderer
+}
+
+func (options *customHTML) Paragraph(out *bytes.Buffer, text func() bool) {
+	marker := out.Len()
+
+	if !text() {
+		out.Truncate(marker)
+		return
+	}
+	out.WriteString("\n")
+}
+
+func (options *customHTML) BlockCode(out *bytes.Buffer, text []byte, lang string) {
+	out.WriteString("<pre>")
+
+	out.WriteString(string(text))
+	out.WriteString("</pre>\n")
+}
+
+func (options *customHTML) CodeSpan(out *bytes.Buffer, text []byte) {
+	out.WriteString("<code>")
+	out.WriteString(string(text))
+	out.WriteString("</code>")
+}
+
+func (options *customHTML) Header(out *bytes.Buffer, text func() bool, level int, id string) {
+	options.Paragraph(out, text)
+}
+
+func (options *customHTML) HRule(out *bytes.Buffer) {
+	out.WriteByte('\n') //nolint:errcheck
+}
+
+func (options *customHTML) BlockQuote(out *bytes.Buffer, text []byte) {
+	out.WriteString("> ")
+	out.Write(text)
+	out.WriteByte('\n')
+}
+
+func (options *customHTML) LineBreak(out *bytes.Buffer) {
+	out.WriteByte('\n')
+}
+
+func (options *customHTML) List(out *bytes.Buffer, text func() bool, flags int) {
+	options.Paragraph(out, text)
+}
+
+func (options *customHTML) ListItem(out *bytes.Buffer, text []byte, flags int) {
+	out.WriteString("- ")
+	out.Write(text)
+	out.WriteByte('\n')
+}
+
+func makeHTML(input string) string {
+	return string(blackfriday.Markdown([]byte(input),
+		&customHTML{blackfriday.HtmlRenderer(blackfriday.HTML_USE_XHTML|blackfriday.HTML_SKIP_IMAGES, "", "")},
+		blackfriday.EXTENSION_NO_INTRA_EMPHASIS|
+			blackfriday.EXTENSION_FENCED_CODE|
+			blackfriday.EXTENSION_AUTOLINK|
+			blackfriday.EXTENSION_SPACE_HEADERS|
+			blackfriday.EXTENSION_HEADER_IDS|
+			blackfriday.EXTENSION_BACKSLASH_LINE_BREAK|
+			blackfriday.EXTENSION_DEFINITION_LISTS))
+}
diff --git a/teleirc/matterbridge/bridge/telegram/telegram.go b/teleirc/matterbridge/bridge/telegram/telegram.go
new file mode 100644
index 0000000..43cb818
--- /dev/null
+++ b/teleirc/matterbridge/bridge/telegram/telegram.go
@@ -0,0 +1,205 @@
+package btelegram
+
+import (
+	"fmt"
+	"html"
+	"log"
+	"strconv"
+	"strings"
+
+	"github.com/42wim/matterbridge/bridge"
+	"github.com/42wim/matterbridge/bridge/config"
+	"github.com/42wim/matterbridge/bridge/helper"
+	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
+)
+
+const (
+	unknownUser = "unknown"
+	HTMLFormat  = "HTML"
+	HTMLNick    = "htmlnick"
+	MarkdownV2  = "MarkdownV2"
+)
+
+type Btelegram struct {
+	c *tgbotapi.BotAPI
+	*bridge.Config
+	avatarMap map[string]string // keep cache of userid and avatar sha
+}
+
+func New(cfg *bridge.Config) bridge.Bridger {
+	tgsConvertFormat := cfg.GetString("MediaConvertTgs")
+	if tgsConvertFormat != "" {
+		err := helper.CanConvertTgsToX()
+		if err != nil {
+			log.Fatalf("Telegram bridge configured to convert .tgs files to '%s', but %s does not appear to work:\n%#v", tgsConvertFormat, helper.LottieBackend(), err)
+		}
+		if !helper.SupportsFormat(tgsConvertFormat) {
+			log.Fatalf("Telegram bridge configured to convert .tgs files to '%s', but %s doesn't support it.", tgsConvertFormat, helper.LottieBackend())
+		}
+	}
+	return &Btelegram{Config: cfg, avatarMap: make(map[string]string)}
+}
+
+func (b *Btelegram) Connect() error {
+	var err error
+	b.Log.Info("Connecting")
+	b.c, err = tgbotapi.NewBotAPI(b.GetString("Token"))
+	if err != nil {
+		b.Log.Debugf("%#v", err)
+		return err
+	}
+	u := tgbotapi.NewUpdate(0)
+	u.Timeout = 60
+	updates := b.c.GetUpdatesChan(u)
+	b.Log.Info("Connection succeeded")
+	go b.handleRecv(updates)
+	return nil
+}
+
+func (b *Btelegram) Disconnect() error {
+	return nil
+}
+
+func (b *Btelegram) JoinChannel(channel config.ChannelInfo) error {
+	return nil
+}
+
+func TGGetParseMode(b *Btelegram, username string, text string) (textout string, parsemode string) {
+	textout = username + text
+	if b.GetString("MessageFormat") == HTMLFormat {
+		b.Log.Debug("Using mode HTML")
+		parsemode = tgbotapi.ModeHTML
+	}
+	if b.GetString("MessageFormat") == "Markdown" {
+		b.Log.Debug("Using mode markdown")
+		parsemode = tgbotapi.ModeMarkdown
+	}
+	if b.GetString("MessageFormat") == MarkdownV2 {
+		b.Log.Debug("Using mode MarkdownV2")
+		parsemode = MarkdownV2
+	}
+	if strings.ToLower(b.GetString("MessageFormat")) == HTMLNick {
+		b.Log.Debug("Using mode HTML - nick only")
+		textout = username + html.EscapeString(text)
+		parsemode = tgbotapi.ModeHTML
+	}
+	return textout, parsemode
+}
+
+func (b *Btelegram) Send(msg config.Message) (string, error) {
+	b.Log.Debugf("=> Receiving %#v", msg)
+
+	// get the chatid
+	chatid, err := strconv.ParseInt(msg.Channel, 10, 64)
+	if err != nil {
+		return "", err
+	}
+
+	// map the file SHA to our user (caches the avatar)
+	if msg.Event == config.EventAvatarDownload {
+		return b.cacheAvatar(&msg)
+	}
+
+	if b.GetString("MessageFormat") == HTMLFormat {
+		msg.Text = makeHTML(html.EscapeString(msg.Text))
+	}
+
+	// Delete message
+	if msg.Event == config.EventMsgDelete {
+		return b.handleDelete(&msg, chatid)
+	}
+
+	// Handle prefix hint for unthreaded messages.
+	if msg.ParentNotFound() {
+		msg.ParentID = ""
+		msg.Text = fmt.Sprintf("[reply]: %s", msg.Text)
+	}
+
+	var parentID int
+	if msg.ParentID != "" {
+		parentID, _ = b.intParentID(msg.ParentID)
+	}
+
+	// Upload a file if it exists
+	if msg.Extra != nil {
+		for _, rmsg := range helper.HandleExtra(&msg, b.General) {
+			if _, msgErr := b.sendMessage(chatid, rmsg.Username, rmsg.Text, parentID); msgErr != nil {
+				b.Log.Errorf("sendMessage failed: %s", msgErr)
+			}
+		}
+		// check if we have files to upload (from slack, telegram or mattermost)
+		if len(msg.Extra["file"]) > 0 {
+			return b.handleUploadFile(&msg, chatid, parentID)
+		}
+	}
+
+	// edit the message if we have a msg ID
+	if msg.ID != "" {
+		return b.handleEdit(&msg, chatid)
+	}
+
+	// Post normal message
+	// TODO: recheck it.
+	// Ignore empty text field needs for prevent double messages from whatsapp to telegram
+	// when sending media with text caption
+	if msg.Text != "" {
+		return b.sendMessage(chatid, msg.Username, msg.Text, parentID)
+	}
+
+	return "", nil
+}
+
+func (b *Btelegram) getFileDirectURL(id string) string {
+	res, err := b.c.GetFileDirectURL(id)
+	if err != nil {
+		return ""
+	}
+	return res
+}
+
+func (b *Btelegram) sendMessage(chatid int64, username, text string, parentID int) (string, error) {
+	m := tgbotapi.NewMessage(chatid, "")
+	m.Text, m.ParseMode = TGGetParseMode(b, username, text)
+	m.ReplyToMessageID = parentID
+	m.DisableWebPagePreview = b.GetBool("DisableWebPagePreview")
+
+	res, err := b.c.Send(m)
+	if err != nil {
+		return "", err
+	}
+	return strconv.Itoa(res.MessageID), nil
+}
+
+// sendMediaFiles native upload media files via media group
+func (b *Btelegram) sendMediaFiles(msg *config.Message, chatid int64, parentID int, media []interface{}) (string, error) {
+	if len(media) == 0 {
+		return "", nil
+	}
+	mg := tgbotapi.MediaGroupConfig{ChatID: chatid, ChannelUsername: msg.Username, Media: media, ReplyToMessageID: parentID}
+	messages, err := b.c.SendMediaGroup(mg)
+	if err != nil {
+		return "", err
+	}
+	// return first message id
+	return strconv.Itoa(messages[0].MessageID), nil
+}
+
+// intParentID return integer parent id for telegram message
+func (b *Btelegram) intParentID(parentID string) (int, error) {
+	pid, err := strconv.Atoi(parentID)
+	if err != nil {
+		return 0, err
+	}
+	return pid, nil
+}
+
+func (b *Btelegram) cacheAvatar(msg *config.Message) (string, error) {
+	fi := msg.Extra["file"][0].(config.FileInfo)
+	/* if we have a sha we have successfully uploaded the file to the media server,
+	so we can now cache the sha */
+	if fi.SHA != "" {
+		b.Log.Debugf("Added %s to %s in avatarMap", fi.SHA, msg.UserID)
+		b.avatarMap[msg.UserID] = fi.SHA
+	}
+	return "", nil
+}