telegramfmt: text formatting TG -> Matrix

Signed-off-by: Sumner Evans <sumner.evans@automattic.com>
2024-07-29 14:55:11 -06:00
parent e7522be252
commit 882582456e
9 changed files with 749 additions and 58 deletions
@@ -0,0 +1,150 @@
+// mautrix-telegram - A Matrix-Telegram puppeting bridge.
+// Copyright (C) 2024 Sumner Evans
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package telegramfmt
+
+import (
+	"context"
+	"fmt"
+	"html"
+	"strings"
+
+	"github.com/gotd/td/tg"
+	"golang.org/x/exp/maps"
+	"maunium.net/go/mautrix/bridgev2/networkid"
+	"maunium.net/go/mautrix/event"
+	"maunium.net/go/mautrix/id"
+
+	"go.mau.fi/mautrix-telegram/pkg/connector/ids"
+)
+
+type UserInfo struct {
+	MXID id.UserID
+	Name string
+}
+
+type FormatParams struct {
+	CustomEmojis map[networkid.EmojiID]string
+	GetUserInfo  func(ctx context.Context, id networkid.UserID) (UserInfo, error)
+	NormalizeURL func(ctx context.Context, url string) string
+}
+
+func (fp FormatParams) GetCustomEmoji(emojiID networkid.EmojiID) (string, id.ContentURIString) {
+	if strings.HasPrefix(fp.CustomEmojis[emojiID], "mxc://") {
+		return "", id.ContentURIString(fp.CustomEmojis[emojiID])
+	} else {
+		return fp.CustomEmojis[emojiID], ""
+	}
+}
+
+func (fp FormatParams) WithCustomEmojis(emojis map[networkid.EmojiID]string) FormatParams {
+	return FormatParams{
+		CustomEmojis: emojis,
+		GetUserInfo:  fp.GetUserInfo,
+		NormalizeURL: fp.NormalizeURL,
+	}
+}
+
+type formatContext struct {
+	IsInCodeblock bool
+}
+
+func (ctx formatContext) TextToHTML(text string) string {
+	if ctx.IsInCodeblock {
+		return html.EscapeString(text)
+	}
+	return event.TextToHTML(text)
+}
+
+func Parse(ctx context.Context, message string, entities []tg.MessageEntityClass, params FormatParams) (*event.MessageEventContent, error) {
+	content := &event.MessageEventContent{
+		MsgType:  event.MsgText,
+		Body:     message,
+		Mentions: &event.Mentions{},
+	}
+	if len(entities) == 0 {
+		return content, nil
+	}
+
+	lrt := &LinkedRangeTree{}
+	mentions := map[id.UserID]struct{}{}
+	utf16Message := NewUTF16String(message)
+	maxLength := len(utf16Message)
+	for _, e := range entities {
+		br := BodyRange{
+			Start:  e.GetOffset(),
+			Length: e.GetLength(),
+		}.TruncateEnd(maxLength)
+		switch entity := e.(type) {
+		case *tg.MessageEntityMention:
+			// TODO
+			fmt.Printf("mention = %+v\n", entity)
+		case *tg.MessageEntityHashtag:
+			br.Value = Style{Type: StyleHashtag}
+		case *tg.MessageEntityBotCommand:
+			br.Value = Style{Type: StyleBotCommand}
+		case *tg.MessageEntityURL:
+			br.Value = Style{Type: StyleURL, URL: params.NormalizeURL(ctx, utf16Message[e.GetOffset():e.GetOffset()+e.GetLength()].String())}
+		case *tg.MessageEntityEmail:
+			br.Value = Style{Type: StyleEmail}
+		case *tg.MessageEntityBold:
+			br.Value = Style{Type: StyleBold}
+		case *tg.MessageEntityItalic:
+			br.Value = Style{Type: StyleItalic}
+		case *tg.MessageEntityCode:
+			br.Value = Style{Type: StyleCode}
+		case *tg.MessageEntityPre:
+			br.Value = Style{Type: StylePre, Language: entity.Language}
+		case *tg.MessageEntityTextURL:
+			br.Value = Style{Type: StyleURL, URL: params.NormalizeURL(ctx, entity.URL)}
+		case *tg.MessageEntityMentionName:
+			userID := ids.MakeUserID(entity.UserID)
+			userInfo, err := params.GetUserInfo(ctx, userID)
+			if err != nil {
+				return nil, err
+			}
+			mentions[userInfo.MXID] = struct{}{}
+			br.Value = Mention{UserInfo: userInfo, UserID: userID}
+		case *tg.MessageEntityPhone:
+			br.Value = Style{Type: StylePhone}
+		case *tg.MessageEntityCashtag:
+			br.Value = Style{Type: StyleCashtag}
+		case *tg.MessageEntityUnderline:
+			br.Value = Style{Type: StyleUnderline}
+		case *tg.MessageEntityStrike:
+			br.Value = Style{Type: StyleStrikethrough}
+		case *tg.MessageEntityBankCard:
+			br.Value = Style{Type: StyleBankCard}
+		case *tg.MessageEntitySpoiler:
+			br.Value = Style{Type: StyleSpoiler}
+		case *tg.MessageEntityCustomEmoji:
+			emoji, contentURI := params.GetCustomEmoji(ids.MakeEmojiIDFromDocumentID(entity.DocumentID))
+			if emoji != "" {
+				br.Value = Style{Type: StyleCustomEmoji, Emoji: emoji}
+			} else {
+				br.Value = Style{Type: StyleCustomEmoji, EmojiURI: contentURI}
+			}
+		case *tg.MessageEntityBlockquote:
+			br.Value = Style{Type: StyleBlockquote}
+		}
+		lrt.Add(br)
+	}
+
+	content.Mentions.UserIDs = maps.Keys(mentions)
+	content.FormattedBody = lrt.Format(utf16Message, formatContext{})
+	content.Format = event.FormatHTML
+	return content, nil
+}