config: re-add displayname template

Fixes #1057

pkg/connector/client.go

@@ -47,7 +47,6 @@ import (
 	"go.mau.fi/mautrix-telegram/pkg/connector/matrixfmt"
 	"go.mau.fi/mautrix-telegram/pkg/connector/store"
 	"go.mau.fi/mautrix-telegram/pkg/connector/telegramfmt"
-	"go.mau.fi/mautrix-telegram/pkg/connector/util"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/auth"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/updates"
@@ -430,12 +429,12 @@ func (t *TelegramClient) onPing() {
 	}
 }
 
-func userToRemoteProfile(
+func (t *TelegramConnector) userToRemoteProfile(
 	self *tg.User,
 	ghost *bridgev2.Ghost,
 	prevState *status.RemoteProfile,
 ) (profile status.RemoteProfile, name string) {
-	profile.Name = util.FormatFullName(self.FirstName, self.LastName, self.Deleted, self.ID)
+	profile.Name = t.Config.FormatDisplayname(self.FirstName, self.LastName, self.Username, self.Deleted, self.ID)
 	if self.Phone != "" {
 		profile.Phone = "+" + strings.TrimPrefix(self.Phone, "+")
 	} else if prevState != nil {
@@ -455,7 +454,7 @@ func userToRemoteProfile(
 }
 
 func (t *TelegramClient) updateRemoteProfile(ctx context.Context, self *tg.User, ghost *bridgev2.Ghost) bool {
-	newProfile, newName := userToRemoteProfile(self, ghost, &t.userLogin.RemoteProfile)
+	newProfile, newName := t.main.userToRemoteProfile(self, ghost, &t.userLogin.RemoteProfile)
 	if t.userLogin.RemoteProfile != newProfile || t.userLogin.RemoteName != newName {
 		t.userLogin.RemoteProfile = newProfile
 		t.userLogin.RemoteName = newName

pkg/connector/config.go

@@ -20,8 +20,11 @@ import (
 	_ "embed"
 	"fmt"
 	"slices"
+	"strings"
+	"text/template"
 
 	up "go.mau.fi/util/configupgrade"
+	"gopkg.in/yaml.v3"
 	"maunium.net/go/mautrix/bridgev2"
 	"maunium.net/go/mautrix/bridgev2/bridgeconfig"
 	"maunium.net/go/mautrix/id"
@@ -86,12 +89,55 @@ type TelegramConfig struct {
 	AlwaysTombstoneOnSupergroupMigration bool                `yaml:"always_tombstone_on_supergroup_migration"`
 	ImageAsFilePixels                    int                 `yaml:"image_as_file_pixels"`
 	DisableViewOnce                      bool                `yaml:"disable_view_once"`
+	DisplaynameTemplate                  string              `yaml:"displayname_template"`
+	displaynameTemplate                  *template.Template  `yaml:"-"`
 }
 
 func (c TelegramConfig) ShouldBridge(participantCount int) bool {
 	return c.MaxMemberCount < 0 || participantCount <= c.MaxMemberCount
 }
 
+type DisplaynameParams struct {
+	FullName  string
+	FirstName string
+	LastName  string
+	Username  string
+	UserID    int64
+	Deleted   bool
+}
+
+func (c *TelegramConfig) FormatDisplayname(firstName, lastName, username string, deleted bool, userID int64) string {
+	var buf strings.Builder
+	err := c.displaynameTemplate.Execute(&buf, DisplaynameParams{
+		FullName:  strings.TrimSpace(firstName + " " + lastName),
+		FirstName: firstName,
+		LastName:  lastName,
+		Username:  username,
+		UserID:    userID,
+		Deleted:   deleted,
+	})
+	if err != nil {
+		panic(fmt.Errorf("displayname template is broken: %w", err))
+	}
+	return buf.String()
+}
+
+type umConfig TelegramConfig
+
+func (c *TelegramConfig) UnmarshalYAML(node *yaml.Node) error {
+	err := node.Decode((*umConfig)(c))
+	if err != nil {
+		return err
+	}
+	return c.PostProcess()
+}
+
+func (c *TelegramConfig) PostProcess() error {
+	var err error
+	c.displaynameTemplate, err = template.New("displayname").Parse(c.DisplaynameTemplate)
+	return err
+}
+
 //go:embed example-config.yaml
 var ExampleConfig string
 
@@ -130,6 +176,7 @@ func upgradeConfig(helper up.Helper) {
 	helper.Copy(up.Bool, "always_tombstone_on_supergroup_migration")
 	helper.Copy(up.Int, "image_as_file_pixels")
 	helper.Copy(up.Bool, "disable_view_once")
+	helper.Copy(up.Str, "displayname_template")
 }
 
 func (tg *TelegramConnector) GetConfig() (example string, data any, upgrader up.Upgrader) {

pkg/connector/example-config.yaml

@@ -104,3 +104,11 @@ always_tombstone_on_supergroup_migration: false
 image_as_file_pixels: 16777216
 # Should view-once messages be disabled entirely?
 disable_view_once: false
+# Displayname template for Telegram users.
+# {{ .FullName }} - the full name of the Telegram user
+# {{ .FirstName }} - the first name of the Telegram user
+# {{ .LastName }} - the last name of the Telegram user
+# {{ .Username }} - the primary username of the Telegram user, if the user has one
+# {{ .UserID }} - the internal user ID of the Telegram user
+# {{ .Deleted }} - true if the user has been deleted, false otherwise
+displayname_template: "{{ if .Deleted }}Deleted account {{ .UserID }}{{ else }}{{ .FullName }}{{ end }}"

pkg/connector/handletelegram.go

@@ -42,7 +42,6 @@ import (
 	"go.mau.fi/mautrix-telegram/pkg/connector/media"
 	"go.mau.fi/mautrix-telegram/pkg/connector/store"
 	"go.mau.fi/mautrix-telegram/pkg/connector/tljson"
-	"go.mau.fi/mautrix-telegram/pkg/connector/util"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/tgerr"
 )
@@ -728,13 +727,7 @@ func (t *TelegramClient) onUserName(ctx context.Context, e tg.Entities, update *
 
 	var userInfo bridgev2.UserInfo
 
-	name := util.FormatFullName(update.FirstName, update.LastName, false, update.UserID)
+	var firstUsername string
-	userInfo.Name = &name
-	if meta.ContactSource != 0 && meta.ContactSource != t.telegramUserID && !t.main.Config.ContactNames {
-		// TODO fetch full info to accurately detect if the user is a contact or not
-		userInfo.Name = nil
-	}
-
 	if len(update.Usernames) > 0 {
 		for _, ident := range ghost.Identifiers {
 			if !strings.HasPrefix(ident, "telegram:") {
@@ -742,7 +735,10 @@ func (t *TelegramClient) onUserName(ctx context.Context, e tg.Entities, update *
 			}
 		}
 
-		for _, username := range update.Usernames {
+		for i, username := range update.Usernames {
+			if i == 0 {
+				firstUsername = username.Username
+			}
 			userInfo.Identifiers = append(userInfo.Identifiers, fmt.Sprintf("telegram:%s", username.Username))
 		}
 
@@ -750,6 +746,13 @@ func (t *TelegramClient) onUserName(ctx context.Context, e tg.Entities, update *
 		userInfo.Identifiers = slices.Compact(userInfo.Identifiers)
 	}
 
+	name := t.main.Config.FormatDisplayname(update.FirstName, update.LastName, firstUsername, false, update.UserID)
+	userInfo.Name = &name
+	if meta.ContactSource != 0 && meta.ContactSource != t.telegramUserID && !t.main.Config.ContactNames {
+		// TODO fetch full info to accurately detect if the user is a contact or not
+		userInfo.Name = nil
+	}
+
 	ghost.UpdateInfo(ctx, &userInfo)
 	if ghost.ID == t.userID {
 		var firstUsername string

pkg/connector/login.go

@@ -216,7 +216,7 @@ func (bl *baseLogin) finalizeLogin(
 	}
 	metadata.Session = bl.session
 	metadata.LoginMethod = bl.flowID
-	profile, name := userToRemoteProfile(self, nil, nil)
+	profile, name := bl.main.userToRemoteProfile(self, nil, nil)
 	userLoginID := ids.MakeUserLoginID(authorization.User.GetID())
 	ul, err := bl.user.NewLogin(ctx, &database.UserLogin{
 		ID:            userLoginID,

pkg/connector/tomatrix.go

@@ -41,7 +41,6 @@ import (
 	"go.mau.fi/mautrix-telegram/pkg/connector/media"
 	"go.mau.fi/mautrix-telegram/pkg/connector/store"
 	"go.mau.fi/mautrix-telegram/pkg/connector/telegramfmt"
-	"go.mau.fi/mautrix-telegram/pkg/connector/util"
 	"go.mau.fi/mautrix-telegram/pkg/connector/waveform"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/tgerr"
@@ -729,7 +728,7 @@ func (c *TelegramClient) convertMediaRequiringUpload(
 
 func (c *TelegramClient) convertContact(media tg.MessageMediaClass) *bridgev2.ConvertedMessagePart {
 	contact := media.(*tg.MessageMediaContact)
-	name := util.FormatFullName(contact.FirstName, contact.LastName, false, contact.UserID)
+	name := c.main.Config.FormatDisplayname(contact.FirstName, contact.LastName, "", false, contact.UserID)
 	formattedPhone := fmt.Sprintf("+%s", strings.TrimPrefix(contact.PhoneNumber, "+"))
 
 	content := event.MessageEventContent{

pkg/connector/userinfo.go

@@ -13,7 +13,6 @@ import (
 
 	"go.mau.fi/mautrix-telegram/pkg/connector/ids"
 	"go.mau.fi/mautrix-telegram/pkg/connector/store"
-	"go.mau.fi/mautrix-telegram/pkg/connector/util"
 	"go.mau.fi/mautrix-telegram/pkg/gotd/tg"
 )
 
@@ -258,7 +257,7 @@ func (t *TelegramClient) wrapUserInfo(ctx context.Context, u tg.UserClass, ghost
 		}
 	}
 
-	name := util.FormatFullName(user.FirstName, user.LastName, user.Deleted, user.ID)
+	name := t.main.Config.FormatDisplayname(user.FirstName, user.LastName, user.Username, user.Deleted, user.ID)
 	namePtr := &name
 	if user.Contact && ghost.Name != "" && oldMeta.ContactSource != t.telegramUserID && oldMeta.ContactSource != 0 && !t.main.Config.ContactNames {
 		namePtr = nil

pkg/connector/util/util.go

@@ -1,29 +0,0 @@
-// mautrix-telegram - A Matrix-Telegram puppeting bridge.
-// Copyright (C) 2025 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 util
-
-import (
-	"fmt"
-	"strings"
-)
-
-func FormatFullName(first, last string, deleted bool, userID int64) string {
-	if deleted {
-		return fmt.Sprintf("Deleted account %d", userID)
-	}
-	return strings.TrimSpace(fmt.Sprintf("%s %s", first, last))
-}