fix: add auto join for messages

Author: gsanchietti

matrix/client.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -128,7 +129,21 @@ func (mc *MatrixClient) JoinRoom(ctx context.Context, userID id.UserID, roomID i
 	defer mc.mu.Unlock()
 
 	mc.cli.UserID = userID
-	return mc.cli.JoinRoom(ctx, string(roomID), nil)
+
+	// Extract homeserver from room ID for federated joins
+	// Room ID format: !opaque:homeserver.name
+	roomIDStr := string(roomID)
+	req := &mautrix.ReqJoinRoom{}
+
+	if idx := strings.Index(roomIDStr, ":"); idx > 0 && idx < len(roomIDStr)-1 {
+		homeserver := roomIDStr[idx+1:]
+		if homeserver != "" {
+			req.Via = []string{homeserver}
+			logger.Debug().Str("user_id", string(userID)).Str("room_id", roomIDStr).Str("homeserver", homeserver).Msg("matrix: joining room with homeserver hint")
+		}
+	}
+
+	return mc.cli.JoinRoom(ctx, roomIDStr, req)
 }
 
 // CreateRoom creates a new room impersonating the specified userID.

service/messages.go

@@ -78,6 +78,13 @@ func (s *MessageService) SendMessage(ctx context.Context, req *models.SendMessag
 
 	logger.Debug().Str("user_id", string(userID)).Str("room_id", string(roomID)).Msg("sending message to room")
 
+	// Ensure the sender is a member of the room
+	_, err = s.matrixClient.JoinRoom(ctx, userID, roomID)
+	if err != nil {
+		logger.Error().Str("user_id", string(userID)).Str("room_id", string(roomID)).Err(err).Msg("failed to join room")
+		return nil, fmt.Errorf("send message: %w", err)
+	}
+
 	content := &event.MessageEventContent{
 		MsgType: event.MsgText,
 		Body:    req.SMSBody,
@@ -326,7 +333,7 @@ func mapAuthErr(err error) error {
 	if errors.Is(err, ErrAuthentication) {
 		return err
 	}
-	if errors.Is(err, mautrix.MUnknownToken) || errors.Is(err, mautrix.MMissingToken) || errors.Is(err, mautrix.MForbidden) {
+	if errors.Is(err, mautrix.MUnknownToken) || errors.Is(err, mautrix.MMissingToken) {
 		return fmt.Errorf("%w", ErrAuthentication)
 	}
 	return err