internal/db/queries.go

@@ -55,76 +55,132 @@ type MemberInfo struct {
 	LastSeen time.Time `json:"lastSeen"`
 }
 
-// CreateUser registers a new user with the given nick.
-func (database *Database) CreateUser(
+// CreateSession registers a new session and its first client.
+func (database *Database) CreateSession(
 	ctx context.Context,
 	nick string,
-) (int64, string, error) {
+) (int64, int64, string, error) {
+	sessionUUID := uuid.New().String()
+	clientUUID := uuid.New().String()
+
 	token, err := generateToken()
 	if err != nil {
-		return 0, "", err
+		return 0, 0, "", err
 	}
 
 	now := time.Now()
 
-	res, err := database.conn.ExecContext(ctx,
-		`INSERT INTO users
-		 (nick, token, created_at, last_seen)
-		 VALUES (?, ?, ?, ?)`,
-		nick, token, now, now)
+	transaction, err := database.conn.BeginTx(ctx, nil)
 	if err != nil {
-		return 0, "", fmt.Errorf("create user: %w", err)
+		return 0, 0, "", fmt.Errorf(
+			"begin tx: %w", err,
+		)
 	}
 
-	userID, _ := res.LastInsertId()
+	res, err := transaction.ExecContext(ctx,
+		`INSERT INTO sessions
+		 (uuid, nick, created_at, last_seen)
+		 VALUES (?, ?, ?, ?)`,
+		sessionUUID, nick, now, now)
+	if err != nil {
+		_ = transaction.Rollback()
 
-	return userID, token, nil
+		return 0, 0, "", fmt.Errorf(
+			"create session: %w", err,
+		)
+	}
+
+	sessionID, _ := res.LastInsertId()
+
+	clientRes, err := transaction.ExecContext(ctx,
+		`INSERT INTO clients
+		 (uuid, session_id, token,
+		  created_at, last_seen)
+		 VALUES (?, ?, ?, ?, ?)`,
+		clientUUID, sessionID, token, now, now)
+	if err != nil {
+		_ = transaction.Rollback()
+
+		return 0, 0, "", fmt.Errorf(
+			"create client: %w", err,
+		)
+	}
+
+	clientID, _ := clientRes.LastInsertId()
+
+	err = transaction.Commit()
+	if err != nil {
+		return 0, 0, "", fmt.Errorf(
+			"commit session: %w", err,
+		)
+	}
+
+	return sessionID, clientID, token, nil
 }
 
-// GetUserByToken returns user id and nick for a token.
-func (database *Database) GetUserByToken(
+// GetSessionByToken returns session id, client id, and
+// nick for a client token.
+func (database *Database) GetSessionByToken(
 	ctx context.Context,
 	token string,
-) (int64, string, error) {
-	var userID int64
-
-	var nick string
+) (int64, int64, string, error) {
+	var (
+		sessionID int64
+		clientID  int64
+		nick      string
+	)
 
 	err := database.conn.QueryRowContext(
 		ctx,
-		"SELECT id, nick FROM users WHERE token = ?",
+		`SELECT s.id, c.id, s.nick
+		 FROM clients c
+		 INNER JOIN sessions s
+		   ON s.id = c.session_id
+		 WHERE c.token = ?`,
 		token,
-	).Scan(&userID, &nick)
+	).Scan(&sessionID, &clientID, &nick)
 	if err != nil {
-		return 0, "", fmt.Errorf("get user by token: %w", err)
+		return 0, 0, "", fmt.Errorf(
+			"get session by token: %w", err,
+		)
 	}
 
+	now := time.Now()
+
 	_, _ = database.conn.ExecContext(
 		ctx,
-		"UPDATE users SET last_seen = ? WHERE id = ?",
-		time.Now(), userID,
+		"UPDATE sessions SET last_seen = ? WHERE id = ?",
+		now, sessionID,
 	)
 
-	return userID, nick, nil
+	_, _ = database.conn.ExecContext(
+		ctx,
+		"UPDATE clients SET last_seen = ? WHERE id = ?",
+		now, clientID,
+	)
+
+	return sessionID, clientID, nick, nil
 }
 
-// GetUserByNick returns user id for a given nick.
-func (database *Database) GetUserByNick(
+// GetSessionByNick returns session id for a given nick.
+func (database *Database) GetSessionByNick(
 	ctx context.Context,
 	nick string,
 ) (int64, error) {
-	var userID int64
+	var sessionID int64
 
 	err := database.conn.QueryRowContext(
 		ctx,
-		"SELECT id FROM users WHERE nick = ?",
+		"SELECT id FROM sessions WHERE nick = ?",
 		nick,
-	).Scan(&userID)
+	).Scan(&sessionID)
 	if err != nil {
-		return 0, fmt.Errorf("get user by nick: %w", err)
+		return 0, fmt.Errorf(
+			"get session by nick: %w", err,
+		)
 	}
 
-	return userID, nil
+	return sessionID, nil
 }
 
 // GetChannelByName returns the channel ID for a name.
@@ -179,16 +235,16 @@ func (database *Database) GetOrCreateChannel(
 	return channelID, nil
 }
 
-// JoinChannel adds a user to a channel.
+// JoinChannel adds a session to a channel.
 func (database *Database) JoinChannel(
 	ctx context.Context,
-	channelID, userID int64,
+	channelID, sessionID int64,
 ) error {
 	_, err := database.conn.ExecContext(ctx,
 		`INSERT OR IGNORE INTO channel_members
-		 (channel_id, user_id, joined_at)
+		 (channel_id, session_id, joined_at)
 		 VALUES (?, ?, ?)`,
-		channelID, userID, time.Now())
+		channelID, sessionID, time.Now())
 	if err != nil {
 		return fmt.Errorf("join channel: %w", err)
 	}
@@ -196,15 +252,15 @@ func (database *Database) JoinChannel(
 	return nil
 }
 
-// PartChannel removes a user from a channel.
+// PartChannel removes a session from a channel.
 func (database *Database) PartChannel(
 	ctx context.Context,
-	channelID, userID int64,
+	channelID, sessionID int64,
 ) error {
 	_, err := database.conn.ExecContext(ctx,
 		`DELETE FROM channel_members
-		 WHERE channel_id = ? AND user_id = ?`,
-		channelID, userID)
+		 WHERE channel_id = ? AND session_id = ?`,
+		channelID, sessionID)
 	if err != nil {
 		return fmt.Errorf("part channel: %w", err)
 	}
@@ -265,18 +321,18 @@ func scanChannels(
 	return out, nil
 }
 
-// ListChannels returns channels the user has joined.
+// ListChannels returns channels the session has joined.
 func (database *Database) ListChannels(
 	ctx context.Context,
-	userID int64,
+	sessionID int64,
 ) ([]ChannelInfo, error) {
 	rows, err := database.conn.QueryContext(ctx,
 		`SELECT c.id, c.name, c.topic
 		 FROM channels c
 		 INNER JOIN channel_members cm
 		   ON cm.channel_id = c.id
-		 WHERE cm.user_id = ?
-		 ORDER BY c.name`, userID)
+		 WHERE cm.session_id = ?
+		 ORDER BY c.name`, sessionID)
 	if err != nil {
 		return nil, fmt.Errorf("list channels: %w", err)
 	}
@@ -306,12 +362,12 @@ func (database *Database) ChannelMembers(
 	channelID int64,
 ) ([]MemberInfo, error) {
 	rows, err := database.conn.QueryContext(ctx,
-		`SELECT u.id, u.nick, u.last_seen
-		 FROM users u
+		`SELECT s.id, s.nick, s.last_seen
+		 FROM sessions s
 		 INNER JOIN channel_members cm
-		   ON cm.user_id = u.id
+		   ON cm.session_id = s.id
 		 WHERE cm.channel_id = ?
-		 ORDER BY u.nick`, channelID)
+		 ORDER BY s.nick`, channelID)
 	if err != nil {
 		return nil, fmt.Errorf(
 			"query channel members: %w", err,
@@ -349,17 +405,17 @@ func (database *Database) ChannelMembers(
 	return members, nil
 }
 
-// IsChannelMember checks if a user belongs to a channel.
+// IsChannelMember checks if a session belongs to a channel.
 func (database *Database) IsChannelMember(
 	ctx context.Context,
-	channelID, userID int64,
+	channelID, sessionID int64,
 ) (bool, error) {
 	var count int
 
 	err := database.conn.QueryRowContext(ctx,
 		`SELECT COUNT(*) FROM channel_members
-		 WHERE channel_id = ? AND user_id = ?`,
-		channelID, userID,
+		 WHERE channel_id = ? AND session_id = ?`,
+		channelID, sessionID,
 	).Scan(&count)
 	if err != nil {
 		return false, fmt.Errorf(
@@ -397,13 +453,13 @@ func scanInt64s(rows *sql.Rows) ([]int64, error) {
 	return ids, nil
 }
 
-// GetChannelMemberIDs returns user IDs in a channel.
+// GetChannelMemberIDs returns session IDs in a channel.
 func (database *Database) GetChannelMemberIDs(
 	ctx context.Context,
 	channelID int64,
 ) ([]int64, error) {
 	rows, err := database.conn.QueryContext(ctx,
-		`SELECT user_id FROM channel_members
+		`SELECT session_id FROM channel_members
 		 WHERE channel_id = ?`, channelID)
 	if err != nil {
 		return nil, fmt.Errorf(
@@ -414,17 +470,17 @@ func (database *Database) GetChannelMemberIDs(
 	return scanInt64s(rows)
 }
 
-// GetUserChannelIDs returns channel IDs the user is in.
-func (database *Database) GetUserChannelIDs(
+// GetSessionChannelIDs returns channel IDs for a session.
+func (database *Database) GetSessionChannelIDs(
 	ctx context.Context,
-	userID int64,
+	sessionID int64,
 ) ([]int64, error) {
 	rows, err := database.conn.QueryContext(ctx,
 		`SELECT channel_id FROM channel_members
-		 WHERE user_id = ?`, userID)
+		 WHERE session_id = ?`, sessionID)
 	if err != nil {
 		return nil, fmt.Errorf(
-			"get user channel ids: %w", err,
+			"get session channel ids: %w", err,
 		)
 	}
 
@@ -467,27 +523,52 @@ func (database *Database) InsertMessage(
 	return dbID, msgUUID, nil
 }
 
-// EnqueueMessage adds a message to a user's queue.
-func (database *Database) EnqueueMessage(
+// EnqueueToSession adds a message to all clients of a
+// session's queues.
+func (database *Database) EnqueueToSession(
 	ctx context.Context,
-	userID, messageID int64,
+	sessionID, messageID int64,
 ) error {
 	_, err := database.conn.ExecContext(ctx,
 		`INSERT OR IGNORE INTO client_queues
-		 (user_id, message_id, created_at)
-		 VALUES (?, ?, ?)`,
-		userID, messageID, time.Now())
+		 (client_id, message_id, created_at)
+		 SELECT c.id, ?, ?
+		 FROM clients c
+		 WHERE c.session_id = ?`,
+		messageID, time.Now(), sessionID)
 	if err != nil {
-		return fmt.Errorf("enqueue message: %w", err)
+		return fmt.Errorf(
+			"enqueue to session: %w", err,
+		)
 	}
 
 	return nil
 }
 
-// PollMessages returns queued messages for a user.
+// EnqueueToClient adds a message to a specific client's
+// queue.
+func (database *Database) EnqueueToClient(
+	ctx context.Context,
+	clientID, messageID int64,
+) error {
+	_, err := database.conn.ExecContext(ctx,
+		`INSERT OR IGNORE INTO client_queues
+		 (client_id, message_id, created_at)
+		 VALUES (?, ?, ?)`,
+		clientID, messageID, time.Now())
+	if err != nil {
+		return fmt.Errorf(
+			"enqueue to client: %w", err,
+		)
+	}
+
+	return nil
+}
+
+// PollMessages returns queued messages for a client.
 func (database *Database) PollMessages(
 	ctx context.Context,
-	userID, afterQueueID int64,
+	clientID, afterQueueID int64,
 	limit int,
 ) ([]IRCMessage, int64, error) {
 	if limit <= 0 {
@@ -501,9 +582,9 @@ func (database *Database) PollMessages(
 		 FROM client_queues cq
 		 INNER JOIN messages m
 		   ON m.id = cq.message_id
-		 WHERE cq.user_id = ? AND cq.id > ?
+		 WHERE cq.client_id = ? AND cq.id > ?
 		 ORDER BY cq.id ASC LIMIT ?`,
-		userID, afterQueueID, limit)
+		clientID, afterQueueID, limit)
 	if err != nil {
 		return nil, afterQueueID, fmt.Errorf(
 			"poll messages: %w", err,
@@ -649,15 +730,15 @@ func reverseMessages(msgs []IRCMessage) {
 	}
 }
 
-// ChangeNick updates a user's nickname.
+// ChangeNick updates a session's nickname.
 func (database *Database) ChangeNick(
 	ctx context.Context,
-	userID int64,
+	sessionID int64,
 	newNick string,
 ) error {
 	_, err := database.conn.ExecContext(ctx,
-		"UPDATE users SET nick = ? WHERE id = ?",
-		newNick, userID)
+		"UPDATE sessions SET nick = ? WHERE id = ?",
+		newNick, sessionID)
 	if err != nil {
 		return fmt.Errorf("change nick: %w", err)
 	}
@@ -681,38 +762,38 @@ func (database *Database) SetTopic(
 	return nil
 }
 
-// DeleteUser removes a user and all their data.
-func (database *Database) DeleteUser(
+// DeleteSession removes a session and all its data.
+func (database *Database) DeleteSession(
 	ctx context.Context,
-	userID int64,
+	sessionID int64,
 ) error {
 	_, err := database.conn.ExecContext(
 		ctx,
-		"DELETE FROM users WHERE id = ?",
-		userID,
+		"DELETE FROM sessions WHERE id = ?",
+		sessionID,
 	)
 	if err != nil {
-		return fmt.Errorf("delete user: %w", err)
+		return fmt.Errorf("delete session: %w", err)
 	}
 
 	return nil
 }
 
-// GetAllChannelMembershipsForUser returns channels
-// a user belongs to.
-func (database *Database) GetAllChannelMembershipsForUser(
+// GetSessionChannels returns channels a session
+// belongs to.
+func (database *Database) GetSessionChannels(
 	ctx context.Context,
-	userID int64,
+	sessionID int64,
 ) ([]ChannelInfo, error) {
 	rows, err := database.conn.QueryContext(ctx,
 		`SELECT c.id, c.name, c.topic
 		 FROM channels c
 		 INNER JOIN channel_members cm
 		   ON cm.channel_id = c.id
-		 WHERE cm.user_id = ?`, userID)
+		 WHERE cm.session_id = ?`, sessionID)
 	if err != nil {
 		return nil, fmt.Errorf(
-			"get memberships: %w", err,
+			"get session channels: %w", err,
 		)
 	}
 

internal/db/queries_test.go

@@ -27,70 +27,91 @@ func setupTestDB(t *testing.T) *db.Database {
 	return database
 }
 
-func TestCreateUser(t *testing.T) {
+func TestCreateSession(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	id, token, err := database.CreateUser(ctx, "alice")
+	sessionID, _, token, err := database.CreateSession(
+		ctx, "alice",
+	)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if id == 0 || token == "" {
+	if sessionID == 0 || token == "" {
 		t.Fatal("expected valid id and token")
 	}
 
-	_, _, err = database.CreateUser(ctx, "alice")
-	if err == nil {
+	_, _, dupToken, dupErr := database.CreateSession(
+		ctx, "alice",
+	)
+	if dupErr == nil {
 		t.Fatal("expected error for duplicate nick")
 	}
+
+	_ = dupToken
 }
 
-func TestGetUserByToken(t *testing.T) {
+func TestGetSessionByToken(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	_, token, err := database.CreateUser(ctx, "bob")
+	_, _, token, err := database.CreateSession(ctx, "bob")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	id, nick, err := database.GetUserByToken(ctx, token)
+	sessionID, clientID, nick, err :=
+		database.GetSessionByToken(ctx, token)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if nick != "bob" || id == 0 {
+	if nick != "bob" || sessionID == 0 || clientID == 0 {
 		t.Fatalf("expected bob, got %s", nick)
 	}
 
-	_, _, err = database.GetUserByToken(ctx, "badtoken")
-	if err == nil {
+	badSID, badCID, badNick, badErr :=
+		database.GetSessionByToken(ctx, "badtoken")
+	if badErr == nil {
 		t.Fatal("expected error for bad token")
 	}
+
+	if badSID != 0 || badCID != 0 || badNick != "" {
+		t.Fatal("expected zero values on error")
+	}
 }
 
-func TestGetUserByNick(t *testing.T) {
+func TestGetSessionByNick(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	_, _, err := database.CreateUser(ctx, "charlie")
+	charlieID, charlieClientID, charlieToken, err :=
+		database.CreateSession(ctx, "charlie")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	id, err := database.GetUserByNick(ctx, "charlie")
+	if charlieID == 0 || charlieClientID == 0 {
+		t.Fatal("expected valid session/client IDs")
+	}
+
+	if charlieToken == "" {
+		t.Fatal("expected non-empty token")
+	}
+
+	id, err := database.GetSessionByNick(ctx, "charlie")
 	if err != nil || id == 0 {
 		t.Fatal("expected to find charlie")
 	}
 
-	_, err = database.GetUserByNick(ctx, "nobody")
+	_, err = database.GetSessionByNick(ctx, "nobody")
 	if err == nil {
 		t.Fatal("expected error for unknown nick")
 	}
@@ -129,7 +150,7 @@ func TestJoinAndPart(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	uid, _, err := database.CreateUser(ctx, "user1")
+	sid, _, _, err := database.CreateSession(ctx, "user1")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -139,22 +160,22 @@ func TestJoinAndPart(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, chID, uid)
+	err = database.JoinChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	ids, err := database.GetChannelMemberIDs(ctx, chID)
-	if err != nil || len(ids) != 1 || ids[0] != uid {
-		t.Fatal("expected user in channel")
+	if err != nil || len(ids) != 1 || ids[0] != sid {
+		t.Fatal("expected session in channel")
 	}
 
-	err = database.JoinChannel(ctx, chID, uid)
+	err = database.JoinChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.PartChannel(ctx, chID, uid)
+	err = database.PartChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -178,17 +199,17 @@ func TestDeleteChannelIfEmpty(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	uid, _, err := database.CreateUser(ctx, "temp")
+	sid, _, _, err := database.CreateSession(ctx, "temp")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, chID, uid)
+	err = database.JoinChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.PartChannel(ctx, chID, uid)
+	err = database.PartChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -204,7 +225,7 @@ func TestDeleteChannelIfEmpty(t *testing.T) {
 	}
 }
 
-func createUserWithChannels(
+func createSessionWithChannels(
 	t *testing.T,
 	database *db.Database,
 	nick, ch1Name, ch2Name string,
@@ -213,7 +234,7 @@ func createUserWithChannels(
 
 	ctx := t.Context()
 
-	uid, _, err := database.CreateUser(ctx, nick)
+	sid, _, _, err := database.CreateSession(ctx, nick)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -232,29 +253,29 @@ func createUserWithChannels(
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, ch1, uid)
+	err = database.JoinChannel(ctx, ch1, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, ch2, uid)
+	err = database.JoinChannel(ctx, ch2, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	return uid, ch1, ch2
+	return sid, ch1, ch2
 }
 
 func TestListChannels(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
-	uid, _, _ := createUserWithChannels(
+	sid, _, _ := createSessionWithChannels(
 		t, database, "lister", "#a", "#b",
 	)
 
 	channels, err := database.ListChannels(
-		t.Context(), uid,
+		t.Context(), sid,
 	)
 	if err != nil || len(channels) != 2 {
 		t.Fatalf(
@@ -295,17 +316,21 @@ func TestChangeNick(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	uid, token, err := database.CreateUser(ctx, "old")
+	sid, _, token, err := database.CreateSession(
+		ctx, "old",
+	)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.ChangeNick(ctx, uid, "new")
+	err = database.ChangeNick(ctx, sid, "new")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	_, nick, err := database.GetUserByToken(ctx, token)
+	_, _, nick, err := database.GetSessionByToken(
+		ctx, token,
+	)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -375,7 +400,16 @@ func TestPollMessages(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	uid, _, err := database.CreateUser(ctx, "poller")
+	sid, _, token, err := database.CreateSession(
+		ctx, "poller",
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, clientID, _, err := database.GetSessionByToken(
+		ctx, token,
+	)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -389,7 +423,7 @@ func TestPollMessages(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = database.EnqueueMessage(ctx, uid, dbID)
+	err = database.EnqueueToSession(ctx, sid, dbID)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -397,7 +431,7 @@ func TestPollMessages(t *testing.T) {
 	const batchSize = 10
 
 	msgs, lastQID, err := database.PollMessages(
-		ctx, uid, 0, batchSize,
+		ctx, clientID, 0, batchSize,
 	)
 	if err != nil {
 		t.Fatal(err)
@@ -420,7 +454,7 @@ func TestPollMessages(t *testing.T) {
 	}
 
 	msgs, _, _ = database.PollMessages(
-		ctx, uid, lastQID, batchSize,
+		ctx, clientID, lastQID, batchSize,
 	)
 
 	if len(msgs) != 0 {
@@ -467,13 +501,15 @@ func TestGetHistory(t *testing.T) {
 	}
 }
 
-func TestDeleteUser(t *testing.T) {
+func TestDeleteSession(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	uid, _, err := database.CreateUser(ctx, "deleteme")
+	sid, _, _, err := database.CreateSession(
+		ctx, "deleteme",
+	)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -485,19 +521,19 @@ func TestDeleteUser(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, chID, uid)
+	err = database.JoinChannel(ctx, chID, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.DeleteUser(ctx, uid)
+	err = database.DeleteSession(ctx, sid)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	_, err = database.GetUserByNick(ctx, "deleteme")
+	_, err = database.GetSessionByNick(ctx, "deleteme")
 	if err == nil {
-		t.Fatal("user should be deleted")
+		t.Fatal("session should be deleted")
 	}
 
 	ids, _ := database.GetChannelMemberIDs(ctx, chID)
@@ -512,12 +548,12 @@ func TestChannelMembers(t *testing.T) {
 	database := setupTestDB(t)
 	ctx := t.Context()
 
-	uid1, _, err := database.CreateUser(ctx, "m1")
+	sid1, _, _, err := database.CreateSession(ctx, "m1")
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	uid2, _, err := database.CreateUser(ctx, "m2")
+	sid2, _, _, err := database.CreateSession(ctx, "m2")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -529,12 +565,12 @@ func TestChannelMembers(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, chID, uid1)
+	err = database.JoinChannel(ctx, chID, sid1)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	err = database.JoinChannel(ctx, chID, uid2)
+	err = database.JoinChannel(ctx, chID, sid2)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -548,17 +584,17 @@ func TestChannelMembers(t *testing.T) {
 	}
 }
 
-func TestGetAllChannelMembershipsForUser(t *testing.T) {
+func TestGetSessionChannels(t *testing.T) {
 	t.Parallel()
 
 	database := setupTestDB(t)
-	uid, _, _ := createUserWithChannels(
+	sid, _, _ := createSessionWithChannels(
 		t, database, "multi", "#m1", "#m2",
 	)
 
 	channels, err :=
-		database.GetAllChannelMembershipsForUser(
-			t.Context(), uid,
+		database.GetSessionChannels(
+			t.Context(), sid,
 		)
 	if err != nil || len(channels) != 2 {
 		t.Fatalf(
@@ -567,3 +603,51 @@ func TestGetAllChannelMembershipsForUser(t *testing.T) {
 		)
 	}
 }
+
+func TestEnqueueToClient(t *testing.T) {
+	t.Parallel()
+
+	database := setupTestDB(t)
+	ctx := t.Context()
+
+	_, _, token, err := database.CreateSession(
+		ctx, "enqclient",
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, clientID, _, err := database.GetSessionByToken(
+		ctx, token,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	body := json.RawMessage(`["test"]`)
+
+	dbID, _, err := database.InsertMessage(
+		ctx, "PRIVMSG", "sender", "#ch", body, nil,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = database.EnqueueToClient(ctx, clientID, dbID)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	const batchSize = 10
+
+	msgs, _, err := database.PollMessages(
+		ctx, clientID, 0, batchSize,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(msgs) != 1 {
+		t.Fatalf("expected 1, got %d", len(msgs))
+	}
+}

internal/db/schema/001_initial.sql

@@ -1,15 +1,28 @@
 -- Chat server schema (pre-1.0 consolidated)
 PRAGMA foreign_keys = ON;
 
--- Users: IRC-style sessions (no passwords, just nick + token)
-CREATE TABLE IF NOT EXISTS users (
+-- Sessions: IRC-style sessions (no passwords, nick + optional signing key)
+CREATE TABLE IF NOT EXISTS sessions (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
+    uuid TEXT NOT NULL UNIQUE,
     nick TEXT NOT NULL UNIQUE,
+    signing_key TEXT NOT NULL DEFAULT '',
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    last_seen DATETIME DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_sessions_uuid ON sessions(uuid);
+
+-- Clients: each session can have multiple connected clients
+CREATE TABLE IF NOT EXISTS clients (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    uuid TEXT NOT NULL UNIQUE,
+    session_id INTEGER NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
     token TEXT NOT NULL UNIQUE,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     last_seen DATETIME DEFAULT CURRENT_TIMESTAMP
 );
-CREATE INDEX IF NOT EXISTS idx_users_token ON users(token);
+CREATE INDEX IF NOT EXISTS idx_clients_token ON clients(token);
+CREATE INDEX IF NOT EXISTS idx_clients_session ON clients(session_id);
 
 -- Channels
 CREATE TABLE IF NOT EXISTS channels (
@@ -24,9 +37,9 @@ CREATE TABLE IF NOT EXISTS channels (
 CREATE TABLE IF NOT EXISTS channel_members (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     channel_id INTEGER NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
-    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    session_id INTEGER NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
     joined_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-    UNIQUE(channel_id, user_id)
+    UNIQUE(channel_id, session_id)
 );
 
 -- Messages: IRC envelope format
@@ -46,9 +59,9 @@ CREATE INDEX IF NOT EXISTS idx_messages_created ON messages(created_at);
 -- Per-client message queues for fan-out delivery
 CREATE TABLE IF NOT EXISTS client_queues (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
-    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    client_id INTEGER NOT NULL REFERENCES clients(id) ON DELETE CASCADE,
     message_id INTEGER NOT NULL REFERENCES messages(id) ON DELETE CASCADE,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-    UNIQUE(user_id, message_id)
+    UNIQUE(client_id, message_id)
 );
-CREATE INDEX IF NOT EXISTS idx_client_queues_user ON client_queues(user_id, id);
+CREATE INDEX IF NOT EXISTS idx_client_queues_client ON client_queues(client_id, id);

internal/handlers/api.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -37,35 +38,37 @@ func (hdlr *Handlers) maxBodySize() int64 {
 	return defaultMaxBodySize
 }
 
-// authUser extracts the user from the Authorization header.
-func (hdlr *Handlers) authUser(
+// authSession extracts the session from the client token.
+func (hdlr *Handlers) authSession(
 	request *http.Request,
-) (int64, string, error) {
+) (int64, int64, string, error) {
 	auth := request.Header.Get("Authorization")
 	if !strings.HasPrefix(auth, "Bearer ") {
-		return 0, "", errUnauthorized
+		return 0, 0, "", errUnauthorized
 	}
 
 	token := strings.TrimPrefix(auth, "Bearer ")
 	if token == "" {
-		return 0, "", errUnauthorized
+		return 0, 0, "", errUnauthorized
 	}
 
-	uid, nick, err := hdlr.params.Database.GetUserByToken(
-		request.Context(), token,
-	)
+	sessionID, clientID, nick, err :=
+		hdlr.params.Database.GetSessionByToken(
+			request.Context(), token,
+		)
 	if err != nil {
-		return 0, "", fmt.Errorf("auth: %w", err)
+		return 0, 0, "", fmt.Errorf("auth: %w", err)
 	}
 
-	return uid, nick, nil
+	return sessionID, clientID, nick, nil
 }
 
 func (hdlr *Handlers) requireAuth(
 	writer http.ResponseWriter,
 	request *http.Request,
-) (int64, string, bool) {
-	uid, nick, err := hdlr.authUser(request)
+) (int64, int64, string, bool) {
+	sessionID, clientID, nick, err :=
+		hdlr.authSession(request)
 	if err != nil {
 		hdlr.respondError(
 			writer, request,
@@ -73,19 +76,19 @@ func (hdlr *Handlers) requireAuth(
 			http.StatusUnauthorized,
 		)
 
-		return 0, "", false
+		return 0, 0, "", false
 	}
 
-	return uid, nick, true
+	return sessionID, clientID, nick, true
 }
 
 // fanOut stores a message and enqueues it to all specified
-// user IDs, then notifies them.
+// session IDs, then notifies them.
 func (hdlr *Handlers) fanOut(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	userIDs []int64,
+	sessionIDs []int64,
 ) (string, error) {
 	dbID, msgUUID, err := hdlr.params.Database.InsertMessage(
 		request.Context(), command, from, target, body, nil,
@@ -94,16 +97,16 @@ func (hdlr *Handlers) fanOut(
 		return "", fmt.Errorf("insert message: %w", err)
 	}
 
-	for _, uid := range userIDs {
-		enqErr := hdlr.params.Database.EnqueueMessage(
-			request.Context(), uid, dbID,
+	for _, sid := range sessionIDs {
+		enqErr := hdlr.params.Database.EnqueueToSession(
+			request.Context(), sid, dbID,
 		)
 		if enqErr != nil {
 			hdlr.log.Error("enqueue failed",
-				"error", enqErr, "user_id", uid)
+				"error", enqErr, "session_id", sid)
 		}
 
-		hdlr.broker.Notify(uid)
+		hdlr.broker.Notify(sid)
 	}
 
 	return msgUUID, nil
@@ -114,10 +117,10 @@ func (hdlr *Handlers) fanOutSilent(
 	request *http.Request,
 	command, from, target string,
 	body json.RawMessage,
-	userIDs []int64,
+	sessionIDs []int64,
 ) error {
 	_, err := hdlr.fanOut(
-		request, command, from, target, body, userIDs,
+		request, command, from, target, body, sessionIDs,
 	)
 
 	return err
@@ -125,16 +128,6 @@ func (hdlr *Handlers) fanOutSilent(
 
 // HandleCreateSession creates a new user session.
 func (hdlr *Handlers) HandleCreateSession() http.HandlerFunc {
-	type createRequest struct {
-		Nick string `json:"nick"`
-	}
-
-	type createResponse struct {
-		ID    int64  `json:"id"`
-		Nick  string `json:"nick"`
-		Token string `json:"token"`
-	}
-
 	return func(
 		writer http.ResponseWriter,
 		request *http.Request,
@@ -143,82 +136,174 @@ func (hdlr *Handlers) HandleCreateSession() http.HandlerFunc {
 			writer, request.Body, hdlr.maxBodySize(),
 		)
 
-		var payload createRequest
-
-		err := json.NewDecoder(request.Body).Decode(&payload)
-		if err != nil {
-			hdlr.respondError(
-				writer, request,
-				"invalid request body",
-				http.StatusBadRequest,
-			)
-
-			return
-		}
-
-		payload.Nick = strings.TrimSpace(payload.Nick)
-
-		if !validNickRe.MatchString(payload.Nick) {
-			hdlr.respondError(
-				writer, request,
-				"invalid nick format",
-				http.StatusBadRequest,
-			)
-
-			return
-		}
-
-		userID, token, err := hdlr.params.Database.CreateUser(
-			request.Context(), payload.Nick,
-		)
-		if err != nil {
-			if strings.Contains(err.Error(), "UNIQUE") {
-				hdlr.respondError(
-					writer, request,
-					"nick already taken",
-					http.StatusConflict,
-				)
-
-				return
-			}
-
-			hdlr.log.Error(
-				"create user failed", "error", err,
-			)
-			hdlr.respondError(
-				writer, request,
-				"internal error",
-				http.StatusInternalServerError,
-			)
-
-			return
-		}
-
-		hdlr.respondJSON(
-			writer, request,
-			&createResponse{
-				ID:    userID,
-				Nick:  payload.Nick,
-				Token: token,
-			},
-			http.StatusCreated,
-		)
+		hdlr.handleCreateSession(writer, request)
 	}
 }
 
-// HandleState returns the current user's info and channels.
+func (hdlr *Handlers) handleCreateSession(
+	writer http.ResponseWriter,
+	request *http.Request,
+) {
+	type createRequest struct {
+		Nick string `json:"nick"`
+	}
+
+	var payload createRequest
+
+	err := json.NewDecoder(request.Body).Decode(&payload)
+	if err != nil {
+		hdlr.respondError(
+			writer, request,
+			"invalid request body",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	payload.Nick = strings.TrimSpace(payload.Nick)
+
+	if !validNickRe.MatchString(payload.Nick) {
+		hdlr.respondError(
+			writer, request,
+			"invalid nick format",
+			http.StatusBadRequest,
+		)
+
+		return
+	}
+
+	sessionID, clientID, token, err :=
+		hdlr.params.Database.CreateSession(
+			request.Context(), payload.Nick,
+		)
+	if err != nil {
+		hdlr.handleCreateSessionError(
+			writer, request, err,
+		)
+
+		return
+	}
+
+	hdlr.deliverMOTD(request, clientID, sessionID)
+
+	hdlr.respondJSON(writer, request, map[string]any{
+		"id":    sessionID,
+		"nick":  payload.Nick,
+		"token": token,
+	}, http.StatusCreated)
+}
+
+func (hdlr *Handlers) handleCreateSessionError(
+	writer http.ResponseWriter,
+	request *http.Request,
+	err error,
+) {
+	if strings.Contains(err.Error(), "UNIQUE") {
+		hdlr.respondError(
+			writer, request,
+			"nick already taken",
+			http.StatusConflict,
+		)
+
+		return
+	}
+
+	hdlr.log.Error(
+		"create session failed", "error", err,
+	)
+	hdlr.respondError(
+		writer, request,
+		"internal error",
+		http.StatusInternalServerError,
+	)
+}
+
+// deliverMOTD sends the MOTD as IRC numeric messages to a
+// new client.
+func (hdlr *Handlers) deliverMOTD(
+	request *http.Request,
+	clientID, sessionID int64,
+) {
+	motd := hdlr.params.Config.MOTD
+	serverName := hdlr.params.Config.ServerName
+
+	if serverName == "" {
+		serverName = "chat"
+	}
+
+	if motd == "" {
+		return
+	}
+
+	ctx := request.Context()
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, "375", serverName,
+		"- "+serverName+" Message of the Day -",
+	)
+
+	for line := range strings.SplitSeq(motd, "\n") {
+		hdlr.enqueueNumeric(
+			ctx, clientID, "372", serverName,
+			"- "+line,
+		)
+	}
+
+	hdlr.enqueueNumeric(
+		ctx, clientID, "376", serverName,
+		"End of /MOTD command.",
+	)
+
+	hdlr.broker.Notify(sessionID)
+}
+
+func (hdlr *Handlers) enqueueNumeric(
+	ctx context.Context,
+	clientID int64,
+	command, serverName, text string,
+) {
+	body, err := json.Marshal([]string{text})
+	if err != nil {
+		hdlr.log.Error(
+			"marshal numeric body", "error", err,
+		)
+
+		return
+	}
+
+	dbID, _, insertErr := hdlr.params.Database.InsertMessage(
+		ctx, command, serverName, "",
+		json.RawMessage(body), nil,
+	)
+	if insertErr != nil {
+		hdlr.log.Error(
+			"insert numeric message", "error", insertErr,
+		)
+
+		return
+	}
+
+	_ = hdlr.params.Database.EnqueueToClient(
+		ctx, clientID, dbID,
+	)
+}
+
+// HandleState returns the current session's info and
+// channels.
 func (hdlr *Handlers) HandleState() http.HandlerFunc {
 	return func(
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
-		uid, nick, ok := hdlr.requireAuth(writer, request)
+		sessionID, _, nick, ok :=
+			hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
 
 		channels, err := hdlr.params.Database.ListChannels(
-			request.Context(), uid,
+			request.Context(), sessionID,
 		)
 		if err != nil {
 			hdlr.log.Error(
@@ -234,7 +319,7 @@ func (hdlr *Handlers) HandleState() http.HandlerFunc {
 		}
 
 		hdlr.respondJSON(writer, request, map[string]any{
-			"id":       uid,
+			"id":       sessionID,
 			"nick":     nick,
 			"channels": channels,
 		}, http.StatusOK)
@@ -247,7 +332,7 @@ func (hdlr *Handlers) HandleListAllChannels() http.HandlerFunc {
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
-		_, _, ok := hdlr.requireAuth(writer, request)
+		_, _, _, ok := hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
@@ -280,7 +365,7 @@ func (hdlr *Handlers) HandleChannelMembers() http.HandlerFunc {
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
-		_, _, ok := hdlr.requireAuth(writer, request)
+		_, _, _, ok := hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
@@ -328,7 +413,8 @@ func (hdlr *Handlers) HandleGetMessages() http.HandlerFunc {
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
-		uid, _, ok := hdlr.requireAuth(writer, request)
+		sessionID, clientID, _, ok :=
+			hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
@@ -349,7 +435,7 @@ func (hdlr *Handlers) HandleGetMessages() http.HandlerFunc {
 		}
 
 		msgs, lastQID, err := hdlr.params.Database.PollMessages(
-			request.Context(), uid,
+			request.Context(), clientID,
 			afterID, pollMessageLimit,
 		)
 		if err != nil {
@@ -374,17 +460,20 @@ func (hdlr *Handlers) HandleGetMessages() http.HandlerFunc {
 			return
 		}
 
-		hdlr.longPoll(writer, request, uid, afterID, timeout)
+		hdlr.longPoll(
+			writer, request,
+			sessionID, clientID, afterID, timeout,
+		)
 	}
 }
 
 func (hdlr *Handlers) longPoll(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid, afterID int64,
+	sessionID, clientID, afterID int64,
 	timeout int,
 ) {
-	waitCh := hdlr.broker.Wait(uid)
+	waitCh := hdlr.broker.Wait(sessionID)
 
 	timer := time.NewTimer(
 		time.Duration(timeout) * time.Second,
@@ -396,15 +485,15 @@ func (hdlr *Handlers) longPoll(
 	case <-waitCh:
 	case <-timer.C:
 	case <-request.Context().Done():
-		hdlr.broker.Remove(uid, waitCh)
+		hdlr.broker.Remove(sessionID, waitCh)
 
 		return
 	}
 
-	hdlr.broker.Remove(uid, waitCh)
+	hdlr.broker.Remove(sessionID, waitCh)
 
 	msgs, lastQID, err := hdlr.params.Database.PollMessages(
-		request.Context(), uid,
+		request.Context(), clientID,
 		afterID, pollMessageLimit,
 	)
 	if err != nil {
@@ -443,7 +532,8 @@ func (hdlr *Handlers) HandleSendCommand() http.HandlerFunc {
 			writer, request.Body, hdlr.maxBodySize(),
 		)
 
-		uid, nick, ok := hdlr.requireAuth(writer, request)
+		sessionID, _, nick, ok :=
+			hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
@@ -492,7 +582,7 @@ func (hdlr *Handlers) HandleSendCommand() http.HandlerFunc {
 		}
 
 		hdlr.dispatchCommand(
-			writer, request, uid, nick,
+			writer, request, sessionID, nick,
 			payload.Command, payload.To,
 			payload.Body, bodyLines,
 		)
@@ -502,7 +592,7 @@ func (hdlr *Handlers) HandleSendCommand() http.HandlerFunc {
 func (hdlr *Handlers) dispatchCommand(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, command, target string,
 	body json.RawMessage,
 	bodyLines func() []string,
@@ -510,20 +600,20 @@ func (hdlr *Handlers) dispatchCommand(
 	switch command {
 	case cmdPrivmsg, "NOTICE":
 		hdlr.handlePrivmsg(
-			writer, request, uid, nick,
+			writer, request, sessionID, nick,
 			command, target, body, bodyLines,
 		)
 	case "JOIN":
 		hdlr.handleJoin(
-			writer, request, uid, nick, target,
+			writer, request, sessionID, nick, target,
 		)
 	case "PART":
 		hdlr.handlePart(
-			writer, request, uid, nick, target, body,
+			writer, request, sessionID, nick, target, body,
 		)
 	case "NICK":
 		hdlr.handleNick(
-			writer, request, uid, nick, bodyLines,
+			writer, request, sessionID, nick, bodyLines,
 		)
 	case "TOPIC":
 		hdlr.handleTopic(
@@ -531,7 +621,7 @@ func (hdlr *Handlers) dispatchCommand(
 		)
 	case "QUIT":
 		hdlr.handleQuit(
-			writer, request, uid, nick, body,
+			writer, request, sessionID, nick, body,
 		)
 	case "PING":
 		hdlr.respondJSON(writer, request,
@@ -552,7 +642,7 @@ func (hdlr *Handlers) dispatchCommand(
 func (hdlr *Handlers) handlePrivmsg(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, command, target string,
 	body json.RawMessage,
 	bodyLines func() []string,
@@ -580,7 +670,7 @@ func (hdlr *Handlers) handlePrivmsg(
 
 	if strings.HasPrefix(target, "#") {
 		hdlr.handleChannelMsg(
-			writer, request, uid, nick,
+			writer, request, sessionID, nick,
 			command, target, body,
 		)
 
@@ -588,7 +678,7 @@ func (hdlr *Handlers) handlePrivmsg(
 	}
 
 	hdlr.handleDirectMsg(
-		writer, request, uid, nick,
+		writer, request, sessionID, nick,
 		command, target, body,
 	)
 }
@@ -596,7 +686,7 @@ func (hdlr *Handlers) handlePrivmsg(
 func (hdlr *Handlers) handleChannelMsg(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, command, target string,
 	body json.RawMessage,
 ) {
@@ -614,7 +704,7 @@ func (hdlr *Handlers) handleChannelMsg(
 	}
 
 	isMember, err := hdlr.params.Database.IsChannelMember(
-		request.Context(), chID, uid,
+		request.Context(), chID, sessionID,
 	)
 	if err != nil {
 		hdlr.log.Error(
@@ -677,11 +767,11 @@ func (hdlr *Handlers) handleChannelMsg(
 func (hdlr *Handlers) handleDirectMsg(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, command, target string,
 	body json.RawMessage,
 ) {
-	targetUID, err := hdlr.params.Database.GetUserByNick(
+	targetSID, err := hdlr.params.Database.GetSessionByNick(
 		request.Context(), target,
 	)
 	if err != nil {
@@ -694,9 +784,9 @@ func (hdlr *Handlers) handleDirectMsg(
 		return
 	}
 
-	recipients := []int64{targetUID}
-	if targetUID != uid {
-		recipients = append(recipients, uid)
+	recipients := []int64{targetSID}
+	if targetSID != sessionID {
+		recipients = append(recipients, sessionID)
 	}
 
 	msgUUID, err := hdlr.fanOut(
@@ -721,7 +811,7 @@ func (hdlr *Handlers) handleDirectMsg(
 func (hdlr *Handlers) handleJoin(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, target string,
 ) {
 	if target == "" {
@@ -766,7 +856,7 @@ func (hdlr *Handlers) handleJoin(
 	}
 
 	err = hdlr.params.Database.JoinChannel(
-		request.Context(), chID, uid,
+		request.Context(), chID, sessionID,
 	)
 	if err != nil {
 		hdlr.log.Error(
@@ -800,7 +890,7 @@ func (hdlr *Handlers) handleJoin(
 func (hdlr *Handlers) handlePart(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, target string,
 	body json.RawMessage,
 ) {
@@ -841,7 +931,7 @@ func (hdlr *Handlers) handlePart(
 	)
 
 	err = hdlr.params.Database.PartChannel(
-		request.Context(), chID, uid,
+		request.Context(), chID, sessionID,
 	)
 	if err != nil {
 		hdlr.log.Error(
@@ -871,7 +961,7 @@ func (hdlr *Handlers) handlePart(
 func (hdlr *Handlers) handleNick(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick string,
 	bodyLines func() []string,
 ) {
@@ -909,7 +999,7 @@ func (hdlr *Handlers) handleNick(
 	}
 
 	err := hdlr.params.Database.ChangeNick(
-		request.Context(), uid, newNick,
+		request.Context(), sessionID, newNick,
 	)
 	if err != nil {
 		if strings.Contains(err.Error(), "UNIQUE") {
@@ -934,7 +1024,7 @@ func (hdlr *Handlers) handleNick(
 		return
 	}
 
-	hdlr.broadcastNick(request, uid, nick, newNick)
+	hdlr.broadcastNick(request, sessionID, nick, newNick)
 
 	hdlr.respondJSON(writer, request,
 		map[string]string{
@@ -945,15 +1035,15 @@ func (hdlr *Handlers) handleNick(
 
 func (hdlr *Handlers) broadcastNick(
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	oldNick, newNick string,
 ) {
 	channels, _ := hdlr.params.Database.
-		GetAllChannelMembershipsForUser(
-			request.Context(), uid,
+		GetSessionChannels(
+			request.Context(), sessionID,
 		)
 
-	notified := map[int64]bool{uid: true}
+	notified := map[int64]bool{sessionID: true}
 
 	nickBody, err := json.Marshal([]string{newNick})
 	if err != nil {
@@ -969,11 +1059,11 @@ func (hdlr *Handlers) broadcastNick(
 		json.RawMessage(nickBody), nil,
 	)
 
-	_ = hdlr.params.Database.EnqueueMessage(
-		request.Context(), uid, dbID,
+	_ = hdlr.params.Database.EnqueueToSession(
+		request.Context(), sessionID, dbID,
 	)
 
-	hdlr.broker.Notify(uid)
+	hdlr.broker.Notify(sessionID)
 
 	for _, chanInfo := range channels {
 		memberIDs, _ := hdlr.params.Database.
@@ -985,7 +1075,7 @@ func (hdlr *Handlers) broadcastNick(
 			if !notified[mid] {
 				notified[mid] = true
 
-				_ = hdlr.params.Database.EnqueueMessage(
+				_ = hdlr.params.Database.EnqueueToSession(
 					request.Context(), mid, dbID,
 				)
 
@@ -1077,13 +1167,13 @@ func (hdlr *Handlers) handleTopic(
 func (hdlr *Handlers) handleQuit(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick string,
 	body json.RawMessage,
 ) {
 	channels, _ := hdlr.params.Database.
-		GetAllChannelMembershipsForUser(
-			request.Context(), uid,
+		GetSessionChannels(
+			request.Context(), sessionID,
 		)
 
 	notified := map[int64]bool{}
@@ -1103,10 +1193,10 @@ func (hdlr *Handlers) handleQuit(
 			)
 
 		for _, mid := range memberIDs {
-			if mid != uid && !notified[mid] {
+			if mid != sessionID && !notified[mid] {
 				notified[mid] = true
 
-				_ = hdlr.params.Database.EnqueueMessage(
+				_ = hdlr.params.Database.EnqueueToSession(
 					request.Context(), mid, dbID,
 				)
 
@@ -1115,7 +1205,7 @@ func (hdlr *Handlers) handleQuit(
 		}
 
 		_ = hdlr.params.Database.PartChannel(
-			request.Context(), chanInfo.ID, uid,
+			request.Context(), chanInfo.ID, sessionID,
 		)
 
 		_ = hdlr.params.Database.DeleteChannelIfEmpty(
@@ -1123,8 +1213,8 @@ func (hdlr *Handlers) handleQuit(
 		)
 	}
 
-	_ = hdlr.params.Database.DeleteUser(
-		request.Context(), uid,
+	_ = hdlr.params.Database.DeleteSession(
+		request.Context(), sessionID,
 	)
 
 	hdlr.respondJSON(writer, request,
@@ -1138,7 +1228,8 @@ func (hdlr *Handlers) HandleGetHistory() http.HandlerFunc {
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
-		uid, nick, ok := hdlr.requireAuth(writer, request)
+		sessionID, _, nick, ok :=
+			hdlr.requireAuth(writer, request)
 		if !ok {
 			return
 		}
@@ -1155,7 +1246,7 @@ func (hdlr *Handlers) HandleGetHistory() http.HandlerFunc {
 		}
 
 		if !hdlr.canAccessHistory(
-			writer, request, uid, nick, target,
+			writer, request, sessionID, nick, target,
 		) {
 			return
 		}
@@ -1198,12 +1289,12 @@ func (hdlr *Handlers) HandleGetHistory() http.HandlerFunc {
 func (hdlr *Handlers) canAccessHistory(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	nick, target string,
 ) bool {
 	if strings.HasPrefix(target, "#") {
 		return hdlr.canAccessChannelHistory(
-			writer, request, uid, target,
+			writer, request, sessionID, target,
 		)
 	}
 
@@ -1225,7 +1316,7 @@ func (hdlr *Handlers) canAccessHistory(
 func (hdlr *Handlers) canAccessChannelHistory(
 	writer http.ResponseWriter,
 	request *http.Request,
-	uid int64,
+	sessionID int64,
 	target string,
 ) bool {
 	chID, err := hdlr.params.Database.GetChannelByName(
@@ -1242,7 +1333,7 @@ func (hdlr *Handlers) canAccessChannelHistory(
 	}
 
 	isMember, err := hdlr.params.Database.IsChannelMember(
-		request.Context(), chID, uid,
+		request.Context(), chID, sessionID,
 	)
 	if err != nil {
 		hdlr.log.Error(

web/dist/style.css

@@ -14,6 +14,9 @@
   --tab-active: #e94560;
   --tab-bg: #16213e;
   --tab-hover: #1a1a3e;
+  --topic-bg: #121a30;
+  --unread-bg: #e94560;
+  --warn: #f0ad4e;
 }
 
 html, body, #root {
@@ -86,6 +89,7 @@ html, body, #root {
   border-bottom: 1px solid var(--border);
   overflow-x: auto;
   flex-shrink: 0;
+  align-items: center;
 }
 
 .tab {
@@ -95,6 +99,7 @@ html, body, #root {
   white-space: nowrap;
   color: var(--text-muted);
   user-select: none;
+  position: relative;
 }
 
 .tab:hover {
@@ -116,6 +121,43 @@ html, body, #root {
   color: var(--accent);
 }
 
+.tab .unread-badge {
+  display: inline-block;
+  background: var(--unread-bg);
+  color: white;
+  font-size: 10px;
+  font-weight: bold;
+  padding: 1px 5px;
+  border-radius: 8px;
+  margin-left: 6px;
+  min-width: 16px;
+  text-align: center;
+}
+
+/* Connection status */
+.connection-status {
+  padding: 4px 12px;
+  background: var(--warn);
+  color: #1a1a2e;
+  font-size: 12px;
+  font-weight: bold;
+  white-space: nowrap;
+  flex-shrink: 0;
+}
+
+/* Topic bar */
+.topic-bar {
+  padding: 6px 12px;
+  background: var(--topic-bg);
+  border-bottom: 1px solid var(--border);
+  color: var(--text-muted);
+  font-size: 12px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  flex-shrink: 0;
+}
+
 /* Content area */
 .content {
   display: flex;
@@ -243,6 +285,7 @@ html, body, #root {
   gap: 8px;
   background: var(--bg-secondary);
   border-bottom: 1px solid var(--border);
+  margin-left: auto;
 }
 
 .join-dialog input {

web/src/app.jsx

@@ -1,13 +1,17 @@
-import { h, render, Component } from 'preact';
+import { h, render } from 'preact';
 import { useState, useEffect, useRef, useCallback } from 'preact/hooks';
 
 const API = '/api/v1';
+const POLL_TIMEOUT = 15;
+const RECONNECT_DELAY = 3000;
+const MEMBER_REFRESH_INTERVAL = 10000;
 
 function api(path, opts = {}) {
   const token = localStorage.getItem('chat_token');
   const headers = { 'Content-Type': 'application/json', ...(opts.headers || {}) };
   if (token) headers['Authorization'] = `Bearer ${token}`;
-  return fetch(API + path, { ...opts, headers }).then(async r => {
+  const { signal, ...rest } = opts;
+  return fetch(API + path, { ...rest, headers, signal }).then(async r => {
     const data = await r.json().catch(() => null);
     if (!r.ok) throw { status: r.status, data };
     return data;
@@ -19,7 +23,6 @@ function formatTime(ts) {
   return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit', second: '2-digit' });
 }
 
-// Nick color hashing
 function nickColor(nick) {
   let h = 0;
   for (let i = 0; i < nick.length; i++) h = nick.charCodeAt(i) + ((h << 5) - h);
@@ -39,10 +42,9 @@ function LoginScreen({ onLogin }) {
       if (s.name) setServerName(s.name);
       if (s.motd) setMotd(s.motd);
     }).catch(() => {});
-    // Check for saved token
     const saved = localStorage.getItem('chat_token');
     if (saved) {
-      api('/state').then(u => onLogin(u.nick, saved)).catch(() => localStorage.removeItem('chat_token'));
+      api('/state').then(u => onLogin(u.nick)).catch(() => localStorage.removeItem('chat_token'));
     }
     inputRef.current?.focus();
   }, []);
@@ -56,7 +58,7 @@ function LoginScreen({ onLogin }) {
         body: JSON.stringify({ nick: nick.trim() })
       });
       localStorage.setItem('chat_token', res.token);
-      onLogin(res.nick, res.token);
+      onLogin(res.nick);
     } catch (err) {
       setError(err.data?.error || 'Connection failed');
     }
@@ -84,11 +86,19 @@ function LoginScreen({ onLogin }) {
 }
 
 function Message({ msg }) {
+  if (msg.system) {
+    return (
+      <div class="message system">
+        <span class="timestamp">{formatTime(msg.ts)}</span>
+        <span class="content">{msg.text}</span>
+      </div>
+    );
+  }
   return (
-    <div class={`message ${msg.system ? 'system' : ''}`}>
-      <span class="timestamp">{formatTime(msg.createdAt)}</span>
-      <span class="nick" style={{ color: msg.system ? undefined : nickColor(msg.nick) }}>{msg.nick}</span>
-      <span class="content">{msg.content}</span>
+    <div class="message">
+      <span class="timestamp">{formatTime(msg.ts)}</span>
+      <span class="nick" style={{ color: nickColor(msg.from) }}>{msg.from}</span>
+      <span class="content">{msg.text}</span>
     </div>
   );
 }
@@ -98,93 +108,194 @@ function App() {
   const [nick, setNick] = useState('');
   const [tabs, setTabs] = useState([{ type: 'server', name: 'Server' }]);
   const [activeTab, setActiveTab] = useState(0);
-  const [messages, setMessages] = useState({ server: [] }); // keyed by tab name
-  const [members, setMembers] = useState({}); // keyed by channel name
+  const [messages, setMessages] = useState({ Server: [] });
+  const [members, setMembers] = useState({});
+  const [topics, setTopics] = useState({});
+  const [unread, setUnread] = useState({});
   const [input, setInput] = useState('');
   const [joinInput, setJoinInput] = useState('');
-  const [lastMsgId, setLastMsgId] = useState(0);
+  const [connected, setConnected] = useState(true);
+
+  const lastIdRef = useRef(0);
+  const seenIdsRef = useRef(new Set());
+  const pollAbortRef = useRef(null);
+  const tabsRef = useRef(tabs);
+  const activeTabRef = useRef(activeTab);
+  const nickRef = useRef(nick);
   const messagesEndRef = useRef();
   const inputRef = useRef();
-  const pollRef = useRef();
+
+  useEffect(() => { tabsRef.current = tabs; }, [tabs]);
+  useEffect(() => { activeTabRef.current = activeTab; }, [activeTab]);
+  useEffect(() => { nickRef.current = nick; }, [nick]);
+
+  // Persist joined channels
+  useEffect(() => {
+    const channels = tabs.filter(t => t.type === 'channel').map(t => t.name);
+    localStorage.setItem('chat_channels', JSON.stringify(channels));
+  }, [tabs]);
+
+  // Clear unread on tab switch
+  useEffect(() => {
+    const tab = tabs[activeTab];
+    if (tab) setUnread(prev => ({ ...prev, [tab.name]: 0 }));
+  }, [activeTab, tabs]);
 
   const addMessage = useCallback((tabName, msg) => {
+    if (msg.id && seenIdsRef.current.has(msg.id)) return;
+    if (msg.id) seenIdsRef.current.add(msg.id);
     setMessages(prev => ({
       ...prev,
       [tabName]: [...(prev[tabName] || []), msg]
     }));
+    const currentTab = tabsRef.current[activeTabRef.current];
+    if (!currentTab || currentTab.name !== tabName) {
+      setUnread(prev => ({ ...prev, [tabName]: (prev[tabName] || 0) + 1 }));
+    }
   }, []);
 
   const addSystemMessage = useCallback((tabName, text) => {
-    addMessage(tabName, {
-      id: Date.now(),
-      nick: '*',
-      content: text,
-      createdAt: new Date().toISOString(),
-      system: true
-    });
-  }, [addMessage]);
+    setMessages(prev => ({
+      ...prev,
+      [tabName]: [...(prev[tabName] || []), {
+        id: 'sys-' + Date.now() + '-' + Math.random(),
+        ts: new Date().toISOString(),
+        text,
+        system: true
+      }]
+    }));
+  }, []);
 
-  const onLogin = useCallback((userNick, token) => {
-    setNick(userNick);
-    setLoggedIn(true);
-    addSystemMessage('server', `Connected as ${userNick}`);
-    // Fetch server info
-    api('/server').then(s => {
-      if (s.motd) addSystemMessage('server', `MOTD: ${s.motd}`);
+  const refreshMembers = useCallback((channel) => {
+    const chName = channel.replace('#', '');
+    api(`/channels/${chName}/members`).then(m => {
+      setMembers(prev => ({ ...prev, [channel]: m }));
     }).catch(() => {});
-  }, [addSystemMessage]);
+  }, []);
 
-  // Poll for new messages
+  const processMessage = useCallback((msg) => {
+    const body = Array.isArray(msg.body) ? msg.body.join('\n') : '';
+    const base = { id: msg.id, ts: msg.ts, from: msg.from, to: msg.to, command: msg.command };
+
+    switch (msg.command) {
+      case 'PRIVMSG':
+      case 'NOTICE': {
+        const parsed = { ...base, text: body, system: false };
+        const target = msg.to;
+        if (target && target.startsWith('#')) {
+          addMessage(target, parsed);
+        } else {
+          const dmPeer = msg.from === nickRef.current ? msg.to : msg.from;
+          setTabs(prev => {
+            if (!prev.find(t => t.type === 'dm' && t.name === dmPeer)) {
+              return [...prev, { type: 'dm', name: dmPeer }];
+            }
+            return prev;
+          });
+          addMessage(dmPeer, parsed);
+        }
+        break;
+      }
+      case 'JOIN': {
+        const text = `${msg.from} has joined ${msg.to}`;
+        if (msg.to) addMessage(msg.to, { ...base, text, system: true });
+        if (msg.to && msg.to.startsWith('#')) refreshMembers(msg.to);
+        break;
+      }
+      case 'PART': {
+        const reason = body ? ': ' + body : '';
+        const text = `${msg.from} has left ${msg.to}${reason}`;
+        if (msg.to) addMessage(msg.to, { ...base, text, system: true });
+        if (msg.to && msg.to.startsWith('#')) refreshMembers(msg.to);
+        break;
+      }
+      case 'QUIT': {
+        const reason = body ? ': ' + body : '';
+        const text = `${msg.from} has quit${reason}`;
+        tabsRef.current.forEach(tab => {
+          if (tab.type === 'channel') {
+            addMessage(tab.name, { ...base, text, system: true });
+          }
+        });
+        break;
+      }
+      case 'NICK': {
+        const newNick = Array.isArray(msg.body) ? msg.body[0] : body;
+        const text = `${msg.from} is now known as ${newNick}`;
+        tabsRef.current.forEach(tab => {
+          if (tab.type === 'channel') {
+            addMessage(tab.name, { ...base, text, system: true });
+          }
+        });
+        if (msg.from === nickRef.current && newNick) setNick(newNick);
+        // Refresh members in all channels
+        tabsRef.current.forEach(tab => {
+          if (tab.type === 'channel') refreshMembers(tab.name);
+        });
+        break;
+      }
+      case 'TOPIC': {
+        const text = `${msg.from} set the topic: ${body}`;
+        if (msg.to) {
+          addMessage(msg.to, { ...base, text, system: true });
+          setTopics(prev => ({ ...prev, [msg.to]: body }));
+        }
+        break;
+      }
+      case '375':
+      case '372':
+      case '376':
+        addMessage('Server', { ...base, text: body, system: true });
+        break;
+      default:
+        addMessage('Server', { ...base, text: body || msg.command, system: true });
+    }
+  }, [addMessage, refreshMembers]);
+
+  // Long-poll loop
   useEffect(() => {
     if (!loggedIn) return;
     let alive = true;
+
     const poll = async () => {
-      try {
-        const msgs = await api(`/messages?after=${lastMsgId}`);
-        if (!alive) return;
-        let maxId = lastMsgId;
-        for (const msg of msgs) {
-          if (msg.id > maxId) maxId = msg.id;
-          if (msg.isDm) {
-            const dmTab = msg.nick === nick ? msg.dmTarget : msg.nick;
-            // Ensure DM tab exists
-            setTabs(prev => {
-              if (!prev.find(t => t.type === 'dm' && t.name === dmTab)) {
-                return [...prev, { type: 'dm', name: dmTab }];
-              }
-              return prev;
-            });
-            addMessage(dmTab, msg);
-          } else if (msg.channel) {
-            addMessage(msg.channel, msg);
+      while (alive) {
+        try {
+          const controller = new AbortController();
+          pollAbortRef.current = controller;
+          const result = await api(
+            `/messages?after=${lastIdRef.current}&timeout=${POLL_TIMEOUT}`,
+            { signal: controller.signal }
+          );
+          if (!alive) break;
+          setConnected(true);
+          if (result.messages) {
+            for (const m of result.messages) processMessage(m);
           }
+          if (result.last_id > lastIdRef.current) {
+            lastIdRef.current = result.last_id;
+          }
+        } catch (err) {
+          if (!alive) break;
+          if (err.name === 'AbortError') continue;
+          setConnected(false);
+          await new Promise(r => setTimeout(r, RECONNECT_DELAY));
         }
-        if (maxId > lastMsgId) setLastMsgId(maxId);
-      } catch (err) {
-        // silent
       }
     };
-    pollRef.current = setInterval(poll, 1500);
-    poll();
-    return () => { alive = false; clearInterval(pollRef.current); };
-  }, [loggedIn, lastMsgId, nick, addMessage]);
 
-  // Fetch members for active channel tab
+    poll();
+    return () => { alive = false; pollAbortRef.current?.abort(); };
+  }, [loggedIn, processMessage]);
+
+  // Refresh members for active channel
   useEffect(() => {
     if (!loggedIn) return;
     const tab = tabs[activeTab];
     if (!tab || tab.type !== 'channel') return;
-    const chName = tab.name.replace('#', '');
-    api(`/channels/${chName}/members`).then(m => {
-      setMembers(prev => ({ ...prev, [tab.name]: m }));
-    }).catch(() => {});
-    const iv = setInterval(() => {
-      api(`/channels/${chName}/members`).then(m => {
-        setMembers(prev => ({ ...prev, [tab.name]: m }));
-      }).catch(() => {});
-    }, 5000);
+    refreshMembers(tab.name);
+    const iv = setInterval(() => refreshMembers(tab.name), MEMBER_REFRESH_INTERVAL);
     return () => clearInterval(iv);
-  }, [loggedIn, activeTab, tabs]);
+  }, [loggedIn, activeTab, tabs, refreshMembers]);
 
   // Auto-scroll
   useEffect(() => {
@@ -192,9 +303,37 @@ function App() {
   }, [messages, activeTab]);
 
   // Focus input on tab change
+  useEffect(() => { inputRef.current?.focus(); }, [activeTab]);
+
+  // Fetch topic for active channel
   useEffect(() => {
-    inputRef.current?.focus();
-  }, [activeTab]);
+    if (!loggedIn) return;
+    const tab = tabs[activeTab];
+    if (!tab || tab.type !== 'channel') return;
+    api('/channels').then(channels => {
+      const ch = channels.find(c => c.name === tab.name);
+      if (ch && ch.topic) setTopics(prev => ({ ...prev, [tab.name]: ch.topic }));
+    }).catch(() => {});
+  }, [loggedIn, activeTab, tabs]);
+
+  const onLogin = useCallback(async (userNick) => {
+    setNick(userNick);
+    setLoggedIn(true);
+    addSystemMessage('Server', `Connected as ${userNick}`);
+    // Auto-rejoin saved channels
+    const saved = JSON.parse(localStorage.getItem('chat_channels') || '[]');
+    for (const ch of saved) {
+      try {
+        await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'JOIN', to: ch }) });
+        setTabs(prev => {
+          if (prev.find(t => t.type === 'channel' && t.name === ch)) return prev;
+          return [...prev, { type: 'channel', name: ch }];
+        });
+      } catch (e) {
+        // Channel may not exist anymore
+      }
+    }
+  }, [addSystemMessage]);
 
   const joinChannel = async (name) => {
     if (!name) return;
@@ -206,22 +345,29 @@ function App() {
         if (prev.find(t => t.type === 'channel' && t.name === name)) return prev;
         return [...prev, { type: 'channel', name }];
       });
-      setActiveTab(tabs.length); // switch to new tab
-      addSystemMessage(name, `Joined ${name}`);
+      setActiveTab(tabs.length);
+      // Load history
+      try {
+        const hist = await api(`/history?target=${encodeURIComponent(name)}&limit=50`);
+        if (Array.isArray(hist)) {
+          for (const m of hist) processMessage(m);
+        }
+      } catch (e) {
+        // History may be empty
+      }
       setJoinInput('');
     } catch (err) {
-      addSystemMessage('server', `Failed to join ${name}: ${err.data?.error || 'error'}`);
+      addSystemMessage('Server', `Failed to join ${name}: ${err.data?.error || 'error'}`);
     }
   };
 
   const partChannel = async (name) => {
     try {
       await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'PART', to: name }) });
-    } catch (err) { /* ignore */ }
-    setTabs(prev => {
-      const next = prev.filter(t => !(t.type === 'channel' && t.name === name));
-      return next;
-    });
+    } catch (e) {
+      // Ignore
+    }
+    setTabs(prev => prev.filter(t => !(t.type === 'channel' && t.name === name)));
     setActiveTab(0);
   };
 
@@ -240,7 +386,8 @@ function App() {
       if (prev.find(t => t.type === 'dm' && t.name === targetNick)) return prev;
       return [...prev, { type: 'dm', name: targetNick }];
     });
-    setActiveTab(tabs.findIndex(t => t.type === 'dm' && t.name === targetNick) || tabs.length);
+    const idx = tabs.findIndex(t => t.type === 'dm' && t.name === targetNick);
+    setActiveTab(idx >= 0 ? idx : tabs.length);
   };
 
   const sendMessage = async () => {
@@ -250,46 +397,45 @@ function App() {
     const tab = tabs[activeTab];
     if (!tab || tab.type === 'server') return;
 
-    // Handle /commands
     if (text.startsWith('/')) {
       const parts = text.split(' ');
       const cmd = parts[0].toLowerCase();
-      if (cmd === '/join' && parts[1]) {
-        joinChannel(parts[1]);
-        return;
-      }
-      if (cmd === '/part') {
-        if (tab.type === 'channel') partChannel(tab.name);
-        return;
-      }
+      if (cmd === '/join' && parts[1]) { joinChannel(parts[1]); return; }
+      if (cmd === '/part') { if (tab.type === 'channel') partChannel(tab.name); return; }
       if (cmd === '/msg' && parts[1] && parts.slice(2).join(' ')) {
         const target = parts[1];
-        const msg = parts.slice(2).join(' ');
+        const body = parts.slice(2).join(' ');
         try {
-          await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'PRIVMSG', to: target, body: [msg] }) });
+          await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'PRIVMSG', to: target, body: [body] }) });
           openDM(target);
         } catch (err) {
-          addSystemMessage('server', `Failed to send DM: ${err.data?.error || 'error'}`);
+          addSystemMessage('Server', `DM failed: ${err.data?.error || 'error'}`);
         }
         return;
       }
       if (cmd === '/nick' && parts[1]) {
         try {
           await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'NICK', body: [parts[1]] }) });
-          setNick(parts[1]);
-          addSystemMessage('server', `Nick changed to ${parts[1]}`);
         } catch (err) {
-          addSystemMessage('server', `Nick change failed: ${err.data?.error || 'error'}`);
+          addSystemMessage('Server', `Nick change failed: ${err.data?.error || 'error'}`);
         }
         return;
       }
-      addSystemMessage('server', `Unknown command: ${cmd}`);
+      if (cmd === '/topic' && tab.type === 'channel') {
+        const topicText = parts.slice(1).join(' ');
+        try {
+          await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'TOPIC', to: tab.name, body: [topicText] }) });
+        } catch (err) {
+          addSystemMessage('Server', `Topic failed: ${err.data?.error || 'error'}`);
+        }
+        return;
+      }
+      addSystemMessage('Server', `Unknown command: ${cmd}`);
       return;
     }
 
-    const to = tab.type === 'channel' ? tab.name : tab.name;
     try {
-      await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'PRIVMSG', to, body: [text] }) });
+      await api('/messages', { method: 'POST', body: JSON.stringify({ command: 'PRIVMSG', to: tab.name, body: [text] }) });
     } catch (err) {
       addSystemMessage(tab.name, `Send failed: ${err.data?.error || 'error'}`);
     }
@@ -300,16 +446,21 @@ function App() {
   const currentTab = tabs[activeTab] || tabs[0];
   const currentMessages = messages[currentTab.name] || [];
   const currentMembers = members[currentTab.name] || [];
+  const currentTopic = topics[currentTab.name] || '';
 
   return (
     <div class="app">
       <div class="tab-bar">
+        {!connected && <div class="connection-status">⚠ Reconnecting...</div>}
         {tabs.map((tab, i) => (
           <div
             class={`tab ${i === activeTab ? 'active' : ''}`}
             onClick={() => setActiveTab(i)}
           >
             {tab.type === 'dm' ? `→${tab.name}` : tab.name}
+            {unread[tab.name] > 0 && i !== activeTab && (
+              <span class="unread-badge">{unread[tab.name]}</span>
+            )}
             {tab.type !== 'server' && (
               <span class="close-btn" onClick={(e) => { e.stopPropagation(); closeTab(i); }}>×</span>
             )}
@@ -326,30 +477,27 @@ function App() {
         </div>
       </div>
 
+      {currentTab.type === 'channel' && currentTopic && (
+        <div class="topic-bar" title={currentTopic}>{currentTopic}</div>
+      )}
+
       <div class="content">
         <div class="messages-pane">
-          {currentTab.type === 'server' ? (
-            <div class="server-messages">
-              {currentMessages.map(m => <Message msg={m} />)}
-              <div ref={messagesEndRef} />
+          <div class={currentTab.type === 'server' ? 'server-messages' : 'messages'}>
+            {currentMessages.map(m => <Message msg={m} />)}
+            <div ref={messagesEndRef} />
+          </div>
+          {currentTab.type !== 'server' && (
+            <div class="input-bar">
+              <input
+                ref={inputRef}
+                placeholder={`Message ${currentTab.name}...`}
+                value={input}
+                onInput={e => setInput(e.target.value)}
+                onKeyDown={e => e.key === 'Enter' && sendMessage()}
+              />
+              <button onClick={sendMessage}>Send</button>
             </div>
-          ) : (
-            <>
-              <div class="messages">
-                {currentMessages.map(m => <Message msg={m} />)}
-                <div ref={messagesEndRef} />
-              </div>
-              <div class="input-bar">
-                <input
-                  ref={inputRef}
-                  placeholder={`Message ${currentTab.name}...`}
-                  value={input}
-                  onInput={e => setInput(e.target.value)}
-                  onKeyDown={e => e.key === 'Enter' && sendMessage()}
-                />
-                <button onClick={sendMessage}>Send</button>
-              </div>
-            </>
           )}
         </div>
 

web/src/style.css

@@ -14,6 +14,9 @@
   --tab-active: #e94560;
   --tab-bg: #16213e;
   --tab-hover: #1a1a3e;
+  --topic-bg: #121a30;
+  --unread-bg: #e94560;
+  --warn: #f0ad4e;
 }
 
 html, body, #root {
@@ -86,6 +89,7 @@ html, body, #root {
   border-bottom: 1px solid var(--border);
   overflow-x: auto;
   flex-shrink: 0;
+  align-items: center;
 }
 
 .tab {
@@ -95,6 +99,7 @@ html, body, #root {
   white-space: nowrap;
   color: var(--text-muted);
   user-select: none;
+  position: relative;
 }
 
 .tab:hover {
@@ -116,6 +121,43 @@ html, body, #root {
   color: var(--accent);
 }
 
+.tab .unread-badge {
+  display: inline-block;
+  background: var(--unread-bg);
+  color: white;
+  font-size: 10px;
+  font-weight: bold;
+  padding: 1px 5px;
+  border-radius: 8px;
+  margin-left: 6px;
+  min-width: 16px;
+  text-align: center;
+}
+
+/* Connection status */
+.connection-status {
+  padding: 4px 12px;
+  background: var(--warn);
+  color: #1a1a2e;
+  font-size: 12px;
+  font-weight: bold;
+  white-space: nowrap;
+  flex-shrink: 0;
+}
+
+/* Topic bar */
+.topic-bar {
+  padding: 6px 12px;
+  background: var(--topic-bg);
+  border-bottom: 1px solid var(--border);
+  color: var(--text-muted);
+  font-size: 12px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  flex-shrink: 0;
+}
+
 /* Content area */
 .content {
   display: flex;
@@ -243,6 +285,7 @@ html, body, #root {
   gap: 8px;
   background: var(--bg-secondary);
   border-bottom: 1px solid var(--border);
+  margin-left: auto;
 }
 
 .join-dialog input {