Multiple meeting lobbies and beta-gated features (3.5.2)

- /meeting add-lobby, remove-lobby, lobbies: up to 10 lobbies per server, capped in the database
- Deleted voice channels are dropped from the lobbies
- Beta features: registered only in the beta server and usable only with the Beta Tester role (BETA_GUILD_ID, BETA_ROLE_ID); fails closed
- /beta (bot owner only) shows how beta access is set up

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

internal/db/repos/settingsrepo/meeting_integration_test.go

@@ -0,0 +1,119 @@
+//go:build integration
+
+// Runs against a real Postgres with the dashboard API's migrations applied
+// (the lobby limit is a trigger from migration 000020):
+//
+//	TEST_DB=postgres://... go test -tags integration ./internal/db/repos/settingsrepo
+package settingsrepo
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"os"
+	"sync"
+	"testing"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+func testRepo(t *testing.T) (*Repo, int64) {
+	t.Helper()
+	dsn := os.Getenv("TEST_DB")
+	if dsn == "" {
+		t.Skip("TEST_DB not set")
+	}
+	db, err := sql.Open("pgx", dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { db.Close() })
+	const guild = 4242
+	if _, err := db.Exec(`DELETE FROM meeting_lobbies WHERE guild_id IN ($1, $2)`, guild, guild+1); err != nil {
+		t.Fatal(err)
+	}
+	return NewRepo(db), guild
+}
+
+func TestMeetingLobbies(t *testing.T) {
+	r, g := testRepo(t)
+	ctx := context.Background()
+
+	if ids, err := r.ListMeetingLobbies(ctx, g); err != nil || len(ids) != 0 {
+		t.Fatalf("a fresh server has no lobbies: %v %v", ids, err)
+	}
+
+	for ch := int64(1); ch <= MaxMeetingLobbies; ch++ {
+		added, err := r.AddMeetingLobby(ctx, g, ch)
+		if err != nil || !added {
+			t.Fatalf("adding lobby %d: added=%v err=%v", ch, added, err)
+		}
+	}
+	if _, err := r.AddMeetingLobby(ctx, g, 99); !errors.Is(err, ErrMeetingLobbyLimit) {
+		t.Errorf("an 11th lobby must hit the limit, got %v", err)
+	}
+	if added, err := r.AddMeetingLobby(ctx, g, 3); err != nil || added {
+		t.Errorf("adding an existing lobby is a no-op even at the limit: added=%v err=%v", added, err)
+	}
+	if added, err := r.AddMeetingLobby(ctx, g+1, 99); err != nil || !added {
+		t.Errorf("the limit is per server: added=%v err=%v", added, err)
+	}
+
+	if ok, _ := r.IsMeetingLobby(ctx, g, 7); !ok {
+		t.Error("7 is a lobby")
+	}
+	if ok, _ := r.IsMeetingLobby(ctx, g, 99); ok {
+		t.Error("99 isn't a lobby of this server (it is one of the other server's)")
+	}
+
+	if removed, err := r.RemoveMeetingLobby(ctx, g, 7); err != nil || !removed {
+		t.Errorf("removing 7: removed=%v err=%v", removed, err)
+	}
+	if removed, _ := r.RemoveMeetingLobby(ctx, g, 7); removed {
+		t.Error("7 was already removed")
+	}
+	if ok, _ := r.IsMeetingLobby(ctx, g, 7); ok {
+		t.Error("7 is no longer a lobby")
+	}
+	if added, err := r.AddMeetingLobby(ctx, g, 99); err != nil || !added {
+		t.Errorf("removing one makes room: added=%v err=%v", added, err)
+	}
+
+	ids, err := r.ListMeetingLobbies(ctx, g)
+	if err != nil || len(ids) != MaxMeetingLobbies || ids[len(ids)-1] != 99 {
+		t.Errorf("oldest first, newest last: %v %v", ids, err)
+	}
+}
+
+// Two people adding a lobby at the same moment must not both fit under the limit.
+func TestMeetingLobbiesConcurrent(t *testing.T) {
+	r, g := testRepo(t)
+	ctx := context.Background()
+	for ch := int64(1); ch < MaxMeetingLobbies; ch++ {
+		if _, err := r.AddMeetingLobby(ctx, g, ch); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+	succeeded := 0
+	for i := 0; i < 8; i++ {
+		wg.Add(1)
+		go func(ch int64) {
+			defer wg.Done()
+			if added, err := r.AddMeetingLobby(ctx, g, ch); err == nil && added {
+				mu.Lock()
+				succeeded++
+				mu.Unlock()
+			}
+		}(int64(100 + i))
+	}
+	wg.Wait()
+	if succeeded != 1 {
+		t.Errorf("exactly one of the concurrent adds fits, %d did", succeeded)
+	}
+	if ids, _ := r.ListMeetingLobbies(ctx, g); len(ids) != MaxMeetingLobbies {
+		t.Errorf("have %d lobbies, want %d", len(ids), MaxMeetingLobbies)
+	}
+}

internal/db/repos/settingsrepo/repo.go

@@ -3,6 +3,9 @@ package settingsrepo
 import (
 	"context"
 	"database/sql"
+	"errors"
+
+	"github.com/jackc/pgx/v5/pgconn"
 )
 
 type Repo struct {
@@ -25,36 +28,75 @@ func NewRepo(db *sql.DB) *Repo {
 	return &Repo{db: db}
 }
 
-func (r *Repo) SetMeetingLobbyChannel(ctx context.Context, guildID int64, lobbyChannelID int64) error {
+// MaxMeetingLobbies is how many lobby channels one server can have. The
+// database enforces it too (a trigger from the API's migration 000020), so
+// the command and the dashboard can't disagree.
+const MaxMeetingLobbies = 10
+
+// ErrMeetingLobbyLimit means the server already has MaxMeetingLobbies.
+var ErrMeetingLobbyLimit = errors.New("meeting lobby limit reached")
+
+// pgLimitExceeded is the error code the database raises for one lobby too many.
+const pgLimitExceeded = "54000"
+
+// AddMeetingLobby makes channelID a lobby. added is false when it already
+// was one; going over the limit is ErrMeetingLobbyLimit.
+func (r *Repo) AddMeetingLobby(ctx context.Context, guildID, channelID int64) (added bool, err error) {
 	const q = `
-		INSERT INTO meeting_settings (guild_id, lobby_channel_id)
+		INSERT INTO meeting_lobbies (guild_id, channel_id)
 		VALUES ($1, $2)
-		ON CONFLICT (guild_id)
-		DO UPDATE SET lobby_channel_id = EXCLUDED.lobby_channel_id
+		ON CONFLICT DO NOTHING
 	`
-	_, err := r.db.ExecContext(ctx, q, guildID, lobbyChannelID)
-	return err
+	res, err := r.db.ExecContext(ctx, q, guildID, channelID)
+	var pgErr *pgconn.PgError
+	if errors.As(err, &pgErr) && pgErr.Code == pgLimitExceeded {
+		return false, ErrMeetingLobbyLimit
+	}
+	if err != nil {
+		return false, err
+	}
+	n, err := res.RowsAffected()
+	return n > 0, err
 }
 
-func (r *Repo) GetMeetingLobbyChannel(ctx context.Context, guildID int64) (channelID int64, ok bool, err error) {
-	const q = `
-		SELECT lobby_channel_id
-		FROM meeting_settings
-		WHERE guild_id = $1
-	`
-	row := r.db.QueryRowContext(ctx, q, guildID)
-	var ch sql.NullInt64
-	switch err := row.Scan(&ch); err {
-	case nil:
-		if !ch.Valid {
-			return 0, false, nil
-		}
-		return ch.Int64, true, nil
-	case sql.ErrNoRows:
-		return 0, false, nil
-	default:
-		return 0, false, err
+// RemoveMeetingLobby takes a channel off the lobby list; removed is false
+// when it wasn't one.
+func (r *Repo) RemoveMeetingLobby(ctx context.Context, guildID, channelID int64) (removed bool, err error) {
+	const q = `DELETE FROM meeting_lobbies WHERE guild_id = $1 AND channel_id = $2`
+	res, err := r.db.ExecContext(ctx, q, guildID, channelID)
+	if err != nil {
+		return false, err
 	}
+	n, err := res.RowsAffected()
+	return n > 0, err
+}
+
+// ListMeetingLobbies returns a server's lobbies, oldest first.
+func (r *Repo) ListMeetingLobbies(ctx context.Context, guildID int64) ([]int64, error) {
+	const q = `SELECT channel_id FROM meeting_lobbies WHERE guild_id = $1 ORDER BY created_at, channel_id`
+	rows, err := r.db.QueryContext(ctx, q, guildID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []int64
+	for rows.Next() {
+		var id int64
+		if err := rows.Scan(&id); err != nil {
+			return nil, err
+		}
+		out = append(out, id)
+	}
+	return out, rows.Err()
+}
+
+// IsMeetingLobby reports whether channelID is one of the server's lobbies.
+// It runs whenever someone joins a voice channel, so it's one indexed lookup.
+func (r *Repo) IsMeetingLobby(ctx context.Context, guildID, channelID int64) (bool, error) {
+	const q = `SELECT EXISTS (SELECT 1 FROM meeting_lobbies WHERE guild_id = $1 AND channel_id = $2)`
+	var ok bool
+	err := r.db.QueryRowContext(ctx, q, guildID, channelID).Scan(&ok)
+	return ok, err
 }
 
 func (r *Repo) AddMeetingTempChannel(ctx context.Context, guildID, channelID, createdBy int64) error {