src to pkg, impl lobby.Closed

pkg/state/lobby/'

@@ -0,0 +1,58 @@
+package lobby
+
+import (
+	"context"
+	"gitea/price-is-wrong/pkg/lib/db"
+	lobby "gitea/price-is-wrong/pkg/state/lobby/internal"
+	"slices"
+)
+
+func (l *Lobby) Join(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerJoin{ID: id})
+}
+
+func (l *Lobby) Leave(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerLeave{ID: id})
+}
+
+func (l *Lobby) Close(ctx context.Context) error {
+	return l.upsertEvent(ctx, &lobby.Close{})
+}
+
+func (l *Lobby) upsertEvent(ctx context.Context, e lobby.Event) error {
+	if err := upsertEvent(ctx, l.id, e); err != nil {
+		return err
+	}
+
+	l2, err := openID(ctx, l.id)
+	if err != nil {
+		return err
+	}
+
+	*l = *l2
+	return nil
+}
+
+func upsertEvent(ctx context.Context, lobbyID int, e lobby.Event) error {
+	b, err := lobby.MarshalEvent(e)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.From(ctx).ExecContext(ctx, `
+      INSERT INTO lobby_events (lobby_id, payload) VALUES (?, ?)
+   `, lobbyID, b)
+	return err
+}
+
+func (l *Lobby) apply(e lobby.Event) error {
+	switch e := e.(type) {
+	case *lobby.PlayerJoin:
+		if !slices.Contains(l.Players, e.ID) {
+			l.Players = append(l.Players, e.ID)
+		}
+	case *lobby.PlayerLeave:
+		l.Players = slices.DeleteFunc(l.Players, func(id int) bool { return id == e.ID })
+	}
+	return nil
+}