package loop

import "context"

// loopSessionIDKey is the context key for the session id the current Run is
// driving. It is seeded at the top of Run and read where the loop emits a
// session-scoped UI event (capacity_awaken), so the event carries the right
// session rather than being treated as global.
type loopSessionIDKey struct{}

// withLoopSession returns a context carrying the Run's session id.
func withLoopSession(ctx context.Context, sessionID string) context.Context {
	return context.WithValue(ctx, loopSessionIDKey{}, sessionID)
}

// loopSession returns the session id on ctx, or "" when none was seeded (a
// defensive fallback for a caller that drives the loop outside Run).
func loopSession(ctx context.Context) string {
	s, _ := ctx.Value(loopSessionIDKey{}).(string)
	return s
}