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
}

// SessionFromContext returns the session id the enclosing Run is driving, or ""
// when none was attached. It is exported so a tool executing inside the loop can
// attribute the work it starts (a spawned sub-agent, a background task) to the
// conversation that launched it — never inferred from model output.
func SessionFromContext(ctx context.Context) string { return loopSession(ctx) }

// loopTurnIDKey is the context key for the assistant turn the current Run is
// producing. The gateway attaches it (WithTurnID) before starting a turn so the
// streaming events the loop emits can be correlated to that turn by the client.
type loopTurnIDKey struct{}

// WithTurnID attaches turnID to ctx so the streaming events the loop emits carry
// the turn they belong to. It is exported because the gateway calls it once per
// turn, before Run; a caller that attaches none leaves the events' TurnID empty,
// which keeps the correlation fields backward compatible.
func WithTurnID(ctx context.Context, turnID string) context.Context {
	return context.WithValue(ctx, loopTurnIDKey{}, turnID)
}

// loopTurn returns the turn id on ctx, or "" when none was attached.
func loopTurn(ctx context.Context) string {
	s, _ := ctx.Value(loopTurnIDKey{}).(string)
	return s
}