ports

type ActionDispatcher interface {
	Dispatch(req domain.ActionRequest) (domain.ActionResponse, error)
}

type DistributedLocker interface {
	// Lock attempts to acquire a distributed lock for the given key (e.g., session ID).
	// It blocks until the lock is acquired, the context is canceled, or the TTL expires (implementation specific).
	// Returns an UnlockFunc that MUST be called to release the lock.
	Lock(ctx context.Context, key string, ttl time.Duration) (UnlockFunc, error)
}

type GraphLoader interface {
	// GetNode retrieves the raw definition of a node by ID.
	// It returns the raw bytes (which the compiler will parse) or an error.
	GetNode(id string) ([]byte, error)

	// ListNodes returns a simplified list of all node IDs available in the graph.
	// This is used for introspection and visualization tools (e.g. 'trellis graph').
	ListNodes() ([]string, error)
}

type StateStore interface {
	// Save persists the state for a given session ID.
	Save(ctx context.Context, sessionID string, state *domain.State) error

	// Load retrieves the state for a given session ID.
	// Returns domain.ErrSessionNotFound if the session does not exist.
	Load(ctx context.Context, sessionID string) (*domain.State, error)

	// Delete removes the state for a given session ID.
	Delete(ctx context.Context, sessionID string) error

	// List returns all active session IDs.
	List(ctx context.Context) ([]string, error)
}

type UnlockFunc func(ctx context.Context) error

type Watchable interface {
	// Watch returns a channel that is signaled when the underlying graph changes.
	// It returns a string (the event type, e.g. "reload") or an error.
	Watch(ctx context.Context) (<-chan string, error)
}