namespace NiuLai;

public enum GameScreen
{
	Title,
	Playing,
	Paused,
	Ending
}

public static class GameFlow
{
	public static GameScreen Screen { get; private set; } = GameScreen.Title;

	public static event Action Changed;

	public static bool BlocksWorld => Screen != GameScreen.Playing || FilmCut.Playing;

	public static void SetScreen( GameScreen screen )
	{
		if ( Screen == screen )
			return;

		Screen = screen;
		ApplyMouse();
		Changed?.Invoke();
	}

	public static void StartNewGame()
	{
		var again = Trophies.EverWon;
		GameAudio.StopMusic();
		GameAudio.PlayTitleSting();
		GameState.Reset();
		WorldBuilder.Rebuild();
		SetScreen( GameScreen.Playing );
		GameState.Talk( "旁白 / Narrator", Lines.Opening );
		Trophies.Unlock( "walk_slow" );
		if ( again )
			Trophies.Unlock( "watch_again" );
	}

	public static void TogglePause()
	{
		if ( Screen == GameScreen.Playing )
			SetScreen( GameScreen.Paused );
		else if ( Screen == GameScreen.Paused )
			SetScreen( GameScreen.Playing );
	}

	public static void BackToTitle()
	{
		GameAudio.StopMusic();
		SetScreen( GameScreen.Title );
		GameAudio.PlayTitleSting();
	}

	public static void Win()
	{
		if ( Screen == GameScreen.Ending )
			return;

		GameState.Won = true;
		GameState.SongWalk = true;
		Trophies.MarkWon();
		GameAudio.PlayClip( GameAudio.Rain, 0.8f );
		GameAudio.PlaySong();
		SetScreen( GameScreen.Ending );
		Trophies.Unlock( "after_rain" );
	}

	public static void ApplyMouse()
	{
		try
		{
			Mouse.Visibility = Screen == GameScreen.Playing
				? MouseVisibility.Hidden
				: MouseVisibility.Visible;
		}
		catch
		{
			// Older runtimes hide the cursor a different way.
		}
	}
}