using Godot;

public partial class Flashlight : Node
{
    [Export] public Player Player;
    [Export] public GameCamera Camera;

    [Export] public Node2D Circle;
    [Export] public Node2D PlayerCircle;
    [Export] public Polygon2D Polygon;

    private float FlashlightRadius = Constants.MaxFlashlightRadius;

    public override void _Process(double delta)
    {
        var playerScreenCenterPosition = Player.Position - Camera.Position;
        var flashlightScreenCenterPosition = Camera.FlashlightPosition - Camera.Position;

        var playerScreenPosition = playerScreenCenterPosition + Constants.HalfScreenSize;
        PlayerCircle.Position = playerScreenPosition;

        var flashlightScreenPosition = flashlightScreenCenterPosition + Constants.HalfScreenSize;
        var flashlightScale = FlashlightRadius / Constants.MaxFlashlightRadius;
        Circle.Position = flashlightScreenPosition;
        Circle.Scale = new Vector2(flashlightScale, flashlightScale);

        var d = Camera.FlashlightPosition.DistanceTo(Player.Position);
        if (d <= FlashlightRadius)
            Polygon.Visible = false;
        else
        {
            Polygon.Visible = true;

            var a = Mathf.Sqrt(d * d - FlashlightRadius * FlashlightRadius);
            var xy2 = Camera.FlashlightPosition - Player.Position;
            var angle = xy2.Angle();

            var arcsinRd = Mathf.Asin(FlashlightRadius / d);
            var dslkhjdsflkhjsdfhlkjdfsjlk = angle + arcsinRd;
            var xy3 = a * new Vector2(Mathf.Cos(dslkhjdsflkhjsdfhlkjdfsjlk), Mathf.Sin(dslkhjdsflkhjsdfhlkjdfsjlk));
            var dslkhjdsflkhjsdfhlkjdfsjlk2 = angle - arcsinRd;
            var xy4 = a * new Vector2(Mathf.Cos(dslkhjdsflkhjsdfhlkjdfsjlk2), Mathf.Sin(dslkhjdsflkhjsdfhlkjdfsjlk2));
            
            Polygon.Polygon = new[]
                { playerScreenPosition, playerScreenPosition + xy3, playerScreenPosition + xy4 };
        }
    }
}