using Godot;

public partial class GameBoard : Node2D
{
    private PuzzleTile[,] _grid = new PuzzleTile[5, 4];

    private PuzzleTile _activeTile;

    // FIX 1: Use GD.Load and explicitly cast it to (PackedScene)
    private PackedScene _tileScene = (PackedScene)GD.Load("res://PuzzleTile.tscn");

    public override void _Ready()
    {
        // FIX 2: Explicitly cast the returned Node to (PuzzleTile)
        _activeTile = (PuzzleTile)GetNode("PuzzleTile");
        _activeTile.GridX = 0;
        _activeTile.GridY = 0;

        _grid[0, 0] = _activeTile;

        SpawnObstacle(4, 0);
    }

    private void SpawnObstacle(int x, int y)
    {
        // FIX 3: Explicitly cast the instantiated object to (PuzzleTile)
        PuzzleTile obstacle = (PuzzleTile)_tileScene.Instantiate();
        AddChild(obstacle);

        obstacle.GridX = x;
        obstacle.GridY = y;
        obstacle.Position = new Vector2(x * 128, y * 128);
        obstacle.Modulate = new Color(1, 0, 0);

        _grid[x, y] = obstacle;
    }

    public override void _Process(double delta)
    {
        if (_activeTile == null || _activeTile.IsMoving) return;

        Vector2 direction = Vector2.Zero;
        if (Input.IsActionJustPressed("ui_right")) direction.X = 1;
        else if (Input.IsActionJustPressed("ui_left")) direction.X = -1;
        else if (Input.IsActionJustPressed("ui_down")) direction.Y = 1;
        else if (Input.IsActionJustPressed("ui_up")) direction.Y = -1;

        if (direction != Vector2.Zero)
        {
            CalculateSlide(_activeTile, (int)direction.X, (int)direction.Y);
        }
    }

    private void CalculateSlide(PuzzleTile tile, int dirX, int dirY)
    {
        int testX = tile.GridX;
        int testY = tile.GridY;

        while (true)
        {
            int nextX = testX + dirX;
            int nextY = testY + dirY;

            if (nextX < 0 || nextX >= 5 || nextY < 0 || nextY >= 4) break;

            if (_grid[nextX, nextY] != null) break;

            testX = nextX;
            testY = nextY;
        }

        if (testX == tile.GridX && testY == tile.GridY) return;

        _grid[tile.GridX, tile.GridY] = null;
        _grid[testX, testY] = tile;

        tile.SlideTo(testX, testY);
    }
}