using Godot;
using System;

public class Overlays : Node
{
    [Signal]
    delegate void OverlayCycled(Overlay overlay);

    [Export]
    private KeyList _cycleOverlayKey;

    [Export] private Resource _overlaysResource;
    public Overlay Current => _overlays[_overlayIdx];
    private OverlayCollection _overlays;
    private int _overlayIdx = 0;

    [Export]
    private Resource _tileGridResource;
    private TileGrid _tileGrid;

    [Export]
    private NodePath _worldGridPath;
    private WorldGrid _worldGrid;

    public override void _Ready()
    {
        _overlays = (OverlayCollection)_overlaysResource;
        _tileGrid = (TileGrid)_tileGridResource;
        _worldGrid = GetNode<WorldGrid>(_worldGridPath);
    }

    public override void _Input(InputEvent @event)
    {
        base._Input(@event);

        if (!(@event is InputEventKey keyEvent))
            return;

        if (!(keyEvent.Pressed))
            return;

        if ((KeyList)keyEvent.Scancode != _cycleOverlayKey)
            return;

        CycleOverlay();
    }

    public override void _Process(float delta)
    {
        base._Process(delta);

        for (int i = 0; i < _tileGrid.Count; i++)
        {
            var tile = _tileGrid[i];
            var material = _worldGrid.GetTileMaterial(i);

            Current.Apply(tile, material);
        }
    }

    public void CycleOverlay()
    {
        _overlayIdx++;
        _overlayIdx %= _overlays.Count;
        EmitSignal(nameof(OverlayCycled), Current);
    }
}