using Godot;

public partial class DragMover : Node
{
    [Export] public Node2D Parent;      // The node that will move
    [Export] public Area2D DragArea;    // Click detection
    [Export] public Area2D CheckArea;   // Overlap validation
    [Export] public Area2D ShootArea; // This gets disabled while dragging

    private bool _tresholdReached = false;
    private bool _dragging;
    private Vector2 _dragOffset;
    private Vector2 _originalPosition;

    private bool _canMove = true;
    
    public override void _Ready()
    {
        if (Parent == null || DragArea == null || CheckArea == null)
        {
            GD.PushError("DragMover exports are not assigned.");
            return;
        }

        DragArea.InputEvent += OnDragAreaInputEvent;
        _originalPosition = Parent.GlobalPosition;
    }

    private void OnDragAreaInputEvent(Node viewport, InputEvent @event, long shapeIdx)
    {
        if (!_canMove) return;
        if (@event is not InputEventMouseButton mb) return;
        if (mb.ButtonIndex != MouseButton.Left) return;
        
        if (mb.Pressed)
        {
            _dragging = true;
            ShootArea.Monitoring = false;
            _originalPosition = Parent.GlobalPosition;

            Parent.SetModulate(Color.FromHtml("ffffff20"));
            _dragOffset = Parent.GlobalPosition - Parent.GetGlobalMousePosition();
        }
        else
        {
            ShootArea.Monitoring = true;
            if (CheckArea.HasOverlappingAreas() || CheckArea.HasOverlappingBodies() || !_tresholdReached)
            {
                Parent.GlobalPosition = _originalPosition;
                Parent.SetModulate(Color.FromHtml("ffffffff"));
            }
            else
            {
                MovementDelay();
            }
            _tresholdReached = false;
            _dragging = false;
        }
    }

    public override void _Process(double delta)
    {
        if ((Parent.GetGlobalMousePosition() + _dragOffset).DistanceTo(_originalPosition) >= 10f && _dragging)
        {
            _tresholdReached = true;
        }
 
        if ((Parent.GetGlobalMousePosition() + _dragOffset).DistanceTo(_originalPosition) <= 10f && !_tresholdReached) return;
        if (!_dragging) return;

        if (CheckArea.HasOverlappingAreas() || CheckArea.HasOverlappingBodies())
        {
            Parent.SetModulate(Color.FromHtml("ff000020"));
        }
        else
        {
            Parent.SetModulate(Color.FromHtml("ffffff20"));
        }
        
        Parent.GlobalPosition = Parent.GetGlobalMousePosition() + _dragOffset;
    }

    private async void MovementDelay()
    {
        ShootArea.Monitoring = false;
        _canMove = false;
        Parent.SetModulate(Color.FromHtml("ffffff20"));
        await ToSignal(GetTree().CreateTimer(1.5), SceneTreeTimer.SignalName.Timeout);
        Parent.SetModulate(Color.FromHtml("ffffffff"));
        ShootArea.Monitoring = true;
        _canMove = true;
    }
}