using Godot;
using System;

public partial class Joystick : Control
{
	private Vector2 _startTouchPos = Vector2.Zero;
	private Vector2 _currentTouchPos = Vector2.Zero;
	private bool _touching = false;

	[Export] public float DeadzoneRadius = 30f;
	[Export] public float MaxRadius = 90f;

	public override void _GuiInput(InputEvent @event)
	{
		if (@event is InputEventScreenTouch touch)
		{
			if (touch.Pressed)
			{
				_touching = true;
				_startTouchPos = touch.Position;
				_currentTouchPos = touch.Position;
			}
			else
			{
				_touching = false;
			}
		}
		else if (@event is InputEventScreenDrag drag && _touching)
		{
			_currentTouchPos = drag.Position;
		}
	}

	public Vector2 GetDirection()
	{
		if (!_touching) return Vector2.Zero;

		Vector2 offset = _currentTouchPos - _startTouchPos;
		if (offset.Length() < DeadzoneRadius)
			return Vector2.Zero;

		return offset.Normalized() * Mathf.Min(offset.Length(), MaxRadius);
	}

	public override void _Draw()
	{
		Vector2 center = new Vector2(0, 0);
		Vector2 handleOffset = _touching ? (_currentTouchPos - _startTouchPos).Normalized() * Mathf.Min((_currentTouchPos - _startTouchPos).Length(), MaxRadius) : Vector2.Zero;

		DrawCircle(center, MaxRadius, new Color(1, 1, 1, 1), false);
		DrawCircle(center, DeadzoneRadius, new Color(1, 1, 0, 1), false);
		DrawCircle(center + handleOffset, DeadzoneRadius, new Color(1, 1, 1, 0.3f), false); // 当前触点
	}

	public override void _Process(double delta)
	{
		QueueRedraw();
	}
}