# VirtualJoystick —— continuous left-thumb movement input.
extends Control

signal axis_changed(axis: Vector2)

const DEAD_ZONE := 0.12
const KNOB_RADIUS := 29.0

var _touch_index := -1
var _axis := Vector2.ZERO
var _knob := Vector2.ZERO

func setup(diameter := 164.0) -> void:
	custom_minimum_size = Vector2(diameter, diameter)
	size = Vector2(diameter, diameter)
	mouse_filter = Control.MOUSE_FILTER_STOP
	queue_redraw()

func axis() -> Vector2:
	return _axis

func _gui_input(event: InputEvent) -> void:
	if event is InputEventScreenTouch:
		if event.pressed and _touch_index < 0:
			_touch_index = event.index
			_update_from_position(event.position)
		elif not event.pressed and event.index == _touch_index:
			_touch_index = -1
			_set_axis(Vector2.ZERO)
		accept_event()
		return
	if event is InputEventScreenDrag and event.index == _touch_index:
		_update_from_position(event.position)
		accept_event()
		return
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_LEFT:
		if event.pressed:
			_touch_index = -2
			_update_from_position(event.position)
		else:
			_touch_index = -1
			_set_axis(Vector2.ZERO)
		accept_event()
		return
	if event is InputEventMouseMotion and _touch_index == -2:
		_update_from_position(event.position)
		accept_event()

func _update_from_position(pos: Vector2) -> void:
	var center := size * 0.5
	var radius := maxf(1.0, minf(size.x, size.y) * 0.5 - KNOB_RADIUS - 8.0)
	var delta := pos - center
	var raw := delta / radius
	var magnitude := minf(raw.length(), 1.0)
	var direction := raw.normalized() if magnitude > 0.001 else Vector2.ZERO
	var output := direction * magnitude
	if output.length() < DEAD_ZONE:
		output = Vector2.ZERO
	else:
		output = output.normalized() * ((output.length() - DEAD_ZONE) / (1.0 - DEAD_ZONE))
	_knob = direction * radius * magnitude
	_set_axis(output)
	queue_redraw()

func _set_axis(value: Vector2) -> void:
	var next := value.limit_length(1.0)
	if next.is_equal_approx(_axis):
		return
	_axis = next
	axis_changed.emit(_axis)
	queue_redraw()

func cancel_press() -> void:
	_touch_index = -1
	_knob = Vector2.ZERO
	_set_axis(Vector2.ZERO)

func _draw() -> void:
	var center := size * 0.5
	var outer := minf(size.x, size.y) * 0.5 - 5.0
	if outer <= 0.0:
		return
	draw_circle(center, outer, Color(0.025, 0.04, 0.07, 0.38))
	draw_arc(center, outer, 0.0, TAU, 48, Color(0.72, 0.83, 0.96, 0.42), 2.0)
	draw_circle(center + _knob, KNOB_RADIUS, Color(0.18, 0.3, 0.48, 0.78))
	draw_arc(center + _knob, KNOB_RADIUS, 0.0, TAU, 32, Color(0.7, 0.85, 1.0, 0.8), 2.0)