extends CameraToolBasic
class_name ReedCameraFollowController

const _CONSTANTS := preload("res://addons/reedcamera/_data/CameraSystemConst.gd")

@export_group("Dead Zone")
@export var dead_zone_ratio := Rect2(
	Vector2.ZERO,   # 屏幕中心
	Vector2(0.4, 0.4)    # 宽高（屏幕比例）
)

@export_group("Follow") 
@export var enabled_follow: bool = true 
@export var follow_lerp := 0.12 # 0~1，越大越“跟手”，越小越“蔚蓝感”的滞后

var _follow_node2d : Node2D = null
var _desired_pos := Vector2.ZERO
var _camera: Camera2D = null

func _update_follow(delta: float) -> void:
	if not enabled_follow:
		return

	if not _follow_node2d:
		return

	var cam := _get_camera_from_pointer()
	if not cam:
		return

	# 初始化
	if not _initialized:
		_pos = cam.global_position
		_desired_pos = _pos
		_initialized = true

	var view_rect := _get_camera_view_rect(cam)
	var dead_rect := _get_dead_zone_world_rect(view_rect)

	var p := player.global_position
	var delta_move := Vector2.ZERO

	if p.x < dead_rect.position.x:
		delta_move.x = p.x - dead_rect.position.x
	elif p.x > dead_rect.position.x + dead_rect.size.x:
		delta_move.x = p.x - (dead_rect.position.x + dead_rect.size.x)

	if p.y < dead_rect.position.y:
		delta_move.y = p.y - dead_rect.position.y
	elif p.y > dead_rect.position.y + dead_rect.size.y:
		delta_move.y = p.y - (dead_rect.position.y + dead_rect.size.y)

	if delta_move != Vector2.ZERO:
		_desired_pos += delta_move

	# 可选 room clamp
	if use_room_clamp:
		_desired_pos = _desired_pos.clamp(
			room_world_rect.position,
			room_world_rect.position + room_world_rect.size
		)

	# 蔚蓝感：滞后 lerp
	_pos = _pos.lerp(_desired_pos, follow_lerp)

func _get_camera_from_pointer() -> Camera2D: 
	if _camera:
		return _camera
	
	var p := get_parent() 
	if p and p.has_method("get_camera"): 
		_camera = p.get_camera() as Camera2D 
		return _camera
	
	return _camera

func _get_camera_view_rect(cam: Camera2D) -> Rect2:
	var screen_size := cam.get_viewport_rect().size
	var zoom := cam.zoom
	zoom.x = maxf(zoom.x, 0.001)
	zoom.y = maxf(zoom.y, 0.001)

	var size := screen_size / zoom
	return Rect2(cam.global_position - size * 0.5, size)