extends Camera3D

## ターゲットとなるNode3Dオブジェクト
@export var target: Node3D

## カメラの回転感度
@export var mouse_sensitivity: float = 0.003

## ターゲットからの距離
@export var distance: float = 5.0

## 最小・最大距離
@export var min_distance: float = 2.0
@export var max_distance: float = 20.0

## ズーム速度
@export var zoom_speed: float = 0.5

## 縦方向の回転制限（ラジアン）
@export var min_pitch: float = -PI / 2 + 0.1
@export var max_pitch: float = PI / 2 - 0.1

## マウスボタン（右クリックでカメラ操作）
@export var rotate_button: MouseButton = MOUSE_BUTTON_RIGHT

# 内部変数
var _yaw: float = 0.0  # 水平回転
var _pitch: float = 0.0  # 垂直回転
var _is_rotating: bool = false


func _ready() -> void:
	# 初期角度を設定
	if target:
		var direction = global_position - target.global_position
		_yaw = atan2(direction.x, direction.z)
		_pitch = asin(direction.y / direction.length())


func _unhandled_input(event: InputEvent) -> void:
	# マウスボタンの押下/離す
	if event is InputEventMouseButton:
		if event.button_index == rotate_button:
			_is_rotating = event.pressed

		# マウスホイールでズーム
		elif event.button_index == MOUSE_BUTTON_WHEEL_UP:
			distance = clamp(distance - zoom_speed, min_distance, max_distance)
		elif event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
			distance = clamp(distance + zoom_speed, min_distance, max_distance)

	# マウス移動で回転
	elif event is InputEventMouseMotion and _is_rotating:
		_yaw -= event.relative.x * mouse_sensitivity
		_pitch += event.relative.y * mouse_sensitivity
		_pitch = clamp(_pitch, min_pitch, max_pitch)


func _process(_delta: float) -> void:
	if not target:
		return

	# 球面座標系でカメラ位置を計算
	var offset = Vector3(
		cos(_pitch) * sin(_yaw),
		sin(_pitch),
		cos(_pitch) * cos(_yaw)
	) * distance

	# カメラ位置を設定
	global_position = target.global_position + offset

	# ターゲットを見る
	look_at(target.global_position, Vector3.UP)