@tool
extends Camera3D
class_name GridCameraController

@export var grid_manager_path: NodePath
@export var ground_mesh_path: NodePath
@export var ground_collision_path: NodePath
@export_range(0.1, 10.0, 0.1) var zoom_min: float = 0.5
@export_range(0.1, 10.0, 0.1) var zoom_max: float = 3.0
@export_range(0.01, 1.0, 0.01) var zoom_step: float = 0.1

var _grid_manager: GridPlaneManager = null
var _ground_mesh: MeshInstance3D = null
var _ground_collision: CollisionShape3D = null
var _zoom_factor: float = 1.0

func _ready() -> void:
	_resolve_references()
	if _grid_manager:
		_grid_manager.grid_layout_changed.connect(_on_grid_layout_changed)
	_update_camera_view()
	_update_ground_assets()

func _on_grid_layout_changed(_cells: Dictionary) -> void:
	_update_camera_view()
	_update_ground_assets()

func _unhandled_input(event: InputEvent) -> void:
	if Engine.is_editor_hint():
		return
	if event is InputEventMouseButton and event.pressed:
		var button_event := event as InputEventMouseButton
		if button_event.button_index == MOUSE_BUTTON_WHEEL_UP:
			_adjust_zoom(-zoom_step)
		elif button_event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
			_adjust_zoom(zoom_step)

func _adjust_zoom(delta: float) -> void:
	var new_zoom: float = clamp(_zoom_factor + delta, zoom_min, zoom_max)
	if is_equal_approx(new_zoom, _zoom_factor):
		return
	_zoom_factor = new_zoom
	_update_camera_view()
	_update_ground_assets()

func _resolve_references() -> void:
	if grid_manager_path != NodePath():
		_grid_manager = get_node_or_null(grid_manager_path) as GridPlaneManager
	else:
		_grid_manager = get_parent() as GridPlaneManager
	if ground_mesh_path != NodePath():
		_ground_mesh = get_node_or_null(ground_mesh_path) as MeshInstance3D
	if ground_collision_path != NodePath():
		_ground_collision = get_node_or_null(ground_collision_path) as CollisionShape3D

func _update_camera_view() -> void:
	if not is_inside_tree():
		return
	var grid_size: Vector2 = Vector2(20, 20)
	var target: Vector3 = global_transform.origin
	if _grid_manager:
		grid_size = _grid_manager.get_grid_size()
		target = _grid_manager.global_transform.origin
	var extent: float = max(grid_size.x, grid_size.y)
	var half_extent: float = max(extent * 0.5, 1.0)
	var distance: float = max(half_extent * 1.1, 6.0) * _zoom_factor
	var height: float = max(half_extent * 0.8, 6.0) * _zoom_factor
	var offset: Vector3 = Vector3(distance, height, distance)
	var desired_position: Vector3 = target + offset
	look_at_from_position(desired_position, target, Vector3.UP)

func _update_ground_assets() -> void:
	if not is_inside_tree():
		return
	var required_size: Vector2 = _compute_required_ground_size()
	if _ground_mesh and _ground_mesh.mesh is PlaneMesh:
		var plane_mesh: PlaneMesh = _ground_mesh.mesh as PlaneMesh
		plane_mesh.size = required_size
	if _ground_collision and _ground_collision.shape is BoxShape3D:
		var box: BoxShape3D = _ground_collision.shape as BoxShape3D
		var thickness: float = _grid_manager.get_ground_thickness() if _grid_manager else 0.4
		box.size = Vector3(required_size.x, thickness, required_size.y)

func _compute_required_ground_size() -> Vector2:
	var grid_size: Vector2 = Vector2(20, 20)
	var padding: float = 20.0
	if _grid_manager:
		grid_size = _grid_manager.get_grid_size()
		padding = _grid_manager.get_ground_padding()
	var base_half: Vector2 = Vector2(max(grid_size.x * 0.5, 1.0), max(grid_size.y * 0.5, 1.0))
	var half_extents: Vector2 = base_half
	var viewport: Viewport = get_viewport()
	if viewport:
		var view_size: Vector2 = viewport.get_visible_rect().size
		var corners: Array = [
			Vector2.ZERO,
			Vector2(view_size.x, 0),
			Vector2(0, view_size.y),
			view_size
		]
		var plane_normal: Vector3 = (_grid_manager.global_transform.basis.y if _grid_manager else global_transform.basis.y).normalized()
		var plane_point: Vector3 = (_grid_manager.global_transform.origin if _grid_manager else global_transform.origin)
		for corner in corners:
			var origin: Vector3 = project_ray_origin(corner)
			var direction: Vector3 = project_ray_normal(corner)
			var denominator: float = plane_normal.dot(direction)
			if abs(denominator) < 0.0001:
				continue
			var t: float = plane_normal.dot(plane_point - origin) / denominator
			if t <= 0.0:
				continue
			var world_point: Vector3 = origin + direction * t
			var local_point: Vector3 = _grid_manager.to_local(world_point) if _grid_manager else to_local(world_point)
			half_extents.x = max(half_extents.x, abs(local_point.x))
			half_extents.y = max(half_extents.y, abs(local_point.z))
	var padding_vec: Vector2 = Vector2.ONE * padding
	return (half_extents + padding_vec) * 2.0