class_name StageGizmos
extends Node2D
## StageGizmos - Hover highlight, selection outline and a rotate gizmo for the
## Sandbox Stage Builder (Phase 2).
##
## Translation is done by dragging the object directly (no translate handle);
## only the rotate ring is a dedicated handle. Pure drawing + distance-based
## handle hit-testing (no Area2D). Dragging drives global_position /
## global_rotation so it works for any Node2D. Hidden and disabled in PLAY mode.

const STAGE_SELECTION := preload("res://scripts/stage_selection.gd")

# ---------------------------------------------------------------------------
# Enums
# ---------------------------------------------------------------------------

enum Handle { NONE, TRANSLATE, ROTATE }

# ---------------------------------------------------------------------------
# Signals
# ---------------------------------------------------------------------------

signal transform_committed(node: Node2D)

# ---------------------------------------------------------------------------
# Style constants (screen-space px; divided by zoom for world-space drawing)
# ---------------------------------------------------------------------------

const SELECTION_COLOR := Color(1.0, 1.0, 1.0, 0.9)
const HOVER_COLOR := Color(1.0, 0.9, 0.2, 0.5)
const ROTATE_COLOR := Color(0.3, 0.6, 1.0, 0.9)

const SELECTION_WIDTH := 2.0
const HOVER_WIDTH := 1.5
const ROTATE_WIDTH := 2.0

const ROTATE_HANDLE_MARGIN_PX := 48.0
const ROTATE_RING_TOLERANCE_PX := 12.0

# ---------------------------------------------------------------------------
# State
# ---------------------------------------------------------------------------

var camera: Camera2D = null

## When > 0, translation drags snap to this grid size (0 = off).
var snap_size: float = 0.0

var _enabled: bool = true
var _target: Node2D = null
var _hovered: Node2D = null
var _dragging: Handle = Handle.NONE
var _drag_last: Vector2 = Vector2.ZERO
var _box_rect: Rect2 = Rect2()

# ---------------------------------------------------------------------------
# Public API
# ---------------------------------------------------------------------------

func set_target(node: Node2D) -> void:
	_target = node
	queue_redraw()


func set_hover(node: Node2D) -> void:
	_hovered = node
	queue_redraw()


func set_enabled(enabled: bool) -> void:
	_enabled = enabled
	visible = enabled
	queue_redraw()


func get_target() -> Node2D:
	return _target


func set_box_rect(rect: Rect2) -> void:
	_box_rect = rect
	queue_redraw()


## Returns ROTATE if the cursor is on the rotate ring of the primary selection.
func hit_test(world_pos: Vector2) -> Handle:
	if _target == null or not is_instance_valid(_target) or not _enabled:
		return Handle.NONE
	var rect := STAGE_SELECTION.get_world_aabb(_target)
	var ring := _rotate_ring_radius(rect)
	if absf(world_pos.distance_to(rect.get_center()) - ring) <= ROTATE_RING_TOLERANCE_PX / _zoom():
		return Handle.ROTATE
	return Handle.NONE


## Begins a rotate drag (used when the ring is clicked).
func begin_drag(world_pos: Vector2) -> void:
	_dragging = hit_test(world_pos)
	_drag_last = world_pos


## Begins a translate drag on `node` (used when an object body is clicked).
func begin_translate_drag(node: Node2D, world_pos: Vector2) -> void:
	_target = node
	_dragging = Handle.TRANSLATE
	_drag_last = world_pos


func drag_to(world_pos: Vector2) -> void:
	if _target == null or not is_instance_valid(_target) or _dragging == Handle.NONE:
		return
	var delta := world_pos - _drag_last
	if _dragging == Handle.TRANSLATE:
		_target.global_position += delta
		if snap_size > 0.0:
			_target.global_position = _snap(_target.global_position)
	elif _dragging == Handle.ROTATE:
		var center := STAGE_SELECTION.get_world_aabb(_target).get_center()
		var before := (_drag_last - center).angle()
		var after := (world_pos - center).angle()
		_target.global_rotation += after - before
	_drag_last = world_pos
	queue_redraw()


func end_drag() -> void:
	if _dragging != Handle.NONE and _target != null and is_instance_valid(_target):
		transform_committed.emit(_target)
	_dragging = Handle.NONE


func is_dragging() -> bool:
	return _dragging != Handle.NONE

# ---------------------------------------------------------------------------
# Frame / drawing
# ---------------------------------------------------------------------------

func _process(_delta: float) -> void:
	if _enabled and (_target != null or _hovered != null or _box_rect.has_area()):
		queue_redraw()


func _draw() -> void:
	if not _enabled:
		return
	var zoom := _zoom()
	if _hovered != null and is_instance_valid(_hovered) and _hovered != _target:
		draw_rect(STAGE_SELECTION.get_world_aabb(_hovered), HOVER_COLOR, false, HOVER_WIDTH / zoom)
	if _target != null and is_instance_valid(_target):
		var rect := STAGE_SELECTION.get_world_aabb(_target)
		draw_rect(rect, SELECTION_COLOR, false, SELECTION_WIDTH / zoom)
		draw_arc(rect.get_center(), _rotate_ring_radius(rect), 0.0, TAU, 64, ROTATE_COLOR, ROTATE_WIDTH / zoom, true)
	if _box_rect.has_area():
		draw_rect(_box_rect, HOVER_COLOR, false, HOVER_WIDTH / zoom)

# ---------------------------------------------------------------------------
# Internal helpers
# ---------------------------------------------------------------------------

func _zoom() -> float:
	if camera != null and is_instance_valid(camera):
		return maxf(camera.zoom.x, 0.0001)
	return 1.0


func _rotate_ring_radius(rect: Rect2) -> float:
	return rect.size.length() * 0.5 + ROTATE_HANDLE_MARGIN_PX / _zoom()


func _snap(v: Vector2) -> Vector2:
	return Vector2(roundf(v.x / snap_size) * snap_size, roundf(v.y / snap_size) * snap_size)