extends BaseTool


var _start_pos : Vector2
var _offset : Vector2

# Used to check if the state of content transformation has been changed
# while draw_move() is being called. For example, pressing Enter while still moving content
var _content_transformation_check := false
var _snap_to_grid := false # Mouse Click + Ctrl

onready var selection_node : Node2D = Global.canvas.selection


func _input(event : InputEvent) -> void:
	if _start_pos != Vector2.INF:
		if event.is_action_pressed("ctrl"):
			_snap_to_grid = true
			var grid_size := Vector2(Global.grid_width, Global.grid_height)
			_offset = _offset.snapped(grid_size)
			if Global.current_project.has_selection:
				var prev_pos = selection_node.big_bounding_rectangle.position
				selection_node.big_bounding_rectangle.position = selection_node.big_bounding_rectangle.position.snapped(grid_size)
				selection_node.marching_ants_outline.offset += selection_node.big_bounding_rectangle.position - prev_pos
		elif event.is_action_released("ctrl"):
			_snap_to_grid = false


func draw_start(position : Vector2) -> void:
	_start_pos = position
	_offset = position
	if Global.current_project.has_selection:
		selection_node.transform_content_start()
	_content_transformation_check = selection_node.is_moving_content


func draw_move(position : Vector2) -> void:
	# This is true if content transformation has been confirmed (pressed Enter for example)
	# while the content is being moved
	if _content_transformation_check != selection_node.is_moving_content:
		return
	if Tools.shift: # Snap to axis
		var angle := position.angle_to_point(_start_pos)
		if abs(angle) <= PI / 4 or abs(angle) >= 3*PI / 4:
			position.y = _start_pos.y
		else:
			position.x = _start_pos.x
	if _snap_to_grid: # Snap to grid
		position = position.snapped(Vector2(Global.grid_width, Global.grid_height))
		position += Vector2(Global.grid_offset_x, Global.grid_offset_y)

	if Global.current_project.has_selection:
		selection_node.move_content(position - _offset)
	else:
		Global.canvas.move_preview_location = position - _start_pos
	_offset = position


func draw_end(position : Vector2) -> void:
	if _start_pos != Vector2.INF and _content_transformation_check == selection_node.is_moving_content:
		if Tools.shift: # Snap to axis
			var angle := position.angle_to_point(_start_pos)
			if abs(angle) <= PI / 4 or abs(angle) >= 3*PI / 4:
				position.y = _start_pos.y
			else:
				position.x = _start_pos.x

		if _snap_to_grid: # Snap to grid
			position = position.snapped(Vector2(Global.grid_width, Global.grid_height))
			position += Vector2(Global.grid_offset_x, Global.grid_offset_y)


		var pixel_diff : Vector2 = position - _start_pos
		var project : Project = Global.current_project
		var image : Image = _get_draw_image()

		if project.has_selection:
			selection_node.move_borders_end()
		else:
			Global.canvas.move_preview_location = Vector2.ZERO
			var image_copy := Image.new()
			image_copy.copy_from(image)
			Global.canvas.handle_undo("Draw")
			image.fill(Color(0, 0, 0, 0))
			image.blit_rect(image_copy, Rect2(Vector2.ZERO, project.size), pixel_diff)

			Global.canvas.handle_redo("Draw")

	_start_pos = Vector2.INF
	_snap_to_grid = false