extends Area2D
class_name SnakePart

const TILE_SIZE = 20
enum PartTypes {HEAD, BODY, TAIL, DEAD}

var part_type : PartTypes = PartTypes.HEAD
var current_direction : Vector2 = Vector2.RIGHT

var inputs : Dictionary[String, Vector2] = {"right": Vector2.RIGHT,
											"left": Vector2.LEFT,
											"up": Vector2.UP,
											"down": Vector2.DOWN}


@onready
var raycast_right = $RightRayCast2D
@onready
var raycast_left = $LeftRayCast2D
@onready
var raycast_up = $UpRayCast2D
@onready
var raycast_down = $DownRayCast2D


var snake_part_obj = preload("res://Scenes/snake_part.tscn")

@onready
var timer_ref = $"../Timer"

signal do_movement(new_dir)

func _ready() -> void:
	if part_type == PartTypes.HEAD:
		
		# Add to group for easy access from other nodes
		add_to_group("Head")
		
		# Set up a body part
		var body = snake_part_obj.instantiate()
		body.part_type = PartTypes.BODY
		body.position = (position - current_direction * TILE_SIZE).snapped(Vector2.ONE * TILE_SIZE)
		get_parent().add_child.call_deferred(body)
		do_movement.connect(body.process_movement)
		
		# Set up a tail part
		var tail = snake_part_obj.instantiate()
		tail.part_type = PartTypes.TAIL
		tail.position = (position - current_direction * TILE_SIZE * 2).snapped(Vector2.ONE * TILE_SIZE)
		get_parent().add_child.call_deferred(tail)
		body.do_movement.connect(tail.process_movement)
	else:
		raycast_down.queue_free()
		raycast_up.queue_free()
		raycast_left.queue_free()
		raycast_right.queue_free()
	#elif part_type == PartTypes.BODY:
		#area_entered.connect(_on_part_area_entered)
	#elif part_type == PartTypes.TAIL:
		#area_entered.connect(_on_part_area_entered)



func process_movement(new_direction : Vector2) -> void:
	if part_type == PartTypes.HEAD:
		check_movement()
	position = (position + current_direction * TILE_SIZE).snapped(Vector2.ONE * TILE_SIZE)
	#process_collisions();
	do_movement.emit(current_direction)
	if new_direction != Vector2.ZERO:
		current_direction = new_direction

func check_movement() -> void:
	# Get the correct raycast for the direction we are moving
	var raycast_to_use : RayCast2D
	if current_direction == Vector2.RIGHT:
		raycast_to_use = raycast_right
	elif current_direction == Vector2.LEFT:
		raycast_to_use = raycast_left
	elif current_direction == Vector2.UP:
		raycast_to_use = raycast_up
	elif current_direction == Vector2.DOWN:
		raycast_to_use = raycast_down
	
	# Look using the raycast for anything to collide with
	var object_in_path : Object = raycast_to_use.get_collider()
	if object_in_path == null:
		return
	if object_in_path is SnakePart:
		match object_in_path.part_type:
			PartTypes.BODY:
				lose_game()
			PartTypes.TAIL:
				ouroboros()

#func process_collisions() -> void:
	#var colliding_areas = get_overlapping_areas()
	#for area in colliding_areas:
		#if area is SnakePart:
			#match area.part_type:
				#PartTypes.BODY:
					#lose_game()
				#PartTypes.TAIL:
					#ouroboros()

func lose_game() -> void:
	# You lose!
	print("Game lost")
	timer_ref.stop()

func ouroboros() -> void:
	print("You have achieved the ouroboros!")

func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventKey and part_type == PartTypes.HEAD:
		for dir in inputs.keys():
			if event.is_action_pressed(dir):
				current_direction = inputs[dir]

#func _on_part_area_entered(area: Area2D) -> void:
	#if area.get("part_type") != PartTypes.HEAD:
		#return
	#if part_type == PartTypes.BODY or part_type == PartTypes.DEAD:
		#lose_game()
	#elif part_type == PartTypes.TAIL:
		#ouroboros()

func _on_level_area_exited(area: Area2D) -> void:
	lose_game()