extends GridContainer

var config = ConfigFile.new()

@export var map_size := 15
@export var texture : Texture2D
@export var speed := 0.25

@export var tile_color := TileColors.new()

var start_scene = preload("res://Scene/Main Menu.tscn").instantiate()

var tiles = []
var snake_move_vector : Vector2
var last_snake_move_vector : Vector2
var snake_length : int

var rng = RandomNumberGenerator.new()
var timer := 0.0

var game_is_running := true

func generate_tiles():
	self.columns = map_size
	
	for x in range(map_size):
		tiles.append([])
		tiles[x] = []
		for y in range(map_size):
			var tile = Tile.new(x ,y, tile_color)
			self.add_child(tile)
			tiles[x].append([])
			tiles[x][y] = tile
	pass
	
func generate_apple():
	var foundViablePosition := false
	var tile : Tile
	while !foundViablePosition:
		tile = tiles[rng.randi_range(0, map_size -1)][rng.randi_range(0, map_size -1)] as Tile
		if(tile.state == Tile.States.EMPTY):
			foundViablePosition = true
			
	tile.state = Tile.States.APPLE
	pass
	
func set_snake_to_start_position():
	#No need for float protection, godot automaticly converts floats to ints in this case
	var tile = (tiles[map_size / 2][map_size / 2] as Tile)
	tile.state = Tile.States.SNAKE
	tile.snake_pos = 1
	pass
	
func read_input() -> Vector2:#
	# cant use Input.get_vector because it normalizes the vector
	return Vector2(Input.get_axis("up", "down"), Input.get_axis("left", "right"))


func process_tiles():
	var new_snake_head : Tile
	for x in range(map_size):
		for y in range(map_size):
			var tile = tiles[x][y] as Tile
			if tile.state == Tile.States.SNAKE:
				if tile.snake_pos == 1:
					if x + snake_move_vector.x >= map_size || x + snake_move_vector.x < 0 || y + snake_move_vector.y >= map_size || y + snake_move_vector.y < 0:
						game_stop()
						return
					new_snake_head = tiles[x + snake_move_vector.x][y + snake_move_vector.y] as Tile
				tile.snake_pos += 1
				if(tile.snake_pos > snake_length):
					tile.snake_pos = 0
					tile.state = Tile.States.EMPTY
	
	var was_apple = new_snake_head.state == Tile.States.APPLE
	if  new_snake_head.state == Tile.States.SNAKE:
		game_stop()
		return
	new_snake_head.snake_pos = 1
	new_snake_head.state = Tile.States.SNAKE
	last_snake_move_vector = snake_move_vector
	if was_apple:
		snake_length += 1
		generate_apple()
	pass

func process_snake_rotation():
	var input = read_input()
	# Return if no Input or Input into multiple directions
	if input.length() == 0 || input.length() > 1:
		return
	#return if input is the inverse of the moving direction
	if input * -1 == last_snake_move_vector:
		return
	# set move direction into inpu direction
	snake_move_vector = input.normalized()

func _ready():
	#load Config
	var err = config.load("user://config.cfg")
	if err != OK:
		return
	map_size = config.get_value("Game Play", "grid_size", 10)
	speed = float(config.get_value("Game Play", "speed", 1))
	print(speed)
	
	game_start()
	pass
	
func game_start():
	snake_move_vector = Vector2.RIGHT
	last_snake_move_vector = snake_move_vector
	snake_length = 3
	tiles.clear()
	generate_tiles()
	set_snake_to_start_position()
	generate_apple()
	pass
	
func game_stop():
	game_is_running = false
	get_tree().change_scene_to_file("res://Scene/Main Menu.tscn")
	pass

func _process(delta):
	if !game_is_running:
		return
	process_snake_rotation()
	if(timer * speed >= 0.25):
		timer = 0
		process_tiles()
	timer += delta
	pass