extends Node

@export var cols : int
@export var cell_size : Vector2i
@export var left_top_of_board : Marker2D
@export var init_card_anchos : Array[Marker2D]

@export var board_area : ReferenceRect

signal dragging_card
signal release_dragging_card

var has_mouse: bool = false
var dragged_card : Card

var hovered_cell_control : ColorRect

var hovered_cell : Vector2 = Global.invalid_cell_index
var board_info : Array = []

const GLOBAL_LEFT_TOP = "global-left-top"
const GLOBAL_CENTER = "global-center"
const INDEX = "index"
const AREA = "area"
const HOLD_CARD = "hold-card"

const hovered_color = "015aafb8"

func _ready() -> void:
	init_game()
	dragging_card.connect(_on_dragging_card)
	release_dragging_card.connect(_on_release_dragging_card)

func init_game() -> void:
	board_info = create_cells()
	send_cards()

func create_cells() -> Array:
	var cells_matrix = []
	var init_pos = Vector2(left_top_of_board.global_position.x, left_top_of_board.global_position.y)
	for i in range(0, cols):
		var row = []
		for j in range(0, cols):
			var left_top_pos = Vector2(init_pos.x + i * cell_size.x, init_pos.y + j * cell_size.y)
			var center_pos = Vector2(left_top_pos.x + cell_size.x / 2, left_top_pos.y + cell_size.y / 2)
			var cell = setup_cell_rect(left_top_pos, cell_size)
			$BoardCells.add_child(cell)
			var dict = {
				GLOBAL_LEFT_TOP : left_top_pos,
				GLOBAL_CENTER : center_pos,
				INDEX: Vector2i(i, j),
				AREA : cell,
				HOLD_CARD : null
			}
			row.append(dict)
		cells_matrix.append(row)
	return cells_matrix
	
func setup_cell_rect(left_top: Vector2, size: Vector2i) -> ColorRect:
	var cell = ColorRect.new()
	cell.color = Color(hovered_color)
	cell.size = cell_size
	cell.global_position = left_top
	cell.visible = false
	return cell

func _process(_delta: float) -> void:
	var cell = clamp_cell()
	if hovered_cell_control != null:
		hovered_cell_control.visible = false
	if cell != null:
		hovered_cell_control = cell
		cell.visible = true

func _on_dragging_card(card: Card) -> void:
	dragged_card = card

func _on_release_dragging_card(card: Card, index: Vector2i) -> void:
	print(index)
	dragged_card = null

func get_hover_cell_index() -> Vector2i:
	var mouse_global_position = $MouseAnchor.get_global_mouse_position()
	return get_cell_on_pos(mouse_global_position)

func get_cell_on_pos(pos: Vector2) -> Vector2i:
	if pos.x < left_top_of_board.global_position.x or  pos.y < left_top_of_board.global_position.y:
		return Global.invalid_cell_index
	var relative_pos = Vector2(pos.x - left_top_of_board.global_position.x, pos.y - left_top_of_board.global_position.y)
	var index = Vector2i(int(relative_pos.x) / cell_size.x, int(relative_pos.y) / cell_size.y)
	if index.x < 0 or index.x >= cols or index.y < 0 or index.y >= cols:
		index = Global.invalid_cell_index
	return index
	
func clamp_cell() -> ColorRect:
	var index = get_hover_cell_index()
	if index != Global.invalid_cell_index:
		var cell_info = board_info[index.x][index.y]
		var cell = cell_info[AREA]
		if cell != null:
			var control = cell as ColorRect
			return control
	return null

func send_cards() -> void:
	var card_prefab = load("res://Scenes/Card.tscn")
	for i in range(init_card_anchos.size()):
		var pos = init_card_anchos[i].global_position
		var card_instance = card_prefab.instantiate()
		var card_size = (card_instance as Card).texture_normal.get_size()
		card_instance.global_position = Vector2(pos.x - card_size.x / 2, pos.y - card_size.y / 2)
		var val = randi() % 10
		var cate_num = randi() % 4
		card_instance.setup_card(cate_num, val)
		$Cards.add_child(card_instance)


func _on_board_area_input_event(viewport: Node, event: InputEvent, shape_idx: int) -> void:
	if event is InputEventMouseButton:
		if event.button_index == MOUSE_BUTTON_LEFT:
			if not event.pressed:
				try_place_card(dragged_card)	

func try_place_card(card: Card) -> void:
	var index = get_hover_cell_index()
	if dragged_card == null or index == Global.invalid_cell_index:
		return
	var cell_info = board_info[index.x][index.y]
	if cell_info[HOLD_CARD] == null:
		var lt = cell_info[GLOBAL_LEFT_TOP]
		card.global_position = lt
		card.settled = true
		cell_info[HOLD_CARD] = card
		emit_signal("release_dragging_card", card, index)