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 score_num_label : Label

signal dragging_card
signal release_dragging_card
signal place_card
signal kill_cards

var score = 0

var waitting_cards_num = 4

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 HOLD_CARD_VALUE = "hold-card-value"
const HOLD_CARD_CATEGORY = "hold-card-category"

const hovered_color = "015aafb8"

func _ready() -> void:
	init_game()
	dragging_card.connect(_on_dragging_card)
	release_dragging_card.connect(_on_release_dragging_card)
	place_card.connect(_on_place_card)
	kill_cards.connect(_on_kill_cards)

func init_game() -> void:
	board_info = create_cells()
	score = 0
	waitting_cards_num = init_card_anchos.size()
	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:
	dragged_card = null
	waitting_cards_num -= 1
	if waitting_cards_num == 0:
		waitting_cards_num = init_card_anchos.size()
		send_cards()

func _on_place_card(card: Card, index: Vector2i) -> void:
	var cell_info = board_info[index.x][index.y]
	var lt = cell_info[GLOBAL_LEFT_TOP]
	card.global_position = lt
	card.settled = true
	cell_info[HOLD_CARD] = card
	cell_info[HOLD_CARD_VALUE] = card.value
	cell_info[HOLD_CARD_CATEGORY] = card.category
	card.index = index
	try_kill_card(index)
	
func try_kill_card(index: Vector2i) -> void:
	var detected_cards = detect_cards(index)
	if detected_cards.size() > 1:
		emit_signal("kill_cards", detected_cards)
	
func detect_cards(index: Vector2i) -> Array[Vector2i]:
	var cell_info = board_info[index.x][index.y]
	var card = cell_info[HOLD_CARD]
	if card == null:
		return []
	return _detect_cards(index, index, [])

func _detect_cards(index: Vector2i, origin_index: Vector2i, visited) -> Array[Vector2i]:
	# 检查是否越界或已经访问
	if index.x < 0 or index.y < 0 or index.x >= cols or index.y >= cols:
		return []
	if index in visited:
		return []
	
	# 标记当前格子为已访问
	visited.append(index)
	
	var cell_info = board_info[index.x][index.y]
	var origin_cell_info = board_info[origin_index.x][origin_index.y]
	
	# 如果当前格子为空（值为0），则返回空列表
	if cell_info[HOLD_CARD] == null:
		return []
	
	# 当前格子含有棋子，将其加入结果
	if cell_info[HOLD_CARD].category == origin_cell_info[HOLD_CARD].category and cell_info[HOLD_CARD].value ==  origin_cell_info[HOLD_CARD].value:
		var result : Array[Vector2i] = [index]
		
		# 检查上下左右相邻格子
		var directions = [
			Vector2i(0, 1),  # 上
			Vector2i(0, -1), # 下
			Vector2i(1, 0),  # 右
			Vector2i(-1, 0)  # 左
			]
		for dir in directions:
			result += _detect_cards(index + dir, index, visited)
		return result
	return []

func _on_kill_cards(index_array: Array[Vector2i]) -> void:
	print("------*****--------")
	for i in index_array:
		var cell_info = board_info[i.x][i.y]
		var card = cell_info[HOLD_CARD] as Card
		cell_info[HOLD_CARD] = null
		cell_info[HOLD_CARD_CATEGORY] = 0
		cell_info[HOLD_CARD_VALUE] = -999
		card.index = Global.invalid_cell_index
		card.queue_free()
		print("kill-" + str(i) + "-" + str(cell_info))
		score += 1
	score_num_label.text = str(score)
	print("-------------------")

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(waitting_cards_num):
		var pos = init_card_anchos[i].global_position
		var card_instance = card_prefab.instantiate() as Card
		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() % 9 + 1
		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:
		emit_signal("release_dragging_card", card, index)
		emit_signal("place_card", card, index)