extends Node

export (PackedScene) var piece_scene
export (PackedScene) var movetile_scene

var board = new_board()
var board_cell = 128
const BOARD_WIDTH = 7 # starting at 0..7
const BOARD_HEIGHT = 7

var movement_layer = false
var movement_layer_piece = null

var en_passant_pawn = null
var en_passant_wait = 0 # how many times any piece on the board must move before en_passant_pawn gets set to null

var team1_king = null
var team2_king = null

# hack to prevent 'clicking' on a killed piece
var safely_handle_movement = false

var team1 = 1
var team2 = 2

func _ready():
	make_player1("green")
	make_player2("red")
	#spawn_piece('pawn', 'teal', 1, 6, team1)
	#spawn_piece('pawn', 'orange', 2, 4, team2)
	
	#team2_king = spawn_piece('king', 'teal', 4, 0, team2)
	#spawn_piece('rook', 'teal', 7, 0, team2)
	#spawn_piece('rook', 'teal', 0, 0, team2)
	OS.set_window_size(Vector2(700,700))
	OS.set_window_always_on_top(true)

# horrifying discovery: this occurs after the signal capturing functions
func _process(_delta):
	safely_handle_movement = false

func remove_movement_layer():
	movement_layer = false
	movement_layer_piece = null
	var movement_tiles = get_tree().get_nodes_in_group("tile")
	for e in movement_tiles:
		e.queue_free()

func piece_clicked(piece):
	if movement_layer:
		print("I was clicked on, but the movement layer is toggled")
		if movement_layer_piece == click_spot():
			remove_movement_layer()
	else:
		if ! safely_handle_movement:
			#var piece_name = piece.get_piece()
			#rint("You clicked on a %s, team %s" % [piece_name, piece.get_team()])
			var location = click_spot()
			#rint("Spot: %s " % location)
			var pattern = get_move_pattern(piece, location)
			if can_chess_move(pattern, location):
				movement_layer = true
				movement_layer_piece = location

func click_spot():
	var square = get_viewport().get_mouse_position()
	square[0] = floor(square[0] / board_cell)
	square[1] = floor(square[1] / board_cell)
	return square

func make_player2(color):
	spawn_piece('rook', color, 0, 0, team2)
	spawn_piece('knight', color, 1, 0, team2)
	spawn_piece('bishop', color, 2, 0, team2)
	spawn_piece('queen', color, 3, 0, team2)
	team2_king = spawn_piece('king', color, 4, 0, team2)
	spawn_piece('bishop', color, 5, 0, team2)
	spawn_piece('knight', color, 6, 0, team2)
	spawn_piece('rook', color, 7, 0, team2)
	for i in BOARD_WIDTH + 1:
		spawn_piece('pawn', color, i , 1, team2)

func make_player1(color):
	spawn_piece('rook', color, 0, 7, team1)
	spawn_piece('knight', color, 1, 7, team1)
	spawn_piece('bishop', color, 2, 7, team1)
	spawn_piece('queen', color, 3, 7, team1)
	team1_king = spawn_piece('king', color, 4, 7, team1)
	spawn_piece('bishop', color, 5, 7, team1)
	spawn_piece('knight', color, 6, 7, team1)
	spawn_piece('rook', color, 7, 7, team1)
	for i in BOARD_WIDTH + 1:
		spawn_piece('pawn', color, i , 6, team1)

func spawn_piece(piece_name, color, x=0, y=0, team=0):
	var piece = piece_scene.instance()
	piece.init(piece.piece_map.get(piece_name), piece.piece_color.get(color), team)
	add_child(piece)
	piece.connect("clicked", self, "piece_clicked", [piece])
	board_add_piece(piece, x, y)
	piece.position = in_square(Vector2(x * board_cell, y * board_cell))
	return piece

func rand_pos():
	return Vector2(rand_range(0, get_viewport().size.x),rand_range(0, get_viewport().size.y))

# needs to be Vector2 as that is what object.position takes
func in_square(vect2):
	#rint(vect2)
	vect2.x = ceil(vect2.x / board_cell)
	#rint(vect2.x)
	vect2.x *= board_cell
	vect2.x += board_cell / 2
	
	vect2.y = ceil(vect2.y / board_cell)
	#rint(vect2.y)
	vect2.y *= board_cell
	vect2.y += board_cell / 2
	
	#rint(vect2)
	return vect2

func new_board():
		#  x →
	# y
	# ↓
	# [0][0] = top left, [0][7] = bottom left, [7][0] = top right, [7][7] = bottom right
	var new_board = []
	for i in BOARD_HEIGHT + 1:
		new_board.append([])
		new_board[i].resize(BOARD_WIDTH + 1)
		for j in BOARD_WIDTH + 1:
			new_board[i][j] = 0
	return new_board

func board_add_piece(piece, x, y):
	board[x][y] = piece

enum {
	move_2_up_pawn,
	move_1_up_pawn,
	attack_1_nw,
	attack_1_ne,
	en_passent_nw,
	en_passent_ne,
	
	move_2_down_pawn,
	move_1_down_pawn,
	attack_1_sw,
	attack_1_se,
	en_passent_sw,
	en_passent_se,
	
	move_1_up,
	move_1_down,
	move_1_left,
	move_1_right,
	move_1_nw,
	move_1_ne,
	move_1_sw,
	move_1_se,
	
	move_up_inf,
	move_down_inf,
	move_left_inf,
	move_right_inf,
	castling,
	
	move_nw_inf,
	move_ne_inf,
	move_sw_inf,
	move_se_inf,
	
	knight,
}

func get_move_pattern(piece, coords):
	var piece_name = piece.get_piece()
	match (piece_name):
		"pawn":
			if piece.get_team() == team1:
				if coords[1] == 6:
					return [attack_1_nw, move_2_up_pawn, attack_1_ne, en_passent_ne, en_passent_nw]
				else:
					return [attack_1_nw, move_1_up_pawn, attack_1_ne, en_passent_ne, en_passent_nw]
			else:
				if coords[1] == 1:
					return [attack_1_sw, move_2_down_pawn, attack_1_se, en_passent_se, en_passent_sw]
				else:
					return [attack_1_sw, move_1_down_pawn, attack_1_se, en_passent_se, en_passent_sw]
		"rook":
			return [move_up_inf, move_left_inf, move_right_inf, move_down_inf]
		"knight":
			return [knight]
		"bishop":
			return [move_ne_inf, move_nw_inf, move_sw_inf, move_se_inf]
		"queen":
			return [move_up_inf, move_down_inf, move_left_inf, move_right_inf, move_ne_inf, move_nw_inf, move_sw_inf, move_se_inf]
		"king":
			return [move_1_down, move_1_left, move_1_right, move_1_up, move_1_ne, move_1_nw, move_1_se, move_1_sw, castling]
		_:
			#rint("no pattern for this one")
			return []

func can_chess_move(pattern, coords):
	var can_move = false
	var curr_piece = board[coords[0]][coords[1]]
	var curr_team = curr_piece.get_team()
	for e in pattern:
		match (e):
			move_1_down_pawn:
				if make_tiles(coords, [0,1], 1, true, curr_team): can_move = true
			move_2_down_pawn:
				if make_tiles(coords, [0,1], 1, true, curr_team):
					can_move = true
					make_tiles(coords, [0,2], 1, true, curr_team, {'tile_is_en_passant': true})
			attack_1_sw:
				if make_tiles(coords, [-1,1], 1, false, curr_team, {"must_attack": true}): can_move = true
			attack_1_se:
				if make_tiles(coords, [1,1], 1, false, curr_team, {"must_attack": true}): can_move = true
			en_passent_sw:
				var pawn_maybe = board[coords[0]-1][coords[1]]
				if pawn_maybe and pawn_maybe.get_piece() == "pawn" and pawn_maybe == en_passant_pawn and pawn_maybe.get_team() != curr_team:
					if make_tiles(coords, [-1,1], 1, true, curr_team, {"en_passant_pawn": pawn_maybe}): can_move = true
			en_passent_se:
				if ! coords[0] + 1 > BOARD_WIDTH:
					var pawn_maybe = board[coords[0]+1][coords[1]]
					if pawn_maybe and pawn_maybe.get_piece() == "pawn" and pawn_maybe == en_passant_pawn and pawn_maybe.get_team() != curr_team:
						if make_tiles(coords, [1,1], 1, true, curr_team, {"en_passant_pawn": pawn_maybe}): can_move = true

			move_1_up_pawn:
				if make_tiles(coords, [0,-1], 1, true, curr_team): can_move = true
			move_2_up_pawn:
				if make_tiles(coords, [0,-1], 1, true, curr_team):
					can_move = true
					make_tiles(coords, [0,-2], 1, true, curr_team, {'tile_is_en_passant': true})
			attack_1_nw:
				if make_tiles(coords, [-1,-1], 1, false, curr_team, {"must_attack": true}): can_move = true
			attack_1_ne:
				if make_tiles(coords, [1,-1], 1, false, curr_team, {"must_attack": true}): can_move = true
			en_passent_nw:
				var pawn_maybe = board[coords[0]-1][coords[1]]
				if pawn_maybe and pawn_maybe.get_piece() == "pawn" and pawn_maybe == en_passant_pawn and pawn_maybe.get_team() != curr_team:
					if make_tiles(coords, [-1,-1], 1, true, curr_team, {"en_passant_pawn": pawn_maybe}): can_move = true
			en_passent_ne:
				if ! coords[0] + 1 > BOARD_WIDTH:
					var pawn_maybe = board[coords[0]+1][coords[1]]
					if pawn_maybe and pawn_maybe.get_piece() == "pawn" and pawn_maybe == en_passant_pawn and pawn_maybe.get_team() != curr_team:
						if make_tiles(coords, [1,-1], 1, true, curr_team, {"en_passant_pawn": pawn_maybe}): can_move = true

			move_up_inf:
				if make_tiles(coords, [0,-1], BOARD_HEIGHT, false, curr_team): can_move =true
			move_down_inf:
				if make_tiles(coords, [0,1], BOARD_HEIGHT, false, curr_team): can_move = true
			move_left_inf:
				if make_tiles(coords, [-1,0], BOARD_WIDTH, false, curr_team): can_move = true
			move_right_inf:
				if make_tiles(coords, [1,0], BOARD_WIDTH, false, curr_team): can_move = true
			castling:
				if ! curr_piece.has_moved and ! curr_piece.in_check:
					var y = coords[1]
					var king_x = coords[0]
					var pieces = get_tree().get_nodes_in_group("piece")
					for ele in pieces:
						if ele.get_team() == curr_team and ele.get_piece() == "rook" and ! ele.has_moved and position_to_board_cell(ele.position)[1] == y:
							print(ele)
							var rook_x = position_to_board_cell(ele.position)[0]
							# king side
							if rook_x > king_x:
								var blocked = false
								pass
								var diff = rook_x - king_x
								for i in range(1, diff):
								#rint(board[king_x + i][y])
									if board[king_x + i][y]:
										blocked = true
										#rint("There is something at (%s,%s) %s" % [king_x + i,y, board[king_x + i][y].get_piece() ])
								if ! blocked:
									if make_tiles(coords, [2,0], 1, false, curr_team, {"castling_rook": ele}): can_move = true
							else:
								var blocked = false
								pass
								var diff = king_x - rook_x
								for i in range(1, diff):
									print(board[rook_x + i][y])
									if board[rook_x + i][y]:
										blocked = true
										#rint("There is something at (%s,%s) %s" % [rook_x + i, y, board[rook_x + i][y].get_piece()])
								if ! blocked:
									if make_tiles(coords, [-2,0], 1, false, curr_team, {"castling_rook": ele}): can_move = true

			move_ne_inf:
				if make_tiles(coords, [1,-1], 8, false, curr_team): can_move = true
			move_nw_inf:
				if make_tiles(coords, [-1,-1], 8, false, curr_team): can_move = true
			move_sw_inf:
				if make_tiles(coords, [-1,1], 8, false, curr_team): can_move = true
			move_se_inf:
				if make_tiles(coords, [1,1], 8, false, curr_team): can_move = true
			
			knight:
				if make_tiles(coords, [1,2], 1, false, curr_team): can_move = true
				if make_tiles(coords, [1,-2], 1, false, curr_team): can_move = true
				if make_tiles(coords, [-1,-2], 1, false, curr_team): can_move = true
				if make_tiles(coords, [-1,2], 1, false, curr_team): can_move = true
				if make_tiles(coords, [2,1], 1, false, curr_team): can_move = true
				if make_tiles(coords, [2,-1], 1, false, curr_team): can_move = true
				if make_tiles(coords, [-2,-1], 1, false, curr_team): can_move = true
				if make_tiles(coords, [-2,1], 1, false, curr_team): can_move = true
			
			move_1_down:
				if make_tiles(coords, [0,1], 1, false, curr_team): can_move = true
			move_1_up:
				if make_tiles(coords, [0,-1], 1, false, curr_team): can_move = true
			move_1_right:
				if make_tiles(coords, [1,0], 1, false, curr_team): can_move = true
			move_1_left:
				if make_tiles(coords, [-1,0], 1, false, curr_team): can_move = true
			move_1_ne:
				if make_tiles(coords, [1,-1], 1, false, curr_team): can_move = true
			move_1_nw:
				if make_tiles(coords, [-1,-1], 1, false, curr_team): can_move = true
			move_1_se:
				if make_tiles(coords, [1,1], 1, false, curr_team): can_move = true
			move_1_sw:
				if make_tiles(coords, [-1,1], 1, false, curr_team): can_move = true
	return can_move

func position_to_board_cell(vect2):
	var x = floor(vect2.x / board_cell)
	var y = floor(vect2.y / board_cell)
	return [x,y]

func movetile_clicked(move_tile):
	#rint("Yep, I was clicked")
	var location = click_spot()
	var check = board[location[0]][location[1]]
	var curr_piece = board[movement_layer_piece[0]][movement_layer_piece[1]]
	if ! check:
		pass
	else:
		check.kill()

	board[location[0]][location[1]] = curr_piece
	if move_tile.en_passant_tile:
		#rint("toggling en passant able...")
		en_passant_pawn = curr_piece
		en_passant_wait = 2 # gets -1 in this script later
	if move_tile.castling_rook:
		var rook_location = position_to_board_cell(move_tile.castling_rook.position)
		# king
		if 7 == rook_location[0]:
			move_tile.castling_rook.position = in_square(Vector2(5 * board_cell, rook_location[1] * board_cell))
			board[5][rook_location[1]] = board[7][rook_location[1]]
			board[7][rook_location[1]] = 0
		# queen
		else:
			move_tile.castling_rook.position = in_square(Vector2(3 * board_cell, rook_location[1] * board_cell))
			board[3][rook_location[1]] = board[0][rook_location[1]]
			board[0][rook_location[1]] = 0
	
	curr_piece.position = in_square(Vector2(location[0] * board_cell, location[1] * board_cell))
	board[movement_layer_piece[0]][movement_layer_piece[1]] = 0
	remove_movement_layer()
	safely_handle_movement = true
	
	curr_piece.has_moved = true
	
	if move_tile.en_passant_kill_tile:
		kill_en_passant_pawn(location)
	
	if en_passant_wait >= 1:
		en_passant_wait -= 1
	if en_passant_wait == 0:
		en_passant_pawn = null

func kill_en_passant_pawn(location):
	if board[location[0]+1][location[1]] is Object and board[location[0]+1][location[1]] == en_passant_pawn:
		board[location[0]+1][location[1]] = 0
	if board[location[0]-1][location[1]] is Object and board[location[0]-1][location[1]] == en_passant_pawn:
		board[location[0]-1][location[1]] = 0
	if board[location[0]][location[1]+1] is Object and board[location[0]][location[1]+1] == en_passant_pawn:
		board[location[0]][location[1]+1] = 0
	if board[location[0]][location[1]-1] is Object and board[location[0]][location[1]-1] == en_passant_pawn:
		board[location[0]][location[1]-1] = 0
	en_passant_pawn.kill()

func spawn_move_tile(coords, en_passant_tile=false, en_passant_kill_tile=null, castling_rook=null):
	var move_tile = movetile_scene.instance()
	add_child(move_tile)
	move_tile.connect("move_clicked", self, "movetile_clicked", [move_tile])
	move_tile.position = in_square(Vector2(coords[0] * board_cell, coords[1] * board_cell))
	if en_passant_tile: move_tile.en_passant_tile = true
	if en_passant_kill_tile: move_tile.en_passant_kill_tile = true
	if castling_rook: move_tile.castling_rook = castling_rook
	#rint(move_tile.position)

func make_tiles(coords, pattern, go_range, cant_attack, curr_team, 
	dict = {
		"must_attack": false,
		'tile_is_en_passant': false,
		'en_passant_pawn': null,
		'castling_rook': null
	}):
	var x = coords[0]
	var y = coords[1]
	var pattern0 = pattern[0]
	var pattern1 = pattern[1]
	var a = 0
	var b = 0
	
	var made_tile = false
	
	for _i in range(1,go_range+1):
		a += pattern0
		b += pattern1
		# dont go out of bounds: not bigger than board size but not smaller than 0
		if (x + a) <= BOARD_WIDTH and (y + b) <= BOARD_HEIGHT and (x + a) >= 0 and (y + b) >= 0 :
			var check = board[x + a][y + b]
			if ! check and ! dict.get("must_attack"):
				spawn_move_tile([x + a, y + b], dict.get("tile_is_en_passant"), dict.get("en_passant_pawn"), dict.get("castling_rook"))
				made_tile = true
			elif dict.get("must_attack"):
				if ! check:
					pass
				elif check.get_team() != curr_team:
					spawn_move_tile([x + a, y + b])
					made_tile = true
			elif ! cant_attack and check.get_team() != curr_team: 
				spawn_move_tile([x + a, y + b], dict.get("tile_is_en_passant"), dict.get("en_passant_pawn"))
				made_tile = true
				break # rules of chess say pieces cant go past another
			else:
				break
	return made_tile

# option (used when we KNOW it is an array)
#   "object" -> sprite object
#   "tile" -> return info about the tile
func array_piece(coords, option=null):
	var element = board[coords[0]][coords[1]]
	#rint(element)
	if element is Array:
		if option == "object":
			return element[0]
		elif option == "tile":
			return element[1]
	return element