extends Node2D

var GRID_SIZE := Vector2i(8, 8)
var TILE_TYPES := 5
const TILE_SCENE := preload("res://scenes/match3/tile.tscn")

var grid := []
var tile_size: float = 48.0
var grid_offset: Vector2

func _ready():
	# Set up initial gem pool
	var gem_indices = []
	for i in range(TILE_TYPES):
		gem_indices.append(i)

	const TileScript = preload("res://scenes/match3/tile.gd")
	TileScript.set_active_gem_pool(gem_indices)

	_calculate_grid_layout()
	_initialize_grid()

func _calculate_grid_layout():
	var viewport_size = get_viewport().get_visible_rect().size
	var available_width = viewport_size.x * 0.8  # Use 80% of screen width
	var available_height = viewport_size.y * 0.7  # Use 70% of screen height

	# Calculate tile size based on available space
	var max_tile_width = available_width / GRID_SIZE.x
	var max_tile_height = available_height / GRID_SIZE.y
	tile_size = min(max_tile_width, max_tile_height)

	# Align grid to left side with some margin
	var total_grid_height = tile_size * GRID_SIZE.y
	grid_offset = Vector2(
		50,  # Left margin
		(viewport_size.y - total_grid_height) / 2 + 50  # Vertically centered with top margin
	)

func _initialize_grid():
	# Update gem pool BEFORE creating any tiles
	var gem_indices = []
	for i in range(TILE_TYPES):
		gem_indices.append(i)

	const TileScript = preload("res://scenes/match3/tile.gd")
	TileScript.set_active_gem_pool(gem_indices)

	for y in range(GRID_SIZE.y):
		grid.append([])
		for x in range(GRID_SIZE.x):
			var tile = TILE_SCENE.instantiate()
			tile.position = grid_offset + Vector2(x, y) * tile_size
			tile.grid_position = Vector2i(x, y)
			add_child(tile)
			# Set tile type after adding to scene tree so sprite reference is available
			var new_type = randi() % TILE_TYPES
			tile.tile_type = new_type
			print("Debug: Created tile at (", x, ",", y, ") with type ", new_type)
			grid[y].append(tile)

func _has_match_at(pos: Vector2i) -> bool:
	# Fixed: Add bounds and null checks
	if pos.x < 0 or pos.y < 0 or pos.x >= GRID_SIZE.x or pos.y >= GRID_SIZE.y:
		return false
	if not grid[pos.y][pos.x]:
		return false

	var matches_horizontal = _get_match_line(pos, Vector2i(1, 0))
	if matches_horizontal.size() >= 3:
		return true

	var matches_vertical = _get_match_line(pos, Vector2i(0, 1))
	return matches_vertical.size() >= 3

# Fixed: Add missing function to check for any matches on the board
func _check_for_matches() -> bool:
	for y in range(GRID_SIZE.y):
		for x in range(GRID_SIZE.x):
			if _has_match_at(Vector2i(x, y)):
				return true
	return false

func _get_match_line(start: Vector2i, dir: Vector2i) -> Array:
	var line = [grid[start.y][start.x]]
	var type = grid[start.y][start.x].tile_type

	# Fixed: Check in both directions separately to avoid infinite loops
	for offset in [1, -1]:
		var current = start + dir * offset
		while current.x >= 0 and current.y >= 0 and current.x < GRID_SIZE.x and current.y < GRID_SIZE.y:
			var neighbor = grid[current.y][current.x]
			# Fixed: Add null check to prevent crashes
			if not neighbor or neighbor.tile_type != type:
				break
			line.append(neighbor)
			current += dir * offset

	return line

func _clear_matches():
	var to_clear := []

	for y in range(GRID_SIZE.y):
		for x in range(GRID_SIZE.x):
			# Fixed: Add null check before processing
			if not grid[y][x]:
				continue
			var pos = Vector2i(x, y)
			var horiz = _get_match_line(pos, Vector2i(1, 0))
			if horiz.size() >= 3:
				to_clear.append_array(horiz)
			var vert = _get_match_line(pos, Vector2i(0, 1))
			if vert.size() >= 3:
				to_clear.append_array(vert)

	# Remove duplicates using dictionary keys trick
	var unique_dict := {}
	for tile in to_clear:
		unique_dict[tile] = true
	to_clear = unique_dict.keys()

	# Fixed: Only proceed if there are matches to clear
	if to_clear.size() == 0:
		return

	for tile in to_clear:
		grid[tile.grid_position.y][tile.grid_position.x] = null
		tile.queue_free()

	_drop_tiles()
	await get_tree().create_timer(0.2).timeout
	_fill_empty_cells()

func _drop_tiles():
	var moved = true
	while moved:
		moved = false
		for x in range(GRID_SIZE.x):
			# Fixed: Start from GRID_SIZE.y - 1 to avoid out of bounds
			for y in range(GRID_SIZE.y - 1, -1, -1):
				var tile = grid[y][x]
				# Fixed: Check bounds before accessing y + 1
				if tile and y + 1 < GRID_SIZE.y and not grid[y + 1][x]:
					grid[y + 1][x] = tile
					grid[y][x] = null
					tile.grid_position = Vector2i(x, y + 1)
					# You can animate position here using Tween for smooth drop:
					# tween.interpolate_property(tile, "position", tile.position, grid_offset + Vector2(x, y + 1) * tile_size, 0.2)
					tile.position = grid_offset + Vector2(x, y + 1) * tile_size
					moved = true

func _fill_empty_cells():
	for y in range(GRID_SIZE.y):
		for x in range(GRID_SIZE.x):
			if not grid[y][x]:
				var tile = TILE_SCENE.instantiate()
				tile.grid_position = Vector2i(x, y)
				tile.tile_type = randi() % TILE_TYPES
				tile.position = grid_offset + Vector2(x, y) * tile_size
				grid[y][x] = tile
				add_child(tile)

	# Fixed: Add recursion protection to prevent stack overflow
	await get_tree().create_timer(0.1).timeout
	var max_iterations = 10
	var iteration = 0
	while _check_for_matches() and iteration < max_iterations:
		_clear_matches()
		await get_tree().create_timer(0.1).timeout
		iteration += 1

func regenerate_grid():
	# Use time-based seed to ensure different patterns each time
	var new_seed = Time.get_ticks_msec()
	seed(new_seed)
	print("Debug: Regenerating grid with seed: ", new_seed)

	# Fixed: Clear ALL tile children, not just ones in grid array
	# This handles any orphaned tiles that might not be tracked in the grid
	var children_to_remove = []
	for child in get_children():
		if child.has_method("get_script") and child.get_script():
			var script_path = child.get_script().resource_path
			if script_path == "res://scenes/match3/tile.gd":
				children_to_remove.append(child)

	# Remove all found tile children
	for child in children_to_remove:
		child.free()

	# Also clear grid array references
	for y in range(grid.size()):
		if grid[y] and grid[y] is Array:
			for x in range(grid[y].size()):
				# Set to null since we already freed the nodes above
				grid[y][x] = null

	# Clear the grid array
	grid.clear()

	# No need to wait for nodes to be freed since we used free()

	# Fixed: Recalculate grid layout before regenerating tiles
	_calculate_grid_layout()

	# Regenerate the grid (gem pool is updated in _initialize_grid)
	_initialize_grid()

func set_tile_types(new_count: int):
	TILE_TYPES = new_count
	# Regenerate grid with new tile types (gem pool is updated in regenerate_grid)
	await regenerate_grid()

func set_grid_size(new_size: Vector2i):
	print("Debug: Changing grid size from ", GRID_SIZE, " to ", new_size)
	GRID_SIZE = new_size
	# Regenerate grid with new size
	await regenerate_grid()