extends TileMapLayer

# Detect and make tiles fall
func detect_and_make_tiles_fall():
	var all_tiles = get_used_cells()
	var grounded_tiles = get_grounded_tiles()
	print("Grounded tiles:", grounded_tiles)

	var floating_tiles = []
	for tile in all_tiles:
		if tile not in grounded_tiles:
			floating_tiles.append(tile)

	print("Floating tiles:", floating_tiles)

	for tile_pos in floating_tiles:
		make_tile_fall(tile_pos)

# Returns all the grounded tiles (tiles connected to the bottom-most tiles)
func get_grounded_tiles() -> Array:
	var grounded_tiles = []
	var bottom_y = get_bottom_y()  # Identify the bottom-most y coordinate
	print("Bottom y:", bottom_y)

	# Get all tiles at the bottom-most y-coordinate
	var bottom_tiles = []
	for tile in get_used_cells():
		if tile.y == bottom_y:
			bottom_tiles.append(tile)
	
	print("Bottom tiles:", bottom_tiles)

	# Traverse all tiles connected to the bottom-most tiles (iteratively)
	var visited = {}  # Dictionary to track visited tiles
	var queue = bottom_tiles.duplicate()  # Initialize the queue with bottom-most tiles
	
	while queue.size() > 0:
		var current = queue.pop_front()  # Get the next tile to process
		
		# Skip if already visited
		if visited.has(current):
			continue
		
		visited[current] = true  # Mark as visited
		grounded_tiles.append(current)  # Add to grounded tiles
		
		# Check neighboring tiles (up, down, left, right)
		var neighbors = [
			current + Vector2i(1, 0),  # Right
			current + Vector2i(-1, 0),  # Left
			current + Vector2i(0, 1),  # Down (already checked for bottom-most)
			current + Vector2i(0, -1)  # Up
		]
		
		for neighbor in neighbors:
			if has_tile(neighbor) and not visited.has(neighbor):
				queue.append(neighbor)  # Add unvisited neighboring tile to the queue
	
	return grounded_tiles


# Function to get the lowest y-coordinate of tiles in the map
func get_bottom_y() -> int:
	var bottom_y = -1
	
	for tile in get_used_cells():
		if tile.y > bottom_y:
			bottom_y = tile.y  # Keep track of the largest y value (lowest tile)
	
	return bottom_y


# Check if a specific tile exists at the given coordinates
func has_tile(coords: Vector2i) -> bool:
	return get_cell_source_id(coords) != -1



# Make a tile fall by erasing it and placing it below
func make_tile_fall(coords: Vector2i) -> void:
	var source_id = get_cell_source_id(coords)   # Get the source ID of the tile
	var atlas_coords = get_cell_atlas_coords(coords)  # Get the atlas coordinates
	var below_coords = coords + Vector2i(0, 1)  # Position where the tile will fall

	# Erase the current tile
	erase_cell(coords)

	# Place the tile one step below
	#set_cell(below_coords, source_id, atlas_coords)


func _ready():
	# Automatically call the function to test it when the scene runs
	detect_and_make_tiles_fall()