-- TODO: collapse nodes when the node under them is removed.

local function attempt_collapse_at (pos, node)
	node = node or minetest.get_node(pos)

	local below = pos + blockgame.vector.dirs.down
	if minetest.get_node(below).name ~= "air" then return end

	local node_def = minetest.registered_nodes[node.name]
	if type(node_def.fall_check) == "function" then
		if not node_def.fall_check(pos, node) then return end
	end

	minetest.spawn_falling_node(pos)
end

-- collapse nodes that somehow managed to stay in the air.
blockgame.register_abm({
	label = "collapse falling nodes",
	nodenames = {"group:can_fall"},
	neighbors = {"air"},
	interval = 15,
	chance = 1,
	action = attempt_collapse_at,
})

return {
	attempt_collapse_at = attempt_collapse_at,
}