SceneConnectMap = SceneConnectMap or BaseClass()

function SceneConnectMap:__init()
	if SceneConnectMap.Instance ~= nil then
		LogError("attempt to create singleton twice!")
	end

	SceneConnectMap.Instance = self

	self.scene_map = {}
	if Config.SceneDoors == nil then
		return
	end
	for scene_id, scene_info in pairs(Config.SceneDoors) do
		self.scene_map[scene_id] = {}
		self.scene_map[scene_id].to_scene_info = scene_info
	end
end

function SceneConnectMap:ClearPath()
	for scene_id, scene_info in pairs(self.scene_map) do
		scene_info.parent = nil
		scene_info.visit = false
	end
end

function SceneConnectMap:FindPath(src_scene_id, tgt_scene_id)

	self:ClearPath()

	local rlt_path = List.New()

	if src_scene_id == tgt_scene_id then
		List.PushFront(rlt_path, tgt_scene_id)
		List.PushFront(rlt_path, src_scene_id)
		return rlt_path
	end

	local visit_queue = List.New()
	
	local handle_scene_info = self.scene_map[src_scene_id]
	if not handle_scene_info then
		return rlt_path
	end

	handle_scene_info.visit = true
	List.PushBack(visit_queue, src_scene_id)

	local is_find = false
	while not List.Empty(visit_queue) do
		local handle_scene_id = List.PopFront(visit_queue)
		local handle_scene_info = self.scene_map[handle_scene_id]

		if handle_scene_id == tgt_scene_id then
			is_find = true
			break
		end

		for _,to_scene_id in pairs(handle_scene_info.to_scene_info) do
			local to_scene_info = self.scene_map[to_scene_id]
			if to_scene_info and not to_scene_info.visit then
				to_scene_info.visit = true
				to_scene_info.parent = handle_scene_id
				List.PushBack(visit_queue, to_scene_id)
			end
		end
	end

	-- 返回查找列表
	if is_find then
		local cur_scene_info = self.scene_map[tgt_scene_id]
		List.PushFront(rlt_path, tgt_scene_id)
		while cur_scene_info.parent do
			List.PushFront(rlt_path, cur_scene_info.parent)
			cur_scene_info = self.scene_map[cur_scene_info.parent]
		end
	end
	return rlt_path	
end