local ipairs, pairs, setmetatable, type = 

        ipairs, pairs, setmetatable, type;

module "pubsub"

local pubsub_node_mt = { __index = _M };

function new_node(name)

	return setmetatable({ name = name, subscribers = {} }, pubsub_node_mt);

end

function set_subscribers(node, subscribers_list, list_type)

	local subscribers = node.subscribers;

	if list_type == "array" then

		for _, jid in ipairs(subscribers_list) do

			if not subscribers[jid] then

				node:add_subscriber(jid);

			end

		end

	elseif (not list_type) or list_type == "set" then

		for jid in pairs(subscribers_list) do

			if type(jid) == "string" then

				node:add_subscriber(jid);

			end

		end

	end

end

function get_subscribers(node)

	return node.subscribers;

end

function publish(node, item, dispatcher, data)

	local subscribers = node.subscribers;

	for i = 1,#subscribers do

		item.attr.to = subscribers[i];

		dispatcher(data, item);

	end

end

function add_subscriber(node, jid)

	local subscribers = node.subscribers;

	if not subscribers[jid] then

		local space = #subscribers;

		subscribers[space] = jid;

		subscribers[jid] = space;

	end

end

function remove_subscriber(node, subscriber)

	local subscribers = node.subscribers;

	if subscribers[jid] then

		subscribers[subscribers[jid]] = nil;

		subscribers[jid] = nil;

	end

end

return _M;