util/pubsub.lua

module("pubsub", package.seeall);

local service = {};
local service_mt = { __index = service };

function new(cb)
	return setmetatable({ cb = cb or {}, nodes = {} }, service_mt);
end

function service:add_subscription(node, actor, jid)
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	node_obj.subscribers[jid] = true;
	return true;
end

function service:remove_subscription(node, actor, jid)
	local node_obj = self.nodes[node];
	if not node_obj then
		return false, "item-not-found";
	end
	if not node_obj.subscribers[jid] then
		return false, "not-subscribed";
	end
	node_obj.subscribers[jid] = nil;
	return true;
end

function service:get_subscription(node, actor, jid)
	local node_obj = self.nodes[node];
	if node_obj then
		return node_obj.subscribers[jid];
	end
end

function service:create(node, actor)
	if not self.nodes[node] then
		self.nodes[node] = { name = node, subscribers = {}, config = {}, data = {} };
		return true;
	end
	return false, "conflict";
end

function service:publish(node, actor, id, item)
	local node_obj = self.nodes[node];
	if not node_obj then
		node_obj = { name = node, subscribers = {}, config = {}, data = {} };
		self.nodes[node] = node_obj;
	end
	node_obj.data[id] = item;
	self.cb.broadcaster(node, node_obj.subscribers, item);
	return true;
end

function service:retract(node, actor, id, retract)
	local node_obj = self.nodes[node];
	if (not node_obj) or (not node_obj.data[id]) then
		return false, "item-not-found";
	end
	node_obj.data[id] = nil;
	if retract then
		self.cb.broadcaster(node, node_obj.subscribers, retract);
	end
	return true
end

function service:get(node, actor, id)
	local node_obj = self.nodes[node];
	if node_obj then
		if id then
			return { node_obj.data[id] };
		else
			return node_obj.data;
		end
	end
end

return _M;