module:depends("http");

module:depends("pubsub");

local streams = {};

local service = hosts[module.host].modules.pubsub.service;

function client_closed(response)

	local node = response._eventsource_node;

	module:log("debug", "Destroying client for %q", node);

	streams[node][response] = nil;

	if next(streams[node]) == nil then

		streams[node] = nil;

	end

end

function serve_stream(event, node)

	module:log("debug", "Client subscribed to: %s", node);

	local response = event.response;

	response.on_destroy = client_closed;

	response._eventsource_node = node;

	response.conn:write(table.concat({

		"HTTP/1.1 200 OK";

		"Content-Type: text/event-stream";

		"Access-Control-Allow-Origin: *";

		"Access-Control-Allow-Methods: GET";

		"Access-Control-Max-Age: 7200";

		"";

		"";

	}, "\r\n"));

	local clientlist = streams[node];

	if not clientlist then

		clientlist = {};

		streams[node] = clientlist;

	end

	clientlist[response] = response.conn;

	return true;

end

function handle_update(event)

	module:log("debug", "Item published: %q", event.node);

	local node = event.node;

	local clientlist = streams[node];

	local item = event.item;

	if (item.name == "json" and item.attr.xmlns == "urn:xmpp:json:0") or (item.name == "data" and item.attr.xmlns == "https://prosody.im/protocol/data") then

		item = item[1];

	end

	local data = "data: "..tostring(item):gsub("\n", "\ndata: ").."\n\n";

	if not clientlist then module:log("debug", "No clients for %q", node); return; end

	for response, conn in pairs(clientlist) do

		conn:write(data);

	end

end

module:provides("http", {

	name = "eventsource";

	route = {

		["GET /*"] = serve_stream;

	};

});

module:hook_object_event(service.events, "item-published", handle_update);