module:depends("http");

local nodeprep = require "util.encodings".stringprep.nodeprep;

local jid_split = require "util.jid".split;

local json = require "util.json";

local streams = {};

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)

	local response = event.response;

	node = nodeprep(node);

	if node == nil then

		return 400;

	end

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

	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_message(event)

	local room, stanza = event.room, event.stanza;

	local node = (jid_split(event.room.jid));

	local clientlist = streams[node];

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

	-- Extract body from message

	local body = event.stanza:get_child_text("body");

	if not body then

		return;

	end

	local nick = select(3, jid_split(stanza.attr.from));

	-- Encode body and broadcast to eventsource subscribers

	local json_data = json.encode({

		nick = nick;

		body = body;

	});

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

	for response, conn in pairs(clientlist) do

		conn:write(data);

	end

end

module:provides("http", {

	name = "eventsource";

	route = {

		["GET /*"] = serve_stream;

	};

});

module:hook("muc-broadcast-message", handle_message);