plugins/xeps.lua

local parse_xeps, xeps_updated_at;
local xeps = {};

function riddim.plugins.xeps(bot)
	bot.stream:add_plugin("http");
	local http = verse.http;
	bot:hook("commands/xep", function(command)
		-- Cache XEP list for an hour
		if os.difftime(os.time(), xeps_updated_at) > (60 * 60) then -- Not refreshed within 1 hour
			http.request('http://xmpp.org/extensions/xeps.xml', nil, function (data, code)
				if code ~= 200 then
					if code > 0 then
						command:reply("Received HTTP "..code.." error trying to fetch the XEP list");
					else
						command:reply("Unable to fetch the XEP list from xmpp.org: "..data:gsub("%-", " "));
					end
					return;
				end
				xeps_updated_at = os.time();
				parse_xeps(data);
				command:reply(handle_xep_command(command));
			end);
		else
			return handle_xep_command(command);
		end
	end);
end

function handle_xep_command(command)
		local xepnum = command.param;
		if not xepnum then return "Please supply an XEP number or a search string :)"; end
			if not tonumber(xepnum) then -- Search for an XEP
				if xepnum:match("^%d+ ex") then
					local num, example = xepnum:match("^(%d+) ex%S* (%d+)$");
					return "http://xmpp.org/extensions/xep-"..string.rep("0", 4-num:len())..num..".html#example-"..tostring(example);
				end
				local results = {};
				for x, xep in pairs(xeps) do
					name = " "..xep.name:lower().." ";
					if name:match(xepnum:lower():gsub("%-", "%%-")) then
						table.insert(results, x);
						--return commands.xep(msg, x);
					end
				end
				if #results == 0 then
					return "Sorry, I couldn't find a match";
				elseif #results == 1 then
					command.param = results[1];
					return handle_xep_command(command);
				else
					-- We have more than one match
					local ret = "Multiple matches:";
					for _, x in ipairs(results) do
						local xepnum = tostring(tonumber(x));
						xepnum = string.rep("0", 4-x:len())..x;
						local xep = xeps[tostring(x)];
						ret = string.format("%s XEP-%s: %s%s", ret, xep.number, xep.name, ((_ < #results) and ",") or "");
					end
					return ret;
				end
			end
			-- Check that xepnum is a valid number
			xepnum = tostring(tonumber(xepnum));
			if not xepnum then return "What XEP? or enter a search string."; end
			-- Expand to full 4 char number
			xepnum = string.rep("0", 4-xepnum:len())..xepnum;
			xep = xeps[tostring(xepnum)];
			if not xep then return "Sorry, I don't think there is a XEP-"..xepnum; end
			return "XEP-"..xep.number..": "..xep.name.." is "..xep.type.." ("..xep.status..", "..xep.updated..") See: http://xmpp.org/extensions/xep-"..xep.number..".html";
end

function parse_xeps(t)
if not t then return nil; end
local currxep = {};
        for b in string.gmatch(t,"<xep>(.-)</xep>") do
                for k,v in string.gmatch(b,"<(%w+)>(.-)</%1>") do
                        currxep[k] = v;
                end
		xeps[currxep.number] = { };
		for k, v in pairs(currxep) do xeps[currxep.number][k] = v end
        end
	xeps["0028"] = { number = "0028", name = "XSF Plans for World Domination", type="Top Secret", status = "Hidden", updated = "Work ongoing" };
	return true;
end