--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_muc_badge/README.markdown	Sat Jun 23 18:08:34 2018 +0200
@@ -0,0 +1,25 @@
+---
+depends:
+- 'mod\_http'
+- 'mod\_muc'
+provides:
+- http
+title: 'mod\_muc\_badge'
+---
+
+# Introduction
+
+This module generates a badge, similar the one
+<https://opkode.com/blog/xmpp-chat-badge/>
+
+# Configuration
+
+  Option             Type     Default
+  ------------------ -------- --------------------------
+  `badge_label`      string   `"Chatroom"`
+  `badge_count`      string   `"%d online"`
+  `badge_template`   string   A SVG image (see source)
+
+The template must be valid XML. If it contains `{label}` then this is
+replaced by `badge_label`, similarly, `{count}` is substituted by
+`badge_count` with `%d` changed to the number of occupants.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_muc_badge/mod_muc_badge.lua	Sat Jun 23 18:08:34 2018 +0200
@@ -0,0 +1,89 @@
+-- MIT License
+--
+-- Copyright (c) 2018 Kim Alvefur
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy
+-- of this software and associated documentation files (the "Software"), to deal
+-- in the Software without restriction, including without limitation the rights
+-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+-- copies of the Software, and to permit persons to whom the Software is
+-- furnished to do so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in
+-- all copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+-- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+-- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+-- IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+-- CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+-- TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+-- SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+module:depends"http";
+
+local jid_prep = require "util.jid".prep;
+
+-- Support both old and new MUC code
+local mod_muc = module:depends"muc";
+local rooms = rawget(mod_muc, "rooms");
+local get_room_from_jid = rawget(mod_muc, "get_room_from_jid") or
+	function (jid)
+		return rooms[jid];
+	end
+
+-- I believe the origins of this template to be in the public domain as per
+-- https://github.com/badges/shields/blob/master/LICENSE.md
+local template = module:get_option_string("badge_template", [[
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="144" height="20">
+<linearGradient id="b" x2="0" y2="100%">
+	<stop offset="0" stop-color="#bbb" stop-opacity=".1"/>
+	<stop offset="1" stop-opacity=".1"/>
+</linearGradient>
+<clipPath id="a">
+	<rect width="144" height="20" rx="3" fill="#fff"/>
+</clipPath>
+<g clip-path="url(#a)">
+	<path fill="#555" d="M0 0h69v20H0z"/>
+	<path fill="#fe7d37" d="M69 0h75v20H69z"/>
+	<path fill="url(#b)" d="M0 0h144v20H0z"/>
+</g>
+<g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="110">
+	<text x="355" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="590">{label}</text>
+	<text x="355" y="140" transform="scale(.1)" textLength="590">{label}</text>
+	<text x="1055" y="150" fill="#010101" fill-opacity=".3" transform="scale(.1)" textLength="650">{number}</text>
+	<text x="1055" y="140" transform="scale(.1)" textLength="650">{number}</text>
+</g>
+</svg>
+]]);
+template = assert(require "util.template"(template));
+
+local label = module:get_option_string("badge_label", "Chatroom");
+local number = module:get_option_string("badge_count", "%d online");
+
+module:provides("http", {
+	route = {
+		["GET /*"] = function (event, path)
+			local jid = jid_prep(path);
+			if not jid then return end
+
+			local room = get_room_from_jid(jid);
+			if not room then return end
+			if (room.get_hidden or room.is_hidden)(room) then return end
+
+			local count = 0;
+			for _ in pairs(room._occupants) do
+				count = count + 1;
+			end
+
+			local response = event.response;
+			response.headers.content_type = "image/svg+xml";
+			local svg = [[<?xml version="1.0"?>]] ..
+				tostring(template.apply({
+					label = label;
+					number = string.format(number, count);
+				}));
+			return svg;
+		end;
+	}
+});