--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_muc_http_defaults/mod_muc_http_defaults.lua	Fri Feb 19 16:01:41 2021 +0100
@@ -0,0 +1,142 @@
+-- Copyright (C) 2021 Kim Alvefur
+--
+-- This file is MIT licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+local http = require "net.http";
+local httperr = require "net.http.errors";
+local async = require "util.async";
+local errors = require "util.error";
+local uh = require "util.http";
+local jid = require "util.jid";
+local json = require "util.json";
+local st = require "util.stanza";
+
+local render = require "util.interpolation".new("%b{}", uh.urlencode);
+
+module:depends"muc";
+
+local url_template = assert(module:get_option_string("muc_create_api_url", nil), "'muc_create_api_url' is a required option");
+local apiauth = module:get_option_string("muc_create_api_auth", nil);
+
+local ex = {
+	headers = {
+		accept = "application/json";
+		authorization = apiauth;
+	}
+};
+
+local function check_status(response)
+	if math.floor(response.code/100) > 2 then
+		error(httperr.new(response.code, response.body));
+	end
+	return response;
+end
+
+local problems = errors.init(module.name, {
+		format = { type = "cancel", condition = "internal-server-error", text = "API server returned invalid data, see logs" },
+		config = { type = "cancel", condition = "internal-server-error", text = "A problem occured while creating the room, see logs" },
+});
+
+local function get_json(response)
+	return assert(json.decode(response.body), problems.new("format"));
+end
+
+local function apply_config(room, settings)
+	local affiliations = settings.affiliations;
+	if type(affiliations) == "table" then
+
+		-- COMPAT the room creator is unconditionally made 'owner'
+		-- clear existing affiliation
+		for existing_affiliation in pairs(room._affiliation) do
+			room:set_affiliation(true, existing_affiliation, "none");
+		end
+
+		if affiliations[1] ~= nil then -- array of ( jid, affiliation, nick )
+			for _, aff in ipairs(affiliations) do
+				if type(aff) == "table" and type(aff.jid) == "string" and (aff.nick == nil or type(aff.nick) == "string") then
+					local prepped_jid = jid.prep(aff.jid);
+					if prepped_jid then
+						local ok, err = room:set_affiliation(true, prepped_jid, aff.affiliation, aff.nick and { nick = aff.nick });
+						if not ok then
+							module:log("error", "Could not set affiliation in %s: %s", room.jid, err);
+							return nil, problems.new("config");
+						end
+					else
+						module:log("error", "Invalid JID returned from API for %s: %q", room.jid, aff.jid);
+						return nil, problems.new("format");
+					end
+				else
+					module:log("error", "Invalid affiliation item returned from API for %s: %q", room.jid, aff);
+					return nil, problems.new("format");
+				end
+			end
+		else -- map of jid : affiliation
+			for user_jid, aff in pairs(affiliations) do
+				if type(user_jid) == "string" and type(aff) == "string" then
+					local prepped_jid = jid.prep(user_jid);
+					if prepped_jid then
+						local ok, err = room:set_affiliation(true, prepped_jid, aff);
+						if not ok then
+							module:log("error", "Could not set affiliation in %s: %s", room.jid, err);
+							return nil, problems.new("config");
+						end
+					else
+						module:log("error", "Invalid JID returned from API: %q", aff.jid);
+						return nil, problems.new("format");
+					end
+				end
+			end
+		end
+	elseif affiliations ~= nil then
+		module:log("error", "Invalid affiliations returned from API for %s: %q", room.jid, affiliations);
+		return nil, problems.new("format", { field = "affiliations" });
+	end
+
+	local config = settings.config;
+	if type(config) == "table" then
+		-- TODO reject invalid fields instead of ignoring them
+		if type(config.name) == "string" then room:set_name(config.name); end
+		if type(config.description) == "string" then room:set_description(config.description); end
+		if type(config.language) == "string" then room:set_language(config.language); end
+		if type(config.password) == "string" then room:set_password(config.password); end
+		if type(config.subject) == "string" then room:set_subject(config.subject); end
+
+		if type(config.public) == "boolean" then room:set_public(config.public); end
+		if type(config.members_only) == "boolean" then room:set_members_only(config.members_only); end
+		if type(config.allow_member_invites) == "boolean" then room:set_allow_member_invites(config.allow_member_invites); end
+		if type(config.moderated) == "boolean" then room:set_moderated(config.moderated); end
+		if type(config.persistent) == "boolean" then room:set_persistent(config.persistent); end
+		if type(config.changesubject) == "boolean" then room:set_changesubject(config.changesubject); end
+
+		if type(config.historylength) == "number" then room:set_historylength(config.historylength); end
+		if type(config.public_jids) == "boolean" then room:set_whois(config.public_jids and "anyone" or "moderators"); end
+		-- Leaving out presence_broadcast for now
+
+		-- mod_muc_mam
+		if type(config.archiving) == "boolean" then room._config.archiving = config.archiving; end
+	elseif config ~= nil then
+		module:log("error", "Invalid config returned from API for %s: %q", room.jid, config);
+		return nil, problems.new("format", { field = "config" });
+	end
+	return true;
+end
+
+module:hook("muc-room-pre-create", function(event)
+	local url = render(url_template, event);
+	module:log("debug", "Calling API at %q for room %s", url, event.room.jid);
+	local ret, err = errors.coerce(async.wait_for(http.request(url, ex):next(check_status):next(get_json)));
+	if not ret then
+		event.room:destroy();
+		event.origin.send(st.error_reply(event.stanza, err));
+		return true;
+	end
+
+	local configured, err = apply_config(event.room, ret);
+	if not configured then
+		event.room:destroy();
+		event.origin.send(st.error_reply(event.stanza, err));
+		return true;
+	end
+end, -2);