--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_component_http/mod_component_http.lua	Mon Mar 26 13:49:13 2018 +0100
@@ -0,0 +1,102 @@
+local http = require "net.http";
+local json = require "util.json";
+local st = require "util.stanza";
+local xml = require "util.xml";
+local unpack = rawget(_G, "unpack") or table.unpack;
+
+local url = module:get_option_string("component_post_url");
+assert(url, "Missing required config option 'component_post_url'");
+
+local stanza_kinds = module:get_option_set("post_stanza_types", { "message" });
+
+local http_error_map = {
+	[0]   = { "cancel", "remote-server-timeout", "Connection failure" };
+	-- 4xx
+	[400] = { "modify", "bad-request" };
+	[401] = { "auth", "not-authorized" };
+	[402] = { "auth", "forbidden", "Payment required" };
+	[403] = { "auth", "forbidden" };
+	[404] = { "cancel", "item-not-found" };
+	[410] = { "cancel", "gone" };
+	-- 5xx
+	[500] = { "cancel", "internal-server-error" };
+	[501] = { "cancel", "feature-not-implemented" };
+	[502] = { "cancel", "remote-server-timeout", "Bad gateway" };
+	[503] = { "wait", "remote-server-timeout", "Service temporarily unavailable" };
+	[504] = { "wait", "remote-server-timeout", "Gateway timeout" };
+}
+
+local function error_reply(stanza, code)
+	local error = http_error_map[code] or { "cancel", "service-unavailable" };
+	return st.error_reply(stanza, unpack(error, 1, 3));
+end
+
+function handle_stanza(event)
+	local origin, stanza = event.origin, event.stanza;
+	local request_body = json.encode({
+		to = stanza.attr.to;
+		from = stanza.attr.from;
+		kind = stanza.name;
+		body = stanza.name == "message" and stanza:get_child_text("body") or nil;
+		stanza = tostring(stanza);
+	});
+	http.request(url, {
+		body = request_body;
+	}, function (response_text, code, req, response)
+		if stanza.attr.type == "error" then return; end -- Avoid error loops, don't reply to error stanzas		
+		if code == 200 and response_text and response.headers["content-type"] == "application/json" then
+			local response_data = json.decode(response_text);
+			if response_data.stanza then
+				local reply_stanza = xml.parse(response_data.stanza);
+				if reply_stanza then
+					reply_stanza.attr.from, reply_stanza.attr.to = stanza.attr.to, stanza.attr.from;
+					return origin.send(reply_stanza);
+				else
+					module:log("warn", "Unable to parse reply stanza");
+				end
+			else
+				local stanza_kind = response_data.kind or "message";
+				local to = response_data.to or stanza.attr.from;
+				local from = response_data.from or stanza.attr.to;
+				local reply_stanza = st.stanza(stanza_kind, {
+					to = to, from = from;
+					type = response_data.type or (stanza_kind == "message" and "chat") or nil;
+				});
+				if stanza_kind == "message" and response_data.body then
+					reply_stanza:tag("body"):text(tostring(response_data.body)):up();
+				end
+				module:log("debug", "Sending %s", tostring(reply_stanza));
+				return origin.send(reply_stanza);
+			end
+			return;
+		elseif code >= 200 and code <= 299 then
+			return true;
+		else
+			return origin.send(error_reply(stanza, code));
+		end
+	end);
+	return true;
+end
+
+for stanza_kind in stanza_kinds do
+	for _, jid_type in ipairs({ "host", "bare", "full" }) do
+		module:hook(stanza_kind.."/"..jid_type, handle_stanza);
+	end
+end
+
+-- Simple handler for an always-online JID that allows everyone to subscribe to presence
+local function default_presence_handler(event)
+	local origin, stanza = event.origin, event.stanza;
+	module:log("debug", "Handling %s", tostring(stanza));
+	if stanza.attr.type == "probe" then
+		module:send(st.presence({ to = stanza.attr.from, from = stanza.attr.to.."/default" }));
+	elseif stanza.attr.type == "subscribe" then
+		module:send(st.presence({ type = "subscribed", to = stanza.attr.from, from = stanza.attr.to.."/default" }));
+		module:send(st.presence({ to = stanza.attr.from, from = stanza.attr.to.."/default" }));
+	elseif stanza.attr.type == "unsubscribe" then
+		module:send(st.presence({ type = "unavailable", to = stanza.attr.from, from = stanza.attr.to.."/default" }));	
+	end
+	return true;
+end
+
+module:hook("presence/bare", default_presence_handler, -1);