-- MAM Subscriptions prototype

-- Copyright (C) 2015 Kim Alvefur

--

-- This file is MIT/X11 licensed.

local mt = require"util.multitable";

local st = require"util.stanza";

local xmlns_mamsub = "http://prosody.im/protocol/mamsub";

module:add_feature(xmlns_mamsub);

local host_sessions = prosody.hosts[module.host].sessions;

local weak = { __mode = "k" };

module:hook("iq-set/self/"..xmlns_mamsub..":subscribe", function (event)

	local origin, stanza = event.origin, event.stanza;

	if origin.mamsub ~= nil then

		origin.send(st.error_reply(stanza, "modify", "conflict"));

		return true;

	end

	origin.mamsub = xmlns_mamsub;

	local mamsub_sessions = host_sessions[origin.username].mamsub_sessions;

	if not mamsub_sessions then

		mamsub_sessions = setmetatable({}, weak);

		host_sessions[origin.username].mamsub_sessions = mamsub_sessions;

	end

	mamsub_sessions[origin] = true;

	origin.send(st.reply(stanza));

	return true;

end);

module:hook("iq-set/self/"..xmlns_mamsub..":unsubscribe", function (event)

	local origin, stanza = event.origin, event.stanza;

	if origin.mamsub ~= xmlns_mamsub then

		origin.send(st.error_reply(stanza, "modify", "conflict"));

		return true;

	end

	origin.mamsub = nil;

	local mamsub_sessions = host_sessions[origin.username].mamsub_sessions;

	if mamsub_sessions then

		mamsub_sessions[origin] = nil;

	end

	origin.send(st.reply(stanza));

	return true;

end);

module:hook("archive-message-added", function (event)

	local user_session = host_sessions[event.for_user];

	local mamsub_sessions = user_session and user_session.mamsub_sessions;

	if not mamsub_sessions then return end;

	local for_broadcast = st.message():tag("mamsub", { xmlns = xmlns_mamsub })

		:tag("forwarded", { xmlns = "urn:xmpp:forward:0" })

			:add_child(event.stanza);

	for session in pairs(mamsub_sessions) do

		if session.mamsub == xmlns_mamsub then

			for_broadcast.attr.to = session.full_jid;

			session.send(for_broadcast);

		end

	end

end);