-- XEP-0357: Push (aka: My mobile OS vendor won't let me have persistent TCP connections)

-- Copyright (C) 2015 Kim Alvefur

--

-- This file is MIT/X11 licensed.

local st = require"util.stanza";

local jid = require"util.jid";

local dataform = require"util.dataforms".new;

local filters = require "util.filters";

local xmlns_push = "urn:xmpp:push:0";

-- configuration

-- For keeping state across reloads

local push_enabled = module:shared("push-enabled-users");

-- http://xmpp.org/extensions/xep-0357.html#disco

module:add_feature(xmlns_push);

-- http://xmpp.org/extensions/xep-0357.html#enabling

module:hook("iq-set/self/"..xmlns_push..":enable", function (event)

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

	-- MUST contain a 'jid' attribute of the XMPP Push Service being enabled

	local push_jid = stanza.tags[1].attr.jid;

	-- SHOULD contain a 'node' attribute

	local push_node = stanza.tags[1].attr.node;

	if not push_jid then

		origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing jid"));

		return true;

	end

	local publish_options = stanza.tags[1].tags[1];

	if publish_options and ( publish_options.name ~= "x" or publish_options.attr.xmlns ~= "jabber:x:data" ) then

		origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid publish options"));

		return true;

	end

	local user_push_services = push_enabled[origin.username];

	if not user_push_services then

		user_push_services = {};

		push_enabled[origin.username] = user_push_services;

	end

	user_push_services[push_jid .. "<" .. (push_node or "")] = {

		jid = push_jid;

		node = push_node;

		count = 0;

		options = publish_options;

	};

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

	return true;

end);

-- http://xmpp.org/extensions/xep-0357.html#disabling

module:hook("iq-set/self/"..xmlns_push..":disable", function (event)

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

	local push_jid = stanza.tags[1].attr.jid; -- MUST include a 'jid' attribute

	local push_node = stanza.tags[1].attr.node; -- A 'node' attribute MAY be included

	if not push_jid then

		origin.send(st.error_reply(stanza, "modify", "bad-request", "Missing jid"));

		return true;

	end

	local user_push_services = push_enabled[origin.username];

	for key, push_info in pairs(user_push_services) do

		if push_info.jid == push_jid and (not push_node or push_info.node == push_node) then

			user_push_services[key] = nil;

		end

	end

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

	return true;

end);

local push_form = dataform {

	{ name = "FORM_TYPE"; type = "hidden"; value = "urn:xmpp:push:summary"; };

	{ name = "message-count"; type = "text-single"; };

	{ name = "pending-subscription-count"; type = "text-single"; };

	{ name = "last-message-sender"; type = "jid-single"; };

	{ name = "last-message-body"; type = "text-single"; };

};

-- http://xmpp.org/extensions/xep-0357.html#publishing

local function handle_notify_request(origin, stanza)

	local to = stanza.attr.to;

	local node = to and jid.split(to) or origin.username;

	local user_push_services = push_enabled[node];

	if not user_push_services then return end

	for _, push_info in pairs(user_push_services) do

		push_info.count = push_info.count + 1;

		local push_jid, push_node = push_info.jid, push_info.node;

		local push_publish = st.iq({ to = push_jid, from = node .. "@" .. module.host, type = "set", id = "push" })

			:tag("pubsub", { xmlns = "http://jabber.org/protocol/pubsub" })

				:tag("publish", { node = push_node })

					:tag("item")

						:tag("notification", { xmlns = xmlns_push });

		local form_data = {

			["message-count"] = tostring(push_info.count);

		};

		if include_sender then

			form_data["last-message-sender"] = stanza.attr.from;

		end

		if include_body then

			form_data["last-message-body"] = stanza:get_child_text("body");

		end

		push_publish:add_child(push_form:form(form_data));

		push_publish:up(); -- / notification

		push_publish:up(); -- / publish

		push_publish:up(); -- / pubsub

		if push_info.options then

			push_publish:tag("publish-options"):add_child(push_info.options);

		end

		module:send(push_publish);

	end

end

-- publish on offline message

module:hook("message/offline/handle", function(event)

	if event.stanza._notify then

		event.stanza._notify = nil;

		return;

	end

	return handle_notify_request(event.origin, event.stanza);

end, 1);

-- publish on unacked smacks message

local function process_new_stanza(stanza, session)

	if getmetatable(stanza) ~= st.stanza_mt then

		return stanza; -- Things we don't want to touch

	end

	if stanza.name == "message" and stanza.attr.xmlns == nil and

			( stanza.attr.type == "chat" or ( stanza.attr.type or "normal" ) == "normal" ) and

			-- not already notified via cloud

			not stanza._notify then

		stanza._notify = true;

		session.log("debug", "Invoking cloud handle_notify_request for new smacks hibernated stanza...");

		handle_notify_request(session, stanza)

	end

	return stanza;

end

-- smacks hibernation is started

local function hibernate_session(event)

	local session = event.origin;

	local queue = event.queue;

	-- process already unacked stanzas

	for i=1,#queue do

		process_new_stanza(queue[i], session);

	end

	-- process future unacked (hibernated) stanzas

	filters.add_filter(session, "stanzas/out", process_new_stanza);

end

-- smacks hibernation is ended

local function restore_session(event)

	local session = event.origin;

	filters.remove_filter(session, "stanzas/out", process_new_stanza);

end

module:hook("smacks-hibernation-start", hibernate_session);

module:hook("smacks-hibernation-end", restore_session);

module:hook("message/offline/broadcast", function(event)

	local user_push_services = push_enabled[event.origin.username];

	if not user_push_services then return end

	for _, push_info in pairs(user_push_services) do

		if push_info then

			push_info.count = 0;

		end

	end

end, 1);