-- XEP-0313: Message Archive Management for Prosody

-- Copyright (C) 2011-2012 Kim Alvefur

--

-- This file is MIT/X11 licensed.

local xmlns_mam     = "urn:xmpp:mam:tmp";

local xmlns_delay   = "urn:xmpp:delay";

local xmlns_forward = "urn:xmpp:forward:0";

local st = require "util.stanza";

local rsm = module:require "rsm";

local prefs = module:require"mamprefs";

local set_prefs, get_prefs = prefs.set, prefs.get;

local jid_bare = require "util.jid".bare;

local jid_split = require "util.jid".split;

local jid_prep = require "util.jid".prep;

local host = module.host;

local rm_load_roster = require "core.rostermanager".load_roster;

local tostring = tostring;

local time_now = os.time;

local m_min = math.min;

local timestamp, timestamp_parse = require "util.datetime".datetime, require "util.datetime".parse;

local default_max_items, max_max_items = 20, module:get_option_number("max_archive_query_results", 50);

local global_default_policy = module:get_option("default_archive_policy", false);

-- TODO Should be possible to enforce it too

-- For translating preference names from string to boolean and back

local default_attrs = {

	always = true, [true] = "always",

	never = false, [false] = "never",

	roster = "roster",

}

local archive_store = "archive2";

-- Handle prefs.

module:hook("iq/self/"..xmlns_mam..":prefs", function(event)

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

	local user = origin.username;

	if stanza.attr.type == "get" then

		local prefs = get_prefs(user);

		local default = prefs[false];

		default = default ~= nil and default_attrs[default] or global_default_policy;

		local reply = st.reply(stanza):tag("prefs", { xmlns = xmlns_mam, default = default })

		local always = st.stanza("always");

		local never = st.stanza("never");

		for k,v in pairs(prefs) do

			if k then

				(v and always or never):tag("jid"):text(k):up();

			end

		end

		reply:add_child(always):add_child(never);

		origin.send(reply);

		return true

	else -- type == "set"

		local prefs = {};

		local new_prefs = stanza:get_child("prefs", xmlns_mam);

		local new_default = new_prefs.attr.default;

		if new_default then

			prefs[false] = default_attrs[new_default];

		end

		local always = new_prefs:get_child("always");

		if always then

			for rule in always:childtags("jid") do

				local jid = rule:get_text();

				prefs[jid] = true;

			end

		end

		local never = new_prefs:get_child("never");

		if never then

			for rule in never:childtags("jid") do

				local jid = rule:get_text();

				prefs[jid] = false;

			end

		end

		local ok, err = set_prefs(user, prefs);

		if not ok then

			origin.send(st.error_reply(stanza, "cancel", "internal-server-error", "Error storing preferences: "..tostring(err)));

		else

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

		end

		return true

	end

end);

-- Handle archive queries

module:hook("iq-get/self/"..xmlns_mam..":query", function(event)

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

	local query = stanza.tags[1];

	local qid = query.attr.queryid;

	-- Search query parameters

	local qwith = query:get_child_text("with");

	local qstart = query:get_child_text("start");

	local qend = query:get_child_text("end");

	module:log("debug", "Archive query, id %s with %s from %s until %s)",

		tostring(qid), qwith or "anyone", qstart or "the dawn of time", qend or "now");

	if qstart or qend then -- Validate timestamps

		local vstart, vend = (qstart and timestamp_parse(qstart)), (qend and timestamp_parse(qend))

		if (qstart and not vstart) or (qend and not vend) then

			origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid timestamp"))

			return true

		end

		qstart, qend = vstart, vend;

	end

	if qwith then -- Validate the 'with' jid

		local pwith = qwith and jid_prep(qwith);

		if pwith and not qwith then -- it failed prepping

			origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid JID"))

			return true

		end

		qwith = jid_bare(pwith);

	end

	-- RSM stuff

	local qmax = m_min(qset and qset.max or default_max_items, max_max_items);

	local reverse = qset and qset.before or false;

		end

	end

	-- That's all folks!

	module:log("debug", "Archive query %s completed", tostring(qid));

	if reverse then first, last = last, first; end

	return origin.send(st.reply(stanza)

		:query(xmlns_mam):add_child(rsm.generate {

end);

local function has_in_roster(user, who)

	local roster = rm_load_roster(user, host);

	module:log("debug", "%s has %s in roster? %s", user, who, roster[who] and "yes" or "no");

	return roster[who];

end

local function shall_store(user, who)

	-- TODO Cache this?

	local prefs = get_prefs(user);

	local rule = prefs[who];

	module:log("debug", "%s's rule for %s is %s", user, who, tostring(rule))

	if rule ~= nil then

		return rule;

	else -- Below could be done by a metatable

		local default = prefs[false];

		module:log("debug", "%s's default rule is %s", user, tostring(default))

		if default == nil then

			default = global_default_policy;

			module:log("debug", "Using global default rule, %s", tostring(default))

		end

		if default == "roster" then

			return has_in_roster(user, who);

		end

		return default;

	end

end

-- Handle messages

local function message_handler(event, c2s)

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

	local orig_type = stanza.attr.type or "normal";

	local orig_to = stanza.attr.to;

	local orig_from = stanza.attr.from;

	if not orig_from and c2s then

		orig_from = origin.full_jid;

	end

	orig_to = orig_to or orig_from; -- Weird corner cases

	-- Don't store messages of these types

	if orig_type == "error"

	or orig_type == "headline"

	or orig_type == "groupchat"

	or not stanza:get_child("body") then

		return;

	end

	local target_jid = c2s and orig_to or orig_from;

	local target_bare = jid_bare(target_jid);

	if shall_store(store_user, target_bare) then

		module:log("debug", "Archiving stanza: %s", stanza:top_tag());

		-- And stash it

		if ok and not c2s then

			stanza:tag("archived", { xmlns = xmlns_mam, by = jid_bare(orig_to), id = id }):up();

		end

	else

		module:log("debug", "Not archiving stanza: %s", stanza:top_tag());

	end

end

local function c2s_message_handler(event)

	return message_handler(event, true);

end

-- Stanzas sent by local clients

module:hook("pre-message/bare", c2s_message_handler, 2);

module:hook("pre-message/full", c2s_message_handler, 2);

-- Stanszas to local clients

module:hook("message/bare", message_handler, 2);

module:hook("message/full", message_handler, 2);

module:add_feature(xmlns_mam);