-- XEP-0313: Message Archive Management for Prosody

-- Copyright (C) 2011-2013 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 muc_form_config_option = "muc#roomconfig_enablelogging"

local st = require "util.stanza";

local rsm = module:require "mod_mam/rsm";

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

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

local room_mt = module:depends"muc".room_mt;

local getmetatable = getmetatable;

local function is_stanza(x)

	return getmetatable(x) == st.stanza_mt;

end

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 max_history_length = module:get_option_number("max_history_messages", 1000);

local log_all_rooms = module:get_option_boolean("muc_log_all_rooms", false);

local log_by_default = module:get_option_boolean("muc_log_by_default", true);

local advertise_archive = module:get_option_boolean("muc_log_advertise", true);

local rooms = hosts[module.host].modules.muc.rooms;

if not log_all_rooms then

	module:hook("muc-config-form", function(event)

		local room, form = event.room, event.form;

		local logging_enabled = room._data.logging;

		if logging_enabled == nil then

			logging_enabled = log_by_default;

		end

		table.insert(form,

		{

			name = muc_form_config_option,

			type = "boolean",

			label = "Enable Logging?",

			value = logging_enabled,

		}

		);

	end);

	module:hook("muc-config-submitted", function(event)

		local room, fields, changed = event.room, event.fields, event.changed;

		local new = fields[muc_form_config_option];

		if new ~= room._data.logging then

			room._data.logging = new;

			if type(changed) == "table" then

				changed[muc_form_config_option] = true;

			else

				event.changed = true;

			end

		end

	end);

end

local _send_history = room_mt.send_history;

local _save_to_history = room_mt.save_to_history;

function module.unload()

	room_mt.send_history = _send_history;

	room_mt.save_to_history = _save_to_history;

end

-- Handle archive queries

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

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

	local room = stanza.attr.to;

	local room_node = jid_split(room);

	local query = stanza.tags[1];

	local room_obj = rooms[room];

	if not room_obj then

		return origin.send(st.error_reply(stanza, "cancel", "item-not-found"))

	end

	local from = jid_bare(stanza.attr.from);

	-- Banned or not a member of a members-only room?

	if room_obj._affiliations[from] == "outcast"

		or room_obj._data.members_only and not room_obj._affiliations[from] then

		return origin.send(st.error_reply(stanza, "auth", "forbidden"))

	end

	local qid = query.attr.queryid;

	-- Search query parameters

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

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

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

		tostring(qid), 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

	-- RSM stuff

	local qset = rsm.get(query);

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

	local reverse = qset and qset.before or false;

	local before, after = qset and qset.before, qset and qset.after;

	if type(before) ~= "string" then before = nil; end

	-- Load all the data!

	local data, err = archive:find(room_node, {

		start = qstart; ["end"] = qend; -- Time range

		limit = qmax;

		before = before; after = after;

		reverse = reverse;

		total = true;

	});

	if not data then

		return origin.send(st.error_reply(stanza, "cancel", "internal-server-error"));

	end

	local count = err;

	-- Wrap it in stuff and deliver

	local first, last;

	for id, item, when in data do

		local fwd_st = st.message{ to = origin.full_jid }

			:tag("result", { xmlns = xmlns_mam, queryid = qid, id = id })

				:tag("forwarded", { xmlns = xmlns_forward })

					:tag("delay", { xmlns = xmlns_delay, stamp = timestamp(when) }):up();

		if not is_stanza(item) then

			item = st.deserialize(item);

		end

		item.attr.xmlns = "jabber:client";

		fwd_st:add_child(item);

		if not first then first = id; end

		last = id;

		origin.send(fwd_st);

	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 {

			first = first, last = last, count = count }));

end);

function room_mt:send_history(to, stanza)

	local maxchars, maxstanzas, seconds, since;

	local history_tag = stanza:find("{http://jabber.org/protocol/muc}x/history")

	if history_tag then

		module:log("debug", tostring(history_tag));

		local history_attr = history_tag.attr;

		maxchars = tonumber(history_attr.maxchars);

		maxstanzas = tonumber(history_attr.maxstanzas);

		seconds = tonumber(history_attr.seconds);

		since = history_attr.since;

		if since then

			since = timestamp_parse(since);

		end

		if seconds then

			since = math.max(os.time() - seconds, since or 0);

		end

	end

	-- Load all the data!

	local data, err = archive:find(jid_split(self.jid), {

		limit = m_min(maxstanzas or 20, max_history_length);

		after = since;

		reverse = true;

	});

	if not data then

		module:log("error", "Could not fetch history: %s", tostring(err));

		return

	end

	local to_send = {};

	local charcount = 0;

	local chars;

	for id, item, when in data do

		item.attr.to = to;

		item:tag("delay", { xmlns = "urn:xmpp:delay", from = self.jid, stamp = timestamp(when) }):up(); -- XEP-0203

		if maxchars then

			chars = #tostring(item);

			if chars + charcount > maxchars then break end

			charcount = charcount + chars;

		end

		to_send[1+#to_send] = item;

	end

	for i = #to_send,1,-1 do

		self:_route_stanza(to_send[i]);

	end

end

-- Handle messages

function room_mt:save_to_history(stanza)

	local orig_to = stanza.attr.to;

	local room = jid_split(self.jid);

	-- Policy check

	if not ( log_all_rooms == true -- Logging forced on all rooms

	or (self._data.logging == nil and log_by_default == true)

	or self._data.logging ) then return end -- Don't log

	module:log("debug", "We're logging this")

	-- And stash it

	local ok, id = archive:append(room, time_now(), "", stanza);

	if ok and advertise_archive then

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

	end

end

module:hook("muc-room-destroyed", function(event)

	archive:delete(jid_split(event.room.jid));

end);

-- TODO should we perhaps log presence as well?

-- And role/affiliation changes?

module:add_feature(xmlns_mam);