-- 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 prefsxml = module:require"mamprefsxml";

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

local prefs_to_stanza, prefs_from_stanza = prefsxml.tostanza, prefsxml.fromstanza;

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

local archive_store = "archive2";

local archive = module:open_store(archive_store, "archive");

if not archive then

	module:log("error", "Could not open archive storage");

	return

elseif not archive.find then

	module:log("error", "mod_%s does not support archiving, switch to mod_storage_sql2", archive._provided_by);

	return

end

-- 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 = prefs_to_stanza(get_prefs(user));

		local reply = st.reply(stanza):add_child(prefs);

		return origin.send(reply);

	else -- type == "set"

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

		local prefs = prefs_from_stanza(new_prefs);

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

		if not ok then

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

		end

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

	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 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(origin.username, {

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

		with = qwith;

		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", err));

	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);

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_from = stanza.attr.from;

	local orig_to = stanza.attr.to or orig_from;

	-- Stanza without 'to' are treated as if it was to their own bare jid

	-- We don't store messages of these types

	if orig_type == "error"

	or orig_type == "headline"

	or orig_type == "groupchat"

	-- or that don't have a <body/>

	or not stanza:get_child("body")

	-- or if hints suggest we shouldn't

	or stanza:get_child("no-permanent-store", "urn:xmpp:hints")

	or stanza:get_child("no-store", "urn:xmpp:hints") then

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

		return;

	end

	-- Whos storage do we put it in?

	local store_user = c2s and origin.username or jid_split(orig_to);

	-- And who are they chatting with?

	local with = jid_bare(c2s and orig_to or orig_from);

	-- Check with the users preferences

	if shall_store(store_user, with) then

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

		-- And stash it

		local ok, id = archive:append(store_user, time_now(), with, stanza);

			stanza:tag("archived", { xmlns = xmlns_mam, by = store_user.."@"..host, id = id }):up();

		end

	else

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