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

local st = require "util.stanza";

local mod_groups = module:depends("groups_internal")

local mod_pep = module:depends("pep")

local XMLNS_BM2 = "urn:xmpp:bookmarks:1";

local XMLNS_XEP0060 = "http://jabber.org/protocol/pubsub";

local default_options = {

	["persist_items"] = true;

	["max_items"] = "max";

	["send_last_published_item"] = "never";

	["access_model"] = "whitelist";

};

local function get_current_bookmarks(jid, service)

	local ok, items = service:get_items(XMLNS_BM2, jid)

	if not ok then

		if items == "item-not-found" then

			return {}, nil;

		else

			return nil, items;

		end

	end

	return items or {};

end

local function update_bookmark(jid, service, room, bookmark)

	local ok, err = service:publish(XMLNS_BM2, jid, room, bookmark, default_options);

	if ok then

		module:log("debug", "found existing matching bookmark, updated")

	else

		module:log("error", "failed to update bookmarks: %s", err)

	end

end

local function find_matching_bookmark(storage, room)

	return storage[room];

end

local function inject_bookmark(jid, room, autojoin, name)

	local pep_service = mod_pep.get_pep_service(jid_split(jid))

	local current, err = get_current_bookmarks(jid, pep_service);

	if err then

		module:log("error", "Could not retrieve existing bookmarks for %s: %s", jid, err);

		return;

	end

	local found = find_matching_bookmark(current, room)

	if found then

		local existing = found:get_child("conference", XMLNS_BM2);

		if autojoin ~= nil then

			existing.attr.autojoin = autojoin and "true" or "false"

		end

		if name ~= nil then

			-- do not change already configured names

			if not existing.attr.name then

				existing.attr.name = name

			end

		end

	else

		module:log("debug", "no existing bookmark found, adding new")

		found = st.stanza("item", { xmlns = XMLNS_XEP0060; id = room })

			:tag("conference", { xmlns = XMLNS_BM2; name = name; autojoin = autojoin and "true" or "false"; })

	end

	update_bookmark(jid, pep_service, room, found)

end

local function remove_bookmark(jid, room, autojoin, name)

	local pep_service = mod_pep.get_pep_service(jid_split(jid))

	return pep_service:retract(XMLNS_BM2, jid, room, st.stanza("retract", { id = room }));

end

local function handle_user_added(event)

	if not event.group_info.muc_jid then

		module:log("debug", "ignoring user added event on group %s because it has no MUC", event.id)

		return

	end

	local jid = event.user .. "@" .. event.host

	inject_bookmark(jid, event.group_info.muc_jid, true, event.group_info.name)

end

local function handle_user_removed(event)

	if not event.group_info.muc_jid then

		module:log("debug", "ignoring user removed event on group %s because it has no MUC", event.id)

		return

	end

	-- Removing the bookmark is fine as the user just lost any privilege to

	-- be in the MUC (as group MUCs are members-only).

	local jid = event.user .. "@" .. event.host

	remove_bookmark(jid, event.group_info.muc_jid, true, event.group_info.name)

end

module:hook("group-user-added", handle_user_added)

module:hook("group-user-removed", handle_user_removed)