local groups = { default = {} };

local members = {};

local groups_file;

local jid, datamanager = require "util.jid", require "util.datamanager";

local jid_bare, jid_prep = jid.bare, jid.prep;

local module_host = module:get_host();

function inject_roster_contacts(username, host, roster)

	module:log("warn", "Injecting group members to roster");

	local bare_jid = username.."@"..host;

	if not members[bare_jid] then return; end -- Not a member of any groups

	-- Find groups this JID is a member of

	for _, group_name in ipairs(members[bare_jid]) do

		-- Find other people in the same group

		for jid in pairs(groups[group_name]) do

			-- Add them to roster

			--module:log("debug", "processing jid %s in group %s", tostring(jid), tostring(group_name));

			if jid ~= bare_jid then

				if not roster[jid] then roster[jid] = {}; end

				roster[jid].subscription = "both";

				if not roster[jid].groups then

					roster[jid].groups = { [group_name] = true };

				end

				roster[jid].groups[group_name] = true;

				roster[jid].persist = false;

			end

		end

	end

end

function remove_virtual_contacts(username, host, datastore, data)

	if host == module_host and datastore == "roster" then

		local new_roster = {};

		for jid, contact in pairs(data) do

			if contact.persist ~= false then

				new_roster[jid] = contact;

			end

		end

		return username, host, datastore, new_roster;

	end

	return username, host, datastore, data;

end

function module.load()

	groups_file = config.get(module:get_host(), "core", "groups_file");

	if not groups_file then return; end

	module:hook("roster-load", inject_roster_contacts);

	datamanager.add_callback(remove_virtual_contacts);

	groups = { default = {} };

	local curr_group = "default";

	for line in io.lines(groups_file) do

		if line:match("^%[%w+%]$") then

			curr_group = line:match("^%[(%w+)%]$");

			groups[curr_group] = groups[curr_group] or {};

		else

			-- Add JID

			local jid = jid_prep(line);

			if jid then

				groups[curr_group][jid] = true;

				members[jid] = members[jid] or {};

				members[jid][#members[jid]+1] = curr_group;

			end

		end

	end

	module:log("info", "Groups loaded successfully");

end

function module.unload()

	datamanager.remove_callback(remove_virtual_contacts);

end