local rostermanager = require"core.rostermanager";

local modulemanager = require"core.modulemanager";

local id = require "util.id";

local jid = require "util.jid";

local st = require "util.stanza";

local jid_join = jid.join;

local host = module.host;

local group_info_store = module:open_store("group_info");

local group_members_store = module:open_store("groups");

local group_memberships = module:open_store("groups", "map");

local muc_host_name = module:get_option("groups_muc_host", "groups."..host);

local muc_host = nil;

local is_contact_subscribed = rostermanager.is_contact_subscribed;

-- Make a *one-way* subscription. User will see when contact is online,

-- contact will not see when user is online.

local function subscribe(user, user_jid, contact, contact_jid)

	-- Update user's roster to say subscription request is pending...

	rostermanager.set_contact_pending_out(user, host, contact_jid);

	-- Update contact's roster to say subscription request is pending...

	rostermanager.set_contact_pending_in(contact, host, user_jid);

	-- Update contact's roster to say subscription request approved...

	rostermanager.subscribed(contact, host, user_jid);

	-- Update user's roster to say subscription request approved...

	rostermanager.process_inbound_subscription_approval(user, host, contact_jid);

	-- Push updates to both rosters

	rostermanager.roster_push(user, host, contact_jid);

	rostermanager.roster_push(contact, host, user_jid);

end

local function user_groups(username)

	return pairs(group_memberships:get_all(username) or {});

end

local function do_single_group_subscriptions(username, group_id)

	local members = group_members_store:get(group_id);

	if not members then return; end

	local user_jid = jid_join(username, host);

	for membername in pairs(members) do

		if membername ~= username then

			local member_jid = jid_join(membername, host);

			if not is_contact_subscribed(username, host, member_jid) then

				module:log("debug", "[group %s] Subscribing %s to %s", member_jid, user_jid);

				subscribe(membername, member_jid, username, user_jid);

			end

			if not is_contact_subscribed(membername, host, user_jid) then

				module:log("debug", "[group %s] Subscribing %s to %s", user_jid, member_jid);

				subscribe(username, user_jid, membername, member_jid);

			end

		end

	end

end

local function do_all_group_subscriptions_by_user(username)

	for group_id in user_groups(username) do

		do_single_group_subscriptions(username, group_id);

	end

end

local function do_all_group_subscriptions_by_group(group_id)

	local members = get_members(group_id)

	if not members then

		return

	end

	for membername in pairs(members) do

		do_single_group_subscriptions(membername, group_id);

	end

end

module:hook("resource-bind", function(event)

	module:log("debug", "Updating group subscriptions...");

	do_all_group_subscriptions_by_user(event.session.username);

end);

--luacheck: ignore 131

function create(group_info, create_muc, group_id)

	if not group_info.name then

		return nil, "group-name-required";

	end

	if group_id then

		if exists(group_id) then

			return nil, "conflict"

		end

	else

		group_id = id.short();

	end

	local muc_jid = nil

	local room = nil

	if create_muc then

		if not muc_host_name then

			module:log("error", "cannot create group with MUC: no MUC host configured")

			return nil, "service-unavailable"

		end

		if not muc_host then

			module:log("error", "cannot create group with MUC: MUC host %s not configured properly", muc_host_name)

			return nil, "internal-server-error"

		end

		muc_jid = jid.prep(id.short() .. "@" .. muc_host_name);

		room = muc_host.create_room(muc_jid)

		if not room then

			delete(group_id)

			return nil, "internal-server-error"

		end

		room:set_public(false)

		room:set_persistent(true)

		room:set_members_only(true)

		room:set_allow_member_invites(false)

		room:set_moderated(false)

		room:set_whois("anyone")

		room:set_name(group_info.name)

	end

	local ok = group_info_store:set(group_id, {

		name = group_info.name;

		muc_jid = muc_jid;

	});

	if not ok then

		if room then

			room:destroy()

		end

		return nil, "internal-server-error";

	end

	return group_id;

end

function get_info(group_id)

	return group_info_store:get(group_id);

end

function set_info(group_id, info)

	if not info then

		return nil, "bad-request"

	end

	if not info.name or #info.name == 0 then

		return nil, "bad-request"

	end

	-- TODO: we should probably prohibit changing/removing the MUC JID of

	-- an existing group.

	if info.muc_jid then

		local room = muc_host.get_room_from_jid(info.muc_jid);

		room:set_name(info.name);

	end

	local ok = group_info_store:set(group_id, info);

	if not ok then

		return nil, "internal-server-error";

	end

	return true

end

function get_members(group_id)

	return group_members_store:get(group_id);

end

function exists(group_id)

	return not not get_info(group_id);

end

function get_user_groups(username)

	local groups = {};

	do

		local group_set = group_memberships:get_all(username);

		if group_set then

			for group_id in pairs(group_set) do

				table.insert(groups, group_id);

			end

		end

	end

	return groups;

end

function delete(group_id)

	if group_members_store:set(group_id, nil) then

		local group_info = get_info(group_id);

		if group_info and group_info.muc_jid then

			local room = muc_host.get_room_from_jid(group_info.muc_jid)

			if room then

				room:destroy()

			end

		end

		return group_info_store:set(group_id, nil);

	end

	return nil, "internal-server-error";

end

function add_member(group_id, username, delay_update)

	local group_info = group_info_store:get(group_id);

	if not group_info then

		return nil, "group-not-found";

	end

	if not group_memberships:set(group_id, username, {}) then

		return nil, "internal-server-error";

	end

	if group_info.muc_jid then

		local room = muc_host.get_room_from_jid(group_info.muc_jid);

		if room then

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

			room:set_affiliation(true, user_jid, "member");

			module:send(st.message(

				{ from = group_info.muc_jid, to = user_jid }

			):tag("x", {

				xmlns = "jabber:x:conference",

				jid = group_info.muc_jid

			}):up());

			module:log("debug", "set user %s to be member in %s and sent invite", username, group_info.muc_jid);

		else

			module:log("warn", "failed to update affiliation for %s in %s", username, group_info.muc_jid);

		end

	end

	module:fire_event(

		"group-user-added",

		{

			id = group_id,

			user = username,

			host = host,

			group_info = group_info,

		}

	)

	if not delay_update then

		do_all_group_subscriptions_by_group(group_id);

	end

	return true;

end

function remove_member(group_id, username)

	local group_info = group_info_store:get(group_id);

	if not group_info then

		return nil, "group-not-found";

	end

	if not group_memberships:set(group_id, username, nil) then

		return nil, "internal-server-error";

	end

	if group_info.muc_jid then

		local room = muc_host.get_room_from_jid(group_info.muc_jid);

		if room then

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

			room:set_affiliation(true, user_jid, nil);

		else

			module:log("warn", "failed to update affiliation for %s in %s", username, group_info.muc_jid);

		end

	end

	module:fire_event(

		"group-user-removed",

		{

			id = group_id,

			user = username,

			host = host,

			group_info = group_info,

		}

	)

	return true;

end

function sync(group_id)

	do_all_group_subscriptions_by_group(group_id);

end

function emit_member_events(group_id)

	local group_info, err = get_info(group_id)

	if group_info == nil then

		return false, err

	end

	for username in pairs(get_members(group_id)) do

		module:fire_event(

			"group-user-added",

			{

				id = group_id,

				user = username,

				host = host,

				group_info = group_info,

			}

		)

	end

	return true

end

-- Returns iterator over group ids

function groups()

	return group_info_store:users();

end

local function setup()

	if not muc_host_name then

		module:log("info", "MUC management disabled (groups_muc_host set to nil)");

		return;

	end

	local target_module = modulemanager.get_module(muc_host_name, "muc");

	if not target_module then

		module:log("error", "host %s is not a MUC host -- group management will not work correctly; check your groups_muc_host setting!", muc_host_name);

	else

		module:log("debug", "found MUC host at %s", muc_host_name);

		muc_host = target_module;

	end

end

module:hook_global("user-deleted", function(event)

	if event.host ~= module.host then return end

	local username = event.username;

	for group_id in user_groups(username) do

		remove_member(group_id, username);

	end

end);

if prosody.start_time then  -- server already started

	setup();

else

	module:hook_global("server-started", setup);

end