-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
-- 
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


local hosts = _G.hosts;
local st = require "util.stanza";
local datamanager = require "util.datamanager";
local usermanager_user_exists = require "core.usermanager".user_exists;
local usermanager_create_user = require "core.usermanager".create_user;
local usermanager_set_password = require "core.usermanager".set_password;
local usermanager_delete_user = require "core.usermanager".delete_user;
local os_time = os.time;
local nodeprep = require "util.encodings".stringprep.nodeprep;
local jid_bare = require "util.jid".bare;

local compat = module:get_option_boolean("registration_compat", true);
local allow_registration = module:get_option_boolean("allow_registration", false);

module:add_feature("jabber:iq:register");

local register_stream_feature = st.stanza("register", {xmlns="http://jabber.org/features/iq-register"}):up();
module:hook("stream-features", function(event)
        local session, features = event.origin, event.features;

	-- Advertise registration to unauthorized clients only.
	if not(allow_registration) or session.type ~= "c2s_unauthed" then
		return
	end

	features:add_child(register_stream_feature);
end);

local function handle_registration_stanza(event)
	local session, stanza = event.origin, event.stanza;

	local query = stanza.tags[1];
	if stanza.attr.type == "get" then
		local reply = st.reply(stanza);
		reply:tag("query", {xmlns = "jabber:iq:register"})
			:tag("registered"):up()
			:tag("username"):text(session.username):up()
			:tag("password"):up();
		session.send(reply);
	else -- stanza.attr.type == "set"
		if query.tags[1] and query.tags[1].name == "remove" then
			-- TODO delete user auth data, send iq response, kick all user resources with a <not-authorized/>, delete all user data
			local username, host = session.username, session.host;
			
			local ok, err = usermanager_delete_user(username, host);
			
			if not ok then
				module:log("debug", "Removing user account %s@%s failed: %s", username, host, err);
				session.send(st.error_reply(stanza, "cancel", "service-unavailable", err));
				return true;
			end
			
			session.send(st.reply(stanza));
			local roster = session.roster;
			for _, session in pairs(hosts[host].sessions[username].sessions) do -- disconnect all resources
				session:close({condition = "not-authorized", text = "Account deleted"});
			end
			-- TODO datamanager should be able to delete all user data itself
			datamanager.store(username, host, "vcard", nil);
			datamanager.store(username, host, "private", nil);
			datamanager.list_store(username, host, "offline", nil);
			local bare = username.."@"..host;
			for jid, item in pairs(roster) do
				if jid and jid ~= "pending" then
					if item.subscription == "both" or item.subscription == "from" or (roster.pending and roster.pending[jid]) then
						core_post_stanza(hosts[host], st.presence({type="unsubscribed", from=bare, to=jid}));
					end
					if item.subscription == "both" or item.subscription == "to" or item.ask then
						core_post_stanza(hosts[host], st.presence({type="unsubscribe", from=bare, to=jid}));
					end
				end
			end
			datamanager.store(username, host, "roster", nil);
			datamanager.store(username, host, "privacy", nil);
			module:log("info", "User removed their account: %s@%s", username, host);
			module:fire_event("user-deregistered", { username = username, host = host, source = "mod_register", session = session });
		else
			local username = nodeprep(query:get_child("username"):get_text());
			local password = query:get_child("password"):get_text();
			if username and password then
				if username == session.username then
					if usermanager_set_password(username, password, session.host) then
						session.send(st.reply(stanza));
					else
						-- TODO unable to write file, file may be locked, etc, what's the correct error?
						session.send(st.error_reply(stanza, "wait", "internal-server-error"));
					end
				else
					session.send(st.error_reply(stanza, "modify", "bad-request"));
				end
			else
				session.send(st.error_reply(stanza, "modify", "bad-request"));
			end
		end
	end
	return true;
end

module:hook("iq/self/jabber:iq:register:query", handle_registration_stanza);
if compat then
	module:hook("iq/host/jabber:iq:register:query", function (event)
		local session, stanza = event.origin, event.stanza;
		if session.type == "c2s" and jid_bare(stanza.attr.to) == session.host then
			return handle_registration_stanza(event);
		end
	end);
end

local recent_ips = {};
local min_seconds_between_registrations = module:get_option("min_seconds_between_registrations");
local whitelist_only = module:get_option("whitelist_registration_only");
local whitelisted_ips = module:get_option("registration_whitelist") or { "127.0.0.1" };
local blacklisted_ips = module:get_option("registration_blacklist") or {};

for _, ip in ipairs(whitelisted_ips) do whitelisted_ips[ip] = true; end
for _, ip in ipairs(blacklisted_ips) do blacklisted_ips[ip] = true; end

module:hook("stanza/iq/jabber:iq:register:query", function(event)
	local session, stanza = event.origin, event.stanza;

	if not(allow_registration) or session.type ~= "c2s_unauthed" then
		session.send(st.error_reply(stanza, "cancel", "service-unavailable"));
	else
		local query = stanza.tags[1];
		if stanza.attr.type == "get" then
			local reply = st.reply(stanza);
			reply:tag("query", {xmlns = "jabber:iq:register"})
				:tag("instructions"):text("Choose a username and password for use with this service."):up()
				:tag("username"):up()
				:tag("password"):up();
			session.send(reply);
		elseif stanza.attr.type == "set" then
			if query.tags[1] and query.tags[1].name == "remove" then
				session.send(st.error_reply(stanza, "auth", "registration-required"));
			else
				local username = query:child_with_name("username");
				local password = query:child_with_name("password");
				if username and password then
					-- Check that the user is not blacklisted or registering too often
					if not session.ip then
						module:log("debug", "User's IP not known; can't apply blacklist/whitelist");
					elseif blacklisted_ips[session.ip] or (whitelist_only and not whitelisted_ips[session.ip]) then
						session.send(st.error_reply(stanza, "cancel", "not-acceptable", "You are not allowed to register an account."));
						return true;
					elseif min_seconds_between_registrations and not whitelisted_ips[session.ip] then
						if not recent_ips[session.ip] then
							recent_ips[session.ip] = { time = os_time(), count = 1 };
						else
							local ip = recent_ips[session.ip];
							ip.count = ip.count + 1;
							
							if os_time() - ip.time < min_seconds_between_registrations then
								ip.time = os_time();
								session.send(st.error_reply(stanza, "wait", "not-acceptable"));
								return true;
							end
							ip.time = os_time();
						end
					end
					-- FIXME shouldn't use table.concat
					username = nodeprep(table.concat(username));
					password = table.concat(password);
					local host = module.host;
					if not username or username == "" then
						session.send(st.error_reply(stanza, "modify", "not-acceptable", "The requested username is invalid."));
					elseif usermanager_user_exists(username, host) then
						session.send(st.error_reply(stanza, "cancel", "conflict", "The requested username already exists."));
					else
						if usermanager_create_user(username, password, host) then
							session.send(st.reply(stanza)); -- user created!
							module:log("info", "User account created: %s@%s", username, host);
							module:fire_event("user-registered", {
								username = username, host = host, source = "mod_register",
								session = session });
						else
							-- TODO unable to write file, file may be locked, etc, what's the correct error?
							session.send(st.error_reply(stanza, "wait", "internal-server-error", "Failed to write data to disk."));
						end
					end
				else
					session.send(st.error_reply(stanza, "modify", "not-acceptable"));
				end
			end
		end
	end
	return true;
end);