-- XEP-0401: Easy User Onboarding

local dataforms = require "util.dataforms";

local datetime = require "util.datetime";

local jid_bare = require "util.jid".bare;

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

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

local rostermanager = require "core.rostermanager";

local st = require "util.stanza";

local invite_only = module:get_option_boolean("registration_invite_only", true);

local require_encryption = module:get_option_boolean("c2s_require_encryption",

	module:get_option_boolean("require_encryption", false));

local new_adhoc = module:require("adhoc").new;

-- Whether local users can invite other users to create an account on this server

local allow_user_invites = module:get_option_boolean("allow_user_invites", true);

local invites = module:depends("invites");

local invite_result_form = dataforms.new({

		title = "Your Invite",

		-- TODO instructions = something helpful

		{

			name = "uri";

			label = "Invite URI";

			-- TODO desc = something helpful

		},

		{

			name = "url" ;

			var = "landing-url";

			label = "Invite landing URL";

		},

		{

			name = "expire";

			label = "Token valid until";

		},

	});

module:depends("adhoc");

module:provides("adhoc", new_adhoc("New Invite", "urn:xmpp:invite#invite",

		function (_, data)

			local username = split_jid(data.from);

			local invite = invites.create_contact(username, allow_user_invites);

			--TODO: check errors

			return {

				status = "completed";

				form = {

					layout = invite_result_form;

					values = {

						uri = invite.uri;

						url = invite.landing_page;

						expire = datetime.datetime(invite.expires);

					};

				};

			};

		end, "local_user"));

-- TODO

-- module:provides("adhoc", new_adhoc("Create account", "urn:xmpp:invite#create-account", function () end, "admin"));

-- XEP-0379: Pre-Authenticated Roster Subscription

module:hook("presence/bare", function (event)

	local stanza = event.stanza;

	if stanza.attr.type ~= "subscribe" then return end

	local preauth = stanza:get_child("preauth", "urn:xmpp:pars:0");

	if not preauth then return end

	local token = preauth.attr.token;

	if not token then return end

	local username, host = jid_split(stanza.attr.to);

	local invite, err = invites.get(token, username);

	if not invite then

		module:log("debug", "Got invalid token, error: %s", err);

		return;

	end

	local contact = jid_bare(stanza.attr.from);

	module:log("debug", "Approving inbound subscription to %s from %s", username, contact);

	if rostermanager.set_contact_pending_in(username, host, contact, stanza) then

		if rostermanager.subscribed(username, host, contact) then

			invite:use();

			rostermanager.roster_push(username, host, contact);

			-- Send back a subscription request (goal is mutual subscription)

			if not rostermanager.is_user_subscribed(username, host, contact)

			and not rostermanager.is_contact_pending_out(username, host, contact) then

				module:log("debug", "Sending automatic subscription request to %s from %s", contact, username);

				if rostermanager.set_contact_pending_out(username, host, contact) then

					rostermanager.roster_push(username, host, contact);

					module:send(st.presence({type = "subscribe", to = contact }));

				else

					module:log("warn", "Failed to set contact pending out for %s", username);

				end

			end

		end

	end

end, 1);

-- TODO sender side, magic automatic mutual subscription

local invite_stream_feature = st.stanza("register", { xmlns = "urn:xmpp:invite" }):up();

module:hook("stream-features", function(event)

	local session, features = event.origin, event.features;

	-- Advertise to unauthorized clients only.

	if session.type ~= "c2s_unauthed" or (require_encryption and not session.secure) then

		return

	end

	features:add_child(invite_stream_feature);

end);

-- Client is submitting a preauth token to allow registration

module:hook("stanza/iq/urn:xmpp:pars:0:preauth", function(event)

	local preauth = event.stanza.tags[1];

	local token = preauth.attr.token;

	local validated_invite = invites.get(token);

	if not validated_invite then

		local reply = st.error_reply(event.stanza, "cancel", "forbidden", "The invite token is invalid or expired");

		event.origin.send(reply);

		return true;

	end

	event.origin.validated_invite = validated_invite;

	local reply = st.reply(event.stanza);

	event.origin.send(reply);

	return true;

end);

-- Registration attempt - ensure a valid preauth token has been supplied

module:hook("user-registering", function (event)

	local validated_invite = event.session.validated_invite;

	if invite_only and not validated_invite then

		event.allowed = false;

		event.reason = "Registration on this server is through invitation only";

		return;

	end

end);

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

-- contact will not see when user is online.

function subscribe(host, user_username, contact_username)

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

	local contact_jid = contact_username.."@"..host;

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

	rostermanager.set_contact_pending_out(user_username, host, contact_jid);

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

	rostermanager.set_contact_pending_in(contact_username, host, user_jid);

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

	rostermanager.subscribed(contact_username, host, user_jid);

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

	rostermanager.process_inbound_subscription_approval(user_username, host, contact_jid);

end

-- Make a mutual subscription between jid1 and jid2. Each JID will see

-- when the other one is online.

function subscribe_both(host, user1, user2)

	subscribe(host, user1, user2);

	subscribe(host, user2, user1);

end

-- Registration successful, if there was a preauth token, mark it as used

module:hook("user-registered", function (event)

	local validated_invite = event.session.validated_invite;

	if not validated_invite then

		return;

	end

	local inviter_username = validated_invite.inviter;

	validated_invite:use();

	if not inviter_username then return; end

	local contact_username = event.username;

	module:log("debug", "Creating mutual subscription between %s and %s", inviter_username, contact_username);

	subscribe_both(module.host, inviter_username, contact_username);

end);