local adhoc_new = module:require "adhoc".new;

local uuid_new = require "util.uuid".generate;

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

local jid_join = require "util.jid".join;

local http_formdecode = require "net.http".formdecode;

local usermanager = require "core.usermanager";

local rostermanager = require "core.rostermanager";

local tohtml = require "util.stanza".xml_escape

local nodeprep = require "util.encodings".stringprep.nodeprep;

local tostring = tostring;

local invite_storage = module:open_store();

local inviter_storage = module:open_store("inviter");

local serve;

if prosody.process_type == "prosody" then

	local http_files = require "net.http.files";

	serve = http_files.serve;

else

	serve = module:depends"http_files".serve;

end

module:depends"adhoc";

module:depends"http";

local function apply_template(template, args)

	return

		template:gsub("{{([^}]*)}}", function (k)

			if args[k] then

				return tohtml(args[k])

			else

				return k

			end

		end)

end

function generate_page(event, token)

	local response = event.response;

	local tokens = invite_storage:get() or {};

	response.headers.content_type = "text/html; charset=utf-8";

	if not token or token == "" then

		local template = assert(module:load_resource("invite/invite_result.html")):read("*a");

		-- TODO maybe show a friendlier information page instead?

		return apply_template(template, { classes = "alert-danger", message = "No token given" })

	elseif not tokens[token] then

		local template = assert(module:load_resource("invite/invite_result.html")):read("*a");

		return apply_template(template, { classes = "alert-danger", message = "This invite has expired." })

	end

	local template = assert(module:load_resource("invite/invite.html")):read("*a");

	return apply_template(template, { user = jid_join(tokens[token], module.host), server = module.host, token = token });

end

function subscribe(user1, user2)

	local user1_jid = jid_join(user1, module.host);

	local user2_jid = jid_join(user2, module.host);

	rostermanager.set_contact_pending_out(user2, module.host, user1_jid);

	rostermanager.set_contact_pending_in(user1, module.host, user2_jid);

	rostermanager.subscribed(user1, module.host, user2_jid);

	rostermanager.process_inbound_subscription_approval(user2, module.host, user1_jid);

end

function handle_form(event)

	local request, response = event.request, event.response;

	local form_data = http_formdecode(request.body);

	local user, password, token = form_data["user"], form_data["password"], form_data["token"];

	local tokens = invite_storage:get() or {};

	local template = assert(module:load_resource("invite/invite_result.html")):read("*a");

	response.headers.content_type = "text/html; charset=utf-8";

	if not user or #user == 0 or not password or #password == 0 or not token then

		return apply_template(template, { classes = "alert-warning", message = "Please fill in all fields." })

	end

	if not tokens[token] then

		return apply_template(template, { classes = "alert-danger", message = "This invite has expired." })

	end

	-- Shamelessly copied from mod_register_web.

	local prepped_username = nodeprep(user);

	if not prepped_username or #prepped_username == 0 then

		return apply_template(template, { classes = "alert-warning", message = "This username contains invalid characters." })

	end

	if usermanager.user_exists(prepped_username, module.host) then

		return apply_template(template, { classes = "alert-warning", message = "This username is already in use." })

	end

	local registering = { username = prepped_username , host = module.host, allowed = true }

	module:fire_event("user-registering", registering);

	if not registering.allowed then

		return apply_template(template, { classes = "alert-danger", message = "Registration is not allowed." })

	end

	local ok, err = usermanager.create_user(prepped_username, password, module.host);

	if ok then

		subscribe(prepped_username, tokens[token]);

		subscribe(tokens[token], prepped_username);

		inviter_storage:set(prepped_username, { inviter = tokens[token] });

		rostermanager.roster_push(tokens[token], module.host, jid_join(prepped_username, module.host));

		tokens[token] = nil;

		invite_storage:set(nil, tokens);

		module:fire_event("user-registered", {

			username = prepped_username, host = module.host, source = "mod_invite", });

		return apply_template(template, { classes = "alert-success",

			message = "Your account has been created! You can now log in using an XMPP client." })

	else

		module:log("debug", "Registration failed: " .. tostring(err));

		return apply_template(template, { classes = "alert-danger", message = "An unknown error has occurred." })

	end

end

module:provides("http", {

	route = {

		["GET /bootstrap.min.css"] = serve(module:get_directory() .. "/invite/bootstrap.min.css");

		["GET /*"] = generate_page;

		POST = handle_form;

	};

});

function invite_command_handler(_, data)

	local uuid = uuid_new();

	local user, host = jid_split(data.from);

	if host ~= module.host then

		return { status = "completed", error = { message = "You are not allowed to invite users to this server." }};

	end

	local tokens = invite_storage:get() or {};

	tokens[uuid] = user;

	invite_storage:set(nil, tokens);

	return { info = module:http_url() .. "/" .. uuid, status = "completed" };

end

local adhoc_invite = adhoc_new("Invite user", "invite", invite_command_handler, "local_user")

module:add_item("adhoc", adhoc_invite);