local captcha_options = module:get_option("captcha_options", {});

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

local usermanager = require "core.usermanager";

local datamanager = require "util.datamanager";

local http = require "net.http";

local path_sep = package.config:sub(1,1);

local json = require "util.json".decode;

local t_concat = table.concat;

pcall(function ()

	module:depends("register_limits");

end);

module:depends"http";

local extra_fields = {

	nick = true; name = true; first = true; last = true; email = true;

	address = true; city = true; state = true; zip = true;

	phone = true; url = true; date = true;

}

local template_path = module:get_option_string("register_web_template", "templates");

function template(data)

	-- Like util.template, but deals with plain text

	return { apply = function(values) return (data:gsub("{([^}]+)}", values)); end }

end

local function get_template(name)

	local fh = assert(module:load_resource(template_path..path_sep..name..".html"));

	local data = assert(fh:read("*a"));

	fh:close();

	return template(data);

end

local function render(template, data)

	return tostring(template.apply(data));

end

local register_tpl = get_template "register";

local success_tpl = get_template "success";

if next(captcha_options) ~= nil then

	local recaptcha_tpl = get_template "recaptcha";

	function generate_captcha(display_options)

		return recaptcha_tpl.apply(setmetatable({

			recaptcha_display_error = display_options and display_options.recaptcha_error

			and ("&error="..display_options.recaptcha_error) or "";

		}, {

			__index = function (_, k)

				if captcha_options[k] then return captcha_options[k]; end

				module:log("error", "Missing parameter from captcha_options: %s", k);

			end

		}));

	end

	function verify_captcha(request, form, callback)

		http.request("https://www.google.com/recaptcha/api/siteverify", {

			body = http.formencode {

				secret = captcha_options.recaptcha_private_key;

				remoteip = request.conn:ip();

				response = form["g-recaptcha-response"];

			};

		}, function (verify_result, code)

			local result = json(verify_result);

			if not result then

				module:log("warn", "Unable to decode response from recaptcha: [%d] %s", code, verify_result);

				callback(false, "Captcha API error");

			elseif result.success == true then

				callback(true);

			else

				callback(false, t_concat(result["error-codes"]));

			end

		end);

	end

else

	module:log("debug", "No Recaptcha options set, using fallback captcha")

	local random = math.random;

	local hmac_sha1 = require "util.hashes".hmac_sha1;

	local secret = require "util.uuid".generate()

	local ops = { '+', '-' };

	local captcha_tpl = get_template "simplecaptcha";

	function generate_captcha()

		local op = ops[random(1, #ops)];

		local x, y = random(1, 9)

		repeat

			y = random(1, 9);

		until x ~= y;

		local answer;

		if op == '+' then

			answer = x + y;

		elseif op == '-' then

			if x < y then

				-- Avoid negative numbers

				x, y = y, x;

			end

			answer = x - y;

		end

		local challenge = hmac_sha1(secret, answer, true);

		return captcha_tpl.apply {

			op = op, x = x, y = y, challenge = challenge;

		};

	end

	function verify_captcha(request, form, callback)

			callback(true);

		else

			callback(false, "Captcha verification failed");

		end

	end

end

function generate_page(event, display_options)

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

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

	return render(register_tpl, {

		path = request.path; hostname = module.host;

		notice = display_options and display_options.register_error or "";

		captcha = generate_captcha(display_options);

	})

end

function register_user(form, origin)

	local username = form.username;

	local password = form.password;

	local confirm_password = form.confirm_password;

	local jid = nil;

	form.username, form.password, form.confirm_password = nil, nil, nil;

	local prepped_username = nodeprep(username);

	if not prepped_username then

		return nil, "Username contains forbidden characters";

	end

	if #prepped_username == 0 then

		return nil, "The username field was empty";

	end

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

		return nil, "Username already taken";

	end

	local registering = { username = prepped_username , host = module.host, additional = form, ip = origin.conn:ip(), allowed = true }

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

	if not registering.allowed then

		return nil, registering.reason or "Registration not allowed";

	end

	if confirm_password ~= password then

		return nil, "Passwords don't match";

	end

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

	if ok then

		jid = prepped_username.."@"..module.host

		local extra_data = {};

		for field in pairs(extra_fields) do

			local field_value = form[field];

			if field_value and #field_value > 0 then

				extra_data[field] = field_value;

			end

		end

		if next(extra_data) ~= nil then

			datamanager.store(prepped_username, module.host, "account_details", extra_data);

		end

		module:fire_event("user-registered", {

			username = prepped_username,

			host = module.host,

			source = module.name,

			ip = origin.conn:ip(),

		});

	end

	return jid, err;

end

function generate_success(event, jid)

	return render(success_tpl, { jid = jid });

end

function generate_register_response(event, jid, err)

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

	if jid then

		return generate_success(event, jid);

	else

		return generate_page(event, { register_error = err });

	end

end

function handle_form(event)

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

	local form = http.formdecode(request.body);

	verify_captcha(request, form, function (ok, err)

		if ok then

			local jid, register_err = register_user(form, request);

			response:send(generate_register_response(event, jid, register_err));

		else

			response:send(generate_page(event, { register_error = err }));

		end

	end);

	return true; -- Leave connection open until we respond above

end

module:provides("http", {

	route = {

		GET = generate_page;

		["GET /"] = generate_page;

		POST = handle_form;

		["POST /"] = handle_form;

	};

});