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

local adhoc_simple_form = require "util.adhoc".new_simple_form;

local new_token = require "util.id".long;

local jid_prepped_split = require "util.jid".prepped_split;

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

local usermanager = require "core.usermanager";

local dataforms_new = require "util.dataforms".new;

local tohtml = require "util.stanza".xml_escape

local tostring = tostring;

local reset_tokens = module:open_store();

local max_token_age = module:get_option_number("password_reset_validity", 86400);

local serve = module:depends"http_files".serve;

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)

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

	local token = request.url.query;

	local reset_info = token and reset_tokens:get(token);

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

	if not reset_info or os.difftime(os.time(), reset_info.generated_at) > max_token_age then

		module:log("warn", "Expired token: %s", token or "<none>");

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

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

	end

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

	return apply_template(template, { jid = reset_info.user.."@"..module.host, token = token });

end

function handle_form(event)

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

	local form_data = http_formdecode(request.body);

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

	local reset_info = reset_tokens:get(token);

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

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

	if not reset_info or os.difftime(os.time(), reset_info.generated_at) > max_token_age then

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

	end

	local ok, err = usermanager.set_password(reset_info.user, password, module.host);

	if ok then

		reset_tokens:set(token, nil);

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

			message = "Your password has been updated! Happy chatting :)" })

	else

		module:log("debug", "Resetting password 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() .. "/password_reset/bootstrap.min.css");

		["GET /reset"] = generate_page;

		["POST /reset"] = handle_form;

	};

});

-- Changing a user's password

local reset_password_layout = dataforms_new{

	title = "Generate password reset link";

	instructions = "Please enter the details of the user who needs a reset link.";

	{ name = "FORM_TYPE", type = "hidden", value = "http://prosody.im/protocol/adhoc/mod_password_reset" };

	{ name = "accountjid", type = "jid-single", required = true, label = "JID" };

};

local reset_command_handler = adhoc_simple_form(reset_password_layout, function (data, errors)

	if errors then

		local errmsg = {};

		for name, text in pairs(errors) do

			errmsg[#errmsg + 1] = name .. ": " .. text;

		end

		return { status = "completed", error = { message = table.concat(errmsg, "\n") } };

	end

	local jid = data.accountjid;

	local user, host = jid_prepped_split(jid);

	if host ~= module.host then

		return {

			status = "completed";

			error = { message = "You may only generate password reset links for users on "..module.host.."." };

		};

	end

	local token = new_token();

	reset_tokens:set(token, {

		generated_at = os.time();

		user = user;

	});

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

end);

local adhoc_reset = adhoc_new(

	"Generate password reset link",

	"password_reset",

	reset_command_handler,

	"admin"

);

module:add_item("adhoc", adhoc_reset);