-- Expose a simple servlet to handle user registrations from web pages

-- via JSON.

--

-- A Good chunk of the code is from mod_data_access.lua by Kim Alvefur

-- aka Zash.

local jid_prep = require "util.jid".prep;

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

local usermanager = require "core.usermanager";

local b64_decode = require "util.encodings".base64.decode;

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

local httpserver = require "net.httpserver";

local os_time = os.time;

module.host = "*" -- HTTP/BOSH Servlets need to be global.

-- Pick up configuration.

local set_realm_name = module:get_option("reg_servlet_realm") or "Restricted";

local throttle_time = module:get_option("reg_servlet_ttime") or false;

local whitelist = module:get_option("reg_servlet_wl") or {};

local blacklist = module:get_option("reg_servlet_bl") or {};

local recent_ips = {};

-- Begin

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

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

local function http_response(code, message, extra_headers)

        local response = {

                status = code .. " " .. message;

                body = message .. "\n"; }

        if extra_headers then response.headers = extra_headers; end

        return response

end

local function handle_req(method, body, request)

	if request.method ~= "POST" then

		return http_response(405, "Bad method...", {["Allow"] = "POST"});

	end

	if not request.headers["authorization"] then

		return http_response(401, "No... No...",

		{["WWW-Authenticate"]='Basic realm="'.. set_realm_name ..'"'})

	end

	local user, password = b64_decode(request.headers.authorization

		:match("[^ ]*$") or ""):match("([^:]*):(.*)");

	user = jid_prep(user);

	if not user or not password then return http_response(400, "What's this..?"); end

	local user_node, user_host = jid_split(user)

	if not hosts[user_host] then return http_response(401, "Negative."); end

	module:log("warn", "%s is authing to submit a new user registration data", user)

	if not usermanager.test_password(user_node, user_host, password) then

		module:log("warn", "%s failed authentication", user)

		return http_response(401, "Who the hell are you?! Guards!");

	end

	local req_body; 

	-- We check that what we have is valid JSON wise else we throw an error...

	if not pcall(function() req_body = json_decode(body) end) then

		module:log("debug", "JSON data submitted for user registration by %s failed to Decode.", user); 

		return http_response(400, "JSON Decoding failed.");

	else

		-- Decode JSON data and check that all bits are there else throw an error

		req_body = json_decode(body);

		if req_body["username"] == nil or req_body["password"] == nil or req_body["host"] == nil or req_body["ip"] == nil then

			module:log("debug", "%s supplied an insufficent number of elements or wrong elements for the JSON registration", user); 

			return http_response(400, "Invalid syntax.");

		end

		-- Check if user is an admin of said host

		if not usermanager.is_admin(user, req_body["host"]) then

			module:log("warn", "%s tried to submit registration data for %s but he's not an admin", user, req_body["host"]);

			return http_response(401, "I obey only to my masters... Have a nice day.");

		else	

			-- Checks for both Throttling/Whitelist and Blacklist (basically copycatted from prosody's register.lua code)

			if blacklist[req_body["ip"]] then module:log("warn", "Attempt of reg. submission to the JSON servlet from blacklisted address: %s", req_body["ip"]); return http_response(403, "The specified address is blacklisted, sorry sorry."); end

			if throttle_time and not whitelist[req_body["ip"]] then

				if not recent_ips[req_body["ip"]] then

					recent_ips[req_body["ip"]] = { time = os_time(), count = 1 };

				else

					local ip = recent_ips[req_body["ip"]];

					ip.count = ip.count + 1;

					if os_time() - ip.time < throttle_time then

						ip.time = os_time();

						module:log("warn", "JSON Registration request from %s has been throttled.", req_body["ip"]);

						return http_response(503, "Woah... How many users you want to register..? Request throttled, wait a bit and try again.");

					end

					ip.time = os_time();

				end

			end

			-- We first check if the supplied username for registration is already there.

					return http_response(406, "Supplied username contains invalid characters, see RFC 6122.");

				else

					return http_response(200, "Done.");

				end

			else

				return http_response(409, "User already exists.");

			end

		end

	end

end

-- Set it up!

local function setup()

	local ports = module:get_option("reg_servlet_ports") or { 9280 };

	local port_number, base_name, ssl_table;

	for _, opts in ipairs(ports) do

		if type(opts) == "number" then

			port_number, base_name = opts, "register_account";

		elseif type(opts) == "table" then

			port_number, base_name, ssl_table = opts.port or 9280, opts.path or "register_account", opts.ssl or nil;

		elseif type(opts) == "string" then

			base_name, port_number = opts, 9280;

		end

	end

	if ssl_table == nil then

		ports = { { port = port_number } };

		httpserver.new_from_config(ports, handle_req, { base = base_name });

	else

		if port_number == 9280 then port_number = 9443; end

		ports = { { port = port_number, ssl = ssl_table } };

		httpserver.new_from_config(ports, handle_req, { base = base_name });

	end

end

if prosody.start_time then -- already started

	setup();

else

	prosody.events.add_handler("server-started", setup);

end