-- 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

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

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

-- Pick up configuration.

local set_realm_name = module:get_option_string("reg_servlet_realm", "Restricted")

local throttle_time = module:get_option_number("reg_servlet_ttime", nil)

local whitelist = module:get_option_set("reg_servlet_wl", {})

local blacklist = module:get_option_set("reg_servlet_bl", {})

local ports = module:get_option_array("reg_servlet_ports", {{ port = 9280 }})

local recent_ips = {}

-- Begin

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:contains(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:contains(req_body["ip"]) then

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

					recent_ips[req_body["ip"]] = os_time()

				else

					if os_time() - recent_ips[req_body["ip"]] < throttle_time then

						recent_ips[req_body["ip"]] = 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

					recent_ips[req_body["ip"]] = os_time()

				end

			end

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

			-- And nodeprep the username

			local username = nodeprep(req_body["username"])

			if not usermanager.user_exists(username, req_body["host"]) then

				if not username then

					module:log("debug", "%s supplied an username containing invalid characters: %s", user, username)

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

				else

					local ok, error = usermanager.create_user(username, req_body["password"], req_body["host"])

					if ok then 

						hosts[req_body["host"]].events.fire_event("user-registered", { username = username, host = req_body["host"], source = "mod_register_json", session = { ip = req_body["ip"] } })

						module:log("debug", "%s registration data submission for %s@%s is successful", user, username, req_body["host"])

						return http_response(200, "Done.")

					else

						module:log("error", "user creation failed: "..error)

						return http_response(500, "Encountered server error while creating the user: "..error)

					end

				end

			else

				module:log("debug", "%s registration data submission for %s failed (user already exists)", user, username)

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

			end

		end

	end

end

-- Set it up!

function regj_cleanup() -- it could be better if module:hook("module-unloaded", ...) actually worked.

	module:log("debug", "Cleaning up handlers and stuff as module is being unloaded.")

	for _, options in ipairs(ports) do

		if options.port then

			httpserver.new.http_servers[options.port].handlers[options.path or "register_account"] = nil

		end

	end

	-- if there are no handlers left clean and close the socket, doesn't work with server_event

	if not event then

		for _, options in ipairs(ports) do

			if options.port and not next(httpserver.new.http_servers[options.port].handlers) then

				httpserver.new.http_servers[options.port] = nil

				if options.interface then

					for _, value in ipairs(options.interface) do

						if server.getserver(value, options.port) then server.removeserver(value, options.port) end

					end

				else if server.getserver("*", options.port) then server.removeserver("*", options.port) end end

			end

		end

	end

	prosody.events.remove_handler("module-unloaded", regj_cleanup)

end

function setup()

	for id, options in ipairs(ports) do 

		if not options.port then 

			if not options.ssl then ports[id].port = 9280

			else ports[id].port = 9443 end

		elseif options.port == 9280 and options.ssl then ports[id].port = 9443 end end

	httpserver.new_from_config(ports, handle_req, { base = "register_account" })

	prosody.events.add_handler("module-unloaded", regj_cleanup)

end

if prosody.start_time then -- already started

	setup()

else

	module:hook("server-started", setup)

end