--
-- NOTE: currently this uses lpc; when waqas fixes process, it can go back to that
--
-- Prosody IM
-- Copyright (C) 2010 Waqas Hussain
-- Copyright (C) 2010 Jeff Mitchell
-- Copyright (C) 2013 Mikael Nordfeldth
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--


--local process = require "process";
local lpc; pcall(function() lpc = require "lpc"; end);

local config = require "core.configmanager";
local log = module._log;
local host = module.host;
local script_type = config.get(host, "core", "external_auth_protocol") or "generic";
assert(script_type == "ejabberd" or script_type == "generic");
local command = config.get(host, "core", "external_auth_command") or "";
assert(type(command) == "string");
assert(not host:find(":"));
local usermanager = require "core.usermanager";
local jid_bare = require "util.jid".bare;
local new_sasl = require "util.sasl".new;

local function send_query(text)
	local tmpname = os.tmpname();
	local p = io.popen(command.." > "..tmpname, "w");	-- dump result to file
	p:write(text);	-- push colon-separated args through pipe to above command
	p:close();
	local tmpfile = io.open(tmpname, "r");	-- open file to read auth result
	local result;
	if script_type == "ejabberd" then
		result = tmpfile:read(4);
	elseif script_type == "generic" then
		result = tmpfile:read();
	end
	tmpfile:close();
	os.remove(tmpname);	-- clean up after us
	return result;
end

if lpc then
	--local proc;
	local pid;
	local readfile;
	local writefile;

	function send_query(text)
		if pid and lpc.wait(pid,1) ~= nil then
	    	    log("debug","error, process died, force reopen");
		    pid=nil;
		end
		if not pid then
			log("debug", "Opening process " .. command);
			-- proc = process.popen(command);
			pid, writefile, readfile = lpc.run(command);
		end
		-- if not proc then
		if not pid then
			log("debug", "Process failed to open");
			return nil;
		end
		-- proc:write(text);
		-- proc:flush();

		writefile:write(text);
		writefile:flush();
		if script_type == "ejabberd" then
			-- return proc:read(4); -- FIXME do properly
			return readfile:read(4); -- FIXME do properly
		elseif script_type == "generic" then
			-- return proc:read(1);
			return readfile:read();
		end
	end
end

function do_query(kind, username, password)
	if not username then return nil, "not-acceptable"; end
	
	local query = (password and "%s:%s:%s:%s" or "%s:%s:%s"):format(kind, username, host, password);
	local len = #query
	if len > 1000 then return nil, "policy-violation"; end
	
	if script_type == "ejabberd" then
		local lo = len % 256;
		local hi = (len - lo) / 256;
		query = string.char(hi, lo)..query;
	end
	if script_type == "generic" then
		query = query..'\n';
	end
	
	local response = send_query(query);
	if (script_type == "ejabberd" and response == "\0\2\0\0") or
		(script_type == "generic" and response == "0") then
			return nil, "not-authorized";
	elseif (script_type == "ejabberd" and response == "\0\2\0\1") or
		(script_type == "generic" and response == "1") then
			return true;
	else
		log("debug", "Nonsense back");
		--proc:close();
		--proc = nil;
		return nil, "internal-server-error";
	end
end

local host = module.host;
local provider = {};

function provider.test_password(username, password)
	return do_query("auth", username, password);
end

function provider.set_password(username, password)
	return do_query("setpass", username, password);
end

function provider.user_exists(username)
	return do_query("isuser", username);
end

function provider.create_user(username, password) return nil, "Account creation/modification not available."; end

function provider.get_sasl_handler()
	local testpass_authentication_profile = {
		plain_test = function(sasl, username, password, realm)
			return usermanager.test_password(username, realm, password), true;
		end,
	};
	return new_sasl(host, testpass_authentication_profile);
end

function provider.is_admin(jid)
	local admins = config.get(host, "core", "admins");
	if admins ~= config.get("*", "core", "admins") then
		if type(admins) == "table" then
			jid = jid_bare(jid);
			for _,admin in ipairs(admins) do
				if admin == jid then return true; end
			end
		elseif admins then
			log("error", "Option 'admins' for host '%s' is not a table", host);
		end
	end
	return usermanager.is_admin(jid); -- Test whether it's a global admin instead
end

module:provides("auth", provider);