-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

module("dependencies", package.seeall)

function softreq(...) local ok, lib =  pcall(require, ...); if ok then return lib; else return nil, lib; end end

-- Required to be able to find packages installed with luarocks

if not softreq "luarocks.loader" then -- LuaRocks 2.x

	softreq "luarocks.require"; -- LuaRocks <1.x

end

function missingdep(name, sources, msg)

	print("");

	print("**************************");

	print("Prosody was unable to find "..tostring(name));

	print("This package can be obtained in the following ways:");

	print("");

	local longest_platform = 0;

	for platform in pairs(sources) do

		longest_platform = math.max(longest_platform, #platform);

	end

	for platform, source in pairs(sources) do

		print("", platform..":"..(" "):rep(4+longest_platform-#platform)..source);

	end

	print("");

	print(msg or (name.." is required for Prosody to run, so we will now exit."));

	print("More help can be found on our website, at http://prosody.im/doc/depends");

	print("**************************");

	print("");

end

-- COMPAT w/pre-0.8 Debian: The Debian config file used to use 

-- util.ztact, which has been removed from Prosody in 0.8. This

-- is to log an error for people who still use it, so they can

-- update their configs.

package.preload["util.ztact"] = function ()

	if not package.loaded["core.loggingmanager"] then

		error("util.ztact has been removed from Prosody and you need to fix your config "

		    .."file. More information can be found at http://prosody.im/doc/packagers#ztact", 0);

	else

		error("module 'util.ztact' has been deprecated in Prosody 0.8.");

	end

end;

function check_dependencies()

	if _VERSION ~= "Lua 5.1" then

		print "***********************************"

		print("Unsupported Lua version: ".._VERSION);

		print("Only Lua 5.1 is supported.");

		print "***********************************"

		return false;

	end

	local fatal;

	local lxp = softreq "lxp"

	if not lxp then

		missingdep("luaexpat", {

				["Debian/Ubuntu"] = "sudo apt-get install liblua5.1-expat0";

				["luarocks"] = "luarocks install luaexpat";

				["Source"] = "http://www.keplerproject.org/luaexpat/";

			});

		fatal = true;

	end

	local socket = softreq "socket"

	if not socket then

		missingdep("luasocket", {

				["Debian/Ubuntu"] = "sudo apt-get install liblua5.1-socket2";

				["luarocks"] = "luarocks install luasocket";

				["Source"] = "http://www.tecgraf.puc-rio.br/~diego/professional/luasocket/";

			});

		fatal = true;

	end

	local lfs, err = softreq "lfs"

	if not lfs then

		missingdep("luafilesystem", {

				["luarocks"] = "luarocks install luafilesystem";

		 		["Debian/Ubuntu"] = "sudo apt-get install liblua5.1-filesystem0";

		 		["Source"] = "http://www.keplerproject.org/luafilesystem/";

		 	});

		fatal = true;

	end

	local ssl = softreq "ssl"

	if not ssl then

		missingdep("LuaSec", {

				["Debian/Ubuntu"] = "http://prosody.im/download/start#debian_and_ubuntu";

				["luarocks"] = "luarocks install luasec";

				["Source"] = "http://www.inf.puc-rio.br/~brunoos/luasec/";

			}, "SSL/TLS support will not be available");

	elseif not _G.ssl then

		_G.ssl = ssl;

		_G.ssl.context = require "ssl.context";

	end

	local encodings, err = softreq "util.encodings"

	if not encodings then

		if err:match("not found") then

			missingdep("util.encodings", { ["Windows"] = "Make sure you have encodings.dll from the Prosody distribution in util/";

		 				["GNU/Linux"] = "Run './configure' and 'make' in the Prosody source directory to build util/encodings.so";

		 			});

		else

			print "***********************************"

			print("util/encodings couldn't be loaded. Check that you have a recent version of libidn");

			print ""

			print("The full error was:");

			print(err)

			print "***********************************"

		end

		fatal = true;

	end

	local hashes, err = softreq "util.hashes"

	if not hashes then

		if err:match("not found") then

			missingdep("util.hashes", { ["Windows"] = "Make sure you have hashes.dll from the Prosody distribution in util/";

		 				["GNU/Linux"] = "Run './configure' and 'make' in the Prosody source directory to build util/hashes.so";

		 			});

	 	else

			print "***********************************"

			print("util/hashes couldn't be loaded. Check that you have a recent version of OpenSSL (libcrypto in particular)");

			print ""

			print("The full error was:");

			print(err)

			print "***********************************"

		end

		fatal = true;

	end

	return not fatal;

end

function log_warnings()

	if ssl then

		local major, minor, veryminor, patched = ssl._VERSION:match("(%d+)%.(%d+)%.?(%d*)(M?)");

		if not major or ((tonumber(major) == 0 and (tonumber(minor) or 0) <= 3 and (tonumber(veryminor) or 0) <= 2) and patched ~= "M") then

			log("error", "This version of LuaSec contains a known bug that causes disconnects, see http://prosody.im/doc/depends");

		end

	end

	if lxp then

		if not pcall(lxp.new, { StartDoctypeDecl = false }) then

			log("error", "The version of LuaExpat on your system leaves Prosody "

				.."vulnerable to denial-of-service attacks. You should upgrade to "

				.."LuaExpat 1.3.0 or higher as soon as possible. See "

				.."http://prosody.im/doc/depends#luaexpat for more information.");

		end

		if not lxp.new({}).getcurrentbytecount then

			log("error", "The version of LuaExpat on your system does not support "

				.."stanza size limits, which may leave servers on untrusted "

				.."networks (e.g. the internet) vulnerable to denial-of-service "

				.."attacks. You should upgrade to LuaExpat 1.3.0 or higher as "

				.."soon as possible. See "

				.."http://prosody.im/doc/depends#luaexpat for more information.");

		end

	end

end

return _M;