#!/usr/bin/env escript
%% -*- erlang -*-

-define(CATLFISH_VER, "catlfish-0.10.0-dev").
-define(PLOP_VER, "plop-0.10.0-dev").
-define(LAGER_VER, "lager-3.2.2").

write_reply(Bin) ->
    Length = size(Bin),
    file:write(standard_io, <<Length:32, Bin/binary>>).

verify(RootCerts, DBEntry) ->
    try
        case catlfish:verify_entry(tlv:decodelist(DBEntry), RootCerts) of
            {ok, _MTLHash} ->
                write_reply(<<0:8>>);
            {error, Reason} ->
                ReasonBin = list_to_binary(io_lib:format("~p", [Reason])),
            write_reply(<<1:8, ReasonBin/binary>>)
        end
    catch
        Type:What ->
            [CrashFunction | Stack] = erlang:get_stacktrace(),
            ErrorBin = list_to_binary(io_lib:format("Crash: ~p ~p~n~p~n~p~n", [Type, What, CrashFunction, Stack])),
            write_reply(<<2:8, ErrorBin/binary>>)
    end.

loop(RootCerts) ->
    {ok, LengthBin} = file:read(standard_io, 4),
    <<Length:32>> = list_to_binary(LengthBin),
    case Length of
        0 ->
            none;
        _ ->
            {ok, DBEntry} = file:read(standard_io, Length),
            verify(RootCerts, list_to_binary(DBEntry)),
            loop(RootCerts)
    end.

add_lib(Dirs, Name) ->
    add_lib(Dirs, Dirs, Name).
add_lib(AllDirs, [], Name) ->
    {ok, Cwd} = file:get_cwd(),
    io:format(standard_error,
              "Could not add lib ~p: tried directories ~p cwd: ~p~n",
              [Name, AllDirs, Cwd]),
    halt(1);
add_lib(AllDirs, [Dir | Rest], Name) ->
    Path = Dir ++ "/" ++ Name ++ ".ez/" ++ Name ++ "/ebin",
    case code:add_path(Path) of
        true ->
            ok;
        {error, bad_directory} ->
            add_lib(AllDirs, Rest, Name)
    end.

main([KnownRoots]) ->
    [ScriptFile | _] = init:get_plain_arguments(),
    BaseDir = filename:dirname(ScriptFile),
    LibDirs = [BaseDir ++ "/../lib", "../lib"],
    add_lib(LibDirs, ?CATLFISH_VER),
    add_lib(LibDirs, ?LAGER_VER),
    add_lib(LibDirs, ?PLOP_VER),

    Certs = x509:read_pemfiles_from_dir(KnownRoots),
    loop(Certs).