learncrypto/source/app.d

import std.getopt;
import std.string : format;
import std.stdio : stderr, writeln;

import cipher : Cipher;
import actions;

int main(string[] args)
{
    bool[string] actions = ["genKey" : false, "encrypt" : false, "decrypt"
        : false, "benchmark" : false];

    Cipher cipher = Cipher.chacha20;
    string keyFileName = "symkey.asc";
    bool armor;

    GetoptResult result;
    try
    {
        result = getopt(args, std.getopt.config.bundling, "gen-key|g",
                "Generate a new 256 bit key.", &actions["genKey"],
                "encrypt|e", "Encrypt a message.", &actions["encrypt"], "decrypt|d",
                "Decrypt a message.", &actions["decrypt"], "benchmark|b",
                "Perform some benchmarks.", &actions["benchmark"], "cipher|c",
                "The cipher to use (default: %s).".format(cipher), &cipher,
                "key|k", "The file which contains the key (default: %s).".format(keyFileName),
                &keyFileName, "armor|a", "use ascii-armored I/O.", &armor);
    }
    catch (Exception e)
    {
        stderr.writeln(e.msg);
        return 1;
    }

    size_t numberOfActions;
    foreach (value; actions.values)
        numberOfActions += value;

    if (numberOfActions == 1)
    {
        try
        {
            if (actions["genKey"])
            {
                generateKey(armor);
            }
            else if (actions["encrypt"])
            {
                encrypt(keyFileName, cipher, armor);
            }
            else if (actions["decrypt"])
            {
                decrypt(keyFileName, cipher, armor);
            }
            else if (actions["benchmark"])
            {
                bench();
            }
        }
        catch (Exception e)
        {
            stderr.writeln(e.msg);
            return 1;
        }
    }
    else
    {
        result.helpWanted = true;
    }

    if (result.helpWanted)
        printHelp(result.options);

    return 0;
}

void printHelp(Option[] options)
{
    defaultGetoptPrinter("Usage: ./learncrypt [options]\n\nCommon options:", options[$ - 1 .. $]);
    defaultGetoptPrinter("\nGlobal options:", options[$ - 2 .. $ - 1]);
    defaultGetoptPrinter("\nActions:", options[0 .. 4]);
    defaultGetoptPrinter("\nAction options:", options[4 .. 5]);
}