package freenet.tools;

import static freenet.keys.InsertableClientSSK.createRandom;
import static java.lang.String.format;
import static java.lang.System.currentTimeMillis;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

import freenet.crypt.RandomSource;
import freenet.crypt.Yarrow;
import freenet.keys.InsertableClientSSK;

/**
 * Generates a vanity key pair, i.e. a keypair with the public key starting
 * with a specific set of characters.
 *
 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 */
public class GenerateVanityKey {

    public static void main(String... arguments) throws Exception {
        RandomSource randomSource = new Yarrow();
        long firstOutput = currentTimeMillis();
        long lastOutput = firstOutput;
        long generatedKeys = 0;
        long foundKeys = 0;
        String prefixToSearch = (arguments.length > 0) ? arguments[0].toLowerCase() : "free";
        while (true) {
            InsertableClientSSK clientSSK = createRandom(randomSource, "");
            generatedKeys++;
            if (clientSSK.getURI().toString().toLowerCase().substring(4).startsWith(prefixToSearch)) {
                System.err.println(format("\r%s <- %s", clientSSK.getURI(),
                        clientSSK.getInsertURI()));
                foundKeys++;
            }
            long currentTime = currentTimeMillis();
            if ((currentTime - lastOutput) > 1000) {
                long timeSpent = currentTime - firstOutput;
                System.out.print(format("\r%d/s, %.3f/s",
                        generatedKeys / MILLISECONDS.toSeconds(timeSpent),
                        (double) foundKeys / MILLISECONDS.toSeconds(timeSpent)));
                lastOutput = currentTime;
            }
        }
    }

}