package fr.xephi.authme.security.crypts;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 */
public class SHA256 implements EncryptionMethod {

    /**
     * Method getSHA256.
     *
     * @param message String
     * @return String * @throws NoSuchAlgorithmException
     */
    private static String getSHA256(String message)
            throws NoSuchAlgorithmException {
        MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
        sha256.reset();
        sha256.update(message.getBytes());
        byte[] digest = sha256.digest();
        return String.format("%0" + (digest.length << 1) + "x", new BigInteger(1, digest));
    }

    /**
     * Method getHash.
     *
     * @param password String
     * @param salt     String
     * @param name     String
     * @return String * @throws NoSuchAlgorithmException * @see fr.xephi.authme.security.crypts.EncryptionMethod#getHash(String, String, String)
     */
    @Override
    public String getHash(String password, String salt, String name)
            throws NoSuchAlgorithmException {
        return "$SHA$" + salt + "$" + getSHA256(getSHA256(password) + salt);
    }

    /**
     * Method comparePassword.
     *
     * @param hash       String
     * @param password   String
     * @param playerName String
     * @return boolean * @throws NoSuchAlgorithmException * @see fr.xephi.authme.security.crypts.EncryptionMethod#comparePassword(String, String, String)
     */
    @Override
    public boolean comparePassword(String hash, String password,
                                   String playerName) throws NoSuchAlgorithmException {
        String[] line = hash.split("\\$");
        return hash.equals(getHash(password, line[2], ""));
    }

}