package odera.projects.appointmentssoftware.services;

import java.nio.charset.StandardCharsets;
import java.security.spec.KeySpec;
import java.util.Base64;
import javax.crypto.*;
import javax.crypto.spec.DESedeKeySpec;

public class EncryptionDecryptionDES {
    private static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
    private final Cipher cipher;
    private final SecretKey key;

    public EncryptionDecryptionDES(String password) throws Exception {
        //key has to be at least 24 bytes long
        if(password.length() < 24) {
            StringBuilder passwordBuilder = new StringBuilder(password);
            while (passwordBuilder.length() < 24) {
                passwordBuilder.append(" ");
            }
            password = passwordBuilder.toString();
        }
        byte[] arrayBytes = password.getBytes(StandardCharsets.UTF_8);
        KeySpec keySpec = new DESedeKeySpec(arrayBytes);
        SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance(DESEDE_ENCRYPTION_SCHEME);
        cipher = Cipher.getInstance(DESEDE_ENCRYPTION_SCHEME);
        key = secretKeyFactory.generateSecret(keySpec);
    }

    public String encrypt(String plainText)
            throws Exception {
        byte[] plainTextByte = plainText.getBytes();
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] encryptedByte = cipher.doFinal(plainTextByte);
        Base64.Encoder encoder = Base64.getEncoder();
        return encoder.encodeToString(encryptedByte);
    }

//    public String decrypt(String encryptedText)
//            throws Exception {
//        Base64.Decoder decoder = Base64.getDecoder();
//        byte[] encryptedTextByte = decoder.decode(encryptedText);
//        cipher.init(Cipher.DECRYPT_MODE, key);
//        byte[] decryptedByte = cipher.doFinal(encryptedTextByte);
//        return new String(decryptedByte);
//    }
}