/**
 *
 * Copyright 2018 Paul Schaub.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jivesoftware.smackx.ox;

import static junit.framework.TestCase.assertEquals;
import static junit.framework.TestCase.assertTrue;

import java.io.File;
import java.io.IOException;
import java.security.InvalidAlgorithmParameterException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.util.Arrays;
import java.util.Collections;

import org.jivesoftware.smack.DummyConnection;
import org.jivesoftware.smack.test.util.SmackTestSuite;

import org.jivesoftware.smackx.ox.crypto.PainlessOpenPgpProvider;
import org.jivesoftware.smackx.ox.element.SecretkeyElement;
import org.jivesoftware.smackx.ox.exception.InvalidBackupCodeException;
import org.jivesoftware.smackx.ox.exception.MissingOpenPgpKeyException;
import org.jivesoftware.smackx.ox.exception.MissingUserIdOnKeyException;
import org.jivesoftware.smackx.ox.store.filebased.FileBasedOpenPgpStore;
import org.jivesoftware.smackx.ox.util.SecretKeyBackupHelper;

import org.bouncycastle.openpgp.PGPException;
import org.bouncycastle.openpgp.PGPSecretKeyRing;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.jupiter.api.Test;
import org.jxmpp.jid.BareJid;
import org.jxmpp.jid.impl.JidCreate;
import org.pgpainless.PGPainless;
import org.pgpainless.key.OpenPgpV4Fingerprint;
import org.pgpainless.key.collection.PGPKeyRing;

public class SecretKeyBackupHelperTest extends SmackTestSuite {

    private static final File basePath;

    static {
        basePath = new File(org.apache.commons.io.FileUtils.getTempDirectory(), "ox_secret_keys");
    }

    @Test
    public void backupPasswordGenerationTest() {
        final String alphabet = "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ";

        String backupCode = SecretKeyBackupHelper.generateBackupPassword();
        assertEquals(29, backupCode.length());
        for (int i = 0; i < backupCode.length(); i++) {
            if ((i + 1) % 5 == 0) {
                assertEquals('-', backupCode.charAt(i));
            } else {
                assertTrue(alphabet.indexOf(backupCode.charAt(i)) != -1);
            }
        }
    }

    @Test
    public void createAndDecryptSecretKeyElementTest()
            throws PGPException, NoSuchAlgorithmException, NoSuchProviderException, InvalidAlgorithmParameterException,
            IOException, MissingUserIdOnKeyException, MissingOpenPgpKeyException, InvalidBackupCodeException {

        // Prepare store and provider and so on...
        FileBasedOpenPgpStore store = new FileBasedOpenPgpStore(basePath);
        PainlessOpenPgpProvider provider = new PainlessOpenPgpProvider(new DummyConnection(), store);

        // Generate and import key
        PGPKeyRing keyRing = PGPainless.generateKeyRing().simpleEcKeyRing("xmpp:alice@wonderland.lit");
        BareJid jid = JidCreate.bareFrom("alice@wonderland.lit");
        provider.getStore().importSecretKey(jid, keyRing.getSecretKeys());

        // Create encrypted backup
        String backupCode = SecretKeyBackupHelper.generateBackupPassword();
        SecretkeyElement element = SecretKeyBackupHelper.createSecretkeyElement(provider, jid, Collections.singleton(new OpenPgpV4Fingerprint(keyRing.getSecretKeys())), backupCode);

        // Decrypt backup and compare
        PGPSecretKeyRing secretKeyRing = SecretKeyBackupHelper.restoreSecretKeyBackup(element, backupCode);
        assertTrue(Arrays.equals(keyRing.getSecretKeys().getEncoded(), secretKeyRing.getEncoded()));
    }

    @AfterClass
    @BeforeClass
    public static void deleteDirs() throws IOException {
        org.apache.commons.io.FileUtils.deleteDirectory(basePath);
    }
}