/*******************************************************************************
 * ============LICENSE_START====================================================
 * * org.onap.aaf
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * 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.
 * * ============LICENSE_END====================================================
 * *
 * *
 ******************************************************************************/
package org.onap.aaf.cadi.test;

import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.nio.file.Files;
import java.nio.file.Paths;

import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;

import org.junit.Test;
import org.onap.aaf.cadi.AES;
import org.onap.aaf.cadi.CadiException;
import org.onap.aaf.cadi.Symm;
import org.junit.Before;

public class JU_AES {
	private AES aes;
	private ByteArrayInputStream baisEncrypt;
	private ByteArrayInputStream baisDecrypt;
	private ByteArrayOutputStream baosEncrypt;
	private ByteArrayOutputStream baosDecrypt;

	@Before
	public void setup() throws Exception {
	 	byte[] keyBytes = new byte[AES.AES_KEY_SIZE/8];
	 	char[] codeset = Symm.base64.codeset;
	 	int offset = (Math.abs(codeset[0])+47)%(codeset.length-keyBytes.length);
	 	for(int i=0;i<keyBytes.length;++i) {
	 		keyBytes[i] = (byte)codeset[i+offset];
	 	}
	 	aes = new AES(keyBytes,0,keyBytes.length);
	}

	@Test
	public void newKeyTest() throws Exception {
		SecretKey secretKey = AES.newKey();
		assertEquals(secretKey.getAlgorithm(), AES.class.getSimpleName());
	}

	@Test
	public void encryptDecrpytFromBytes() throws Exception {
		String orig = "I'm a password, really";
		byte[] encrypted = aes.encrypt(orig.getBytes());
		byte[] decrypted = aes.decrypt(encrypted);
		assertEquals(orig, new String(decrypted));
 
		Field aeskeySpec_field = AES.class.getDeclaredField("aeskeySpec");
		aeskeySpec_field.setAccessible(true);
		aeskeySpec_field.set(aes, null);

		try {
			aes.encrypt(orig.getBytes());
			fail("Should have thrown an exception");
		} catch (CadiException e) {
		}
		try {
			aes.decrypt(encrypted);
			fail("Should have thrown an exception");
		} catch (CadiException e) {
		}
	}

	@Test
	public void saveToFileTest() throws Exception {
		String filePath = "test/output_key";
		File keyfile = new File(filePath);
		aes.save(keyfile);
		assertTrue(Files.isReadable(Paths.get(filePath)));
		assertFalse(Files.isWritable(Paths.get(filePath)));
		assertFalse(Files.isExecutable(Paths.get(filePath)));
		keyfile.delete();
	}

	@Test
	public void encryptDecryptFromInputStream() throws Exception {
		String orig = "I'm a password, really";
		byte[] b64encrypted;
		String output;

		CipherInputStream cisEncrypt;
		CipherInputStream cisDecrypt;
		
		// Test CipherInputStream
		baisEncrypt = new ByteArrayInputStream(orig.getBytes());
		cisEncrypt = aes.inputStream(baisEncrypt, true);
		baosEncrypt = new ByteArrayOutputStream();
		transferFromInputStreamToOutputStream(cisEncrypt, baosEncrypt);
		cisEncrypt.close();

		b64encrypted = baosEncrypt.toByteArray();

		baisDecrypt = new ByteArrayInputStream(b64encrypted);
		cisDecrypt = aes.inputStream(baisDecrypt, false);
		baosDecrypt = new ByteArrayOutputStream();
		transferFromInputStreamToOutputStream(cisDecrypt, baosDecrypt);
		cisDecrypt.close();

		output = new String(baosDecrypt.toByteArray());
		assertEquals(orig, output);

		Field aeskeySpec_field = AES.class.getDeclaredField("aeskeySpec");
		aeskeySpec_field.setAccessible(true);
		aeskeySpec_field.set(aes, null);

		assertNull(aes.inputStream(baisEncrypt, true));
	}

	@Test
	public void encryptDecryptFromOutputStream() throws Exception {
		String orig = "I'm a password, really";
		byte[] b64encrypted;
		String output;

		CipherOutputStream cosEncrypt;
		CipherOutputStream cosDecrypt;
		
		// Test CipherOutputStream
		baisEncrypt = new ByteArrayInputStream(orig.getBytes());
		baosEncrypt = new ByteArrayOutputStream();
		cosEncrypt = aes.outputStream(baosEncrypt, true);
		transferFromInputStreamToOutputStream(baisEncrypt, cosEncrypt);
		cosEncrypt.close();

		b64encrypted = baosEncrypt.toByteArray();

		baosDecrypt = new ByteArrayOutputStream();
		cosDecrypt = aes.outputStream(baosDecrypt, false);
		baisDecrypt = new ByteArrayInputStream(b64encrypted);
		transferFromInputStreamToOutputStream(baisDecrypt, cosDecrypt);
		cosDecrypt.close();

		output = new String(baosDecrypt.toByteArray());
		assertEquals(orig, output);

		Field aeskeySpec_field = AES.class.getDeclaredField("aeskeySpec");
		aeskeySpec_field.setAccessible(true);
		aeskeySpec_field.set(aes, null);

		assertNull(aes.outputStream(baosEncrypt, true));
	}

	public void transferFromInputStreamToOutputStream(InputStream is, OutputStream os) throws IOException {
		byte[] buffer = new byte[200];
		int len;
		while ((len = is.read(buffer)) != -1) {
		    os.write(buffer, 0, len);
		}
	}
	
}