/*******************************************************************************
 * Copyright 2013 EMBL-EBI
 *
 * 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 uk.ac.sanger.artemis.cramtools.ref;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * A cut-down version of the EBI cramtools Utils class.
 * Contains only the bits needed for CRAM reference related functionality.
 * 
 * @author kp11
 *
 */
public class Utils
{

	public static int readInto(ByteBuffer buf, InputStream inputStream) throws IOException {
		int read = 0;
		while (buf.hasRemaining()) {
			int count = inputStream.read(buf.array(), buf.position(), buf.remaining());
			if (count < 0)
				throw new EOFException();
			read += count;
		}
		return read;
	}
	
	public static String calculateMD5String(byte[] data) {
		return calculateMD5String(data, 0, data.length);
	}

	public static String calculateMD5String(byte[] data, int offset, int len) {
		byte[] digest = calculateMD5(data, offset, len);
		return String.format("%032x", new BigInteger(1, digest));
	}

	public static byte[] calculateMD5(byte[] data, int offset, int len) {
		MessageDigest md5_MessageDigest;
		try {
			md5_MessageDigest = MessageDigest.getInstance("MD5");
			md5_MessageDigest.reset();

			md5_MessageDigest.update(data, offset, len);
			return md5_MessageDigest.digest();
		} catch (NoSuchAlgorithmException e) {
			throw new RuntimeException(e);
		}
	}
	
	public static final byte upperCase(byte base) {
		return base >= 'a' ? (byte) (base - ('a' - 'A')) : base;
	}

	public static final byte[] upperCase(byte[] bases) {
		for (int i = 0; i < bases.length; i++)
			bases[i] = upperCase(bases[i]);
		return bases;
	}
	
	public static boolean isValidSequence(byte[] bases, int checkOnlyThisManyBases) {
		for (int i = 0; i < checkOnlyThisManyBases && i < bases.length; i++) {
			switch (bases[i]) {
			case 'A':
			case 'C':
			case 'G':
			case 'T':
			case 'U':
			case 'R':
			case 'Y':
			case 'S':
			case 'W':
			case 'K':
			case 'M':
			case 'B':
			case 'D':
			case 'H':
			case 'V':
			case 'N':
			case '.':
			case '-':
				break;

			default:
				return false;
			}
		}
		return true;
	}
}