/*
 * Copyright [2013] [Cloud4SOA, www.cloud4soa.eu]
 *
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */


/*
 * Copyright 2009-2012 the original author or authors.
 *
 * 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.cloudfoundry.client.lib.util;


import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

/**
 * Some helper utilities used by the Cloud Foundry Java client.
 *
 * @author Ramnivas Laddad
 * @author A.B.Srinivasan
 *
 */
public class CloudUtil {

    public static final int BUFFER_SIZE = 16 * 1024;

	private static Double DEFAULT_DOUBLE = new Double(0.0);

	private static Integer DEFAULT_INTEGER = new Integer(0);

	private static Long DEFAULT_LONG = new Long(0);

	private static final String HEX_CHARS = "0123456789ABCDEF";

	private static final char EXTENSION_SEPARATOR = '.';

	public static String parse(Object object) {
		return parse(String.class, object);
	}

	@SuppressWarnings("unchecked")
	public static <T> T parse(Class<T> clazz, Object object) {
		T defaultValue = null;
		try {
			if (clazz == Date.class) {
				String stringValue = parse(String.class, object);
				return clazz.cast(new SimpleDateFormat("EEE MMM d HH:mm:ss Z yyyy",
						Locale.US).parse(stringValue));
			}

			if (clazz == Integer.class) {
				defaultValue = (T) DEFAULT_INTEGER;
			} else if (clazz == Long.class) {
				defaultValue = (T) DEFAULT_LONG;
			} else if (clazz == Double.class) {
				defaultValue = (T) DEFAULT_DOUBLE;
			}

			if (object == null) {
				return defaultValue;
			}

			// special handling for int and long since smaller numbers become ints
			// but may be requested as long and vice versa
			if (clazz == Integer.class) {
				return clazz.cast(Integer.valueOf(((Number)object).intValue()));
			}
			if (clazz == Long.class) {
				return clazz.cast(Long.valueOf(((Number)object).longValue()));
			}

			return clazz.cast(object);
		} catch (ClassCastException e) {
			// ignore
		} catch (ParseException e) {
			// ignore
		}
		return defaultValue;
	}

	public static boolean isWar(String filePath) {
	    return "war".equalsIgnoreCase(extension(filePath));
	}

	public static String computeSha1Digest(InputStream in) throws IOException {
	    MessageDigest digest;
	    try {
	        digest = MessageDigest.getInstance("SHA-1");
	    } catch (NoSuchAlgorithmException e) {
	        throw new RuntimeException(e);
	    }

	    byte[] buffer = new byte[CloudUtil.BUFFER_SIZE];
	    while(true) {
	        int read = in.read(buffer);
	        if (read == -1) {
	            break;
	        }
	        digest.update(buffer, 0, read);
	    }
	    in.close();
	    return bytesToHex(digest.digest());
	}

	private static String bytesToHex(byte[] bytes) {
	    if (bytes == null) {
	        return null;
	    }
	    final StringBuilder hex = new StringBuilder(2 * bytes.length);
	    for (final byte b : bytes) {
	        hex.append(HEX_CHARS.charAt((b & 0xF0) >> 4)).append(HEX_CHARS.charAt((b & 0x0F)));
	    }
	    return hex.toString();
	}

	private static String extension(String filePath) {
	    int dot = filePath.lastIndexOf(EXTENSION_SEPARATOR);
	    return filePath.substring(dot + 1);
	}

}