/*
 * Copyright 2011 Federal Chancellery Austria and
 * Graz University of Technology
 * 
 * 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 at.gv.egovernment.moa.util;

import iaik.logging.Log;
import iaik.logging.LogFactory;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.Properties;

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.xml.sax.SAXException;

import at.gv.egovernment.moa.util.ex.EgovUtilException;



/**
 * Class providing several utility methods.
 * 
 * @author <a href="mailto:Arne.Tauber@egiz.gv.at">Arne Tauber</a>
 * 
 */
public class MiscUtil {

	public static final String DEFAULT_SLASH = "/";

	public static Log log = LogFactory.getLog(MiscUtil.class);
	
	private static final int IO_BUFFER_SIZE = 4 * 1024;  
	
	public static void copyStream(InputStream is, OutputStream os) throws IOException {
		byte[] b = new byte[IO_BUFFER_SIZE];  
		int read;  
		while ((read = is.read(b)) != -1) {  
		os.write(b, 0, read);  
		}  
	}
	
	public static void assertNotNull(Object param, String name) {
		if (param == null) {
			throw new NullPointerException(name + " must not be null.");
		}
	}

	public static boolean areAllNull(Object... objects) {
		for (Object o : objects) {
			if (o != null) {
				return false;
			}
		}
		return true;
	}

	public static String extractContentType(String contentTypeString) {
		if (contentTypeString == null) {
			return "";
		}
		if (contentTypeString.indexOf(";") != -1) {
			return contentTypeString.substring(0, contentTypeString.indexOf(";"));
		}
		return contentTypeString;
	}

	public static XMLGregorianCalendar getXMLGregorianCalendar(Date date)
	    throws DatatypeConfigurationException {
		GregorianCalendar cal = (GregorianCalendar) GregorianCalendar.getInstance();
		cal.setTime(date);
		return DatatypeFactory.newInstance().newXMLGregorianCalendar(cal);
	}

	public static XMLGregorianCalendar getXMLGregorianCalendar(String str)
	    throws DatatypeConfigurationException {
		return DatatypeFactory.newInstance().newXMLGregorianCalendar(str);
	}

	public static X509Certificate readCertificate(InputStream certStream)
	    throws CertificateException {
		CertificateFactory cf = CertificateFactory.getInstance("X.509");
		return (X509Certificate) cf.generateCertificate(certStream);
	}

	public static boolean isEmpty(String str) {
		return str == null || "".equals(str);
	}

	public static boolean isNotEmpty(String str) {
		return str != null && !"".equals(str);
	}

	public static byte[] sourceToByteArray(Source result)
	    throws TransformerException {
		TransformerFactory factory = TransformerFactory.newInstance();
		Transformer transformer = factory.newTransformer();
		transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
		transformer.setOutputProperty(OutputKeys.METHOD, "xml");
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		StreamResult streamResult = new StreamResult();
		streamResult.setOutputStream(out);
		transformer.transform(result, streamResult);
		return out.toByteArray();
	}

//	public static Document parseDocument(InputStream inputStream)
//	    throws IOException {
//		try {
//			DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory
//			    .newInstance();
//			docBuilderFactory.setNamespaceAware(true);
//			DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
//			return docBuilder.parse(inputStream);
//		} catch (ParserConfigurationException e) {
//			throw new IOException(e);
//		} catch (SAXException e) {
//			throw new IOException(e);
//		}
//	}

	public static String removePrecedingSlash(String path, String slash) {
		assertNotEmpty(slash, "Shash");
		if (!isEmpty(path)) {
			while (path.startsWith(slash)) {
				path = path.substring(slash.length(), path.length());
			}
		}
		return path;
	}

	public static String removePrecedingSlash(String path) {
		return removePrecedingSlash(path, DEFAULT_SLASH);
	}

	public static void assertNotEmpty(String param, String name) {
		if (param == null) {
			throw new NullPointerException(name + " must not be null.");
		}
		if (param.length() == 0) {
			throw new IllegalArgumentException(name + " must not be empty.");
		}
	}

	@SuppressWarnings("rawtypes")
  public static boolean isEmpty(Properties props) {
		if (props == null || props.isEmpty()) {
			return true;
		}
		Iterator it = props.values().iterator();
		while (it.hasNext()) {
			if (MiscUtil.isNotEmpty((String) it.next())) {
				return false;
			}
		}
		return true;
	}

	public static boolean isEmpty(Empty empty) {
		return empty == null || empty.isEmpty();
	}

	public static boolean isNotEmpty(Empty empty) {
		return !isEmpty(empty);
	}

	public static boolean isEmpty(byte[] data) {
		return data == null || data.length == 0;
	}

	public static boolean isNotEmpty(byte[] data) {
		return !isEmpty(data);
	}

	public static <T> boolean isEmpty(Collection<T> c) {
		return c == null || c.isEmpty();
	}

	public static <T> boolean isNotEmpty(Collection<T> c) {
		return !isEmpty(c);
	}

	public static boolean areAllEmpty(String... strings) {
		for (String s : strings) {
			if (s != null && s.trim().length() != 0) {
				return false;
			}
		}
		return true;
	}

	public static boolean areAllEmpty(Empty... empties) {
		if (empties != null) {
			for (Empty e : empties) {
				if (e != null && !e.isEmpty()) {
					return false;
				}
			}
		}
		return true;
	}

	public static <T> void assertNotEmpty(T[] param, String name) {
		if (param == null) {
			throw new NullPointerException(name + " must not be null.");
		}
		if (param.length == 0) {
			throw new IllegalArgumentException(name + " must not be empty.");
		}
	}

	public static void assertNotEmpty(Empty empty, String name) {
		if (empty == null) {
			throw new NullPointerException(name + " must not be null.");
		}
		if (empty.isEmpty()) {
			throw new IllegalArgumentException(name + " must not be empty.");
		}
	}

	public static void assertNotEmpty(byte[] param, String name) {
		if (param == null) {
			throw new NullPointerException(name + " must not be null.");
		}
		if (param.length == 0) {
			throw new IllegalArgumentException(name + " must not be empty.");
		}
	}

	public static Date parseXMLDate(String xmlDate) throws EgovUtilException {
		if (xmlDate == null) {
			return null;
		}
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		try {
			return sdf.parse(xmlDate);
		} catch (ParseException e) {
			throw new EgovUtilException(e);
		}
	}

	public static <T> boolean isEmpty(T[] array) {
		return array == null || array.length == 0;
	}

	public static <T> boolean isNotEmpty(T[] array) {
		return !isEmpty(array);
	}

	public static String convertDateFromStandardToXML(String dateString) {
		MiscUtil.assertNotNull(dateString, "dateString");
		Date date = parseDate(dateString);
		return formatDate(date, "yyyy-MM-dd");
	}
	
	public static Date parseDate(String dateString) {
		return parseDate(dateString, "dd.MM.yyyy");
	}
	
	public static Date parseDate(String dateString, String pattern) {
		MiscUtil.assertNotNull(dateString, "dateString");
		MiscUtil.assertNotNull(pattern, "pattern");
		SimpleDateFormat sdf = new SimpleDateFormat(pattern);
		try {
	    return sdf.parse(dateString);
    } catch (ParseException e) {
    	log.warn(null, "Error parsing date.", e);
	    return null;
    }
	}	
	
	public static String formatDate(Date date, String format) {
		SimpleDateFormat sdf = new SimpleDateFormat(format);
		return sdf.format(date);
	}
  
}