/**
 * 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.
 */
package org.apache.hadoop.test;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URL;
import java.nio.ByteBuffer;
import java.util.Properties;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
import org.apache.velocity.runtime.RuntimeConstants;
import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;
import org.eclipse.jetty.http.HttpTester;
import org.eclipse.jetty.servlet.ServletTester;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class TestUtils {

  private static Logger LOG = Logger.getLogger(TestUtils.class);

  public static final long SHORT_TIMEOUT = 1000L;
  public static final long MEDIUM_TIMEOUT = 20 * 1000L;
  public static final long LONG_TIMEOUT = 60 * 1000L;

  public static String getResourceName( Class clazz, String name ) {
    name = clazz.getName().replaceAll( "\\.", "/" ) + "/" + name;
    return name;
  }

  public static URL getResourceUrl( Class clazz, String name ) throws FileNotFoundException {
    name = getResourceName( clazz, name );
    URL url = ClassLoader.getSystemResource( name );
    if( url == null ) {
      throw new FileNotFoundException( name );
    }
    return url;
  }

  public static URL getResourceUrl( String name ) throws FileNotFoundException {
    URL url = ClassLoader.getSystemResource( name );
    if( url == null ) {
      throw new FileNotFoundException( name );
    }
    return url;
  }

  public static InputStream getResourceStream( String name ) throws IOException {
    URL url = ClassLoader.getSystemResource( name );
    InputStream stream = url.openStream();
    return stream;
  }

  public static InputStream getResourceStream( Class clazz, String name ) throws IOException {
    URL url = getResourceUrl( clazz, name );
    InputStream stream = url.openStream();
    return stream;
  }

  public static Reader getResourceReader( String name, String charset ) throws IOException {
    return new InputStreamReader( getResourceStream( name ), charset );
  }

  public static Reader getResourceReader( Class clazz, String name, String charset ) throws IOException {
    return new InputStreamReader( getResourceStream( clazz, name ), charset );
  }

  public static String getResourceString( Class clazz, String name, String charset ) throws IOException {
    return IOUtils.toString( getResourceReader( clazz, name, charset ) );
  }

  public static File createTempDir( String prefix ) throws IOException {
    File targetDir = new File( System.getProperty( "user.dir" ), "target" );
    File tempDir = new File( targetDir, prefix + UUID.randomUUID() );
    FileUtils.forceMkdir( tempDir );
    return tempDir;
  }

  public static Document parseXml( InputStream stream ) throws ParserConfigurationException, IOException, SAXException {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document document = builder.parse( new InputSource( stream ) );
    return document;
  }

  public static void dumpXml( Document document ) throws TransformerException {
    Transformer transformer = TransformerFactory.newInstance().newTransformer();
    transformer.setOutputProperty( OutputKeys.INDENT, "yes" );
    StreamResult result = new StreamResult( new StringWriter() );
    DOMSource source = new DOMSource( document );
    transformer.transform( source, result );
    String xmlString = result.getWriter().toString();
    System.out.println( xmlString );
  }

  public static void LOG_ENTER() {
    StackTraceElement caller = Thread.currentThread().getStackTrace()[2];
    System.out.flush();
    System.out.println( String.format( "Running %s#%s", caller.getClassName(), caller.getMethodName() ) );
    System.out.flush();
  }

  public static void LOG_EXIT() {
    StackTraceElement caller = Thread.currentThread().getStackTrace()[2];
    System.out.flush();
    System.out.println( String.format( "Exiting %s#%s", caller.getClassName(), caller.getMethodName() ) );
    System.out.flush();
  }

  public static void awaitPortOpen( InetSocketAddress address, int timeout, int delay ) throws InterruptedException {
    long maxTime = System.currentTimeMillis() + timeout;
    do {
      try {
        Socket socket = new Socket();
        socket.connect( address, delay );
        socket.close();
        return;
      } catch ( IOException e ) {
        //e.printStackTrace();
      }
    } while( System.currentTimeMillis() < maxTime );
    throw new IllegalStateException( "Timed out " + timeout + " waiting for port " + address );
  }

  public static void awaitNon404HttpStatus( URL url, int timeout, int delay ) throws InterruptedException {
    long maxTime = System.currentTimeMillis() + timeout;
    do {
      Thread.sleep( delay );
      HttpURLConnection conn = null;
      try {
        conn = (HttpURLConnection)url.openConnection();
        conn.getInputStream().close();
        return;
      } catch ( IOException e ) {
        //e.printStackTrace();
        try {
          if( conn != null && conn.getResponseCode() != 404 ) {
            return;
          }
        } catch ( IOException ee ) {
          //ee.printStackTrace();
        }
      }
    } while( System.currentTimeMillis() < maxTime );
    throw new IllegalStateException( "Timed out " + timeout + " waiting for URL " + url );
  }

  public static String merge( String resource, Properties properties ) {
    ClasspathResourceLoader loader = new ClasspathResourceLoader();
    loader.getResourceStream( resource );

    VelocityEngine engine = new VelocityEngine();
    Properties config = new Properties();
    config.setProperty( RuntimeConstants.RUNTIME_LOG_LOGSYSTEM_CLASS, "org.apache.velocity.runtime.log.NullLogSystem" );
    config.setProperty( RuntimeConstants.RESOURCE_LOADER, "classpath" );
    config.setProperty( "classpath.resource.loader.class", ClasspathResourceLoader.class.getName() );
    engine.init( config );

    VelocityContext context = new VelocityContext( properties );
    Template template = engine.getTemplate( resource );
    StringWriter writer = new StringWriter();
    template.merge( context, writer );
    return writer.toString();
  }

  public static String merge( Class base, String resource, Properties properties ) {
    String baseResource = base.getName().replaceAll( "\\.", "/" );
    String fullResource = baseResource + "/" + resource;
    return merge( fullResource, properties );
  }

  public static int findFreePort() throws IOException {
    ServerSocket socket = new ServerSocket(0);
    int port = socket.getLocalPort();
    socket.close();
    return port;
  }

  public static void waitUntilNextSecond() {
    long before = System.currentTimeMillis();
    long wait;
    while( ( wait = ( 1000 - ( System.currentTimeMillis() - before ) ) ) > 0 ) {
      try {
        Thread.sleep( wait );
      } catch( InterruptedException e ) {
        // Ignore.
      }
    }
  }

  public static HttpTester.Response execute( ServletTester server, HttpTester.Request request ) throws Exception {
    LOG.debug( "execute: request=" + request );
    ByteBuffer requestBuffer = request.generate();
    LOG.trace( "execute: requestBuffer=[" + new String(requestBuffer.array(),0,requestBuffer.limit()) + "]" );
    ByteBuffer responseBuffer = server.getResponses( requestBuffer, 30, TimeUnit.SECONDS );
    HttpTester.Response response = HttpTester.parseResponse( responseBuffer );
    LOG.trace( "execute: responseBuffer=[" + new String(responseBuffer.array(),0,responseBuffer.limit()) + "]" );
    LOG.debug( "execute: reponse=" + response );
    return response;
  }


}