/*

  * Copyright 2006-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.core.api.util;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.api.config.property.ConfigContext;

 import org.springframework.core.io.DefaultResourceLoader;

 import org.springframework.core.io.FileSystemResource;

 import org.springframework.core.io.FileSystemResourceLoader;

 import org.springframework.core.io.Resource;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.InetAddress;

 import java.net.MalformedURLException;

 import java.net.NetworkInterface;

 import java.net.SocketException;

 import java.net.UnknownHostException;

 import java.util.Enumeration;

 /**

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public final class RiceUtilities {

     private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(RiceUtilities.class);

         private static String instanceIpAddress;

         private static String instanceHostName;

         private RiceUtilities() {

                 throw new UnsupportedOperationException("do not call");

         }

     public static synchronized String getIpNumber() {

         if ( instanceIpAddress == null ) {

             // protect from running upon startup

             if ( ConfigContext.getCurrentContextConfig() != null ) {

                 // attempt to load from environment

                 String ip = System.getProperty("host.ip");

                 if ( StringUtils.isBlank(ip) ) {

                     ip = ConfigContext.getCurrentContextConfig().getProperty("host.ip");

                 }

                 // if not set at all just return

                 if ( StringUtils.isBlank(ip) ) {                    

                     return getCurrentEnvironmentNetworkIp();

                 } else { 

                     // ok - it was set in configuration or by this method, set it permanently for this instance

                     instanceIpAddress = ip;

                 }

             } else {

                 // prior to startup, just return it

                 return getCurrentEnvironmentNetworkIp();

             }

         }

         return instanceIpAddress;

     }

     /** * @return the current environment's IP address, taking into account the Internet connection to any of the available

          *         machine's Network interfaces. Examples of the outputs can be in octatos or in IPV6 format.

          *

          *         fec0:0:0:9:213:e8ff:fef1:b717%4 siteLocal: true isLoopback: false isIPV6: true

          *         ============================================ 130.212.150.216 <<<<<<<<<<<------------- This is the one we

          *         want to grab so that we can. siteLocal: false address the DSP on the network. isLoopback: false isIPV6:

          *         false ==> lo ============================================ 0:0:0:0:0:0:0:1%1 siteLocal: false isLoopback:

          *         true isIPV6: true ============================================ 127.0.0.1 siteLocal: false isLoopback:

          *         true isIPV6: false

          */

         private static String getCurrentEnvironmentNetworkIp() {

              Enumeration<NetworkInterface> netInterfaces = null;

              try {

                   netInterfaces = NetworkInterface.getNetworkInterfaces();

              } catch (SocketException e) {

                   LOG.error("Somehow we have a socket error...",e);

                   return "127.0.0.1";

              }

              while (netInterfaces.hasMoreElements()) {

                   NetworkInterface ni = netInterfaces.nextElement();

                   Enumeration<InetAddress> address = ni.getInetAddresses();

                   while (address.hasMoreElements()) {

                        InetAddress addr = address.nextElement();

                        if (!addr.isLoopbackAddress() && !addr.isSiteLocalAddress()

                                  && !(addr.getHostAddress().indexOf(":") > -1)) {

                             return addr.getHostAddress();

                        }

                   }

              }

              try {

                   return InetAddress.getLocalHost().getHostAddress();

              } catch (UnknownHostException e) {

                   return "127.0.0.1";

              }

         }

         public static synchronized String getHostName() {

         if ( instanceHostName == null ) {

             try {

                 // protect from running upon startup

                 if ( ConfigContext.getCurrentContextConfig() != null ) {

                     String host = System.getProperty("host.name");

                     if ( StringUtils.isBlank(host) ) {

                         host = ConfigContext.getCurrentContextConfig().getProperty("host.name");

                     }

                     // if not set at all just return

                     if ( StringUtils.isBlank(host) ) {

                         return InetAddress.getByName( getCurrentEnvironmentNetworkIp() ).getHostName();

                     } else { 

                         // ok - it was set in configuration or by this method, set it permanently for this instance

                         instanceHostName = host;

                     }

                 } else {

                     // prior to startup, just return it

                     return InetAddress.getByName( getCurrentEnvironmentNetworkIp() ).getHostName();

                 }

             } catch ( Exception ex ) {

                 return "localhost";

             }

         }

         return instanceHostName;

         }

         /**

          * The standard Spring FileSystemResourceLoader does not support normal absolute file paths

          * for historical backwards-compatibility reasons.  This class simply circumvents that behavior

          * to allow proper interpretation of absolute paths (i.e. not stripping a leading slash)  

          */

         private static class AbsoluteFileSystemResourceLoader extends FileSystemResourceLoader {

         @Override

         protected Resource getResourceByPath(String path) {

             return new FileSystemResource(path);

         }

         }

         /**

          * Attempts to retrieve the resource stream.

          * 

          * @param resourceLoc resource location; syntax supported by {@link DefaultResourceLoader} 

          * @return the resource stream or null if the resource could not be obtained

          * @throws MalformedURLException

          * @throws IOException

          * @see DefaultResourceLoader

          */

         public static InputStream getResourceAsStream(String resourceLoc) throws MalformedURLException, IOException {

             Resource resource = getResource(resourceLoc);

             if (resource.exists()) {

                 return resource.getInputStream();

             }

             return null;

     }

         /**

          * Returns a handle to the requested Resource.

          * 

          * @param resourceLoc resource location; syntax supported by {@link DefaultResourceLoader}

          * @return a handle to the Resource

          */

         private static Resource getResource(String resourceLoc) {

                 AbsoluteFileSystemResourceLoader resourceLoader = new AbsoluteFileSystemResourceLoader();

                 resourceLoader.setClassLoader(ClassLoaderUtils.getDefaultClassLoader());

             return resourceLoader.getResource(resourceLoc);

         }

         /**

      * This method searches for an exception of the specified type in the stack trace of the given

      * exception.

      * @param topLevelException the exception whose stack to traverse

      * @param exceptionClass the exception class to look for

      * @return the first instance of an exception of the specified class if found, or null otherwise

      */

     public static <T extends Throwable> T findExceptionInStack(Throwable topLevelException, Class<T> exceptionClass) {

         Throwable t = topLevelException;

         while (t != null) {

             if (exceptionClass.isAssignableFrom(t.getClass())) return (T) t;

             t = t.getCause();

         }

         return null;

     }

     /**

      * Converts a given file size in bytes to a unit of bytes, kilobyte,

      * megabyte, or gigabyte

      * 

      * @param fileSize

      *            - size in bytes

      * @return String with format 'size units'

      */

     public static String getFileSizeUnits(Long fileSize) {

         Long newFileSize = fileSize;

         String fileSizeUnits = "bytes";

         if (fileSize > 1024) {

             Long kiloSize = fileSize / 1024;

             if (kiloSize < 1024) {

                 newFileSize = kiloSize;

                 fileSizeUnits = "KB";

             } else {

                 Long megaSize = kiloSize / 1024;

                 if (megaSize < 1024) {

                     newFileSize = megaSize;

                     fileSizeUnits = "MB";

                 } else {

                     Long gigaSize = megaSize / 1024;

                     newFileSize = gigaSize;

                     fileSizeUnits = "GB";

                 }

             }

         }

         return newFileSize + fileSizeUnits;

     }

 }