/*
    *  Copyright 2012 Chris Pheby
    *
    *  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.jadira.scanner.file.locator;
  
  import java.io.FilenameFilter;
  import java.net.MalformedURLException;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.jadira.scanner.core.api.Locator;
  import org.jadira.scanner.core.exception.ClasspathAccessException;
  import org.jadira.scanner.core.helper.filenamefilter.JarFilenameFilter;
  
  /**
   * Resolves a list of classpaths representing the core 'rt.jar' and any endorsed libraries
   */
  public class JdkBaseClasspathUrlLocator implements Locator<URL> {
  
  	private static final FilenameFilter JAR_FILENAME_FILTER = new JarFilenameFilter();
      
  	private boolean includeRtJar;
  
  	public JdkBaseClasspathUrlLocator() {
          this(true);
      }
  	
  	public JdkBaseClasspathUrlLocator(boolean includeRtJar) {
  	    this.includeRtJar = includeRtJar;
  	}
  	
  	@Override
  	public List<URL> locate() {
  
          List<URL> classpaths = new ArrayList<URL>();
  
          String[] endorsedDirs = System.getProperty("java.endorsed.dirs").split(System.getProperty("path.separator"));
          processClasspathDefinition(classpaths, endorsedDirs);
  
          try {
              // Can't resolve using sun.boot.class.path - vendor specific
              if (includeRtJar) {
                  URL javaClasspath = new java.io.File(System.getProperty("java.home") + System.getProperty("file.separator") + "lib" + System.getProperty("file.separator") + "rt.jar").toURI().toURL();
                  classpaths.add(javaClasspath);
              }
          } catch (MalformedURLException e) {
              throw new ClasspathAccessException("Problem constructing Java classpath: " + e.getMessage(), e);
          }
  
          String[] extensionDirs = System.getProperty("java.ext.dirs").split(System.getProperty("path.separator"));
          processClasspathDefinition(classpaths, extensionDirs);
  
  
          return classpaths;
      }
  
      private static void processClasspathDefinition(List<URL> classpaths, String[] extensionDirs) {
          for (int i = 0; i < extensionDirs.length; i++) {
              java.io.File nextDir = new java.io.File(extensionDirs[i]);
              
              String[] jars = nextDir.list(JAR_FILENAME_FILTER);
              
              if (jars != null) {
                  for (int jarIdx = 0; jarIdx < jars.length; jarIdx++) {
                      try {
                          URL nextJar = new URL(nextDir.toURI().toURL().toString() + jars[jarIdx]);
                          classpaths.add(nextJar);
                      } catch (MalformedURLException e) {
                          throw new ClasspathAccessException("Problem constructing Java extension classpath: " + e.getMessage(), e);
                      }
                  }
              }
          }
      }
  }