/*
    * 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.maven.surefire.booter;
  
  import javax.annotation.Nonnull;
  
  import java.io.File;
  import java.net.MalformedURLException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedHashSet;
  import java.util.List;
  
  import static java.io.File.pathSeparatorChar;
  
  /**
   * An ordered list of classpath elements with set behaviour
   *
   * A Classpath is immutable and thread safe.
   *
   * Immutable and thread safe.
   *
   * @author Kristian Rosenvold
   */
  public final class Classpath implements Iterable<String>, Cloneable {
      private final List<String> unmodifiableElements;
  
      public static Classpath join(Classpath firstClasspath, Classpath secondClasspath) {
          LinkedHashSet<String> accumulated = new LinkedHashSet<>();
          if (firstClasspath != null) {
              firstClasspath.addTo(accumulated);
          }
          if (secondClasspath != null) {
              secondClasspath.addTo(accumulated);
          }
          return new Classpath(accumulated);
      }
  
      private void addTo(@Nonnull Collection<String> c) {
          c.addAll(unmodifiableElements);
      }
  
      private Classpath() {
          unmodifiableElements = Collections.emptyList();
      }
  
      public Classpath(@Nonnull Classpath other, @Nonnull String additionalElement) {
          ArrayList<String> elems = new ArrayList<>(other.unmodifiableElements);
          elems.add(additionalElement);
          unmodifiableElements = Collections.unmodifiableList(elems);
      }
  
      public Classpath(@Nonnull Collection<String> elements) {
          List<String> newCp = new ArrayList<>(elements.size());
          for (String element : elements) {
              element = element.trim();
              if (!element.isEmpty()) {
                  newCp.add(element);
              }
          }
          unmodifiableElements = Collections.unmodifiableList(newCp);
      }
  
      public static Classpath emptyClasspath() {
          return new Classpath();
      }
  
      public Classpath addClassPathElementUrl(String path) {
          if (path == null) {
              throw new IllegalArgumentException("Null is not a valid class path element url.");
          }
          return unmodifiableElements.contains(path) ? this : new Classpath(this, path);
      }
  
      @Nonnull
      public List<String> getClassPath() {
          return unmodifiableElements;
      }
  
      public void writeToSystemProperty(@Nonnull String propertyName) {
          System.setProperty(propertyName, String.join(String.valueOf(pathSeparatorChar), unmodifiableElements));
     }
 
     @Override
     public boolean equals(Object o) {
         if (this == o) {
             return true;
         }
         if (o == null || getClass() != o.getClass()) {
             return false;
         }
 
         Classpath classpath = (Classpath) o;
 
         return unmodifiableElements.equals(classpath.unmodifiableElements);
     }
 
     public ClassLoader createClassLoader(boolean childDelegation, boolean enableAssertions, @Nonnull String roleName)
             throws SurefireExecutionException {
         try {
             ClassLoader parent = SystemUtils.platformClassLoader();
             IsolatedClassLoader classLoader = new IsolatedClassLoader(parent, childDelegation, roleName);
             for (String classPathElement : unmodifiableElements) {
                 classLoader.addURL(new File(classPathElement).toURI().toURL());
             }
             if (parent != null) {
                 parent.setDefaultAssertionStatus(enableAssertions);
             }
             classLoader.setDefaultAssertionStatus(enableAssertions);
             return classLoader;
         } catch (MalformedURLException e) {
             throw new SurefireExecutionException("When creating classloader", e);
         }
     }
 
     @Override
     public int hashCode() {
         return unmodifiableElements.hashCode();
     }
 
     public String getLogMessage(@Nonnull String descriptor) {
         StringBuilder result = new StringBuilder(descriptor);
         for (String element : unmodifiableElements) {
             result.append("  ").append(element);
         }
         return result.toString();
     }
 
     public String getCompactLogMessage(@Nonnull String descriptor) {
         StringBuilder result = new StringBuilder(descriptor);
         for (String element : unmodifiableElements) {
             result.append("  ");
             int pos = element.lastIndexOf(File.separatorChar);
             result.append(pos == -1 ? element : element.substring(pos + 1));
         }
         return result.toString();
     }
 
     @Override
     public Iterator<String> iterator() {
         return unmodifiableElements.iterator();
     }
 
     @Override
     public Classpath clone() {
         return new Classpath(unmodifiableElements);
     }
 }