/*
    * 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
    *
   *   https://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.commons.compress.harmony.pack200;
  
  import java.io.BufferedOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.jar.JarEntry;
  import java.util.jar.JarFile;
  import java.util.jar.JarInputStream;
  import java.util.zip.GZIPOutputStream;
  import java.util.zip.ZipEntry;
  
  /**
   * Main entry point to pack200 and represents a packed archive. An archive is constructed with either a {@link JarInputStream} and an output stream or a
   * {@link JarFile} as input and an OutputStream. Options can be set, then {@link #pack()} is called, to pack the Jar file into a pack200 archive.
   */
  public class Archive {
  
      static final class PackingFile {
  
          private final String name;
          private byte[] contents;
          private final long modtime;
          private final boolean deflateHint;
          private final boolean isDirectory;
  
          PackingFile(final byte[] bytes, final JarEntry jarEntry) {
              name = jarEntry.getName();
              contents = bytes;
              modtime = jarEntry.getTime();
              deflateHint = jarEntry.getMethod() == ZipEntry.DEFLATED;
              isDirectory = jarEntry.isDirectory();
          }
  
          PackingFile(final String name, final byte[] contents, final long modtime) {
              this.name = name;
              this.contents = contents;
              this.modtime = modtime;
              deflateHint = false;
              isDirectory = false;
          }
  
          public byte[] getContents() {
              return contents;
          }
  
          public long getModtime() {
              return modtime;
          }
  
          public String getName() {
              return name;
          }
  
          public boolean isDefalteHint() {
              return deflateHint;
          }
  
          public boolean isDirectory() {
              return isDirectory;
          }
  
          public void setContents(final byte[] contents) {
              this.contents = contents;
          }
  
          @Override
          public String toString() {
              return name;
          }
      }
  
      static final class SegmentUnit {
  
          private final List<Pack200ClassReader> classList;
  
          private final List<PackingFile> fileList;
  
          private int byteAmount;
  
         private int packedByteAmount;
 
         SegmentUnit(final List<Pack200ClassReader> classes, final List<PackingFile> files) {
             classList = classes;
             fileList = files;
             byteAmount = 0;
             // Calculate the amount of bytes in classes and files before packing
             byteAmount += classList.stream().mapToInt(element -> element.b.length).sum();
             byteAmount += fileList.stream().mapToInt(element -> element.contents.length).sum();
         }
 
         public void addPackedByteAmount(final int amount) {
             packedByteAmount += amount;
         }
 
         public int classListSize() {
             return classList.size();
         }
 
         public int fileListSize() {
             return fileList.size();
         }
 
         public int getByteAmount() {
             return byteAmount;
         }
 
         public List<Pack200ClassReader> getClassList() {
             return classList;
         }
 
         public List<PackingFile> getFileList() {
             return fileList;
         }
 
         public int getPackedByteAmount() {
             return packedByteAmount;
         }
     }
 
     private static final byte[] EMPTY_BYTE_ARRAY = {};
 
     private final JarInputStream jarInputStream;
     private final OutputStream outputStream;
     private JarFile jarFile;
 
     private long currentSegmentSize;
 
     private final PackingOptions options;
 
     /**
      * Creates an Archive with the given input file and a stream for the output.
      *
      * @param jarFile      the input file.
      * @param outputStream target output stream for the compressed data.
      * @param options      packing options (if null then defaults are used).
      * @throws IOException If an I/O error occurs.
      */
     public Archive(final JarFile jarFile, OutputStream outputStream, PackingOptions options) throws IOException {
         if (options == null) { // use all defaults
             options = new PackingOptions();
         }
         this.options = options;
         if (options.isGzip()) {
             outputStream = new GZIPOutputStream(outputStream);
         }
         this.outputStream = new BufferedOutputStream(outputStream);
         this.jarFile = jarFile;
         this.jarInputStream = null;
         PackingUtils.config(options);
     }
 
     /**
      * Creates an Archive with streams for the input and output.
      *
      * @param inputStream  input stream of uncompressed JAR data.
      * @param outputStream target output stream for the compressed data.
      * @param options      packing options (if null then defaults are used).
      * @throws IOException If an I/O error occurs.
      */
     public Archive(final JarInputStream inputStream, OutputStream outputStream, PackingOptions options) throws IOException {
         jarInputStream = inputStream;
         if (options == null) {
             // use all defaults
             options = new PackingOptions();
         }
         this.options = options;
         if (options.isGzip()) {
             outputStream = new GZIPOutputStream(outputStream);
         }
         this.outputStream = new BufferedOutputStream(outputStream);
         PackingUtils.config(options);
     }
 
     private boolean addJarEntry(final PackingFile packingFile, final List<Pack200ClassReader> javaClasses, final List<PackingFile> files) {
         final long segmentLimit = options.getSegmentLimit();
         if (segmentLimit != -1 && segmentLimit != 0) {
             // -1 is a special case where only one segment is created and
             // 0 is a special case where one segment is created for each file
             // except for files in "META-INF"
             final long packedSize = estimateSize(packingFile);
             if (packedSize + currentSegmentSize > segmentLimit && currentSegmentSize > 0) {
                 // don't add this JarEntry to the current segment
                 return false;
             }
             // do add this JarEntry
             currentSegmentSize += packedSize;
         }
 
         final String name = packingFile.getName();
         if (name.endsWith(".class") && !options.isPassFile(name)) {
             final Pack200ClassReader classParser = new Pack200ClassReader(packingFile.contents);
             classParser.setFileName(name);
             javaClasses.add(classParser);
             packingFile.contents = EMPTY_BYTE_ARRAY;
         }
         files.add(packingFile);
         return true;
     }
 
     private void doNormalPack() throws IOException, Pack200Exception {
         PackingUtils.log("Start to perform a normal packing");
         final List<PackingFile> packingFileList;
         if (jarInputStream != null) {
             packingFileList = PackingUtils.getPackingFileListFromJar(jarInputStream, options.isKeepFileOrder());
         } else {
             packingFileList = PackingUtils.getPackingFileListFromJar(jarFile, options.isKeepFileOrder());
         }
 
         final List<SegmentUnit> segmentUnitList = splitIntoSegments(packingFileList);
         int previousByteAmount = 0;
         int packedByteAmount = 0;
 
         final int segmentSize = segmentUnitList.size();
         SegmentUnit segmentUnit;
         for (int index = 0; index < segmentSize; index++) {
             segmentUnit = segmentUnitList.get(index);
             new Segment().pack(segmentUnit, outputStream, options);
             previousByteAmount += segmentUnit.getByteAmount();
             packedByteAmount += segmentUnit.getPackedByteAmount();
         }
 
         PackingUtils.log("Total: Packed " + previousByteAmount + " input bytes of " + packingFileList.size() + " files into " + packedByteAmount + " bytes in "
                 + segmentSize + " segments");
 
         outputStream.close();
     }
 
     private void doZeroEffortPack() throws IOException {
         PackingUtils.log("Start to perform a zero-effort packing");
         if (jarInputStream != null) {
             PackingUtils.copyThroughJar(jarInputStream, outputStream);
         } else {
             PackingUtils.copyThroughJar(jarFile, outputStream);
         }
     }
 
     private long estimateSize(final PackingFile packingFile) {
         // The heuristic used here is for compatibility with the RI and should
         // not be changed
         final String name = packingFile.getName();
         if (name.startsWith("META-INF") || name.startsWith("/META-INF")) {
             return 0;
         }
         long fileSize = packingFile.contents.length;
         if (fileSize < 0) {
             fileSize = 0;
         }
         return name.length() + fileSize + 5;
     }
 
     /**
      * Packs the archive.
      *
      * @throws Pack200Exception If a Pack200 semantic error occurs.
      * @throws IOException      If an I/O error occurs.
      */
     public void pack() throws Pack200Exception, IOException {
         if (0 == options.getEffort()) {
             doZeroEffortPack();
         } else {
             doNormalPack();
         }
     }
 
     private List<SegmentUnit> splitIntoSegments(final List<PackingFile> packingFileList) {
         final List<SegmentUnit> segmentUnitList = new ArrayList<>();
         List<Pack200ClassReader> classes = new ArrayList<>();
         List<PackingFile> files = new ArrayList<>();
         final long segmentLimit = options.getSegmentLimit();
 
         final int size = packingFileList.size();
         PackingFile packingFile;
         for (int index = 0; index < size; index++) {
             packingFile = packingFileList.get(index);
             if (!addJarEntry(packingFile, classes, files)) {
                 // not added because segment has reached maximum size
                 segmentUnitList.add(new SegmentUnit(classes, files));
                 classes = new ArrayList<>();
                 files = new ArrayList<>();
                 currentSegmentSize = 0;
                 // add the jar to a new segment
                 addJarEntry(packingFile, classes, files);
                 // ignore the size of first entry for compatibility with RI
                 currentSegmentSize = 0;
             } else if (segmentLimit == 0 && estimateSize(packingFile) > 0) {
                 // create a new segment for each class unless size is 0
                 segmentUnitList.add(new SegmentUnit(classes, files));
                 classes = new ArrayList<>();
                 files = new ArrayList<>();
             }
         }
         // Change for Apache Commons Compress based on Apache Harmony.
         // if (classes.size() > 0 && files.size() > 0) {
         if (classes.size() > 0 || files.size() > 0) {
             segmentUnitList.add(new SegmentUnit(classes, files));
         }
         return segmentUnitList;
     }
 
 }