/*
    *  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.commons.compress.archivers.sevenz;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  import org.apache.commons.compress.MemoryLimitException;
  import org.apache.commons.compress.utils.ByteUtils;
  import org.apache.commons.compress.utils.FlushShieldFilterOutputStream;
  import org.tukaani.xz.LZMA2Options;
  import org.tukaani.xz.LZMAInputStream;
  import org.tukaani.xz.LZMAOutputStream;
  
  final class LZMADecoder extends AbstractCoder {
  
      LZMADecoder() {
          super(LZMA2Options.class, Number.class);
      }
  
      @Override
      InputStream decode(final String archiveName, final InputStream in, final long uncompressedLength, final Coder coder, final byte[] password,
              final int maxMemoryLimitInKb) throws IOException {
          if (coder.properties == null) {
              throw new IOException("Missing LZMA properties");
          }
          if (coder.properties.length < 1) {
              throw new IOException("LZMA properties too short");
          }
          final byte propsByte = coder.properties[0];
          final int dictSize = getDictionarySize(coder);
          if (dictSize > LZMAInputStream.DICT_SIZE_MAX) {
              throw new IOException("Dictionary larger than 4GiB maximum size used in " + archiveName);
          }
          final int memoryUsageInKb = LZMAInputStream.getMemoryUsage(dictSize, propsByte);
          if (memoryUsageInKb > maxMemoryLimitInKb) {
              throw new MemoryLimitException(memoryUsageInKb, maxMemoryLimitInKb);
          }
          final LZMAInputStream lzmaIn = new LZMAInputStream(in, uncompressedLength, propsByte, dictSize);
          lzmaIn.enableRelaxedEndCondition();
          return lzmaIn;
      }
  
      @Override
      OutputStream encode(final OutputStream out, final Object opts) throws IOException {
          // NOOP as LZMAOutputStream throws an exception in flush
          return new FlushShieldFilterOutputStream(new LZMAOutputStream(out, getOptions(opts), false));
      }
  
      private int getDictionarySize(final Coder coder) throws IllegalArgumentException {
          return (int) ByteUtils.fromLittleEndian(coder.properties, 1, 4);
      }
  
      private LZMA2Options getOptions(final Object opts) throws IOException {
          if (opts instanceof LZMA2Options) {
              return (LZMA2Options) opts;
          }
          final LZMA2Options options = new LZMA2Options();
          options.setDictSize(numberOptionOrDefault(opts));
          return options;
      }
  
      @Override
      byte[] getOptionsAsProperties(final Object opts) throws IOException {
          final LZMA2Options options = getOptions(opts);
          final byte props = (byte) ((options.getPb() * 5 + options.getLp()) * 9 + options.getLc());
          final int dictSize = options.getDictSize();
          final byte[] o = new byte[5];
          o[0] = props;
          ByteUtils.toLittleEndian(o, dictSize, 1, 4);
          return o;
      }
  
      @Override
      Object getOptionsFromCoder(final Coder coder, final InputStream in) throws IOException {
          if (coder.properties == null) {
              throw new IOException("Missing LZMA properties");
          }
          if (coder.properties.length < 1) {
              throw new IOException("LZMA properties too short");
          }
          final byte propsByte = coder.properties[0];
          int props = propsByte & 0xFF;
          final int pb = props / (9 * 5);
         props -= pb * 9 * 5;
         final int lp = props / 9;
         final int lc = props - lp * 9;
         final LZMA2Options opts = new LZMA2Options();
         opts.setPb(pb);
         opts.setLcLp(lc, lp);
         opts.setDictSize(getDictionarySize(coder));
         return opts;
     }
 
     private int numberOptionOrDefault(final Object opts) {
         return toInt(opts, LZMA2Options.DICT_SIZE_DEFAULT);
     }
 }