/*
    * 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.compressors.zstandard;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.apache.commons.compress.compressors.CompressorInputStream;
  import org.apache.commons.compress.utils.InputStreamStatistics;
  import org.apache.commons.io.input.BoundedInputStream;
  
  import com.github.luben.zstd.BufferPool;
  import com.github.luben.zstd.ZstdInputStream;
  
  /**
   * {@link CompressorInputStream} implementation to decode Zstandard encoded stream. Library relies on <a href="https://github.com/luben/zstd-jni/">Zstandard
   * JNI</a>
   *
   * @since 1.16
   */
  public class ZstdCompressorInputStream extends CompressorInputStream implements InputStreamStatistics {
  
      private final BoundedInputStream countingStream;
      private final ZstdInputStream decIS;
  
      public ZstdCompressorInputStream(final InputStream in) throws IOException {
          this.decIS = new ZstdInputStream(countingStream = BoundedInputStream.builder().setInputStream(in).get());
      }
  
      /**
       * Creates a new input stream that decompresses zstd-compressed data from the specific input stream
       *
       * @param in         the input stream of compressed data
       * @param bufferPool a configuration of zstd-jni that allows users to customize how buffers are recycled. Either a {@link com.github.luben.zstd.NoPool} or a
       *                   {@link com.github.luben.zstd.RecyclingBufferPool} is allowed here.
       * @throws IOException if an IO error occurs.
       */
      public ZstdCompressorInputStream(final InputStream in, final BufferPool bufferPool) throws IOException {
          this.decIS = new ZstdInputStream(countingStream = BoundedInputStream.builder().setInputStream(in).get(), bufferPool);
      }
  
      @Override
      public int available() throws IOException {
          return decIS.available();
      }
  
      @Override
      public void close() throws IOException {
          decIS.close();
      }
  
      /**
       * @since 1.17
       */
      @Override
      public long getCompressedCount() {
          return countingStream.getCount();
      }
  
      @Override
      public synchronized void mark(final int readLimit) {
          decIS.mark(readLimit);
      }
  
      @Override
      public boolean markSupported() {
          return decIS.markSupported();
      }
  
      @Override
      public int read() throws IOException {
          final int ret = decIS.read();
          count(ret == -1 ? 0 : 1);
          return ret;
      }
  
      @Override
      public int read(final byte[] b) throws IOException {
          return read(b, 0, b.length);
      }
  
      @Override
      public int read(final byte[] buf, final int off, final int len) throws IOException {
          if (len == 0) {
             return 0;
         }
         final int ret = decIS.read(buf, off, len);
         count(ret);
         return ret;
     }
 
     @Override
     public synchronized void reset() throws IOException {
         decIS.reset();
     }
 
     @Override
     public long skip(final long n) throws IOException {
         return org.apache.commons.io.IOUtils.skip(decIS, n);
     }
 
     @Override
     public String toString() {
         return decIS.toString();
     }
 }