content: /*
  * Copyright 2010 Srikanth Reddy Lingala  
  * 
  * 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 
  * 
  * 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 net.lingala.zip4j.io;
  
  import java.io.EOFException;
  import java.io.IOException;
  import java.io.RandomAccessFile;
  import java.util.zip.DataFormatException;
  import java.util.zip.Inflater;
  
  import net.lingala.zip4j.unzip.UnzipEngine;
  import net.lingala.zip4j.util.InternalZipConstants;
  import net.lingala.zip4j.util.Zip4jConstants;
  
  public class InflaterInputStream extends PartInputStream {
  	
  	private Inflater inflater;
  	private byte[] buff;
  	private byte[] oneByteBuff = new byte[1];
  	private UnzipEngine unzipEngine;
  	private long bytesWritten;
  	private long uncompressedSize;
  	
  	public InflaterInputStream(RandomAccessFile raf, long start, long len, UnzipEngine unzipEngine) {
  		super(raf, start, len, unzipEngine);
  		this.inflater = new Inflater(true);
  		this.buff = new byte[InternalZipConstants.BUFF_SIZE];
  		this.unzipEngine = unzipEngine;
  		bytesWritten = 0;
  		uncompressedSize = unzipEngine.getFileHeader().getUncompressedSize();
  	}
  
  	public int read() throws IOException {
  		return read(oneByteBuff, 0, 1) == -1 ? -1 : oneByteBuff[0] & 0xff;
  	}
  	
  	public int read(byte[] b) throws IOException {
  		if (b == null) {
  			throw new NullPointerException("input buffer is null");
  		}
  		
  		return read(b, 0, b.length);
  	}
  	
  	public int read(byte[] b, int off, int len) throws IOException {
  		
  		if (b == null) {
  			throw new NullPointerException("input buffer is null");
  		} else if (off < 0 || len < 0 || len > b.length - off) {
  		    throw new IndexOutOfBoundsException();
  		} else if (len == 0) {
  		    return 0;
  		}
  		
  		try {
  		    int n;
  		    if (bytesWritten >= uncompressedSize) {
  		    	finishInflating();
  		    	return -1;
  		    }
  		    while ((n = inflater.inflate(b, off, len)) == 0) {
  				if (inflater.finished() || inflater.needsDictionary()) {
  					finishInflating();
  				    return -1;
  				}
  				if (inflater.needsInput()) {
  					fill();
  				}
  		    }
  		    bytesWritten += n;
  		    return n;
  		} catch (DataFormatException e) {
  		    String s = "Invalid ZLIB data format";
  		    if (e.getMessage() != null) {
  		    	s = e.getMessage();
  		    }
  		    if (unzipEngine != null) {
  		    	if (unzipEngine.getLocalFileHeader().isEncrypted() && 
  		    			unzipEngine.getLocalFileHeader().getEncryptionMethod() == Zip4jConstants.ENC_METHOD_STANDARD) {
  		    		s += " - Wrong Password?";
  		    	}
  		    }
  		    throw new IOException(s);
  		}
  	}
  	
  	private void finishInflating() throws IOException {
  		//In some cases, compelte data is not read even though inflater is complete
  		//make sure to read complete data before returning -1
  		byte[] b = new byte[1024];
  		while (super.read(b, 0, 1024) != -1) {
  			//read all data
  		}
  		checkAndReadAESMacBytes();
  	}
  	
  	private void fill() throws IOException {
  		int len = super.read(buff, 0, buff.length);
  		if (len == -1) {
  		    throw new EOFException("Unexpected end of ZLIB input stream");
  		}
  		inflater.setInput(buff, 0, len);
  	}
  	
  	/**
       * Skips specified number of bytes of uncompressed data.
       * @param n the number of bytes to skip
       * @return the actual number of bytes skipped.
       * @exception IOException if an I/O error has occurred
       * @exception IllegalArgumentException if n < 0
       */
  	public long skip(long n) throws IOException {
          if (n < 0) {
              throw new IllegalArgumentException("negative skip length");
          }
  		int max = (int)Math.min(n, Integer.MAX_VALUE);
  		int total = 0;
  		byte[] b = new byte[512];
  		while (total < max) {
  		    int len = max - total;
  		    if (len > b.length) {
  		    	len = b.length;
  		    }
  		    len = read(b, 0, len);
  		    if (len == -1) {
  	            break;
  		    }
  		    total += len;
  		}
  		return total;
      }
  	
  	
  	public void seek(long pos) throws IOException {
  		super.seek(pos);
  	}
  	
  	/**
       * Returns 0 after EOF has been reached, otherwise always return 1.
       * <p>
       * Programs should not count on this method to return the actual number
       * of bytes that could be read without blocking.
       *
       * @return     1 before EOF and 0 after EOF.
       * @exception  IOException  if an I/O error occurs.
       * 
       */
  	public int available() {
  		return inflater.finished() ? 0 : 1;
  	}
  	
  	public void close() throws IOException {
  		inflater.end();
  		super.close();
  	}
  	
  	public UnzipEngine getUnzipEngine() {
  		return super.getUnzipEngine();
  	}
  }
  