using System;
using System.IO;
/*
 * $Id: ZInflaterInputStream.cs 229 2011-02-18 22:05:59Z psoares33 $
 *
 * This file is part of the iText project.
 * Copyright (c) 1998-2012 1T3XT BVBA
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * you must retain the producer line in every PDF that is created or manipulated
 * using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */

namespace System.util.zlib {
    /// <summary>
    /// Summary description for DeflaterOutputStream.
    /// </summary>
    public class ZInflaterInputStream : Stream {
        protected ZStream z=new ZStream();
        protected int flushLevel=JZlib.Z_NO_FLUSH;
        private const int BUFSIZE = 4192;
        protected byte[] buf=new byte[BUFSIZE];
        private byte[] buf1=new byte[1];

        protected Stream inp=null;
        private bool nomoreinput=false;

        public ZInflaterInputStream(Stream inp) : this(inp, false) {
        }
    
        public ZInflaterInputStream(Stream inp, bool nowrap) {
            this.inp=inp;
            z.inflateInit(nowrap);
            z.next_in=buf;
            z.next_in_index=0;
            z.avail_in=0;
        }
    
        public override bool CanRead {
            get {
                // TODO:  Add DeflaterOutputStream.CanRead getter implementation
                return true;
            }
        }
    
        public override bool CanSeek {
            get {
                // TODO:  Add DeflaterOutputStream.CanSeek getter implementation
                return false;
            }
        }
    
        public override bool CanWrite {
            get {
                // TODO:  Add DeflaterOutputStream.CanWrite getter implementation
                return false;
            }
        }
    
        public override long Length {
            get {
                // TODO:  Add DeflaterOutputStream.Length getter implementation
                return 0;
            }
        }
    
        public override long Position {
            get {
                // TODO:  Add DeflaterOutputStream.Position getter implementation
                return 0;
            }
            set {
                // TODO:  Add DeflaterOutputStream.Position setter implementation
            }
        }
    
        public override void Write(byte[] b, int off, int len) {
        }
    
        public override long Seek(long offset, SeekOrigin origin) {
            // TODO:  Add DeflaterOutputStream.Seek implementation
            return 0;
        }
    
        public override void SetLength(long value) {
            // TODO:  Add DeflaterOutputStream.SetLength implementation

        }
    
        public override int Read(byte[] b, int off, int len) {
            if(len==0)
                return(0);
            int err;
            z.next_out=b;
            z.next_out_index=off;
            z.avail_out=len;
            do {
                if((z.avail_in==0)&&(!nomoreinput)) { // if buffer is empty and more input is avaiable, refill it
                    z.next_in_index=0;
                    z.avail_in=inp.Read(buf, 0, BUFSIZE);//(BUFSIZE<z.avail_out ? BUFSIZE : z.avail_out));
                    if(z.avail_in<=0) {
                        z.avail_in=0;
                        nomoreinput=true;
                    }
                }
                err=z.inflate(flushLevel);
                if(nomoreinput&&(err==JZlib.Z_BUF_ERROR))
                    return(0);
                if(err!=JZlib.Z_OK && err!=JZlib.Z_STREAM_END)
                    throw new IOException("inflating: "+z.msg);
                if((nomoreinput||err==JZlib.Z_STREAM_END)&&(z.avail_out==len))
                    return(0);
            } 
            while(z.avail_out==len&&err==JZlib.Z_OK);
            //System.err.print("("+(len-z.avail_out)+")");
            return(len-z.avail_out);
        }
    
        public override void Flush() {
            inp.Flush();
        }
    
        public override void WriteByte(byte b) {
        }

        public override void Close() {
            inp.Close();
        }
    
        public override int ReadByte() {
            if(Read(buf1, 0, 1)<=0)
                return -1;
            return(buf1[0]&0xFF);
        }
    }
}
