/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */
package com.sun.star.lib.uno.adapter;

import java.io.IOException;

import com.sun.star.io.XInputStream;

import java.io.InputStream;

/**
 * The <code>XInputStreamToInputStreamAdapter</code> wraps
 * the UNO <code>XInputStream</code> object in a Java
 * <code>InputStream</code>.  This allows users to access
 * an <code>XInputStream</code> as if it were an
 * <code>InputStream</code>.
 */
public final class XInputStreamToInputStreamAdapter extends InputStream {

    /**
     *  Internal handle to the XInputStream
     */
    private final XInputStream xin;

    /**
     *  Constructor.
     *
     *  @param  in  The <code>XInputStream</code> to be
     *              accessed as an <code>InputStream</code>.
     */
    public XInputStreamToInputStreamAdapter (XInputStream in) {
        xin = in;
    }

    @Override
    public int available() throws IOException {

        int bytesAvail;

        try {
            bytesAvail = xin.available();
        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }

        return bytesAvail;
    }

    @Override
    public void close() throws IOException {
        try {
            xin.closeInput();
        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }
    }

    @Override
    public int read () throws IOException {
        byte [][] tmp = new byte [1][1];
        try {
            long bytesRead = xin.readBytes(tmp, 1);

            if (bytesRead <= 0) {
               return (-1);
            } else {
                int tmpInt = tmp[0][0];
                if (tmpInt< 0 ){
                    tmpInt = 256 +tmpInt;
                }
                return tmpInt;
            }

        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }
    }

    @Override
    public int read (byte[] b) throws IOException {

        byte [][] tmp = new byte [1][b.length];
        int bytesRead;

        try {
            bytesRead = xin.readBytes(tmp, b.length);
            if (bytesRead <= 0) {
                return -1;
            } else if (bytesRead < b.length) {
                System.arraycopy(tmp[0], 0, b, 0, bytesRead);
            } else {
                System.arraycopy(tmp[0], 0, b, 0, b.length);
            }
        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }

        return bytesRead;
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        byte [][] tmp = new byte [1][b.length];
        try {
            long bytesRead;
            int av = xin.available();
            if ( av != 0 && len > av) {
                bytesRead = xin.readBytes(tmp, av);
            }
            else{
                bytesRead = xin.readBytes(tmp,len);
            }
            // Casting bytesRead to an int is okay, since the user can
            // only pass in an integer length to read, so the bytesRead
            // must <= len.

            if (bytesRead <= 0) {
                return -1;
            } else if (bytesRead < len) {
                System.arraycopy(tmp[0], 0, b, off, (int)bytesRead);
            } else {
                System.arraycopy(tmp[0], 0, b, off, len);
            }

            return ((int)bytesRead);
        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }
    }

    @Override
    public long skip(long n) throws IOException {

        int avail;
        long tmpLongVal = n;
        int  tmpIntVal;

        try {
            avail = xin.available();
        } catch (Exception e) {
            IOException newEx = new IOException(e.getMessage());
            newEx.initCause(e);
            throw newEx;
        }

        do {
            if (tmpLongVal >= Integer.MAX_VALUE) {
               tmpIntVal = Integer.MAX_VALUE;
            } else {
               // Casting is safe here.
               tmpIntVal = (int)tmpLongVal;
            }
            tmpLongVal -= tmpIntVal;

            try {
                xin.skipBytes(tmpIntVal);
            } catch (Exception e) {
                IOException newEx = new IOException(e.getMessage());
                newEx.initCause(e);
                throw newEx;
            }
        } while (tmpLongVal > 0);

        if ( avail != 0 && avail < n) {
            return avail;
        } else {
            return n;
        }
    }

   /**
    *  Tests if this input stream supports the mark and reset methods.
    *  The markSupported method of
    *  <code>XInputStreamToInputStreamAdapter</code> returns false.
    *
    *  @return  false
    */
    @Override
    public boolean markSupported() {
       return false;
    }

    @Override
    public synchronized void mark(int readlimit) {
        // Not supported.
    }

    @Override
    public synchronized void reset() throws IOException {
        // Not supported.
    }
}

