/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.media.sound;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import javax.sound.sampled.AudioFileFormat;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.UnsupportedAudioFileException;


/**
 * AU file reader.
 *
 * @author Kara Kytle
 * @author Jan Borgersen
 * @author Florian Bomers
 */
public final class AuFileReader extends SunFileReader {

    // METHODS TO IMPLEMENT AudioFileReader

    /**
     * Obtains the audio file format of the input stream provided.  The stream must
     * point to valid audio file data.  In general, audio file providers may
     * need to read some data from the stream before determining whether they
     * support it.  These parsers must
     * be able to mark the stream, read enough data to determine whether they
     * support the stream, and, if not, reset the stream's read pointer to its original
     * position.  If the input stream does not support this, this method may fail
     * with an IOException.
     * @param stream the input stream from which file format information should be
     * extracted
     * @return an <code>AudioFileFormat</code> object describing the audio file format
     * @throws UnsupportedAudioFileException if the stream does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     * @see InputStream#markSupported
     * @see InputStream#mark
     */
    public AudioFileFormat getAudioFileFormat(InputStream stream) throws UnsupportedAudioFileException, IOException {

        AudioFormat format = null;
        AuFileFormat fileFormat = null;
        int maxReadLength = 28;
        boolean bigendian  = false;
        int magic          = -1;
        int headerSize     = -1;
        int dataSize       = -1;
        int encoding_local = -1;
        int sampleRate     = -1;
        int frameRate      = -1;
        int frameSize      = -1;
        int channels       = -1;
        final int sampleSizeInBits;
        int length = 0;
        int nread = 0;
        AudioFormat.Encoding encoding = null;

        DataInputStream dis = new DataInputStream( stream );

        dis.mark(maxReadLength);

        magic = dis.readInt();

        if (! (magic == AuFileFormat.AU_SUN_MAGIC) || (magic == AuFileFormat.AU_DEC_MAGIC) ||
            (magic == AuFileFormat.AU_SUN_INV_MAGIC) || (magic == AuFileFormat.AU_DEC_INV_MAGIC) ) {

            // not AU, reset the stream, place into exception, throw exception
            dis.reset();
            throw new UnsupportedAudioFileException("not an AU file");
        }

        if ((magic == AuFileFormat.AU_SUN_MAGIC) || (magic == AuFileFormat.AU_DEC_MAGIC)) {
            bigendian = true;        // otherwise little-endian
        }

        headerSize     = (bigendian==true ? dis.readInt() : rllong(dis) );  nread += 4;
        dataSize       = (bigendian==true ? dis.readInt() : rllong(dis) );  nread += 4;
        encoding_local = (bigendian==true ? dis.readInt() : rllong(dis) );  nread += 4;
        sampleRate     = (bigendian==true ? dis.readInt() : rllong(dis) );  nread += 4;
        channels       = (bigendian==true ? dis.readInt() : rllong(dis) );  nread += 4;
        if (channels <= 0) {
            dis.reset();
            throw new UnsupportedAudioFileException("Invalid number of channels");
        }

        frameRate = sampleRate;

        switch (encoding_local) {
        case AuFileFormat.AU_ULAW_8:
            encoding = AudioFormat.Encoding.ULAW;
            sampleSizeInBits = 8;
            break;
        case AuFileFormat.AU_ALAW_8:
            encoding = AudioFormat.Encoding.ALAW;
            sampleSizeInBits = 8;
            break;
        case AuFileFormat.AU_LINEAR_8:
            // $$jb: 04.29.99: 8bit linear is *signed*, not *unsigned*
            encoding = AudioFormat.Encoding.PCM_SIGNED;
            sampleSizeInBits = 8;
            break;
        case AuFileFormat.AU_LINEAR_16:
            encoding = AudioFormat.Encoding.PCM_SIGNED;
            sampleSizeInBits = 16;
            break;
        case AuFileFormat.AU_LINEAR_24:
            encoding = AudioFormat.Encoding.PCM_SIGNED;

            sampleSizeInBits = 24;
            break;
        case AuFileFormat.AU_LINEAR_32:
            encoding = AudioFormat.Encoding.PCM_SIGNED;

            sampleSizeInBits = 32;
            break;
            // $jb: 03.19.99: we don't support these ...
            /*          case AuFileFormat.AU_FLOAT:
                        encoding = new AudioFormat.FLOAT;
                        sampleSizeInBits = 32;
                        break;
                        case AuFileFormat.AU_DOUBLE:
                        encoding = new AudioFormat.DOUBLE;
                        sampleSizeInBits = 8;
                        break;
                        case AuFileFormat.AU_ADPCM_G721:
                        encoding = new AudioFormat.G721_ADPCM;
                        sampleSizeInBits = 16;
                        break;
                        case AuFileFormat.AU_ADPCM_G723_3:
                        encoding = new AudioFormat.G723_3;
                        sampleSize = 24;
                        SamplePerUnit = 8;
                        break;
                        case AuFileFormat.AU_ADPCM_G723_5:
                        encoding = new AudioFormat.G723_5;
                        sampleSize = 40;
                        SamplePerUnit = 8;
                        break;
            */
        default:
                // unsupported filetype, throw exception
                dis.reset();
                throw new UnsupportedAudioFileException("not a valid AU file");
        }

        frameSize = calculatePCMFrameSize(sampleSizeInBits, channels);
        //$$fb 2002-11-02: fix for 4629669: AU file reader: problems with empty files
        if( dataSize < 0 ) {
            length = AudioSystem.NOT_SPECIFIED;
        } else {
            //$$fb 2003-10-20: fix for 4940459: AudioInputStream.getFrameLength() returns 0 instead of NOT_SPECIFIED
            length = dataSize / frameSize;
        }

        format = new AudioFormat( encoding, (float)sampleRate, sampleSizeInBits,
                                  channels, frameSize, (float)frameRate, bigendian);

        fileFormat = new AuFileFormat( AudioFileFormat.Type.AU, dataSize+headerSize,
                                       format, length);

        dis.reset(); // Throws IOException
        return fileFormat;

    }


    /**
     * Obtains the audio file format of the URL provided.  The URL must
     * point to valid audio file data.
     * @param url the URL from which file format information should be
     * extracted
     * @return an <code>AudioFileFormat</code> object describing the audio file format
     * @throws UnsupportedAudioFileException if the URL does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public AudioFileFormat getAudioFileFormat(URL url) throws UnsupportedAudioFileException, IOException {

        InputStream                             urlStream = null;
        BufferedInputStream             bis = null;
        AudioFileFormat                 fileFormat = null;
        AudioFormat                             format = null;

        urlStream = url.openStream();   // throws IOException

        try {
            bis = new BufferedInputStream( urlStream, bisBufferSize );

            fileFormat = getAudioFileFormat( bis );             // throws UnsupportedAudioFileException
        } finally {
            urlStream.close();
        }

        return fileFormat;
    }


    /**
     * Obtains the audio file format of the File provided.  The File must
     * point to valid audio file data.
     * @param file the File from which file format information should be
     * extracted
     * @return an <code>AudioFileFormat</code> object describing the audio file format
     * @throws UnsupportedAudioFileException if the File does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public AudioFileFormat getAudioFileFormat(File file) throws UnsupportedAudioFileException, IOException {

        FileInputStream                 fis = null;
        BufferedInputStream             bis = null;
        AudioFileFormat                 fileFormat = null;
        AudioFormat                             format = null;

        fis = new FileInputStream( file );      // throws IOException
        // part of fix for 4325421
        try {
            bis = new BufferedInputStream( fis, bisBufferSize );
            fileFormat = getAudioFileFormat( bis );             // throws UnsupportedAudioFileException
        } finally {
            fis.close();
        }

        return fileFormat;
    }


    /**
     * Obtains an audio stream from the input stream provided.  The stream must
     * point to valid audio file data.  In general, audio file providers may
     * need to read some data from the stream before determining whether they
     * support it.  These parsers must
     * be able to mark the stream, read enough data to determine whether they
     * support the stream, and, if not, reset the stream's read pointer to its original
     * position.  If the input stream does not support this, this method may fail
     * with an IOException.
     * @param stream the input stream from which the <code>AudioInputStream</code> should be
     * constructed
     * @return an <code>AudioInputStream</code> object based on the audio file data contained
     * in the input stream.
     * @throws UnsupportedAudioFileException if the stream does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     * @see InputStream#markSupported
     * @see InputStream#mark
     */
    public AudioInputStream getAudioInputStream(InputStream stream) throws UnsupportedAudioFileException, IOException {

        DataInputStream dis = null;
        int headerSize;
        AudioFileFormat fileFormat = null;
        AudioFormat format = null;


        fileFormat = getAudioFileFormat( stream ); // throws UnsupportedAudioFileException, IOException

        // if we passed this call, we have an AU file.

        format = fileFormat.getFormat();

        dis = new DataInputStream(stream);

        // now seek past the header

        dis.readInt(); // magic
        headerSize     = (format.isBigEndian()==true ? dis.readInt() : rllong(dis) );
        dis.skipBytes( headerSize - 8 );


        // we've got everything, and the stream should be at the
        // beginning of the data chunk, so return an AudioInputStream.

        return new AudioInputStream(dis, format, fileFormat.getFrameLength());
    }


    /**
     * Obtains an audio stream from the URL provided.  The URL must
     * point to valid audio file data.
     * @param url the URL for which the <code>AudioInputStream</code> should be
     * constructed
     * @return an <code>AudioInputStream</code> object based on the audio file data pointed
     * to by the URL
     * @throws UnsupportedAudioFileException if the URL does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public AudioInputStream getAudioInputStream(URL url) throws UnsupportedAudioFileException, IOException {

        InputStream                             urlStream = null;
        BufferedInputStream             bis = null;
        AudioFileFormat                 fileFormat = null;

        urlStream = url.openStream();   // throws IOException
        AudioInputStream result = null;
        try {
            bis = new BufferedInputStream( urlStream, bisBufferSize );
            result = getAudioInputStream( (InputStream)bis );
        } finally {
            if (result == null) {
                urlStream.close();
            }
        }
        return result;
    }


    /**
     * Obtains an audio stream from the File provided.  The File must
     * point to valid audio file data.
     * @param file the File for which the <code>AudioInputStream</code> should be
     * constructed
     * @return an <code>AudioInputStream</code> object based on the audio file data pointed
     * to by the File
     * @throws UnsupportedAudioFileException if the File does not point to valid audio
     * file data recognized by the system
     * @throws IOException if an I/O exception occurs
     */
    public AudioInputStream getAudioInputStream(File file) throws UnsupportedAudioFileException, IOException {

        FileInputStream                 fis = null;
        BufferedInputStream             bis = null;
        AudioFileFormat                 fileFormat = null;

        fis = new FileInputStream( file );      // throws IOException
        AudioInputStream result = null;
        // part of fix for 4325421
        try {
            bis = new BufferedInputStream( fis, bisBufferSize );
            result = getAudioInputStream( (InputStream)bis );
        } finally {
            if (result == null) {
                fis.close();
            }
        }

        return result;
    }
}