/*
 * 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.sound.sampled.spi;

import java.io.InputStream;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;

/**
 * A format conversion provider provides format conversion services
 * from one or more input formats to one or more output formats.
 * Converters include codecs, which encode and/or decode audio data,
 * as well as transcoders, etc.  Format converters provide methods for
 * determining what conversions are supported and for obtaining an audio
 * stream from which converted data can be read.
 * <p>
 * The source format represents the format of the incoming
 * audio data, which will be converted.
 * <p>
 * The target format represents the format of the processed, converted
 * audio data.  This is the format of the data that can be read from
 * the stream returned by one of the <code>getAudioInputStream</code> methods.
 *
 * @author Kara Kytle
 * @since 1.3
 */
public abstract class FormatConversionProvider {


    // NEW METHODS

    /**
     * Obtains the set of source format encodings from which format
     * conversion services are provided by this provider.
     * @return array of source format encodings. If for some reason provider
     * does not provide any conversion services, an array of length 0 is
     * returned.
     */
    public abstract AudioFormat.Encoding[] getSourceEncodings();


    /**
     * Obtains the set of target format encodings to which format
     * conversion services are provided by this provider.
     * @return array of target format encodings. If for some reason provider
     * does not provide any conversion services, an array of length 0 is
     * returned.
     */
    public abstract AudioFormat.Encoding[] getTargetEncodings();


    /**
     * Indicates whether the format converter supports conversion from the
     * specified source format encoding.
     * @param sourceEncoding the source format encoding for which support is queried
     * @return <code>true</code> if the encoding is supported, otherwise <code>false</code>
     */
    public boolean isSourceEncodingSupported(AudioFormat.Encoding sourceEncoding){

        AudioFormat.Encoding sourceEncodings[] = getSourceEncodings();

        for(int i=0; i<sourceEncodings.length; i++) {
            if( sourceEncoding.equals( sourceEncodings[i]) ) {
                return true;
            }
        }
        return false;
    }


    /**
     * Indicates whether the format converter supports conversion to the
     * specified target format encoding.
     * @param targetEncoding the target format encoding for which support is queried
     * @return <code>true</code> if the encoding is supported, otherwise <code>false</code>
     */
    public boolean isTargetEncodingSupported(AudioFormat.Encoding targetEncoding){

        AudioFormat.Encoding targetEncodings[] = getTargetEncodings();

        for(int i=0; i<targetEncodings.length; i++) {
            if( targetEncoding.equals( targetEncodings[i]) ) {
                return true;
            }
        }
        return false;
    }


    /**
     * Obtains the set of target format encodings supported by the format converter
     * given a particular source format.
     * If no target format encodings are supported for this source format,
     * an array of length 0 is returned.
     * @param sourceFormat format of the incoming data
     * @return array of supported target format encodings.
     */
    public abstract AudioFormat.Encoding[] getTargetEncodings(AudioFormat sourceFormat);


    /**
     * Indicates whether the format converter supports conversion to a particular encoding
     * from a particular format.
     * @param targetEncoding desired encoding of the outgoing data
     * @param sourceFormat format of the incoming data
     * @return <code>true</code> if the conversion is supported, otherwise <code>false</code>
     */
    public boolean isConversionSupported(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat){

        AudioFormat.Encoding targetEncodings[] = getTargetEncodings(sourceFormat);

        for(int i=0; i<targetEncodings.length; i++) {
            if( targetEncoding.equals( targetEncodings[i]) ) {
                return true;
            }
        }
        return false;
    }


    /**
     * Obtains the set of target formats with the encoding specified
     * supported by the format converter
     * If no target formats with the specified encoding are supported
     * for this source format, an array of length 0 is returned.
     * @param targetEncoding desired encoding of the stream after processing
     * @param sourceFormat format of the incoming data
     * @return array of supported target formats.
     */
    public abstract AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat);


    /**
     * Indicates whether the format converter supports conversion to one
     * particular format from another.
     * @param targetFormat desired format of outgoing data
     * @param sourceFormat format of the incoming data
     * @return <code>true</code> if the conversion is supported, otherwise <code>false</code>
     */
    public boolean isConversionSupported(AudioFormat targetFormat, AudioFormat sourceFormat){

        AudioFormat targetFormats[] = getTargetFormats( targetFormat.getEncoding(), sourceFormat );

        for(int i=0; i<targetFormats.length; i++) {
            if( targetFormat.matches( targetFormats[i] ) ) {
                return true;
            }
        }
        return false;
    }


    /**
     * Obtains an audio input stream with the specified encoding from the given audio
     * input stream.
     * @param targetEncoding desired encoding of the stream after processing
     * @param sourceStream stream from which data to be processed should be read
     * @return stream from which processed data with the specified target encoding may be read
     * @throws IllegalArgumentException if the format combination supplied is
     * not supported.
     */
    public abstract AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding, AudioInputStream sourceStream);


    /**
     * Obtains an audio input stream with the specified format from the given audio
     * input stream.
     * @param targetFormat desired data format of the stream after processing
     * @param sourceStream stream from which data to be processed should be read
     * @return stream from which processed data with the specified format may be read
     * @throws IllegalArgumentException if the format combination supplied is
     * not supported.
     */
    public abstract AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream);

}
