/*
 * FLAC library (Java)
 * Copyright (c) Project Nayuki
 * https://www.nayuki.io/page/flac-library-java
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 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 Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program (see COPYING.txt and COPYING.LESSER.txt).
 * If not, see <http://www.gnu.org/licenses/>.
 */

package com.coloryr.allmusic.server.core.decoder.flac;

import java.io.IOException;
import java.util.Objects;

/**
 * A FLAC input stream based on a fixed byte array.
 */
public final class ByteArrayFlacInput extends AbstractFlacLowLevelInput {

    /*---- Fields ----*/

    // The underlying byte array to read from.
    private byte[] data;
    private int offset;

    /*---- Constructors ----*/

    public ByteArrayFlacInput(byte[] b) {
        super();
        data = Objects.requireNonNull(b);
        offset = 0;
    }

    /*---- Methods ----*/

    public long getLength() {
        return data.length;
    }

    public void seekTo(long pos) {
        offset = (int) pos;
        positionChanged(pos);
    }

    protected int readUnderlying(byte[] buf, int off, int len) {
        if (off < 0 || off > buf.length || len < 0 || len > buf.length - off)
            throw new ArrayIndexOutOfBoundsException();
        int n = Math.min(data.length - offset, len);
        if (n == 0) return -1;
        System.arraycopy(data, offset, buf, off, n);
        offset += n;
        return n;
    }

    // Discards data buffers and invalidates this stream. Because this class and its superclass
    // only use memory and have no native resources, it's okay to simply let a ByteArrayFlacInput
    // be garbage-collected without calling close().
    public void close() throws IOException {
        if (data != null) {
            data = null;
            super.close();
        }
    }

}