/*
 * Copyright 2016 higherfrequencytrading.com
 *
 * Licensed 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.openhft.chronicle.bytes;

import org.jetbrains.annotations.NotNull;

import java.io.IOException;
import java.io.InputStream;

/*
 * Created by Peter Lawrey on 17/08/15.
 */
public class StreamingInputStream extends InputStream {

    private StreamingDataInput in;

    public StreamingInputStream() {
        this(NoBytesStore.NO_BYTES);
    }

    public StreamingInputStream(StreamingDataInput in) {
        this.in = in;
    }

    @NotNull
    public StreamingInputStream init(StreamingDataInput in) {
        this.in = in;
        return this;
    }

    @Override
    public long skip(long n) throws IOException {
        long len = Math.min(in.readRemaining(), n);
        in.readSkip(len);
        return len;
    }

    @Override
    public int available() throws IOException {
        return (int) Math.min(Integer.MAX_VALUE, in.readRemaining());
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (len == 0) {
            return 0;
        }
        int len2 = in.read(b, off, len);
        return len2 == 0 ? -1 : len2;
    }

    @Override
    public int read() throws IOException {
        return in.readRemaining() > 0 ? in.readUnsignedByte() : -1;
    }
}
