/*
 * Adapted from The MIT License (MIT)
 *
 * Copyright (c) 2018-2022 DaPorkchop_
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software
 * is furnished to do so, subject to the following conditions:
 *
 * Any persons and/or organizations using this software must include the above copyright notice and this permission notice,
 * provide sufficient credit to the original authors of the project (IE: DaPorkchop_), as well as provide a link to the original project.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

package net.daporkchop.lib.binary.stream.stream;

import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NonNull;
import lombok.experimental.Accessors;
import net.daporkchop.lib.binary.stream.AbstractHeapDataIn;
import net.daporkchop.lib.binary.stream.DataIn;
import net.daporkchop.lib.common.annotation.param.Positive;

import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.ClosedChannelException;

/**
 * Wraps an {@link InputStream} as a {@link DataIn}.
 *
 * @author DaPorkchop_
 */
@AllArgsConstructor
@Getter
@Accessors(fluent = true)
public class StreamIn extends AbstractHeapDataIn {
    static {
        //InputStream#read() returns -1 on EOF, while AbstractDataIn#read0() returns RESULT_EOF. there is no practical reason for me to change this, but let's
        //  double-check to be safe.
        //noinspection ConstantConditions
        if (-1 != RESULT_EOF) {
            throw new AssertionError("RESULT_EOF must be -1!");
        }
    }

    @NonNull
    protected final InputStream delegate;

    @Override
    protected int read0() throws IOException {
        return this.delegate.read();
    }

    @Override
    protected int read0(@NonNull byte[] dst, int start, @Positive int length) throws IOException {
        int totalRead = this.delegate.read(dst, start, length);
        if (totalRead < 0)  {
            return RESULT_EOF;
        }
        while (totalRead < length) {
            int read = this.delegate.read(dst, start + totalRead, length - totalRead);
            if (read < 0)   {
                break;
            }
            totalRead += read;
        }
        return totalRead;
    }

    @Override
    protected long skip0(@Positive long count) throws IOException {
        return this.delegate.skip(count);
    }

    @Override
    protected long remaining0() throws IOException {
        return this.delegate.available();
    }

    @Override
    protected void close0() throws IOException {
        this.delegate.close();
    }

    @Override
    public InputStream asInputStream() throws ClosedChannelException, IOException {
        this.ensureOpen();
        return this.delegate;
    }

    /**
     * An extension of {@link StreamIn} which doesn't forward the {@link DataIn#close()} method to the delegate {@link InputStream}.
     *
     * @author DaPorkchop_
     */
    public static final class NonClosing extends StreamIn {
        public NonClosing(InputStream in) {
            super(in);
        }

        @Override
        protected void close0() throws IOException {
            //no-op
        }
    }
}
