/*

 * Copyright (c) 2016, 2018, 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.

 *

 * 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.

 */

import java.io.*;

import java.nio.ByteBuffer;

import java.util.List;

/**

 * InputStream reads frames off stream q and supplies read demand from any

 * DataFrames it finds. Window updates are sent back on the connections send

 * q.

 */

class BodyInputStream extends InputStream {

    final Queue<Http2Frame> q;

    final int streamid;

    boolean closed;

    boolean eof;

    final Http2TestServerConnection conn;

    @SuppressWarnings({"rawtypes","unchecked"})

    BodyInputStream(Queue q, int streamid, Http2TestServerConnection conn) {

        this.q = q;

        this.streamid = streamid;

        this.conn = conn;

    }

    DataFrame df;

    ByteBuffer[] buffers;

    ByteBuffer buffer;

    int nextIndex = -1;

    private DataFrame getData() throws IOException {

        if (eof) {

            return null;

        }

        Http2Frame frame;

        do {

            frame = q.take();

            // ignoring others for now Wupdates handled elsewhere

            if (frame.type() != DataFrame.TYPE) {

                System.out.println("Ignoring " + frame.toString() + " CHECK THIS");

            }

        } while (frame.type() != DataFrame.TYPE);

        df = (DataFrame) frame;

        int len = df.payloadLength();

        eof = frame.getFlag(DataFrame.END_STREAM);

        // acknowledge

        conn.sendWindowUpdates(len, streamid);

        return (DataFrame) frame;

    }

    // null return means EOF

    private ByteBuffer getBuffer() throws IOException {

        if (buffer == null || !buffer.hasRemaining()) {

            if (nextIndex == -1 || nextIndex == buffers.length) {

                DataFrame df = getData();

                if (df == null) {

                    return null;

                }

                List<ByteBuffer> data = df.getData();

                long len = Utils.remaining(data);

                if ((len == 0) && eof) {

                    return null;

                }

                buffers = data.toArray(Utils.EMPTY_BB_ARRAY);

                nextIndex = 0;

            }

            buffer = buffers[nextIndex++];

        }

        return buffer;

    }

    @Override

    public int read(byte[] buf, int offset, int length) throws IOException {

        if (closed) {

            throw new IOException("closed");

        }

        ByteBuffer b = getBuffer();

        if (b == null) {

            return -1;

        }

        int remaining = b.remaining();

        if (remaining < length) {

            length = remaining;

        }

        b.get(buf, offset, length);

        return length;

    }

    byte[] one = new byte[1];

    @Override

    public int read() throws IOException {

        int c = read(one, 0, 1);

        if (c == -1) {

            return -1;

        }

        return one[0] & 0xFF;

    }

    @Override

    public void close() {

        // TODO reset this stream

        closed = true;

    }

}