/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.coyote.http2;

import java.nio.ByteBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.junit.Assert;
import org.junit.Test;

/**
 * Unit tests for Section 5.§ of <a href="https://tools.ietf.org/html/rfc7540">RFC 7540</a>. <br>
 * The order of tests in this class is aligned with the order of the requirements in the RFC.
 */
public class TestHttp2Section_5_1 extends Http2TestBase {

    @Test
    public void testIdleStateInvalidFrame01() throws Exception {
        http2Connect();

        sendWindowUpdate(3, 200);

        handleGoAwayResponse(1);
    }


    @Test
    public void testIdleStateInvalidFrame02() throws Exception {
        http2Connect();

        sendData(3, new byte[] {});

        handleGoAwayResponse(1);
    }


    // TODO: reserved local
    // TODO: reserved remote


    @Test
    public void halfClosedRemoteInvalidFrame() throws Exception {
        http2Connect();

        // This half-closes the stream since it includes the end of stream flag
        sendSimpleGetRequest(3);
        readSimpleGetResponse();
        Assert.assertEquals(getSimpleResponseTrace(3), output.getTrace());
        output.clearTrace();

        // This should trigger a connection error
        sendData(3, new byte[] {});

        handleGoAwayResponse(3, Http2Error.STREAM_CLOSED);
    }


    @Test
    public void testClosedInvalidFrame01() throws Exception {
        // HTTP2 upgrade
        http2Connect();

        // Build the simple request
        byte[] frameHeader = new byte[9];
        ByteBuffer headersPayload = ByteBuffer.allocate(128);
        buildSimpleGetRequest(frameHeader, headersPayload, null, 3);

        // Remove the end of stream and end of headers flags
        frameHeader[4] = 0;

        // Process the request
        writeFrame(frameHeader, headersPayload);

        // Send a rst
        sendRst(3, Http2Error.INTERNAL_ERROR.getCode());

        // Then try sending some data (which should fail)
        sendData(3, new byte[] {});
        parser.readFrame();

        Assert.assertTrue(output.getTrace(),
                output.getTrace().startsWith("3-RST-[" + Http2Error.STREAM_CLOSED.getCode() + "]"));
    }


    @Test
    public void testClosedInvalidFrame02() throws Exception {
        http2Connect();

        // Stream 1 is closed. This should trigger a connection error
        sendData(1, new byte[] {});

        handleGoAwayResponse(1, Http2Error.STREAM_CLOSED);
    }


    // TODO: Invalid frames for each of the remaining states

    // Section 5.1.1

    @Test
    public void testClientSendEvenStream() throws Exception {
        // HTTP2 upgrade
        http2Connect();

        // Part 1
        byte[] frameHeader = new byte[9];
        ByteBuffer headersPayload = ByteBuffer.allocate(128);
        buildSimpleGetRequestPart1(frameHeader, headersPayload, 4);
        writeFrame(frameHeader, headersPayload);

        handleGoAwayResponse(1);
    }


    @Test
    public void testClientSendOldStream() throws Exception {
        http2Connect();
        sendSimpleGetRequest(5);
        readSimpleGetResponse();
        Assert.assertEquals(getSimpleResponseTrace(5), output.getTrace());
        output.clearTrace();


        // Build the simple request on an old stream
        sendSimpleGetRequest(3);

        handleGoAwayResponse(5);
    }


    @Test
    public void testImplicitClose() throws Exception {
        doTestImplicitClose(5);
    }


    // https://bz.apache.org/bugzilla/show_bug.cgi?id=64467
    @Test
    public void testImplicitCloseLargeId() throws Exception {
        doTestImplicitClose(Integer.MAX_VALUE - 8);
    }


    private void doTestImplicitClose(int lastStreamId) throws Exception {

        long startFirst = System.nanoTime();
        http2Connect();
        long durationFirst = System.nanoTime() - startFirst;

        sendPriority(3, 0, 16);
        sendPriority(lastStreamId, 0, 16);

        long startSecond = System.nanoTime();
        sendSimpleGetRequest(lastStreamId);
        readSimpleGetResponse();
        long durationSecond = System.nanoTime() - startSecond;

        Assert.assertEquals(getSimpleResponseTrace(lastStreamId), output.getTrace());
        output.clearTrace();

        // Allow second request to take up to 5 times first request or up to 1 second - whichever is the larger - mainly
        // to allow for CI systems under load that can exhibit significant timing variation.
        Assert.assertTrue(
                "First request took [" + durationFirst / 1000000 + "ms], second request took [" +
                        durationSecond / 1000000 + "ms]",
                durationSecond < 1000000000 || durationSecond < durationFirst * 3);

        // Should trigger an error since stream 3 should have been implicitly
        // closed.
        sendSimpleGetRequest(3);

        handleGoAwayResponse(lastStreamId);
    }


    @Test
    public void testExceedMaxActiveStreams01() throws Exception {
        // http2Connect() - modified
        enableHttp2(1);
        configureAndStartWebApplication();
        openClientConnection();
        doHttpUpgrade();
        sendClientPreface();

        // validateHttp2InitialResponse() - modified
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();

        Assert.assertEquals("0-Settings-[3]-[1]\n" + "0-Settings-End\n" + "0-Settings-Ack\n" +
                "0-Ping-[0,0,0,0,0,0,0,1]\n" + getSimpleResponseTrace(1), output.getTrace());
        output.clearTrace();

        sendLargeGetRequest(3);

        sendSimpleGetRequest(5);

        // Default connection window size is 64k-1.
        // Initial request will have used 8k leaving 56k-1.
        // Stream window will be 64k-1.
        // Expecting
        // 1 * headers
        // 56k-1 of body (7 * ~8k)
        // 1 * error
        // for a total of 9 frames (could be in any order)
        for (int i = 0; i < 9; i++) {
            parser.readFrame();
        }

        Assert.assertTrue(output.getTrace(),
                output.getTrace().contains("5-RST-[" + Http2Error.REFUSED_STREAM.getCode() + "]"));
        output.clearTrace();

        // Connection window is zero.
        // Stream window is 8k

        // Release the remaining body
        sendWindowUpdate(0, (1 << 31) - 2);
        // Allow for the ~8k still in the stream window
        sendWindowUpdate(3, (1 << 31) - 8193);

        // Read until the end of stream 3
        while (!output.getTrace().contains("3-EndOfStream")) {
            parser.readFrame();
        }
        output.clearTrace();

        // Confirm another request can be sent once concurrency falls back below limit
        sendSimpleGetRequest(7);
        parser.readFrame();
        parser.readFrame();
        Assert.assertEquals(getSimpleResponseTrace(7), output.getTrace());
    }


    @Test
    public void testExceedMaxActiveStreams02() throws Exception {
        // http2Connect() - modified
        enableHttp2(1);
        configureAndStartWebApplication();
        openClientConnection();
        doHttpUpgrade();
        sendClientPreface();

        // validateHttp2InitialResponse() - modified
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();

        Assert.assertEquals("0-Settings-[3]-[1]\n" + "0-Settings-End\n" + "0-Settings-Ack\n" +
                "0-Ping-[0,0,0,0,0,0,0,1]\n" + getSimpleResponseTrace(1), output.getTrace());
        output.clearTrace();

        sendLargeGetRequest(3);

        sendSimpleGetRequest(5);

        // Default connection window size is 64k-1.
        // Initial request will have used 8k leaving 56k-1.
        // Stream window will be 64k-1.
        // Expecting
        // 1 * headers
        // 56k-1 of body (7 * ~8k)
        // 1 * error
        // for a total of 9 frames (could be in any order)
        for (int i = 0; i < 9; i++) {
            parser.readFrame();
        }

        Assert.assertTrue(output.getTrace(),
                output.getTrace().contains("5-RST-[" + Http2Error.REFUSED_STREAM.getCode() + "]"));
        output.clearTrace();

        // Connection window is zero.
        // Stream window is 8k

        // Reset stream 3 (client cancel)
        sendRst(3, Http2Error.NO_ERROR.getCode());
        // Client reset triggers both a read error and a write error which in turn trigger two server resets
        parser.readFrame();
        Assert.assertEquals("3-RST-[5]\n", output.getTrace());
        output.clearTrace();

        // Open up the connection window.
        sendWindowUpdate(0, (1 << 31) - 2);

        // Confirm another request can be sent once concurrency falls back below limit
        sendSimpleGetRequest(7);
        parser.readFrame();
        parser.readFrame();
        Assert.assertEquals(getSimpleResponseTrace(7), output.getTrace());
    }


    @Test
    public void testErrorOnWaitingStream01() throws Exception {
        Logger.getLogger("org.apache.coyote.http2").setLevel(Level.ALL);
        try {
            // http2Connect() - modified
            enableHttp2(1);
            configureAndStartWebApplication();
            openClientConnection();
            doHttpUpgrade();
            sendClientPreface();

            // validateHttp2InitialResponse() - modified
            parser.readFrame();
            parser.readFrame();
            parser.readFrame();
            parser.readFrame();
            parser.readFrame();

            Assert.assertEquals("0-Settings-[3]-[1]\n" + "0-Settings-End\n" + "0-Settings-Ack\n" +
                    "0-Ping-[0,0,0,0,0,0,0,1]\n" + getSimpleResponseTrace(1), output.getTrace());
            output.clearTrace();

            sendLargeGetRequest(3);

            sendSimpleGetRequest(5);

            // Default connection window size is 64k-1.
            // Initial request will have used 8k leaving 56k-1.
            // Stream window will be 64k-1.
            // Expecting
            // 1 * headers
            // 56k-1 of body (7 * ~8k)
            // 1 * error (could be in any order)
            for (int i = 0; i < 8; i++) {
                parser.readFrame();
            }
            parser.readFrame();

            Assert.assertTrue(output.getTrace(),
                    output.getTrace().contains("5-RST-[" + Http2Error.REFUSED_STREAM.getCode() + "]"));
            output.clearTrace();

            // Connection window is zero.
            // Stream window is 8k

            // Expand the stream window too much to trigger an error
            // Allow for the 8k still in the stream window
            sendWindowUpdate(3, (1 << 31) - 1);

            parser.readFrame();
            Assert.assertEquals("3-RST-[" + Http2Error.FLOW_CONTROL_ERROR.getCode() + "]\n", output.getTrace());
        } finally {
            Logger.getLogger("org.apache.coyote.http2").setLevel(Level.INFO);
        }
    }


    @Test
    public void testErrorOnWaitingStream02() throws Exception {
        // http2Connect() - modified
        enableHttp2(1);
        configureAndStartWebApplication();
        openClientConnection();
        doHttpUpgrade();
        sendClientPreface();

        // validateHttp2InitialResponse() - modified
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();
        parser.readFrame();

        Assert.assertEquals("0-Settings-[3]-[1]\n" + "0-Settings-End\n" + "0-Settings-Ack\n" +
                "0-Ping-[0,0,0,0,0,0,0,1]\n" + getSimpleResponseTrace(1), output.getTrace());
        output.clearTrace();

        // Default connection window size is 64k-1.
        // Initial request will have used 8k leaving 56k-1.
        // Stream window will be 64k-1.

        // Increase Connection window by 16k
        // Do this before sending the requests to ensure the connection window
        // is increased before request processing starts else stream 5 may
        // consume the connection window before the update is processed which
        // will result in at least one addition body frame and break the tests
        // below.
        sendWindowUpdate(0, 16 * 1024);

        sendLargeGetRequest(3);

        sendSimpleGetRequest(5);

        // Expecting
        // 1 * headers
        // 64k-1 of body (8 * ~8k)
        // 1 * error
        // Could be in any order
        //
        for (int i = 0; i < 9; i++) {
            parser.readFrame();
        }
        parser.readFrame();

        Assert.assertTrue(output.getTrace(),
                output.getTrace().contains("5-RST-[" + Http2Error.REFUSED_STREAM.getCode() + "]"));

        // Connection window is 8k.
        // Stream window is zero.

        // Expand the connection window too much to trigger an error
        // Allow for the 8k still in the connection window
        sendWindowUpdate(0, (1 << 31) - 1);

        parser.readFrame();
        Assert.assertTrue(output.getTrace(),
                output.getTrace().contains("0-Goaway-[5]-[" + Http2Error.FLOW_CONTROL_ERROR.getCode() + "]"));
    }
}