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/*

 * @test

 * @summary Test for CONTINUATION frame handling

 * @modules java.base/sun.net.www.http

 * @library /lib/testlibrary server

 * @build Http2TestServer

 * @build jdk.testlibrary.SimpleSSLContext

 * @run testng/othervm ContinuationFrameTest

 */

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

import java.nio.ByteBuffer;

import java.util.ArrayList;

import java.util.List;

import java.util.function.BiFunction;

import javax.net.ssl.SSLContext;

import javax.net.ssl.SSLSession;

import jdk.testlibrary.SimpleSSLContext;

import org.testng.annotations.AfterTest;

import org.testng.annotations.BeforeTest;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

import static java.lang.System.out;

import static org.testng.Assert.assertEquals;

import static org.testng.Assert.assertTrue;

public class ContinuationFrameTest {

    SSLContext sslContext;

    Http2TestServer http2TestServer;   // HTTP/2 ( h2c )

    Http2TestServer https2TestServer;  // HTTP/2 ( h2  )

    String http2URI;

    String https2URI;

    /**

     * A function that returns a list of 1) a HEADERS frame ( with an empty

     * payload ), and 2) a CONTINUATION frame with the actual headers.

     */

    static BiFunction<Integer,List<ByteBuffer>,List<Http2Frame>> oneContinuation =

        (Integer streamid, List<ByteBuffer> encodedHeaders) -> {

            List<ByteBuffer> empty =  List.of(ByteBuffer.wrap(new byte[0]));

            HeadersFrame hf = new HeadersFrame(streamid, 0, empty);

            ContinuationFrame cf = new ContinuationFrame(streamid,

                                                         HeaderFrame.END_HEADERS,

                                                         encodedHeaders);

            return List.of(hf, cf);

        };

    /**

     * A function that returns a list of a HEADERS frame followed by a number of

     * CONTINUATION frames. Each frame contains just a single byte of payload.

     */

    static BiFunction<Integer,List<ByteBuffer>,List<Http2Frame>> byteAtATime =

        (Integer streamid, List<ByteBuffer> encodedHeaders) -> {

            assert encodedHeaders.get(0).hasRemaining();

            List<Http2Frame> frames = new ArrayList<>();

            ByteBuffer hb = ByteBuffer.wrap(new byte[] {encodedHeaders.get(0).get()});

            HeadersFrame hf = new HeadersFrame(streamid, 0, hb);

            frames.add(hf);

            for (ByteBuffer bb : encodedHeaders) {

                while (bb.hasRemaining()) {

                    List<ByteBuffer> data = List.of(ByteBuffer.wrap(new byte[] {bb.get()}));

                    ContinuationFrame cf = new ContinuationFrame(streamid, 0, data);

                    frames.add(cf);

                }

            }

            frames.get(frames.size() - 1).setFlag(HeaderFrame.END_HEADERS);

            return frames;

        };

    @DataProvider(name = "variants")

    public Object[][] variants() {

        return new Object[][] {

                { http2URI,  false, oneContinuation },

                { https2URI, false, oneContinuation },

                { http2URI,  true,  oneContinuation },

                { https2URI, true,  oneContinuation },

                { http2URI,  false, byteAtATime },

                { https2URI, false, byteAtATime },

                { http2URI,  true,  byteAtATime },

                { https2URI, true,  byteAtATime },

        };

    }

    static final int ITERATION_COUNT = 20;

    @Test(dataProvider = "variants")

    void test(String uri,

              boolean sameClient,

              BiFunction<Integer,List<ByteBuffer>,List<Http2Frame>> headerFramesSupplier)

        throws Exception

    {

        CFTHttp2TestExchange.setHeaderFrameSupplier(headerFramesSupplier);

        HttpClient client = null;

        for (int i=0; i< ITERATION_COUNT; i++) {

            if (!sameClient || client == null)

                client = HttpClient.newBuilder().sslContext(sslContext).build();

            HttpRequest request = HttpRequest.newBuilder(URI.create(uri))

                                             .build();

            HttpResponse<String> resp;

            if (i % 2 == 0) {

            } else {

            }

            out.println("Got response: " + resp);

            out.println("Got body: " + resp.body());

            assertTrue(resp.statusCode() == 200,

                       "Expected 200, got:" + resp.statusCode());

            assertEquals(resp.body(), "Hello there!");

            assertEquals(resp.version(), HTTP_2);

        }

    }

    @BeforeTest

    public void setup() throws Exception {

        sslContext = new SimpleSSLContext().get();

        if (sslContext == null)

            throw new AssertionError("Unexpected null sslContext");

        http2TestServer.addHandler(new Http2EchoHandler(), "/http2/echo");

        int port = http2TestServer.getAddress().getPort();

        https2TestServer.addHandler(new Http2EchoHandler(), "/https2/echo");

        port = https2TestServer.getAddress().getPort();

        // Override the default exchange supplier with a custom one to enable

        // particular test scenarios

        http2TestServer.setExchangeSupplier(CFTHttp2TestExchange::new);

        https2TestServer.setExchangeSupplier(CFTHttp2TestExchange::new);

        http2TestServer.start();

        https2TestServer.start();

    }

    @AfterTest

    public void teardown() throws Exception {

        http2TestServer.stop();

        https2TestServer.stop();

    }

    static class Http2EchoHandler implements Http2Handler {

        @Override

        public void handle(Http2TestExchange t) throws IOException {

            try (InputStream is = t.getRequestBody();

                 OutputStream os = t.getResponseBody()) {

                byte[] bytes = is.readAllBytes();

                t.sendResponseHeaders(200, bytes.length);

                os.write(bytes);

            }

        }

    }

    // A custom Http2TestExchangeImpl that overrides sendResponseHeaders to

    // allow headers to be sent with a number of CONTINUATION frames.

    static class CFTHttp2TestExchange extends Http2TestExchangeImpl {

        static volatile BiFunction<Integer,List<ByteBuffer>,List<Http2Frame>> headerFrameSupplier;

        static void setHeaderFrameSupplier(BiFunction<Integer,List<ByteBuffer>,List<Http2Frame>> hfs) {

            headerFrameSupplier = hfs;

        }

        CFTHttp2TestExchange(int streamid, String method, HttpHeadersImpl reqheaders,

                             HttpHeadersImpl rspheaders, URI uri, InputStream is,

                             SSLSession sslSession, BodyOutputStream os,

                             Http2TestServerConnection conn, boolean pushAllowed) {

            super(streamid, method, reqheaders, rspheaders, uri, is, sslSession,

                  os, conn, pushAllowed);

        }

        @Override

        public void sendResponseHeaders(int rCode, long responseLength) throws IOException {

            this.responseLength = responseLength;

            if (responseLength > 0 || responseLength < 0) {

                long clen = responseLength > 0 ? responseLength : 0;

                rspheaders.setHeader("Content-length", Long.toString(clen));

            }

            rspheaders.setHeader(":status", Integer.toString(rCode));

            List<ByteBuffer> encodeHeaders = conn.encodeHeaders(rspheaders);

            List<Http2Frame> headerFrames = headerFrameSupplier.apply(streamid, encodeHeaders);

            assert headerFrames.size() > 0;  // there must always be at least 1

            if (responseLength < 0) {

                headerFrames.get(headerFrames.size() -1).setFlag(HeadersFrame.END_STREAM);

                os.closeInternal();

            }

            for (Http2Frame f : headerFrames)

                conn.outputQ.put(f);

            os.goodToGo();

            System.err.println("Sent response headers " + rCode);

        }

    }

}