/*

 * Copyright (c) 2015, 2017, 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 org.testng.annotations.Test;

import java.io.IOException;

import java.io.UncheckedIOException;

import java.nio.ByteBuffer;

import java.util.Iterator;

import java.util.LinkedList;

import java.util.List;

import java.util.function.Supplier;

import java.util.stream.Collectors;

import static org.testng.Assert.assertEquals;

import static org.testng.Assert.assertNotNull;

//

// Tests whose names start with "testX" are the ones captured from real HPACK

// use cases

//

public final class DecoderTest {

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.2.1

    //

    @Test

    public void example1() {

        // @formatter:off

        test("400a 6375 7374 6f6d 2d6b 6579 0d63 7573\n" +

             "746f 6d2d 6865 6164 6572",

             "[  1] (s =  55) custom-key: custom-header\n" +

             "      Table size:  55",

             "custom-key: custom-header");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.2.2

    //

    @Test

    public void example2() {

        // @formatter:off

        test("040c 2f73 616d 706c 652f 7061 7468",

             "empty.",

             ":path: /sample/path");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.2.3

    //

    @Test

    public void example3() {

        // @formatter:off

        test("1008 7061 7373 776f 7264 0673 6563 7265\n" +

             "74",

             "empty.",

             "password: secret");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.2.4

    //

    @Test

    public void example4() {

        // @formatter:off

        test("82",

             "empty.",

             ":method: GET");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.3

    //

    @Test

    public void example5() {

        // @formatter:off

        Decoder d = new Decoder(256);

        test(d, "8286 8441 0f77 7777 2e65 7861 6d70 6c65\n" +

                "2e63 6f6d",

                "[  1] (s =  57) :authority: www.example.com\n" +

                "      Table size:  57",

                ":method: GET\n" +

                ":scheme: http\n" +

                ":path: /\n" +

                ":authority: www.example.com");

        test(d, "8286 84be 5808 6e6f 2d63 6163 6865",

                "[  1] (s =  53) cache-control: no-cache\n" +

                "[  2] (s =  57) :authority: www.example.com\n" +

                "      Table size: 110",

                ":method: GET\n" +

                ":scheme: http\n" +

                ":path: /\n" +

                ":authority: www.example.com\n" +

                "cache-control: no-cache");

        test(d, "8287 85bf 400a 6375 7374 6f6d 2d6b 6579\n" +

                "0c63 7573 746f 6d2d 7661 6c75 65",

                "[  1] (s =  54) custom-key: custom-value\n" +

                "[  2] (s =  53) cache-control: no-cache\n" +

                "[  3] (s =  57) :authority: www.example.com\n" +

                "      Table size: 164",

                ":method: GET\n" +

                ":scheme: https\n" +

                ":path: /index.html\n" +

                ":authority: www.example.com\n" +

                "custom-key: custom-value");

        // @formatter:on

    }

    @Test

    public void example5AllSplits() {

        // @formatter:off

        testAllSplits(

                "8286 8441 0f77 7777 2e65 7861 6d70 6c65\n" +

                "2e63 6f6d",

                "[  1] (s =  57) :authority: www.example.com\n" +

                "      Table size:  57",

                ":method: GET\n" +

                ":scheme: http\n" +

                ":path: /\n" +

                ":authority: www.example.com");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.4

    //

    @Test

    public void example6() {

        // @formatter:off

        Decoder d = new Decoder(256);

        test(d, "8286 8441 8cf1 e3c2 e5f2 3a6b a0ab 90f4\n" +

                "ff",

                "[  1] (s =  57) :authority: www.example.com\n" +

                "      Table size:  57",

                ":method: GET\n" +

                ":scheme: http\n" +

                ":path: /\n" +

                ":authority: www.example.com");

        test(d, "8286 84be 5886 a8eb 1064 9cbf",

                "[  1] (s =  53) cache-control: no-cache\n" +

                "[  2] (s =  57) :authority: www.example.com\n" +

                "      Table size: 110",

                ":method: GET\n" +

                ":scheme: http\n" +

                ":path: /\n" +

                ":authority: www.example.com\n" +

                "cache-control: no-cache");

        test(d, "8287 85bf 4088 25a8 49e9 5ba9 7d7f 8925\n" +

                "a849 e95b b8e8 b4bf",

                "[  1] (s =  54) custom-key: custom-value\n" +

                "[  2] (s =  53) cache-control: no-cache\n" +

                "[  3] (s =  57) :authority: www.example.com\n" +

                "      Table size: 164",

                ":method: GET\n" +

                ":scheme: https\n" +

                ":path: /index.html\n" +

                ":authority: www.example.com\n" +

                "custom-key: custom-value");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.5

    //

    @Test

    public void example7() {

        // @formatter:off

        Decoder d = new Decoder(256);

        test(d, "4803 3330 3258 0770 7269 7661 7465 611d\n" +

                "4d6f 6e2c 2032 3120 4f63 7420 3230 3133\n" +

                "2032 303a 3133 3a32 3120 474d 546e 1768\n" +

                "7474 7073 3a2f 2f77 7777 2e65 7861 6d70\n" +

                "6c65 2e63 6f6d",

                "[  1] (s =  63) location: https://www.example.com\n" +

                "[  2] (s =  65) date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "[  3] (s =  52) cache-control: private\n" +

                "[  4] (s =  42) :status: 302\n" +

                "      Table size: 222",

                ":status: 302\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "location: https://www.example.com");

        test(d, "4803 3330 37c1 c0bf",

                "[  1] (s =  42) :status: 307\n" +

                "[  2] (s =  63) location: https://www.example.com\n" +

                "[  3] (s =  65) date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "[  4] (s =  52) cache-control: private\n" +

                "      Table size: 222",

                ":status: 307\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "location: https://www.example.com");

        test(d, "88c1 611d 4d6f 6e2c 2032 3120 4f63 7420\n" +

                "3230 3133 2032 303a 3133 3a32 3220 474d\n" +

                "54c0 5a04 677a 6970 7738 666f 6f3d 4153\n" +

                "444a 4b48 514b 425a 584f 5157 454f 5049\n" +

                "5541 5851 5745 4f49 553b 206d 6178 2d61\n" +

                "6765 3d33 3630 303b 2076 6572 7369 6f6e\n" +

                "3d31",

                "[  1] (s =  98) set-cookie: foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU; max-age=3600; version=1\n" +

                "[  2] (s =  52) content-encoding: gzip\n" +

                "[  3] (s =  65) date: Mon, 21 Oct 2013 20:13:22 GMT\n" +

                "      Table size: 215",

                ":status: 200\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:22 GMT\n" +

                "location: https://www.example.com\n" +

                "content-encoding: gzip\n" +

                "set-cookie: foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU; max-age=3600; version=1");

        // @formatter:on

    }

    //

    // http://tools.ietf.org/html/rfc7541#appendix-C.6

    //

    @Test

    public void example8() {

        // @formatter:off

        Decoder d = new Decoder(256);

        test(d, "4882 6402 5885 aec3 771a 4b61 96d0 7abe\n" +

                "9410 54d4 44a8 2005 9504 0b81 66e0 82a6\n" +

                "2d1b ff6e 919d 29ad 1718 63c7 8f0b 97c8\n" +

                "e9ae 82ae 43d3",

                "[  1] (s =  63) location: https://www.example.com\n" +

                "[  2] (s =  65) date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "[  3] (s =  52) cache-control: private\n" +

                "[  4] (s =  42) :status: 302\n" +

                "      Table size: 222",

                ":status: 302\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "location: https://www.example.com");

        test(d, "4883 640e ffc1 c0bf",

                "[  1] (s =  42) :status: 307\n" +

                "[  2] (s =  63) location: https://www.example.com\n" +

                "[  3] (s =  65) date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "[  4] (s =  52) cache-control: private\n" +

                "      Table size: 222",

                ":status: 307\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:21 GMT\n" +

                "location: https://www.example.com");

        test(d, "88c1 6196 d07a be94 1054 d444 a820 0595\n" +

                "040b 8166 e084 a62d 1bff c05a 839b d9ab\n" +

                "77ad 94e7 821d d7f2 e6c7 b335 dfdf cd5b\n" +

                "3960 d5af 2708 7f36 72c1 ab27 0fb5 291f\n" +

                "9587 3160 65c0 03ed 4ee5 b106 3d50 07",

                "[  1] (s =  98) set-cookie: foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU; max-age=3600; version=1\n" +

                "[  2] (s =  52) content-encoding: gzip\n" +

                "[  3] (s =  65) date: Mon, 21 Oct 2013 20:13:22 GMT\n" +

                "      Table size: 215",

                ":status: 200\n" +

                "cache-control: private\n" +

                "date: Mon, 21 Oct 2013 20:13:22 GMT\n" +

                "location: https://www.example.com\n" +

                "content-encoding: gzip\n" +

                "set-cookie: foo=ASDJKHQKBZXOQWEOPIUAXQWEOIU; max-age=3600; version=1");

        // @formatter:on

    }

    @Test

    // One of responses from Apache Server that helped to catch a bug

    public void testX() {

        Decoder d = new Decoder(4096);

        // @formatter:off

        test(d, "3fe1 1f88 6196 d07a be94 03ea 693f 7504\n" +

                "00b6 a05c b827 2e32 fa98 b46f 769e 86b1\n" +

                "9272 b025 da5c 2ea9 fd70 a8de 7fb5 3556\n" +

                "5ab7 6ece c057 02e2 2ad2 17bf 6c96 d07a\n" +

                "be94 0854 cb6d 4a08 0075 40bd 71b6 6e05\n" +

                "a531 68df 0f13 8efe 4522 cd32 21b6 5686\n" +

                "eb23 781f cf52 848f d24a 8f0f 0d02 3435\n" +

                "5f87 497c a589 d34d 1f",

                "[  1] (s =  53) content-type: text/html\n" +

                "[  2] (s =  50) accept-ranges: bytes\n" +

                "[  3] (s =  74) last-modified: Mon, 11 Jun 2007 18:53:14 GMT\n" +

                "[  4] (s =  77) server: Apache/2.4.17 (Unix) OpenSSL/1.0.2e-dev\n" +

                "[  5] (s =  65) date: Mon, 09 Nov 2015 16:26:39 GMT\n" +

                "      Table size: 319",

                ":status: 200\n" +

                "date: Mon, 09 Nov 2015 16:26:39 GMT\n" +

                "server: Apache/2.4.17 (Unix) OpenSSL/1.0.2e-dev\n" +

                "last-modified: Mon, 11 Jun 2007 18:53:14 GMT\n" +

                "etag: \"2d-432a5e4a73a80\"\n" +

                "accept-ranges: bytes\n" +

                "content-length: 45\n" +

                "content-type: text/html");

        // @formatter:on

    }

    @Test

    public void testX1() {

        // Supplier of a decoder with a particular state

        Supplier<Decoder> s = () -> {

            Decoder d = new Decoder(4096);

            // @formatter:off

            test(d, "88 76 92 ca 54 a7 d7 f4 fa ec af ed 6d da 61 d7 bb 1e ad ff" +

                    "df 61 97 c3 61 be 94 13 4a 65 b6 a5 04 00 b8 a0 5a b8 db 77" +

                    "1b 71 4c 5a 37 ff 0f 0d 84 08 00 00 03",

                    "[  1] (s =  65) date: Fri, 24 Jun 2016 14:55:56 GMT\n" +

                    "[  2] (s =  59) server: Jetty(9.3.z-SNAPSHOT)\n" +

                    "      Table size: 124",

                    ":status: 200\n" +

                    "server: Jetty(9.3.z-SNAPSHOT)\n" +

                    "date: Fri, 24 Jun 2016 14:55:56 GMT\n" +

                    "content-length: 100000"

            );

            // @formatter:on

            return d;

        };

        // For all splits of the following data fed to the supplied decoder we

        // must get what's expected

        // @formatter:off

        testAllSplits(s,

                "88 bf be 0f 0d 84 08 00 00 03",

                "[  1] (s =  65) date: Fri, 24 Jun 2016 14:55:56 GMT\n" +

                "[  2] (s =  59) server: Jetty(9.3.z-SNAPSHOT)\n" +

                "      Table size: 124",

                ":status: 200\n" +

                "server: Jetty(9.3.z-SNAPSHOT)\n" +

                "date: Fri, 24 Jun 2016 14:55:56 GMT\n" +

                "content-length: 100000");

        // @formatter:on

    }

    //

    // This test is missing in the spec

    //

    @Test

    public void sizeUpdate() throws IOException {

        Decoder d = new Decoder(4096);

        assertEquals(d.getTable().maxSize(), 4096);

        d.decode(ByteBuffer.wrap(new byte[]{0b00111110}), true, nopCallback()); // newSize = 30

        assertEquals(d.getTable().maxSize(), 30);

    }

    @Test

    public void incorrectSizeUpdate() {

        ByteBuffer b = ByteBuffer.allocate(8);

        Encoder e = new Encoder(8192) {

            @Override

            protected int calculateCapacity(int maxCapacity) {

                return maxCapacity;

            }

        };

        e.header("a", "b");

        e.encode(b);

        b.flip();

        {

            Decoder d = new Decoder(4096);

            assertVoidThrows(IOException.class,

                    () -> d.decode(b, true, (name, value) -> { }));

        }

        b.flip();

        {

            Decoder d = new Decoder(4096);

            assertVoidThrows(IOException.class,

                    () -> d.decode(b, false, (name, value) -> { }));

        }

    }

    @Test

    public void corruptedHeaderBlockInteger() {

        Decoder d = new Decoder(4096);

        ByteBuffer data = ByteBuffer.wrap(new byte[]{

                (byte) 0b11111111, // indexed

                (byte) 0b10011010  // 25 + ...

        });

        IOException e = assertVoidThrows(IOException.class,

                () -> d.decode(data, true, nopCallback()));

        assertExceptionMessageContains(e, "Unexpected end of header block");

    }

    // 5.1.  Integer Representation

    // ...

    // Integer encodings that exceed implementation limits -- in value or octet

    // length -- MUST be treated as decoding errors. Different limits can

    // be set for each of the different uses of integers, based on

    // implementation constraints.

    @Test

    public void headerBlockIntegerNoOverflow() {

        Decoder d = new Decoder(4096);

        ByteBuffer data = ByteBuffer.wrap(new byte[]{

                (byte) 0b11111111, // indexed + 127

                // Integer.MAX_VALUE - 127 (base 128, little-endian):

                (byte) 0b10000000,

                (byte) 0b11111111,

                (byte) 0b11111111,

                (byte) 0b11111111,

                (byte) 0b00000111

        });

        IOException e = assertVoidThrows(IOException.class,

                () -> d.decode(data, true, nopCallback()));

        assertExceptionMessageContains(e.getCause(), "index=2147483647");

    }

    @Test

    public void headerBlockIntegerOverflow() {

        Decoder d = new Decoder(4096);

        ByteBuffer data = ByteBuffer.wrap(new byte[]{

                (byte) 0b11111111, // indexed + 127

                // Integer.MAX_VALUE - 127 + 1 (base 128, little endian):

                (byte) 0b10000001,

                (byte) 0b11111111,

                (byte) 0b11111111,

                (byte) 0b11111111,

                (byte) 0b00000111

        });

        IOException e = assertVoidThrows(IOException.class,

                () -> d.decode(data, true, nopCallback()));

        assertExceptionMessageContains(e, "Integer overflow");

    }

    @Test

    public void corruptedHeaderBlockString1() {

        Decoder d = new Decoder(4096);

        ByteBuffer data = ByteBuffer.wrap(new byte[]{

                0b00001111, // literal, index=15

                0b00000000,

                0b00001000, // huffman=false, length=8

                0b00000000, // \

                0b00000000, //  but only 3 octets available...

                0b00000000  // /

        });

        IOException e = assertVoidThrows(IOException.class,

                () -> d.decode(data, true, nopCallback()));

        assertExceptionMessageContains(e, "Unexpected end of header block");

    }

    @Test

    public void corruptedHeaderBlockString2() {

        Decoder d = new Decoder(4096);

        ByteBuffer data = ByteBuffer.wrap(new byte[]{

                0b00001111, // literal, index=15

                0b00000000,

                (byte) 0b10001000, // huffman=true, length=8

                0b00000000, // \

                0b00000000, //  \

                0b00000000, //   but only 5 octets available...

                0b00000000, //  /

                0b00000000  // /

        });

        IOException e = assertVoidThrows(IOException.class,

                () -> d.decode(data, true, nopCallback()));

        assertExceptionMessageContains(e, "Unexpected end of header block");

    }

    // 5.2.  String Literal Representation

    // ...A Huffman-encoded string literal containing the EOS symbol MUST be