/** @file

    Basic test cases for the Huffman encoding.

    @section license License

    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.
*/

#include "HuffmanCodec.h"
#include <cstdlib>
#include <iostream>
#include <cassert>
#include <cstring>

using namespace std;

uint32_t test_values[] = {
  0x1ff8,     13, 0x7fffd8,  23, 0xfffffe2,  28, 0xfffffe3, 28, 0xfffffe4, 28, 0xfffffe5,  28, 0xfffffe6,  28, 0xfffffe7, 28,
  0xfffffe8,  28, 0xffffea,  24, 0x3ffffffc, 30, 0xfffffe9, 28, 0xfffffea, 28, 0x3ffffffd, 30, 0xfffffeb,  28, 0xfffffec, 28,
  0xfffffed,  28, 0xfffffee, 28, 0xfffffef,  28, 0xffffff0, 28, 0xffffff1, 28, 0xffffff2,  28, 0x3ffffffe, 30, 0xffffff3, 28,
  0xffffff4,  28, 0xffffff5, 28, 0xffffff6,  28, 0xffffff7, 28, 0xffffff8, 28, 0xffffff9,  28, 0xffffffa,  28, 0xffffffb, 28,
  0x14,       6,  0x3f8,     10, 0x3f9,      10, 0xffa,     12, 0x1ff9,    13, 0x15,       6,  0xf8,       8,  0x7fa,     11,
  0x3fa,      10, 0x3fb,     10, 0xf9,       8,  0x7fb,     11, 0xfa,      8,  0x16,       6,  0x17,       6,  0x18,      6,
  0x0,        5,  0x1,       5,  0x2,        5,  0x19,      6,  0x1a,      6,  0x1b,       6,  0x1c,       6,  0x1d,      6,
  0x1e,       6,  0x1f,      6,  0x5c,       7,  0xfb,      8,  0x7ffc,    15, 0x20,       6,  0xffb,      12, 0x3fc,     10,
  0x1ffa,     13, 0x21,      6,  0x5d,       7,  0x5e,      7,  0x5f,      7,  0x60,       7,  0x61,       7,  0x62,      7,
  0x63,       7,  0x64,      7,  0x65,       7,  0x66,      7,  0x67,      7,  0x68,       7,  0x69,       7,  0x6a,      7,
  0x6b,       7,  0x6c,      7,  0x6d,       7,  0x6e,      7,  0x6f,      7,  0x70,       7,  0x71,       7,  0x72,      7,
  0xfc,       8,  0x73,      7,  0xfd,       8,  0x1ffb,    13, 0x7fff0,   19, 0x1ffc,     13, 0x3ffc,     14, 0x22,      6,
  0x7ffd,     15, 0x3,       5,  0x23,       6,  0x4,       5,  0x24,      6,  0x5,        5,  0x25,       6,  0x26,      6,
  0x27,       6,  0x6,       5,  0x74,       7,  0x75,      7,  0x28,      6,  0x29,       6,  0x2a,       6,  0x7,       5,
  0x2b,       6,  0x76,      7,  0x2c,       6,  0x8,       5,  0x9,       5,  0x2d,       6,  0x77,       7,  0x78,      7,
  0x79,       7,  0x7a,      7,  0x7b,       7,  0x7ffe,    15, 0x7fc,     11, 0x3ffd,     14, 0x1ffd,     13, 0xffffffc, 28,
  0xfffe6,    20, 0x3fffd2,  22, 0xfffe7,    20, 0xfffe8,   20, 0x3fffd3,  22, 0x3fffd4,   22, 0x3fffd5,   22, 0x7fffd9,  23,
  0x3fffd6,   22, 0x7fffda,  23, 0x7fffdb,   23, 0x7fffdc,  23, 0x7fffdd,  23, 0x7fffde,   23, 0xffffeb,   24, 0x7fffdf,  23,
  0xffffec,   24, 0xffffed,  24, 0x3fffd7,   22, 0x7fffe0,  23, 0xffffee,  24, 0x7fffe1,   23, 0x7fffe2,   23, 0x7fffe3,  23,
  0x7fffe4,   23, 0x1fffdc,  21, 0x3fffd8,   22, 0x7fffe5,  23, 0x3fffd9,  22, 0x7fffe6,   23, 0x7fffe7,   23, 0xffffef,  24,
  0x3fffda,   22, 0x1fffdd,  21, 0xfffe9,    20, 0x3fffdb,  22, 0x3fffdc,  22, 0x7fffe8,   23, 0x7fffe9,   23, 0x1fffde,  21,
  0x7fffea,   23, 0x3fffdd,  22, 0x3fffde,   22, 0xfffff0,  24, 0x1fffdf,  21, 0x3fffdf,   22, 0x7fffeb,   23, 0x7fffec,  23,
  0x1fffe0,   21, 0x1fffe1,  21, 0x3fffe0,   22, 0x1fffe2,  21, 0x7fffed,  23, 0x3fffe1,   22, 0x7fffee,   23, 0x7fffef,  23,
  0xfffea,    20, 0x3fffe2,  22, 0x3fffe3,   22, 0x3fffe4,  22, 0x7ffff0,  23, 0x3fffe5,   22, 0x3fffe6,   22, 0x7ffff1,  23,
  0x3ffffe0,  26, 0x3ffffe1, 26, 0xfffeb,    20, 0x7fff1,   19, 0x3fffe7,  22, 0x7ffff2,   23, 0x3fffe8,   22, 0x1ffffec, 25,
  0x3ffffe2,  26, 0x3ffffe3, 26, 0x3ffffe4,  26, 0x7ffffde, 27, 0x7ffffdf, 27, 0x3ffffe5,  26, 0xfffff1,   24, 0x1ffffed, 25,
  0x7fff2,    19, 0x1fffe3,  21, 0x3ffffe6,  26, 0x7ffffe0, 27, 0x7ffffe1, 27, 0x3ffffe7,  26, 0x7ffffe2,  27, 0xfffff2,  24,
  0x1fffe4,   21, 0x1fffe5,  21, 0x3ffffe8,  26, 0x3ffffe9, 26, 0xffffffd, 28, 0x7ffffe3,  27, 0x7ffffe4,  27, 0x7ffffe5, 27,
  0xfffec,    20, 0xfffff3,  24, 0xfffed,    20, 0x1fffe6,  21, 0x3fffe9,  22, 0x1fffe7,   21, 0x1fffe8,   21, 0x7ffff3,  23,
  0x3fffea,   22, 0x3fffeb,  22, 0x1ffffee,  25, 0x1ffffef, 25, 0xfffff4,  24, 0xfffff5,   24, 0x3ffffea,  26, 0x7ffff4,  23,
  0x3ffffeb,  26, 0x7ffffe6, 27, 0x3ffffec,  26, 0x3ffffed, 26, 0x7ffffe7, 27, 0x7ffffe8,  27, 0x7ffffe9,  27, 0x7ffffea, 27,
  0x7ffffeb,  27, 0xffffffe, 28, 0x7ffffec,  27, 0x7ffffed, 27, 0x7ffffee, 27, 0x7ffffef,  27, 0x7fffff0,  27, 0x3ffffee, 26,
  0x3fffffff, 30};

void
random_test()
{
  const int size  = 1024;
  char *dst_start = (char *)malloc(size * 2);
  char string[size];
  for (char &i : string) {
    // coverity[dont_call]
    long num = lrand48();
    i        = (char)num;
  }
  const uint8_t *src = (const uint8_t *)string;
  uint32_t src_len   = sizeof(string);

  int bytes = huffman_decode(dst_start, src, src_len);

  // cout << "bytes: " << bytes << endl;
  for (int i = 0; i < bytes; i++) {
    // cout << i << " " << (int)dst_start[i] << " " << dst_start[i] << endl;
  }

  free(dst_start);
}

union Value {
  uint32_t x;
  uint8_t y[4];
};

void
values_test()
{
  char dst_start[4];
  int size = sizeof(test_values) / 4;
  for (int i = 0; i < size; i += 2) {
    const uint32_t value = test_values[i];
    const uint32_t bits  = test_values[i + 1];

    // copy the bits and set remaining bits to 1
    union Value encoded;
    union Value encoded_mapped;
    encoded.x             = 0;
    uint32_t bits_counter = bits;
    for (uint32_t pos = 32; pos > 0; pos--) {
      if (bits_counter > 0) {
        if (value & (1 << (bits_counter - 1))) {
          encoded.x = encoded.x | (1 << (pos - 1));
        }
        bits_counter--;
      } else {
        encoded.x = encoded.x | (1 << (pos - 1));
      }
    }

    int encoded_size = 0;
    if (bits > 24) {
      encoded_size = 4;
    } else if (bits > 16) {
      encoded_size = 3;
    } else if (bits > 8) {
      encoded_size = 2;
    } else {
      encoded_size = 1;
    }

    encoded_mapped.y[0] = encoded.y[3];
    encoded_mapped.y[1] = encoded.y[2];
    encoded_mapped.y[2] = encoded.y[1];
    encoded_mapped.y[3] = encoded.y[0];

    int bytes        = huffman_decode(dst_start, encoded_mapped.y, encoded_size);
    char ascii_value = i / 2;

    // EOS is treated as invalid so check for an error
    if (value == 0x3fffffff) {
      assert(bytes == -1);
      continue;
    }
    assert(dst_start[0] == ascii_value);
    assert(bytes == 1);
  }
}

// NOTE: Test data from "C.6.1 First Response" in RFC 7541.
const static struct {
  uint8_t *src;
  int64_t src_len;
  uint8_t *expect;
  int64_t expect_len;
} huffman_encode_test_data[] = {
  {(uint8_t *)"", 0, (uint8_t *)"", 0},
  {(uint8_t *)"0", 1, (uint8_t *)"\x07", 1},
  {(uint8_t *)"302", 3, (uint8_t *)"\x64\x02", 2},
  {(uint8_t *)"private", 7, (uint8_t *)"\xae\xc3\x77\x1a\x4b", 5},
  {(uint8_t *)"Mon, 21 Oct 2013 20:13:21 GMT", 29,
   (uint8_t *)"\xd0\x7a\xbe\x94\x10\x54\xd4\x44\xa8\x20\x05\x95\x04\x0b\x81\x66\xe0\x82\xa6\x2d\x1b\xff", 22},
  {(uint8_t *)"https://www.example.com", 23, (uint8_t *)"\x9d\x29\xad\x17\x18\x63\xc7\x8f\x0b\x97\xc8\xe9\xae\x82\xae\x43\xd3",
   17}};

void
encode_test()
{
  for (const auto &i : huffman_encode_test_data) {
    uint8_t *dst        = static_cast<uint8_t *>(malloc(i.expect_len));
    int64_t encoded_len = huffman_encode(dst, i.src, i.src_len);

    assert(encoded_len == i.expect_len);
    assert(memcmp(i.expect, dst, encoded_len) == 0);

    free(dst);
  }
}

void
decode_errors_test()
{
  const static struct {
    char *input;
    int input_len;
  } test_cases[] = {
    {(char *)"\x00", 1}, {(char *)"\xff", 1}, {(char *)"\x1f\xff", 2}, {(char *)"\xff\xae", 2}, {(char *)"\xff\x9f\xff\xff\xff", 5},
  };

  for (unsigned int i = 0; i < sizeof(test_cases) / sizeof(test_cases[0]); i++) {
    int dst_len = 2 * test_cases[i].input_len;
    char *dst   = (char *)malloc(dst_len);
    int len     = huffman_decode(dst, (uint8_t *)test_cases[i].input, test_cases[i].input_len);
    assert(len == -1);
    free(dst);
  }
}

int
main()
{
  hpack_huffman_init();

  for (int i = 0; i < 100; i++) {
    random_test();
  }
  values_test();
  decode_errors_test();

  hpack_huffman_fin();

  encode_test();
  return 0;
}