// Copyright (c) 2014-2017, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <array>
#include <boost/range/algorithm/equal.hpp>
#include <boost/range/algorithm_ext/iota.hpp>
#include <cstdint>
#include <gtest/gtest.h>
#include <iterator>
#include <string>
#include <sstream>
#include <vector>

#ifdef _WIN32
# include <winsock.h>
#else
# include <arpa/inet.h>
#endif

#include "hex.h"
#include "span.h"
#include "string_tools.h"

namespace
{
  template<typename Destination, typename Source>
  bool can_construct()
  {
    const unsigned count =
      unsigned(std::is_constructible<Destination, Source>()) +
      unsigned(std::is_constructible<Destination, Source&>()) +
      unsigned(std::is_convertible<Source, Destination>()) +
      unsigned(std::is_convertible<Source&, Destination>()) +
      unsigned(std::is_assignable<Destination, Source>()) +
      unsigned(std::is_assignable<Destination, Source&>());
    EXPECT_TRUE(count == 6 || count == 0) <<
      "Mismatch on construction results - " << count << " were true";
    return count == 6; 
  }

  // This is probably stressing the compiler more than the implementation ...
  constexpr const epee::span<const char> test_string("a string");
  static_assert(!test_string.empty(), "test failure");
  static_assert(test_string.size() == 9, "test failure");
  static_assert(test_string.size_bytes() == 9, "test_failure");
  static_assert(test_string.begin() == test_string.cbegin(), "test failure");
  static_assert(test_string.end() == test_string.cend(), "test failure");
  static_assert(test_string.cend() - test_string.cbegin() == 9, "test failure");
  static_assert(*test_string.cbegin() == 'a', "test failure");
  static_assert(*(test_string.cend() - 2) == 'g', "test failure");
  static_assert(
    epee::span<const char>(test_string).cbegin() + 3 == test_string.cbegin() + 3,
    "test failure"
  );

  static_assert(epee::span<char>().empty(), "test failure");
  static_assert(epee::span<char>(nullptr).empty(), "test failure");
  static_assert(epee::span<const char>("foo", 2).size() == 2, "test failure");

  std::string std_to_hex(const std::vector<unsigned char>& source)
  {
    std::stringstream out;
    out << std::hex;
    for (const unsigned char byte : source)
    {
      out << std::setw(2) << std::setfill('0') << int(byte);
    }
    return out.str();
  }

  std::vector<unsigned char> get_all_bytes()
  {
    std::vector<unsigned char> out;
    out.resize(256);
    boost::range::iota(out, 0);
    return out;
  }
}

TEST(Span, Traits)
{
  EXPECT_TRUE((std::is_same<std::size_t, typename epee::span<char>::size_type>()));
  EXPECT_TRUE((std::is_same<std::ptrdiff_t, typename epee::span<char>::difference_type>()));
  EXPECT_TRUE((std::is_same<char, typename epee::span<char>::value_type>()));
  EXPECT_TRUE((std::is_same<char*, typename epee::span<char>::pointer>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<char>::const_pointer>()));
  EXPECT_TRUE((std::is_same<char*, typename epee::span<char>::iterator>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<char>::const_iterator>()));
  EXPECT_TRUE((std::is_same<char&, typename epee::span<char>::reference>()));
  EXPECT_TRUE((std::is_same<const char&, typename epee::span<char>::const_reference>()));

  EXPECT_TRUE((std::is_same<std::size_t, typename epee::span<const char>::size_type>()));
  EXPECT_TRUE((std::is_same<std::ptrdiff_t, typename epee::span<const char>::difference_type>()));
  EXPECT_TRUE((std::is_same<const char, typename epee::span<const char>::value_type>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<const char>::pointer>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<const char>::const_pointer>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<const char>::iterator>()));
  EXPECT_TRUE((std::is_same<const char*, typename epee::span<const char>::const_iterator>()));
  EXPECT_TRUE((std::is_same<const char&, typename epee::span<const char>::reference>()));
  EXPECT_TRUE((std::is_same<const char&, typename epee::span<const char>::const_reference>()));
}

TEST(Span, MutableConstruction)
{
  struct no_conversion{};

  EXPECT_TRUE(std::is_constructible<epee::span<char>>());
  EXPECT_TRUE((std::is_constructible<epee::span<char>, char*, std::size_t>()));
  EXPECT_FALSE((std::is_constructible<epee::span<char>, const char*, std::size_t>()));
  EXPECT_FALSE((std::is_constructible<epee::span<char>, unsigned char*, std::size_t>()));

  EXPECT_TRUE((can_construct<epee::span<char>, std::nullptr_t>()));
  EXPECT_TRUE((can_construct<epee::span<char>, char(&)[1]>()));

  EXPECT_FALSE((can_construct<epee::span<char>, std::vector<char>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, std::array<char, 1>>()));

  EXPECT_FALSE((can_construct<epee::span<char>, std::wstring>()));
  EXPECT_FALSE((can_construct<epee::span<char>, const std::vector<char>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, std::vector<unsigned char>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, const std::array<char, 1>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, std::array<unsigned char, 1>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, const char[1]>()));
  EXPECT_FALSE((can_construct<epee::span<char>, unsigned char[1]>()));
  EXPECT_FALSE((can_construct<epee::span<char>, epee::span<const char>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, epee::span<unsigned char>>()));
  EXPECT_FALSE((can_construct<epee::span<char>, no_conversion>()));
}

TEST(Span, ImmutableConstruction)
{
  struct no_conversion{};

  EXPECT_TRUE(std::is_constructible<epee::span<const char>>());
  EXPECT_TRUE((std::is_constructible<epee::span<const char>, char*, std::size_t>()));
  EXPECT_TRUE((std::is_constructible<epee::span<const char>, const char*, std::size_t>()));
  EXPECT_FALSE((std::is_constructible<epee::span<const char>, unsigned char*, std::size_t>()));

  EXPECT_FALSE((can_construct<epee::span<const char>, std::string>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, std::vector<char>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, const std::vector<char>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, std::array<char, 1>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, const std::array<char, 1>>()));

  EXPECT_TRUE((can_construct<epee::span<const char>, std::nullptr_t>()));
  EXPECT_TRUE((can_construct<epee::span<const char>, char[1]>()));
  EXPECT_TRUE((can_construct<epee::span<const char>, const char[1]>()));
  EXPECT_TRUE((can_construct<epee::span<const char>, epee::span<const char>>()));

  EXPECT_FALSE((can_construct<epee::span<const char>, std::wstring>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, std::vector<unsigned char>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, std::array<unsigned char, 1>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, unsigned char[1]>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, epee::span<unsigned char>>()));
  EXPECT_FALSE((can_construct<epee::span<const char>, no_conversion>()));
}

TEST(Span, NoExcept)
{
  EXPECT_TRUE(std::is_nothrow_default_constructible<epee::span<char>>());
  EXPECT_TRUE(std::is_nothrow_move_constructible<epee::span<char>>());
  EXPECT_TRUE(std::is_nothrow_copy_constructible<epee::span<char>>());
  EXPECT_TRUE(std::is_move_assignable<epee::span<char>>());
  EXPECT_TRUE(std::is_copy_assignable<epee::span<char>>());

  char data[10];
  epee::span<char> lvalue(data);
  const epee::span<char> clvalue(data);
  EXPECT_TRUE(noexcept(epee::span<char>()));
  EXPECT_TRUE(noexcept(epee::span<char>(nullptr)));
  EXPECT_TRUE(noexcept(epee::span<char>(nullptr, 0)));
  EXPECT_TRUE(noexcept(epee::span<char>(data)));
  EXPECT_TRUE(noexcept(epee::span<char>(lvalue)));
  EXPECT_TRUE(noexcept(epee::span<char>(clvalue)));

  // conversion from mutable to immutable not yet implemented
  // EXPECT_TRUE(noexcept(epee::span<const char>(lvalue)));
  // EXPECT_TRUE(noexcept(epee::span<const char>(clvalue)));

  EXPECT_TRUE(noexcept(epee::span<char>(epee::span<char>(lvalue))));
  EXPECT_TRUE(noexcept(lvalue = lvalue));
  EXPECT_TRUE(noexcept(lvalue = clvalue));
  EXPECT_TRUE(noexcept(lvalue = epee::span<char>(lvalue)));
}

TEST(Span, Nullptr)
{
  const auto check_empty = [](epee::span<const char> data)
  {
    EXPECT_TRUE(data.empty());
    EXPECT_EQ(data.cbegin(), data.begin());
    EXPECT_EQ(data.cend(), data.end());
    EXPECT_EQ(data.cend(), data.cbegin());
    EXPECT_EQ(0, data.size());
    EXPECT_EQ(0, data.size_bytes());
  };
  check_empty({});
  check_empty(nullptr); 
}

TEST(Span, Writing)
{
  const int expected[] = {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
  std::vector<int> source;

  epee::span<int> span;
  EXPECT_TRUE(span.empty());
  EXPECT_EQ(0, span.size());
  EXPECT_EQ(0, span.size_bytes());

  source.resize(15);
  span = {source.data(), source.size()};
  EXPECT_FALSE(span.empty());
  EXPECT_EQ(15, span.size());
  EXPECT_EQ(15 * 4, span.size_bytes());

  boost::range::iota(span, -5);
  EXPECT_EQ(span.begin(), span.cbegin());
  EXPECT_EQ(span.end(), span.cend());
  EXPECT_TRUE(boost::range::equal(expected, source));
  EXPECT_TRUE(boost::range::equal(expected, span));
}

TEST(Span, ToByteSpan)
{
  const char expected[] = {56, 44, 11, 5};
  EXPECT_TRUE(
    boost::range::equal(
      std::array<std::uint8_t, 4>{{56, 44, 11, 5}},
      epee::to_byte_span<char>(expected)
    )
  );
  EXPECT_TRUE(
    boost::range::equal(
      std::array<char, 4>{{56, 44, 11, 5}},
      epee::to_byte_span(epee::span<const char>{expected})
    )
  );
}

TEST(Span, AsByteSpan)
{
  struct some_pod { char value[4]; };
  const some_pod immutable {{ 5, 10, 12, 127 }};
  EXPECT_TRUE(
    boost::range::equal(
      std::array<unsigned char, 4>{{5, 10, 12, 127}},
      epee::as_byte_span(immutable)
    )
  );
  EXPECT_TRUE(
    boost::range::equal(
      std::array<std::uint8_t, 3>{{'a', 'y', 0x00}}, epee::as_byte_span("ay")
    )
  );
}

TEST(ToHex, String)
{
  EXPECT_TRUE(epee::to_hex::string(nullptr).empty());
  EXPECT_EQ(
    std::string{"ffab0100"},
    epee::to_hex::string(epee::as_byte_span("\xff\xab\x01"))
  );

  const std::vector<unsigned char> all_bytes = get_all_bytes();
  EXPECT_EQ(
    std_to_hex(all_bytes), epee::to_hex::string(epee::to_span(all_bytes))
  );
}

TEST(ToHex, Array)
{
  EXPECT_EQ(
    (std::array<char, 8>{{'f', 'f', 'a', 'b', '0', '1', '0', '0'}}),
    (epee::to_hex::array(std::array<unsigned char, 4>{{0xFF, 0xAB, 0x01, 0x00}}))
  );
}

TEST(ToHex, Ostream)
{
  std::stringstream out;
  epee::to_hex::buffer(out, nullptr);
  EXPECT_TRUE(out.str().empty());

  {
    const std::uint8_t source[] = {0xff, 0xab, 0x01, 0x00};
    epee::to_hex::buffer(out, source);
  }

  std::string expected{"ffab0100"};
  EXPECT_EQ(expected, out.str());

  const std::vector<unsigned char> all_bytes = get_all_bytes();

  expected.append(std_to_hex(all_bytes));
  epee::to_hex::buffer(out, epee::to_span(all_bytes));
  EXPECT_EQ(expected, out.str());
}

TEST(ToHex, Formatted)
{
  std::stringstream out;
  std::string expected{"<>"};

  epee::to_hex::formatted(out, nullptr);
  EXPECT_EQ(expected, out.str());

  expected.append("<ffab0100>");
  epee::to_hex::formatted(out, epee::as_byte_span("\xFF\xAB\x01"));
  EXPECT_EQ(expected, out.str());

  const std::vector<unsigned char> all_bytes = get_all_bytes();

  expected.append("<").append(std_to_hex(all_bytes)).append(">");
  epee::to_hex::formatted(out, epee::to_span(all_bytes));
  EXPECT_EQ(expected, out.str());
}

TEST(StringTools, BuffToHex)
{
  const std::vector<unsigned char> all_bytes = get_all_bytes();

  EXPECT_EQ(
    std_to_hex(all_bytes),
    (epee::string_tools::buff_to_hex_nodelimer(
      std::string{reinterpret_cast<const char*>(all_bytes.data()), all_bytes.size()}
    ))
  );
}

TEST(StringTools, PodToHex)
{
  struct some_pod { unsigned char data[4]; };
  EXPECT_EQ(
    std::string{"ffab0100"},
    (epee::string_tools::pod_to_hex(some_pod{{0xFF, 0xAB, 0x01, 0x00}}))
  );
}

TEST(StringTools, GetIpString)
{
  EXPECT_EQ(
    std::string{"0.0.0.0"}, epee::string_tools::get_ip_string_from_int32(0)
  );
  EXPECT_EQ(
    std::string{"255.0.255.0"},
    epee::string_tools::get_ip_string_from_int32(htonl(0xff00ff00))
  );
  EXPECT_EQ(
    std::string{"255.255.255.255"},
    epee::string_tools::get_ip_string_from_int32(htonl(0xffffffff))
  );
}

TEST(StringTools, GetIpInt32)
{
  std::uint32_t ip = 0;
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, ""));
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, "1."));
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, "1.1."));
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, "1.1.1."));
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, "ff.0.ff.0"));
  EXPECT_FALSE(epee::string_tools::get_ip_int32_from_string(ip, "1.1.1.256"));

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "1"));
  EXPECT_EQ(htonl(1), ip);

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "1.1"));
  EXPECT_EQ(htonl(0x1000001), ip);

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "1.1.1"));
  EXPECT_EQ(htonl(0x1010001), ip);

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "0.0.0.0"));
  EXPECT_EQ(0, ip);

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "1.1.1.1"));
  EXPECT_EQ(htonl(0x01010101), ip);

/*
  The existing epee conversion function does not work with 255.255.255.255, for
  the reasons specified in the inet_addr documentation. Consider fixing in a
  future patch. This address is not likely to be used for purposes within
  monero.
  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "255.255.255.255"));
  EXPECT_EQ(htonl(0xffffffff), ip);
*/

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "10.0377.0.0377"));
  EXPECT_EQ(htonl(0xaff00ff), ip);

  EXPECT_TRUE(epee::string_tools::get_ip_int32_from_string(ip, "0xff.10.0xff.0"));
  EXPECT_EQ(htonl(0xff0aff00), ip);
}