/*

  This file is part of solidity.

  solidity is free software: you can redistribute it and/or modify

  it under the terms of the GNU General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  solidity 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 for more details.

  You should have received a copy of the GNU General Public License

  along with solidity.  If not, see <http://www.gnu.org/licenses/>.

*/

// SPDX-License-Identifier: GPL-3.0

/** @file CommonData.cpp

 * @author Gav Wood <i@gavwood.com>

 * @date 2014

 */

#include <libsolutil/Assertions.h>

#include <libsolutil/CommonData.h>

#include <libsolutil/Exceptions.h>

#include <libsolutil/FixedHash.h>

#include <libsolutil/Keccak256.h>

#include <libsolutil/StringUtils.h>

#include <boost/algorithm/string.hpp>

using namespace std;

using namespace solidity;

using namespace solidity::util;

namespace

{

static char const* upperHexChars = "0123456789ABCDEF";

static char const* lowerHexChars = "0123456789abcdef";

}

string solidity::util::toHex(uint8_t _data, HexCase _case)

{

  assertThrow(_case != HexCase::Mixed, BadHexCase, "Mixed case can only be used for byte arrays.");

  char const* chars = _case == HexCase::Upper ? upperHexChars : lowerHexChars;

  return std::string{

    chars[(unsigned(_data) / 16) & 0xf],

    chars[unsigned(_data) & 0xf]

  };

}

string solidity::util::toHex(bytes const& _data, HexPrefix _prefix, HexCase _case)

{

  std::string ret(_data.size() * 2 + (_prefix == HexPrefix::Add ? 2 : 0), 0);

  size_t i = 0;

  if (_prefix == HexPrefix::Add)

  {

    ret[i++] = '0';

    ret[i++] = 'x';

  }

  // Mixed case will be handled inside the loop.

  char const* chars = _case == HexCase::Upper ? upperHexChars : lowerHexChars;

  size_t rix = _data.size() - 1;

  for (uint8_t c: _data)

  {

    // switch hex case every four hexchars

    if (_case == HexCase::Mixed)

      chars = (rix-- & 2) == 0 ? lowerHexChars : upperHexChars;

    ret[i++] = chars[(static_cast<size_t>(c) >> 4ul) & 0xfu];

    ret[i++] = chars[c & 0xfu];

  }

  assertThrow(i == ret.size(), Exception, "");

  return ret;

}

int solidity::util::fromHex(char _i, WhenError _throw)

{

  if (_i >= '0' && _i <= '9')

    return _i - '0';

  if (_i >= 'a' && _i <= 'f')

    return _i - 'a' + 10;

  if (_i >= 'A' && _i <= 'F')

    return _i - 'A' + 10;

  if (_throw == WhenError::Throw)

    assertThrow(false, BadHexCharacter, to_string(_i));

  else

    return -1;

}

bytes solidity::util::fromHex(std::string const& _s, WhenError _throw)

{

  if (_s.empty())

    return {};

  unsigned s = (_s.size() >= 2 && _s[0] == '0' && _s[1] == 'x') ? 2 : 0;

  std::vector<uint8_t> ret;

  ret.reserve((_s.size() - s + 1) / 2);

  if (_s.size() % 2)

  {

    int h = fromHex(_s[s++], _throw);

    if (h != -1)

      ret.push_back(static_cast<uint8_t>(h));

    else

      return bytes();

  }

  for (unsigned i = s; i < _s.size(); i += 2)

  {

    int h = fromHex(_s[i], _throw);

    int l = fromHex(_s[i + 1], _throw);

    if (h != -1 && l != -1)

      ret.push_back(static_cast<uint8_t>(h * 16 + l));

    else

      return bytes();

  }

  return ret;

}

bool solidity::util::passesAddressChecksum(string const& _str, bool _strict)

{

  string s = _str.substr(0, 2) == "0x" ? _str : "0x" + _str;

  if (s.length() != 42)

    return false;

  if (!_strict && (

    s.find_first_of("abcdef") == string::npos ||

    s.find_first_of("ABCDEF") == string::npos

  ))

    return true;

  return s == solidity::util::getChecksummedAddress(s);

}

string solidity::util::getChecksummedAddress(string const& _addr)

{

  string s = _addr.substr(0, 2) == "0x" ? _addr.substr(2) : _addr;

  assertThrow(s.length() == 40, InvalidAddress, "");

  assertThrow(s.find_first_not_of("0123456789abcdefABCDEF") == string::npos, InvalidAddress, "");

  h256 hash = keccak256(boost::algorithm::to_lower_copy(s, std::locale::classic()));

  string ret = "0x";

  for (unsigned i = 0; i < 40; ++i)

  {

    char addressCharacter = s[i];

    uint8_t nibble = hash[i / 2u] >> (4u * (1u - (i % 2u))) & 0xf;

    if (nibble >= 8)

      ret += toUpper(addressCharacter);

    else

      ret += toLower(addressCharacter);

  }

  return ret;

}

bool solidity::util::isValidHex(string const& _string)

{

  if (_string.substr(0, 2) != "0x")

    return false;

  if (_string.find_first_not_of("0123456789abcdefABCDEF", 2) != string::npos)

    return false;

  return true;

}

bool solidity::util::isValidDecimal(string const& _string)

{

  if (_string.empty())

    return false;

  if (_string == "0")

    return true;

  // No leading zeros

  if (_string.front() == '0')

    return false;

  if (_string.find_first_not_of("0123456789") != string::npos)

    return false;

  return true;

}

string solidity::util::formatAsStringOrNumber(string const& _value)

{

  assertThrow(_value.length() <= 32, StringTooLong, "String to be formatted longer than 32 bytes.");

  for (auto const& c: _value)

    if (c <= 0x1f || c >= 0x7f || c == '"')

      return "0x" + h256(_value, h256::AlignLeft).hex();

  return escapeAndQuoteString(_value);

}

string solidity::util::escapeAndQuoteString(string const& _input)

{

  string out;

  for (char c: _input)

    if (c == '\\')

      out += "\\\\";

    else if (c == '"')

      out += "\\\"";

    else if (c == '\n')

      out += "\\n";

    else if (c == '\r')

      out += "\\r";

    else if (c == '\t')

      out += "\\t";

    else if (!isPrint(c))

    {

      ostringstream o;

      o << "\\x" << std::hex << setfill('0') << setw(2) << (unsigned)(unsigned char)(c);

      out += o.str();

    }

    else

      out += c;

  return "\"" + std::move(out) + "\"";

}