/*

  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

/**

 * Some useful snippets for the optimiser.

 */

#include <libyul/Utilities.h>

#include <libyul/backends/evm/EVMDialect.h>

#include <libyul/AST.h>

#include <libyul/Dialect.h>

#include <libyul/Exceptions.h>

#include <libsolutil/CommonData.h>

#include <libsolutil/FixedHash.h>

#include <libsolutil/Visitor.h>

#include <boost/algorithm/string.hpp>

#include <algorithm>

#include <sstream>

#include <vector>

using namespace solidity;

using namespace solidity::yul;

using namespace solidity::util;

std::string solidity::yul::reindent(std::string const& _code)

{

  int constexpr indentationWidth = 4;

  auto constexpr static countBraces = [](std::string const& _s) noexcept -> int

  {

    auto const i = _s.find("//");

    auto const e = i == _s.npos ? end(_s) : next(begin(_s), static_cast<ptrdiff_t>(i));

    auto const opening = count_if(begin(_s), e, [](auto ch) { return ch == '{' || ch == '('; });

    auto const closing = count_if(begin(_s), e, [](auto ch) { return ch == '}' || ch == ')'; });

    return int(opening - closing);

  };

  std::vector<std::string> lines;

  boost::split(lines, _code, boost::is_any_of("\n"));

  for (std::string& line: lines)

    boost::trim(line);

  // Reduce multiple consecutive empty lines.

  lines = fold(lines, std::vector<std::string>{}, [](auto&& _lines, auto&& _line) {

    if (!(_line.empty() && !_lines.empty() && _lines.back().empty()))

      _lines.emplace_back(std::move(_line));

    return std::move(_lines);

  });

  std::stringstream out;

  int depth = 0;

  for (std::string const& line: lines)

  {

    int const diff = countBraces(line);

    if (diff < 0)

      depth += diff;

    if (!line.empty())

    {

      for (int i = 0; i < depth * indentationWidth; ++i)

        out << ' ';

      out << line;

    }

    out << '\n';

    if (diff > 0)

      depth += diff;

  }

  return out.str();

}

LiteralValue solidity::yul::valueOfNumberLiteral(std::string_view const _literal)

{

  return LiteralValue{LiteralValue::Data(_literal), std::string(_literal)};

}

LiteralValue solidity::yul::valueOfStringLiteral(std::string_view const _literal)

{

  std::string const s(_literal);

  return LiteralValue{u256(h256(s, h256::FromBinary, h256::AlignLeft)), s};

}

LiteralValue solidity::yul::valueOfBuiltinStringLiteralArgument(std::string_view _literal)

{

  return LiteralValue{std::string(_literal)};

}

LiteralValue solidity::yul::valueOfBoolLiteral(std::string_view const _literal)

{

  if (_literal == "true")

    return LiteralValue{true};

  else if (_literal == "false")

    return LiteralValue{false};

  yulAssert(false, "Unexpected bool literal value!");

}

LiteralValue solidity::yul::valueOfLiteral(std::string_view const _literal, LiteralKind const& _kind, bool const _unlimitedLiteralArgument)

{

  switch (_kind)

  {

  case LiteralKind::Number:

    return valueOfNumberLiteral(_literal);

  case LiteralKind::Boolean:

    return valueOfBoolLiteral(_literal);

  case LiteralKind::String:

    return _unlimitedLiteralArgument ? valueOfBuiltinStringLiteralArgument(_literal) : valueOfStringLiteral(_literal);

  }

  util::unreachable();

}

std::string solidity::yul::formatLiteral(solidity::yul::Literal const& _literal, bool const _validated)

{

  if (_validated)

    yulAssert(validLiteral(_literal), "Encountered invalid literal in formatLiteral.");

  if (_literal.value.unlimited())

    return _literal.value.builtinStringLiteralValue();

  if (_literal.value.hint())

    return *_literal.value.hint();

  if (_literal.kind == LiteralKind::Boolean)

    return _literal.value.value() == false ? "false" : "true";

  // if there is no hint and it is not a boolean, just stringify the u256 word

  return _literal.value.value().str();

}

bool solidity::yul::validLiteral(solidity::yul::Literal const& _literal)

{

  switch (_literal.kind)

  {

  case LiteralKind::Number:

    return validNumberLiteral(_literal);

  case LiteralKind::Boolean:

    return validBoolLiteral(_literal);

  case LiteralKind::String:

    return validStringLiteral(_literal);

  }

  util::unreachable();

}

bool solidity::yul::validStringLiteral(solidity::yul::Literal const& _literal)

{

  if (_literal.kind != LiteralKind::String)

    return false;

  if (_literal.value.unlimited())

    return true;

  if (_literal.value.hint())

    return _literal.value.hint()->size() <= 32 && _literal.value.value() == valueOfLiteral(*_literal.value.hint(), _literal.kind).value();

  return true;

}

bool solidity::yul::validNumberLiteral(solidity::yul::Literal const& _literal)

{

  if (_literal.kind != LiteralKind::Number || _literal.value.unlimited())

    return false;

  if (!_literal.value.hint())

    return true;

  auto const& repr = *_literal.value.hint();

  if (!isValidDecimal(repr) && !isValidHex(repr))

    return false;

  if (bigint(repr) > u256(-1))

    return false;

  if (_literal.value.value() != valueOfLiteral(repr, _literal.kind).value())

    return false;

  return true;

}

bool solidity::yul::validBoolLiteral(solidity::yul::Literal const& _literal)

{

  if (_literal.kind != LiteralKind::Boolean || _literal.value.unlimited())

    return false;

  if (_literal.value.hint() && !(*_literal.value.hint() == "true" || *_literal.value.hint() == "false"))

    return false;

  yulAssert(u256(0) == u256(false));

  yulAssert(u256(1) == u256(true));

  if (_literal.value.hint())

  {

    if (*_literal.value.hint() == "false")

      return _literal.value.value() == false;

    else

      return _literal.value.value() == true;

  }

  return _literal.value.value() == true || _literal.value.value() == false;

}

template<>

bool Less<Literal>::operator()(Literal const& _lhs, Literal const& _rhs) const

{

  if (_lhs.kind != _rhs.kind)

    return _lhs.kind < _rhs.kind;

  if (_lhs.value.unlimited() && _rhs.value.unlimited())

    yulAssert(

      _lhs.kind == LiteralKind::String && _rhs.kind == LiteralKind::String,

      "Cannot have unlimited value that is not of String kind."

    );

  return _lhs.value < _rhs.value;

}

bool SwitchCaseCompareByLiteralValue::operator()(Case const* _lhs, Case const* _rhs) const

{

  yulAssert(_lhs && _rhs, "");

  return Less<Literal*>{}(_lhs->value.get(), _rhs->value.get());

}

std::string_view yul::resolveFunctionName(FunctionName const& _functionName, Dialect const& _dialect)

{

  GenericVisitor visitor{

    [&](Identifier const& _identifier) -> std::string const& { return _identifier.name.str(); },

    [&](BuiltinName const& _builtin) -> std::string const& { return _dialect.builtin(_builtin.handle).name; }

  };

  return std::visit(visitor, _functionName);

}

BuiltinFunction const* yul::resolveBuiltinFunction(FunctionName const& _functionName, Dialect const& _dialect)

{

  GenericVisitor visitor{

    [&](Identifier const&) -> BuiltinFunction const* { return nullptr; },

    [&](BuiltinName const& _builtin) -> BuiltinFunction const* { return &_dialect.builtin(_builtin.handle); }

  };

  return std::visit(visitor, _functionName);

}

BuiltinFunctionForEVM const* yul::resolveBuiltinFunctionForEVM(FunctionName const& _functionName, EVMDialect const& _dialect)

{

  GenericVisitor visitor{

    [&](Identifier const&) -> BuiltinFunctionForEVM const* { return nullptr; },

    [&](BuiltinName const& _builtin) -> BuiltinFunctionForEVM const* { return &_dialect.builtin(_builtin.handle); }

  };

  return std::visit(visitor, _functionName);

}

FunctionHandle yul::functionNameToHandle(FunctionName const& _functionName)

{

  GenericVisitor visitor{

    [&](Identifier const& _identifier) -> FunctionHandle { return _identifier.name; },

    [&](BuiltinName const& _builtin) -> FunctionHandle { return _builtin.handle; }

  };

  return std::visit(visitor, _functionName);

}