/*

  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

#include <libsolidity/experimental/codegen/IRGenerator.h>

#include <libsolidity/experimental/codegen/IRGenerationContext.h>

#include <libsolidity/experimental/codegen/IRGeneratorForStatements.h>

#include <libsolidity/experimental/codegen/Common.h>

#include <libsolidity/experimental/analysis/Analysis.h>

#include <libsolidity/experimental/analysis/TypeInference.h>

#include <libsolidity/experimental/ast/TypeSystemHelper.h>

#include <libyul/AsmPrinter.h>

#include <libyul/AST.h>

#include <libyul/optimiser/ASTCopier.h>

#include <liblangutil/SourceReferenceFormatter.h>

#include <libsolutil/Whiskers.h>

#include <range/v3/view/drop_last.hpp>

#include <variant>

using namespace solidity;

using namespace solidity::frontend::experimental;

using namespace solidity::langutil;

using namespace solidity::util;

IRGenerator::IRGenerator(

  EVMVersion _evmVersion,

  frontend::RevertStrings, std::map<std::string, unsigned int>,

  DebugInfoSelection const&,

  CharStreamProvider const*,

  Analysis const& _analysis

):

  m_evmVersion(_evmVersion),

  //m_debugInfoSelection(_debugInfoSelection),

  //m_soliditySourceProvider(_soliditySourceProvider),

  m_env(_analysis.typeSystem().env().clone()),

  m_context{_analysis, &m_env, {}, {}}

{

}

std::string IRGenerator::run(

  ContractDefinition const& _contract,

  bytes const& /*_cborMetadata*/,

  std::map<ContractDefinition const*, std::string_view const> const& /*_otherYulSources*/

)

{

  Whiskers t(R"(

    object "<CreationObject>" {

      code {

        codecopy(0, dataoffset("<DeployedObject>"), datasize("<DeployedObject>"))

        return(0, datasize("<DeployedObject>"))

      }

      object "<DeployedObject>" {

        code {

          <code>

        }

      }

    }

  )");

  t("CreationObject", IRNames::creationObject(_contract));

  t("DeployedObject", IRNames::deployedObject(_contract));

  t("code", generate(_contract));

  return t.render();

}

std::string IRGenerator::generate(ContractDefinition const& _contract)

{

  std::stringstream code;

  code << "{\n";

  if (_contract.fallbackFunction())

  {

    auto type = m_context.analysis.annotation<TypeInference>(*_contract.fallbackFunction()).type;

    solAssert(type);

    type = m_context.env->resolve(*type);

    code << IRNames::function(*m_context.env, *_contract.fallbackFunction(), *type) << "()\n";

    m_context.enqueueFunctionDefinition(_contract.fallbackFunction(), *type);

  }

  code << "revert(0,0)\n";

  code << "}\n";

  while (!m_context.functionQueue.empty())

  {

    auto queueEntry = m_context.functionQueue.front();

    m_context.functionQueue.pop_front();

    auto& generatedTypes = m_context.generatedFunctions.insert(std::make_pair(queueEntry.function, std::vector<Type>{})).first->second;

    if (!util::contains_if(generatedTypes, [&](auto const& _generatedType) { return m_context.env->typeEquals(_generatedType, queueEntry.type); }))

    {

      generatedTypes.emplace_back(queueEntry.type);

      code << generate(*queueEntry.function, queueEntry.type);

    }

  }

  return code.str();

}

std::string IRGenerator::generate(FunctionDefinition const& _function, Type _type)

{

  TypeEnvironment newEnv = m_context.env->clone();

  ScopedSaveAndRestore envRestore{m_context.env, &newEnv};

  auto type = m_context.analysis.annotation<TypeInference>(_function).type;

  solAssert(type);

  for (auto err: newEnv.unify(*type, _type))

  {

    TypeEnvironmentHelpers helper{newEnv};

    solAssert(false, helper.typeToString(*type) + " <-> " + helper.typeToString(_type));

  }

  std::stringstream code;

  code << "function " << IRNames::function(newEnv, _function, _type) << "(";

  if (_function.parameters().size() > 1)

    for (auto const& arg: _function.parameters() | ranges::views::drop_last(1))

      code << IRNames::localVariable(*arg) << ", ";

  if (!_function.parameters().empty())

    code << IRNames::localVariable(*_function.parameters().back());

  code << ")";

  if (_function.experimentalReturnExpression())

  {

    auto returnType = m_context.analysis.annotation<TypeInference>(*_function.experimentalReturnExpression()).type;

    solAssert(returnType);

    if (!m_env.typeEquals(*returnType, m_context.analysis.typeSystem().type(PrimitiveType::Unit, {})))

    {

      // TODO: destructure tuples.

      code << " -> " << IRNames::localVariable(*_function.experimentalReturnExpression()) << " ";

    }

  }

  code << "{\n";

  for (auto _statement: _function.body().statements())

  {

    IRGeneratorForStatements statementGenerator{m_context};

    code << statementGenerator.generate(*_statement);

  }

  code << "}\n";

  return code.str();

}