/*

  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

#pragma once

#include <libyul/ASTForward.h>

#include <libyul/optimiser/ASTWalker.h>

#include <libyul/YulString.h>

#include <libyul/optimiser/OptimiserStep.h>

#include <map>

#include <set>

#include <string>

namespace solidity::yul

{

struct Dialect;

/**

 * Pass to normalize identifier suffixes.

 *

 * That is, for each function scope, nested suffixes get flattened and all suffixes

 * renumbered by their base name.

 * Function names are not modified.

 *

 * NOTE: This step destroys the promise of the Disambiguator and thus cannot

 * be used in the main loop of the optimizer without running the disambiguator again.

 * Because of that, it is not included in the step list of the Optimizer Suite.

 *

 * Prerequisites: Disambiguator, FunctionHoister, FunctionGrouper

 */

class VarNameCleaner: public ASTModifier

{

public:

  static constexpr char const* name{"VarNameCleaner"};

  static void run(OptimiserStepContext& _context, Block& _ast)

  {

    VarNameCleaner{_ast, _context.dialect, _context.reservedIdentifiers}(_ast);

  }

  using ASTModifier::operator();

  void operator()(VariableDeclaration& _varDecl) override;

  void operator()(Identifier& _identifier) override;

  void operator()(FunctionDefinition& _funDef) override;

private:

  VarNameCleaner(

    Block const& _ast,

    Dialect const& _dialect,

    std::set<YulString> _namesToKeep = {}

  );

  /// Tries to rename a list of variables.

  void renameVariables(std::vector<TypedName>& _variables);

  /// @returns suffix-stripped name, if a suffix was detected, none otherwise.

  YulString stripSuffix(YulString const& _name) const;

  /// Looks out for a "clean name" the given @p name could be trimmed down to.

  /// @returns a trimmed down and "clean name" in case it found one, none otherwise.

  YulString findCleanName(YulString const& name) const;

  /// Tests whether a given name was already used within this pass

  /// or was set to be kept.

  bool isUsedName(YulString const& _name) const;

  Dialect const& m_dialect;

  /// These names will not be modified.

  std::set<YulString> m_namesToKeep;

  /// Set of names that are in use.

  std::set<YulString> m_usedNames;

  /// Maps old to new names.

  std::map<YulString, YulString> m_translatedNames;

  /// Whether the traverse is inside a function definition.

  /// Used to assert that a function definition cannot be inside another.

  bool m_insideFunction = false;

};

}