/*

  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

/**

 * @author Christian <c@ethdev.com>

 * @date 2014

 * Scope - object that holds declaration of names.

 */

#pragma once

#include <libsolidity/ast/ASTForward.h>

#include <liblangutil/Exceptions.h>

#include <liblangutil/SourceLocation.h>

#include <memory>

namespace solidity::frontend

{

/**

 * Settings for how the function DeclarationContainer::resolveName operates.

 */

struct ResolvingSettings

{

  /// if true and there are no matching declarations in the current container,

  /// recursively searches the enclosing containers as well.

  bool recursive = false;

  /// if true, include invisible declaration in the results.

  bool alsoInvisible = false;

  /// if true, do not include declarations which can never actually be referenced using their

  /// name alone (without being qualified with the name of scope in which they are declared).

  bool onlyVisibleAsUnqualifiedNames = false;

};

/**

 * Container that stores mappings between names and declarations. It also contains a link to the

 * enclosing scope.

 */

class DeclarationContainer

{

public:

  using Homonyms = std::vector<std::pair<langutil::SourceLocation const*, std::vector<Declaration const*>>>;

  DeclarationContainer() = default;

  explicit DeclarationContainer(ASTNode const* _enclosingNode, DeclarationContainer* _enclosingContainer):

    m_enclosingNode(_enclosingNode),

    m_enclosingContainer(_enclosingContainer)

  {

    if (_enclosingContainer)

      _enclosingContainer->m_innerContainers.emplace_back(this);

  }

  /// Registers the declaration in the scope unless its name is already declared or the name is empty.

  /// @param _name the name to register, if nullptr the intrinsic name of @a _declaration is used.

  /// @param _location alternative location, used to point at homonymous declarations.

  /// @param _invisible if true, registers the declaration, reports name clashes but does not return it in @a resolveName.

  /// @param _update if true, replaces a potential declaration that is already present.

  /// @returns false if the name was already declared.

  bool registerDeclaration(Declaration const& _declaration, ASTString const* _name, langutil::SourceLocation const* _location, bool _invisible, bool _update);

  bool registerDeclaration(Declaration const& _declaration, bool _invisible, bool _update);

  /// Finds all declarations that in the current scope can be referred to using specified name.

  /// @param _name the name to look for.

  /// @param _settings see ResolvingSettings

  std::vector<Declaration const*> resolveName(ASTString const& _name, ResolvingSettings _settings = ResolvingSettings{}) const;

  ASTNode const* enclosingNode() const { return m_enclosingNode; }

  DeclarationContainer const* enclosingContainer() const { return m_enclosingContainer; }

  std::map<ASTString, std::vector<Declaration const*>> const& declarations() const { return m_declarations; }

  /// @returns whether declaration is valid, and if not also returns previous declaration.

  Declaration const* conflictingDeclaration(Declaration const& _declaration, ASTString const* _name = nullptr) const;

  /// Activates a previously inactive (invisible) variable. To be used in C99 scoping for

  /// VariableDeclarationStatements.

  void activateVariable(ASTString const& _name);

  /// @returns true if declaration is currently invisible.

  bool isInvisible(ASTString const& _name) const;

  /// @returns existing declaration names similar to @a _name.

  /// Searches this and all parent containers.

  std::vector<ASTString> similarNames(ASTString const& _name) const;

  /// Populates a vector of (location, declaration) pairs, where location is a location of an inner-scope declaration,

  /// and declaration is the corresponding homonymous outer-scope declaration.

  void populateHomonyms(std::back_insert_iterator<Homonyms> _it) const;

private:

  ASTNode const* m_enclosingNode = nullptr;

  DeclarationContainer const* m_enclosingContainer = nullptr;

  std::vector<DeclarationContainer const*> m_innerContainers;

  std::map<ASTString, std::vector<Declaration const*>> m_declarations;

  std::map<ASTString, std::vector<Declaration const*>> m_invisibleDeclarations;

  /// List of declarations (name and location) to check later for homonymity.

  std::vector<std::pair<std::string, langutil::SourceLocation const*>> m_homonymCandidates;

};

}