/*
 * GDevelop Core
 * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
 * reserved. This project is released under the MIT License.
 */

#ifndef GDCORE_EXPRESSION_H
#define GDCORE_EXPRESSION_H

#include "GDCore/String.h"
#include <memory>

namespace gd {
class ExpressionParser2;
class ObjectsContainer;
struct ExpressionNode;
}  // namespace gd

namespace gd {

/**
 * \brief Class representing an expression used as a parameter of a
 * gd::Instruction. This class is nothing more than a wrapper around a
 * gd::String.
 *
 * \see gd::Instruction
 *
 * \ingroup Events
 */
class GD_CORE_API Expression {
 public:
  /**
   * \brief Construct an empty expression
   */
  Expression();

  /**
   * \brief Construct an expression from a string
   */
  Expression(gd::String plainString_);

  /**
   * \brief Construct an expression from a const char *
   */
  Expression(const char* plainString_);

  /**
   * \brief Copy construct an expression.
   */
  Expression(const Expression& copy);

  /**
   * \brief Expression affectation overriding.
   */
  Expression& operator=(const Expression& expression);

  /**
   * \brief Get the plain string representing the expression
   */
  inline const gd::String& GetPlainString() const { return plainString; };

  /**
   * @brief Get the expression node.
   * @return std::unique_ptr<gd::ExpressionNode>
   */
  gd::ExpressionNode* GetRootNode() const;

  /**
   * \brief Mimics std::string::c_str
   */
  inline const char* c_str() const { return plainString.c_str(); };

  virtual ~Expression();

 private:
  gd::String plainString;  ///< The expression string
  mutable std::unique_ptr<gd::ExpressionNode> node;
};

}  // namespace gd

#endif  // GDCORE_EXPRESSION_H