/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#ifndef cmVariableWatchCommand_h
#define cmVariableWatchCommand_h

#include "cmConfigure.h"  // IWYU pragma: keep

#include <set>
#include <string>
#include <vector>

#include "cmCommand.h"

class cmExecutionStatus;

/** \class cmVariableWatchCommand
 * \brief Watch when the variable changes and invoke command
 *
 */
class cmVariableWatchCommand : public cmCommand
{
public:
    /**
     * This is a virtual constructor for the command.
     */
    cmCommand* Clone() override { return new cmVariableWatchCommand; }

    //! Default constructor
    cmVariableWatchCommand();

    //! Destructor.
    ~cmVariableWatchCommand() override;

    /**
     * This is called when the command is first encountered in
     * the CMakeLists.txt file.
     */
    bool InitialPass(std::vector<std::string> const& args,
                     cmExecutionStatus&              status) override;

    /** This command does not really have a final pass but it needs to
        stay alive since it owns variable watch callback information. */
    bool HasFinalPass() const override { return true; }

protected:
    std::set<std::string> WatchedVariables;
};

#endif
