/*=========================================================================

  Program:   CMake - Cross-Platform Makefile Generator
  Module:    $RCSfile$
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
  See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef cmIfCommand_h
#define cmIfCommand_h

#include "cmStandardIncludes.h"
#include "cmCommand.h"
#include "cmFunctionBlocker.h"

/** \class cmIfFunctionBlocker
 * \brief subclass of function blocker
 *
 * 
 */
class cmIfFunctionBlocker : public cmFunctionBlocker
{
public:
  cmIfFunctionBlocker() {}
  virtual ~cmIfFunctionBlocker() {}
  virtual bool IsFunctionBlocked(const cmListFileFunction& lff,
                                 cmMakefile &mf);
  virtual bool ShouldRemove(const cmListFileFunction& lff,
                            cmMakefile &mf);
  virtual void ScopeEnded(cmMakefile &mf);
  
  std::vector<cmListFileArgument> m_Args;
  bool m_IsBlocking;
};

/** \class cmIfCommand
 * \brief starts an if block
 *
 * cmIfCommand starts an if block
 */
class cmIfCommand : public cmCommand
{
public:
  /**
   * This is a virtual constructor for the command.
   */
  virtual cmCommand* Clone() 
    {
    return new cmIfCommand;
    }

  /**
   * This overrides the default InvokeInitialPass implementation.
   * It records the arguments before expansion.
   */
  virtual bool InvokeInitialPass(const std::vector<cmListFileArgument>& args);
    
  /**
   * This is called when the command is first encountered in
   * the CMakeLists.txt file.
   */
  virtual bool InitialPass(std::vector<std::string> const& args) { return false; }

  /**
   * The name of the command as specified in CMakeList.txt.
   */
  virtual const char* GetName() { return "IF";}

  /**
   * Succinct documentation.
   */
  virtual const char* GetTerseDocumentation() 
    {
    return "start an if block";
    }
  
  /**
   * This determines if the command gets propagated down
   * to makefiles located in subdirectories.
   */
  virtual bool IsInherited() {return true;}

  /**
   * More documentation.
   */
  virtual const char* GetFullDocumentation()
    {
    return
      "IF (define) Starts an if block. Optionally it can be invoked "
      "using (NOT define) (def AND def2) (def OR def2) (def MATCHES def2) "
      "(COMMAND cmd) (EXISTS file) MATCHES checks if def matches the "
      "regular expression def2. COMMAND checks if the cmake command cmd "
      "is in this cmake executable. EXISTS file checks if file exists."
      "Additionally you can do comparisons using LESS GREATER STRLESS "
      "and STRGREATER. LESS and GREATER do numeric comparison while "
      "STRLESS and STRGREATER do string comparisons.";
    }

  // this is a shared function for both If and Else to determine if
  // the arguments were valid, and if so, was the response true
  static bool IsTrue(const std::vector<std::string> &args, 
                     bool &isValid, const cmMakefile *mf);
  
  // Get a definition from the makefile.  If it doesn't exist,
  // return the original string.
  static const char* GetVariableOrString(const char* str,
                                         const cmMakefile* mf);
  
  cmTypeMacro(cmIfCommand, cmCommand);
};


#endif