/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmUnsetCommand.h"

#include "cmExecutionStatus.h"

#include "cmMakefile.h"

#include "cmStringAlgorithms.h"

#include "cmSystemTools.h"

// cmUnsetCommand

bool cmUnsetCommand(std::vector<std::string> const& args,

                    cmExecutionStatus& status)

{

  if (args.empty() || args.size() > 2) {

    status.SetError("called with incorrect number of arguments");

    return false;

  }

  auto const& variable = args[0];

  // unset(ENV{VAR})

  if (cmHasLiteralPrefix(variable, "ENV{") && variable.size() > 5) {

    // what is the variable name

    auto const& envVarName = variable.substr(4, variable.size() - 5);

#ifndef CMAKE_BOOTSTRAP

    cmSystemTools::UnsetEnv(envVarName.c_str());

#endif

    return true;

  }

  // unset(CACHE{VAR})

  if (cmHasLiteralPrefix(variable, "CACHE{") && variable.size() > 7 &&

      cmHasSuffix(variable, '}')) {

    // get the variable name

    auto const& varName = variable.substr(6, variable.size() - 7);

    status.GetMakefile().RemoveCacheDefinition(varName);

    return true;

  }

  // unset(VAR)

  if (args.size() == 1) {

    status.GetMakefile().RemoveDefinition(variable);

    return true;

  }

  // unset(VAR CACHE)

  if ((args.size() == 2) && (args[1] == "CACHE")) {

    status.GetMakefile().RemoveCacheDefinition(variable);

    return true;

  }

  // unset(VAR PARENT_SCOPE)

  if ((args.size() == 2) && (args[1] == "PARENT_SCOPE")) {

    status.GetMakefile().RaiseScope(variable, nullptr);

    return true;

  }

  // ERROR: second argument isn't CACHE or PARENT_SCOPE

  status.SetError("called with an invalid second argument");

  return false;

}