/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#include "cmUnsetCommand.h"

#include "cmAlgorithms.h"
#include "cmMakefile.h"
#include "cmSystemTools.h"

class cmExecutionStatus;

// cmUnsetCommand
bool
cmUnsetCommand::InitialPass(std::vector<std::string> const& args,
                            cmExecutionStatus&)
{
    if(args.empty() || args.size() > 2)
    {
        this->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);

#ifdef CMAKE_BUILD_WITH_CMAKE
        cmSystemTools::UnsetEnv(envVarName.c_str());
#endif
        return true;
    }
    // unset(VAR)
    if(args.size() == 1)
    {
        this->Makefile->RemoveDefinition(variable);
        return true;
    }
    // unset(VAR CACHE)
    if((args.size() == 2) && (args[1] == "CACHE"))
    {
        this->Makefile->RemoveCacheDefinition(variable);
        return true;
    }
    // unset(VAR PARENT_SCOPE)
    if((args.size() == 2) && (args[1] == "PARENT_SCOPE"))
    {
        this->Makefile->RaiseScope(variable, nullptr);
        return true;
    }
    // ERROR: second argument isn't CACHE or PARENT_SCOPE
    this->SetError("called with an invalid second argument");
    return false;
}
