/*============================================================================
  CMake - Cross Platform Makefile Generator
  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium

  Distributed under the OSI-approved BSD License (the "License");
  see accompanying file Copyright.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the License for more information.
============================================================================*/
#include "cmSetCommand.h"

// cmSetCommand
bool cmSetCommand
::InitialPass(std::vector<std::string> const& args, cmExecutionStatus &)
{
  if(args.size() < 1 )
    {
    this->SetError("called with incorrect number of arguments");
    return false;
    }

  // watch for ENV signatures
  const char* variable = args[0].c_str(); // VAR is always first
  if (cmHasLiteralPrefix(variable, "ENV{") && strlen(variable) > 5)
    {
    // what is the variable name
    char *varName = new char [strlen(variable)];
    strncpy(varName,variable+4,strlen(variable)-5);
    varName[strlen(variable)-5] = '\0';
    std::string putEnvArg = varName;
    putEnvArg += "=";

    // what is the current value if any
    const char *currValue = getenv(varName);
    delete [] varName;

    // will it be set to something, then set it
    if (args.size() > 1 && !args[1].empty())
      {
      // but only if it is different from current value
      if (!currValue || strcmp(currValue,args[1].c_str()))
        {
        putEnvArg += args[1];
        cmSystemTools::PutEnv(putEnvArg);
        }
      return true;
      }

    // if it will be cleared, then clear it if it isn't already clear
    if (currValue)
      {
      cmSystemTools::PutEnv(putEnvArg);
      }
    return true;
    }

  // SET (VAR) // Removes the definition of VAR.
  if (args.size() == 1)
    {
    this->Makefile->RemoveDefinition(variable);
    return true;
    }
  // SET (VAR PARENT_SCOPE) // Removes the definition of VAR
                            // in the parent scope.
  else if (args.size() == 2 && args[args.size()-1] == "PARENT_SCOPE")
    {
    this->Makefile->RaiseScope(variable, 0);
    return true;
    }

  // here are the remaining options
  //  SET (VAR value )
  //  SET (VAR value PARENT_SCOPE)
  //  SET (VAR CACHE TYPE "doc String" [FORCE])
  //  SET (VAR value CACHE TYPE "doc string" [FORCE])
  std::string value;  // optional
  bool cache = false; // optional
  bool force = false; // optional
  bool parentScope = false;
  cmState::CacheEntryType type
    = cmState::STRING; // required if cache
  const char* docstring = 0; // required if cache

  unsigned int ignoreLastArgs = 0;
  // look for PARENT_SCOPE argument
  if (args.size() > 1 && args[args.size()-1] == "PARENT_SCOPE")
    {
    parentScope = true;
    ignoreLastArgs++;
    }
  else
    {
    // look for FORCE argument
    if (args.size() > 4 && args[args.size()-1] == "FORCE")
      {
      force = true;
      ignoreLastArgs++;
      }

    // check for cache signature
    if (args.size() > 3 && args[args.size() - 3 - (force ? 1 : 0)] == "CACHE")
      {
      cache = true;
      ignoreLastArgs+=3;
      }
    }

  // collect any values into a single semi-colon separated value list
  value = cmJoin(cmMakeRange(args).advance(1).retreat(ignoreLastArgs), ";");

  if (parentScope)
    {
    this->Makefile->RaiseScope(variable, value.c_str());
    return true;
    }


  // we should be nice and try to catch some simple screwups if the last or
  // next to last args are CACHE then they screwed up.  If they used FORCE
  // without CACHE they screwed up
  if ((args[args.size() - 1] == "CACHE") ||
      (args.size() > 1 && args[args.size() - 2] == "CACHE") ||
      (force && !cache))
    {
    this->SetError("given invalid arguments for CACHE mode.");
    return false;
    }

  if(cache)
    {
    std::string::size_type cacheStart = args.size() - 3 - (force ? 1 : 0);
    type = cmState::StringToCacheEntryType(args[cacheStart+1].c_str());
    docstring = args[cacheStart+2].c_str();
    }

  // see if this is already in the cache
  cmState* state = this->Makefile->GetState();
  const char* existingValue = state->GetCacheEntryValue(variable);
  if(existingValue &&
      (state->GetCacheEntryType(variable) != cmState::UNINITIALIZED))
    {
    // if the set is trying to CACHE the value but the value
    // is already in the cache and the type is not internal
    // then leave now without setting any definitions in the cache
    // or the makefile
    if(cache && type != cmState::INTERNAL && !force)
      {
      return true;
      }
    }

  // if it is meant to be in the cache then define it in the cache
  if(cache)
    {
    this->Makefile->AddCacheDefinition(variable,
                                   value.c_str(),
                                   docstring,
                                   type, force);
    }
  else
    {
    // add the definition
    this->Makefile->AddDefinition(variable, value.c_str());
    }
  return true;
}