/*============================================================================
  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 "cmIfCommand.h"
#include "cmStringCommand.h"

#include "cmConditionEvaluator.h"

#include <stdlib.h> // required for atof
#include <list>
#include <cmsys/RegularExpression.hxx>


static std::string cmIfCommandError(
  cmMakefile* mf, std::vector<std::string> const& args)
{
  cmLocalGenerator* lg = mf->GetLocalGenerator();
  std::string err = "given arguments:\n ";
  for(std::vector<std::string>::const_iterator i = args.begin();
      i != args.end(); ++i)
    {
    err += " ";
    err += lg->EscapeForCMake(*i);
    }
  err += "\n";
  return err;
}

//=========================================================================
bool cmIfFunctionBlocker::
IsFunctionBlocked(const cmListFileFunction& lff,
                  cmMakefile &mf,
                  cmExecutionStatus &inStatus)
{
  // we start by recording all the functions
  if (!cmSystemTools::Strucmp(lff.Name.c_str(),"if"))
    {
    this->ScopeDepth++;
    }
  if (!cmSystemTools::Strucmp(lff.Name.c_str(),"endif"))
    {
    this->ScopeDepth--;
    // if this is the endif for this if statement, then start executing
    if (!this->ScopeDepth)
      {
      // Remove the function blocker for this scope or bail.
      cmsys::auto_ptr<cmFunctionBlocker>
        fb(mf.RemoveFunctionBlocker(this, lff));
      if(!fb.get()) { return false; }

      // execute the functions for the true parts of the if statement
      cmExecutionStatus status;
      int scopeDepth = 0;
      for(unsigned int c = 0; c < this->Functions.size(); ++c)
        {
        // keep track of scope depth
        if (!cmSystemTools::Strucmp(this->Functions[c].Name.c_str(),"if"))
          {
          scopeDepth++;
          }
        if (!cmSystemTools::Strucmp(this->Functions[c].Name.c_str(),"endif"))
          {
          scopeDepth--;
          }
        // watch for our state change
        if (scopeDepth == 0 &&
            !cmSystemTools::Strucmp(this->Functions[c].Name.c_str(),"else"))
          {
          this->IsBlocking = this->HasRun;
          this->HasRun = true;

          // if trace is enabled, print a (trivially) evaluated "else"
          // statement
          if(!this->IsBlocking && mf.GetCMakeInstance()->GetTrace())
            {
            mf.PrintCommandTrace(this->Functions[c]);
            }
          }
        else if (scopeDepth == 0 && !cmSystemTools::Strucmp
                 (this->Functions[c].Name.c_str(),"elseif"))
          {
          if (this->HasRun)
            {
            this->IsBlocking = true;
            }
          else
            {
            // Place this call on the call stack.
            cmMakefileCall stack_manager(&mf, this->Functions[c], status);
            static_cast<void>(stack_manager);

            // if trace is enabled, print the evaluated "elseif" statement
            if(mf.GetCMakeInstance()->GetTrace())
              {
              mf.PrintCommandTrace(this->Functions[c]);
              }

            std::string errorString;

            std::vector<std::string> expandedArguments;
            mf.ExpandArguments(this->Functions[c].Arguments,
                               expandedArguments);

            cmake::MessageType messType;

            cmConditionEvaluator conditionEvaluator(mf);

            bool isTrue = conditionEvaluator.IsTrue(
              expandedArguments, errorString, messType);

            if (errorString.size())
              {
              std::string err = cmIfCommandError(&mf, expandedArguments);
              err += errorString;
              mf.IssueMessage(messType, err);
              if (messType == cmake::FATAL_ERROR)
                {
                cmSystemTools::SetFatalErrorOccured();
                return true;
                }
              }

            if (isTrue)
              {
              this->IsBlocking = false;
              this->HasRun = true;
              }
            }
          }

        // should we execute?
        else if (!this->IsBlocking)
          {
          status.Clear();
          mf.ExecuteCommand(this->Functions[c],status);
          if (status.GetReturnInvoked())
            {
            inStatus.SetReturnInvoked(true);
            return true;
            }
          if (status.GetBreakInvoked())
            {
            inStatus.SetBreakInvoked(true);
            return true;
            }
          }
        }
      return true;
      }
    }

  // record the command
  this->Functions.push_back(lff);

  // always return true
  return true;
}

//=========================================================================
bool cmIfFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
                                       cmMakefile&)
{
  if (!cmSystemTools::Strucmp(lff.Name.c_str(),"endif"))
    {
    // if the endif has arguments, then make sure
    // they match the arguments of the matching if
    if (lff.Arguments.size() == 0 ||
        lff.Arguments == this->Args)
      {
      return true;
      }
    }

  return false;
}

//=========================================================================
bool cmIfCommand
::InvokeInitialPass(const std::vector<cmListFileArgument>& args,
                    cmExecutionStatus &)
{
  std::string errorString;

  std::vector<std::string> expandedArguments;
  this->Makefile->ExpandArguments(args, expandedArguments);

  cmake::MessageType status;

  cmConditionEvaluator conditionEvaluator(*(this->Makefile));

  bool isTrue = conditionEvaluator.IsTrue(
    expandedArguments, errorString, status);

  if (errorString.size())
    {
    std::string err = cmIfCommandError(this->Makefile, expandedArguments);
    err += errorString;
    if (status == cmake::FATAL_ERROR)
      {
      this->SetError(err);
      cmSystemTools::SetFatalErrorOccured();
      return false;
      }
    else
      {
      this->Makefile->IssueMessage(status, err);
      }
    }

  cmIfFunctionBlocker *f = new cmIfFunctionBlocker();
  // if is isn't true block the commands
  f->ScopeDepth = 1;
  f->IsBlocking = !isTrue;
  if (isTrue)
    {
    f->HasRun = true;
    }
  f->Args = args;
  this->Makefile->AddFunctionBlocker(f);

  return true;
}