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

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

#include "cmIfCommand.h"

#include <string>

#include <utility>

#include <cm/memory>

#include <cm/string_view>

#include <cmext/string_view>

#include "cmConditionEvaluator.h"

#include "cmExecutionStatus.h"

#include "cmExpandedCommandArgument.h"

#include "cmFunctionBlocker.h"

#include "cmListFileCache.h"

#include "cmMakefile.h"

#include "cmMessageType.h"

#include "cmOutputConverter.h"

#include "cmStringAlgorithms.h"

#include "cmSystemTools.h"

#include "cmake.h"

static std::string cmIfCommandError(

  std::vector<cmExpandedCommandArgument> const& args)

{

  std::string err = "given arguments:\n ";

  for (cmExpandedCommandArgument const& i : args) {

    err += " ";

    err += cmOutputConverter::EscapeForCMake(i.GetValue());

  }

  err += "\n";

  return err;

}

class cmIfFunctionBlocker : public cmFunctionBlocker

{

public:

  cm::string_view StartCommandName() const override { return "if"_s; }

  cm::string_view EndCommandName() const override { return "endif"_s; }

  bool ArgumentsMatch(cmListFileFunction const& lff,

                      cmMakefile&) const override;

  bool Replay(std::vector<cmListFileFunction> functions,

              cmExecutionStatus& inStatus) override;

  std::vector<cmListFileArgument> Args;

  bool IsBlocking;

  bool HasRun = false;

  bool ElseSeen = false;

};

bool cmIfFunctionBlocker::ArgumentsMatch(cmListFileFunction const& lff,

                                         cmMakefile&) const

{

  return lff.Arguments().empty() || lff.Arguments() == this->Args;

}

bool cmIfFunctionBlocker::Replay(std::vector<cmListFileFunction> functions,

                                 cmExecutionStatus& inStatus)

{

  cmMakefile& mf = inStatus.GetMakefile();

  // execute the functions for the true parts of the if statement

  int scopeDepth = 0;

  for (cmListFileFunction const& func : functions) {

    // keep track of scope depth

    if (func.LowerCaseName() == "if") {

      scopeDepth++;

    }

    if (func.LowerCaseName() == "endif") {

      scopeDepth--;

    }

    // watch for our state change

    if (scopeDepth == 0 && func.LowerCaseName() == "else") {

      cmListFileBacktrace elseBT = mf.GetBacktrace().Push(

        cmListFileContext{ func.OriginalName(),

                           this->GetStartingContext().FilePath, func.Line() });

      if (this->ElseSeen) {

        mf.GetCMakeInstance()->IssueMessage(

          MessageType::FATAL_ERROR,

          "A duplicate ELSE command was found inside an IF block.", elseBT);

        cmSystemTools::SetFatalErrorOccurred();

        return true;

      }

      this->IsBlocking = this->HasRun;

      this->HasRun = true;

      this->ElseSeen = true;

      // if trace is enabled, print a (trivially) evaluated "else"

      // statement

      if (!this->IsBlocking && mf.GetCMakeInstance()->GetTrace()) {

        mf.PrintCommandTrace(func, elseBT,

                             cmMakefile::CommandMissingFromStack::Yes);

      }

    } else if (scopeDepth == 0 && func.LowerCaseName() == "elseif") {

      cmListFileBacktrace elseifBT = mf.GetBacktrace().Push(

        cmListFileContext{ func.OriginalName(),

                           this->GetStartingContext().FilePath, func.Line() });

      if (this->ElseSeen) {

        mf.GetCMakeInstance()->IssueMessage(

          MessageType::FATAL_ERROR,

          "An ELSEIF command was found after an ELSE command.", elseifBT);

        cmSystemTools::SetFatalErrorOccurred();

        return true;

      }

      if (func.Arguments().empty()) {

        mf.GetCMakeInstance()->IssueMessage(

          MessageType::AUTHOR_WARNING,

          "ELSEIF called with no arguments, it will be skipped. ", elseifBT);

      }

      if (this->HasRun) {

        this->IsBlocking = true;

      } else {

        // if trace is enabled, print the evaluated "elseif" statement

        if (mf.GetCMakeInstance()->GetTrace()) {

          mf.PrintCommandTrace(func, elseifBT,

                               cmMakefile::CommandMissingFromStack::Yes);

        }

        std::string errorString;

        std::vector<cmExpandedCommandArgument> expandedArguments;

        mf.ExpandArguments(func.Arguments(), expandedArguments);

        MessageType messType;

        cmConditionEvaluator conditionEvaluator(mf, elseifBT);

        bool isTrue =

          conditionEvaluator.IsTrue(expandedArguments, errorString, messType);

        if (!errorString.empty()) {

          std::string err =

            cmStrCat(cmIfCommandError(expandedArguments), errorString);

          mf.GetCMakeInstance()->IssueMessage(messType, err, elseifBT);

          if (messType == MessageType::FATAL_ERROR) {

            cmSystemTools::SetFatalErrorOccurred();

            return true;

          }

        }

        if (isTrue) {

          this->IsBlocking = false;

          this->HasRun = true;

        }

      }

    }

    // should we execute?

    else if (!this->IsBlocking) {

      cmExecutionStatus status(mf);

      mf.ExecuteCommand(func, status);

      if (status.GetReturnInvoked()) {

        inStatus.SetReturnInvoked(status.GetReturnVariables());

        return true;

      }

      if (status.GetBreakInvoked()) {

        inStatus.SetBreakInvoked();

        return true;

      }

      if (status.GetContinueInvoked()) {

        inStatus.SetContinueInvoked();

        return true;

      }

      if (status.HasExitCode()) {

        inStatus.SetExitCode(status.GetExitCode());

        return true;

      }

    }

  }

  return true;

}

//=========================================================================

bool cmIfCommand(std::vector<cmListFileArgument> const& args,

                 cmExecutionStatus& inStatus)

{

  cmMakefile& makefile = inStatus.GetMakefile();

  std::string errorString;

  std::vector<cmExpandedCommandArgument> expandedArguments;

  makefile.ExpandArguments(args, expandedArguments);

  MessageType status;

  cmConditionEvaluator conditionEvaluator(makefile, makefile.GetBacktrace());

  bool isTrue =

    conditionEvaluator.IsTrue(expandedArguments, errorString, status);

  if (!errorString.empty()) {

    std::string err =

      cmStrCat("if ", cmIfCommandError(expandedArguments), errorString);

    if (status == MessageType::FATAL_ERROR) {

      makefile.IssueMessage(MessageType::FATAL_ERROR, err);

      cmSystemTools::SetFatalErrorOccurred();

      return true;

    }

    makefile.IssueMessage(status, err);

  }

  {

    auto fb = cm::make_unique<cmIfFunctionBlocker>();

    // if is isn't true block the commands

    fb->IsBlocking = !isTrue;

    if (isTrue) {

      fb->HasRun = true;

    }

    fb->Args = args;

    makefile.AddFunctionBlocker(std::move(fb));

  }

  return true;

}