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

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

#include "cmGccDepfileLexerHelper.h"

#include <algorithm>

#include <cstdio>

#include <string>

#include <vector>

#include "cmGccDepfileReaderTypes.h"

#include "LexerParser/cmGccDepfileLexer.h"

#ifdef _WIN32

#  include <cctype>

#  include "cmsys/Encoding.h"

#endif

bool cmGccDepfileLexerHelper::readFile(char const* filePath)

{

#ifdef _WIN32

  wchar_t* wpath = cmsysEncoding_DupToWide(filePath);

  FILE* file = _wfopen(wpath, L"rb");

  free(wpath);

#else

  FILE* file = fopen(filePath, "r");

#endif

  if (!file) {

    return false;

  }

  this->newEntry();

  yyscan_t scanner;

  cmGccDepfile_yylex_init(&scanner);

  cmGccDepfile_yyset_extra(this, scanner);

  cmGccDepfile_yyrestart(file, scanner);

  cmGccDepfile_yylex(scanner);

  cmGccDepfile_yylex_destroy(scanner);

  this->sanitizeContent();

  fclose(file);

  return this->HelperState != State::Failed;

}

void cmGccDepfileLexerHelper::newEntry()

{

  if (this->HelperState == State::Rule && !this->Content.empty()) {

    if (!this->Content.back().rules.empty() &&

        !this->Content.back().rules.back().empty()) {

      this->HelperState = State::Failed;

    }

    return;

  }

  this->HelperState = State::Rule;

  this->Content.emplace_back();

  this->newRule();

}

void cmGccDepfileLexerHelper::newRule()

{

  auto& entry = this->Content.back();

  if (entry.rules.empty() || !entry.rules.back().empty()) {

    entry.rules.emplace_back();

  }

}

void cmGccDepfileLexerHelper::newDependency()

{

  if (this->HelperState == State::Failed) {

    return;

  }

  this->HelperState = State::Dependency;

  auto& entry = this->Content.back();

  if (entry.paths.empty() || !entry.paths.back().empty()) {

    entry.paths.emplace_back();

  }

}

void cmGccDepfileLexerHelper::newRuleOrDependency()

{

  if (this->HelperState == State::Rule) {

    this->newRule();

  } else if (this->HelperState == State::Dependency) {

    this->newDependency();

  }

}

void cmGccDepfileLexerHelper::addToCurrentPath(char const* s)

{

  if (this->Content.empty()) {

    return;

  }

  cmGccStyleDependency* dep = &this->Content.back();

  std::string* dst = nullptr;

  switch (this->HelperState) {

    case State::Rule: {

      if (dep->rules.empty()) {

        return;

      }

      dst = &dep->rules.back();

    } break;

    case State::Dependency: {

      if (dep->paths.empty()) {

        return;

      }

      dst = &dep->paths.back();

    } break;

    case State::Failed:

      return;

  }

  dst->append(s);

}

void cmGccDepfileLexerHelper::sanitizeContent()

{

  for (auto it = this->Content.begin(); it != this->Content.end();) {

    // remove duplicate path entries

    std::sort(it->paths.begin(), it->paths.end());

    auto last = std::unique(it->paths.begin(), it->paths.end());

    it->paths.erase(last, it->paths.end());

    // Remove empty paths and normalize windows paths

    for (auto pit = it->paths.begin(); pit != it->paths.end();) {

      if (pit->empty()) {

        pit = it->paths.erase(pit);

      } else {

#if defined(_WIN32)

        // Unescape the colon following the drive letter.

        // Some versions of GNU compilers can escape this character.

        // c\:\path must be transformed to c:\path

        if (pit->size() >= 3) {

          auto pit0 = static_cast<char>(

            std::toupper(static_cast<unsigned char>((*pit)[0])));

          if (pit0 >= 'A' && pit0 <= 'Z' && (*pit)[1] == '\\' &&

              (*pit)[2] == ':') {

            pit->erase(1, 1);

          }

        }

#endif

        ++pit;

      }

    }

    // Remove empty rules

    for (auto rit = it->rules.begin(); rit != it->rules.end();) {

      if (rit->empty()) {

        rit = it->rules.erase(rit);

      } else {

        ++rit;

      }

    }

    // Remove the entry if rules are empty

    if (it->rules.empty()) {

      it = this->Content.erase(it);

    } else {

      ++it;

    }

  }

}