/*

 * Copyright 2016 Google Inc. All rights reserved.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

// clang-format off

// Dont't remove `format off`, it prevent reordering of win-includes.

#include <cstring>

#if defined(__MINGW32__) || defined(__MINGW64__) || defined(__CYGWIN__) || \

    defined(__QNXNTO__)

#  define _POSIX_C_SOURCE 200809L

#  define _XOPEN_SOURCE 700L

#endif

#if defined(_WIN32) || defined(__MINGW32__) || defined(__MINGW64__) || defined(__CYGWIN__)

#  ifndef WIN32_LEAN_AND_MEAN

#    define WIN32_LEAN_AND_MEAN

#  endif

#  ifndef NOMINMAX

#    define NOMINMAX

#  endif

#  ifdef _MSC_VER

#    include <crtdbg.h>

#  endif

#  include <windows.h>  // Must be included before <direct.h>

#  ifndef __CYGWIN__

#    include <direct.h>

#  endif

#  include <winbase.h>

#  undef interface  // This is also important because of reasons

#endif

// clang-format on

#include "flatbuffers/util.h"

#include <sys/stat.h>

#include <clocale>

#include <cstdlib>

#include <fstream>

#include <functional>

#include "flatbuffers/base.h"

namespace flatbuffers {

namespace {

static bool FileExistsRaw(const char* name) {

  std::ifstream ifs(name);

  return ifs.good();

}

static bool LoadFileRaw(const char* name, bool binary, std::string* buf) {

  if (DirExists(name)) return false;

  std::ifstream ifs(name, binary ? std::ifstream::binary : std::ifstream::in);

  if (!ifs.is_open()) return false;

  if (binary) {

    // The fastest way to read a file into a string.

    ifs.seekg(0, std::ios::end);

    auto size = ifs.tellg();

    (*buf).resize(static_cast<size_t>(size));

    ifs.seekg(0, std::ios::beg);

    ifs.read(&(*buf)[0], (*buf).size());

  } else {

    // This is slower, but works correctly on all platforms for text files.

    std::ostringstream oss;

    oss << ifs.rdbuf();

    *buf = oss.str();

  }

  return !ifs.bad();

}

LoadFileFunction g_load_file_function = LoadFileRaw;

FileExistsFunction g_file_exists_function = FileExistsRaw;

static std::string ToCamelCase(const std::string& input, bool is_upper) {

  std::string s;

  for (size_t i = 0; i < input.length(); i++) {

    if (!i && input[i] == '_') {

      s += input[i];

      // we ignore leading underscore but make following

      // alphabet char upper.

      if (i + 1 < input.length() && is_alpha(input[i + 1]))

        s += CharToUpper(input[++i]);

    } else if (!i)

      s += is_upper ? CharToUpper(input[i]) : CharToLower(input[i]);

    else if (input[i] == '_' && i + 1 < input.length())

      s += CharToUpper(input[++i]);

    else

      s += input[i];

  }

  return s;

}

static std::string ToSnakeCase(const std::string& input, bool screaming) {

  std::string s;

  for (size_t i = 0; i < input.length(); i++) {

    if (i == 0) {

      s += screaming ? CharToUpper(input[i]) : CharToLower(input[i]);

    } else if (input[i] == '_') {

      s += '_';

    } else if (!islower(input[i])) {

      // Prevent duplicate underscores for Upper_Snake_Case strings

      // and UPPERCASE strings.

      if (islower(input[i - 1]) ||

          (isdigit(input[i - 1]) && !isdigit(input[i]))) {

        s += '_';

      }

      s += screaming ? CharToUpper(input[i]) : CharToLower(input[i]);

    } else {

      s += screaming ? CharToUpper(input[i]) : input[i];

    }

  }

  return s;

}

std::string ToAll(const std::string& input,

                  std::function<char(const char)> transform) {

  std::string s;

  for (size_t i = 0; i < input.length(); i++) {

    s += transform(input[i]);

  }

  return s;

}

std::string CamelToSnake(const std::string& input) {

  std::string s;

  for (size_t i = 0; i < input.length(); i++) {

    if (i == 0) {

      s += CharToLower(input[i]);

    } else if (input[i] == '_') {

      s += '_';

    } else if (!islower(input[i])) {

      // Prevent duplicate underscores for Upper_Snake_Case strings

      // and UPPERCASE strings.

      if (islower(input[i - 1]) ||

          (isdigit(input[i - 1]) && !isdigit(input[i]))) {

        s += '_';

      }

      s += CharToLower(input[i]);

    } else {

      s += input[i];

    }

  }

  return s;

}

std::string DasherToSnake(const std::string& input) {

  std::string s;

  for (size_t i = 0; i < input.length(); i++) {

    if (input[i] == '-') {

      s += "_";

    } else {

      s += input[i];

    }

  }

  return s;

}

std::string ToDasher(const std::string& input) {

  std::string s;

  char p = 0;

  for (size_t i = 0; i < input.length(); i++) {

    char const& c = input[i];

    if (c == '_') {

      if (i > 0 && p != kPathSeparator &&

          // The following is a special case to ignore digits after a _. This is

          // because ThisExample3 would be converted to this_example_3 in the

          // CamelToSnake conversion, and then dasher would do this-example-3,

          // but it expects this-example3.

          !(i + 1 < input.length() && isdigit(input[i + 1])))

        s += "-";

    } else {

      s += c;

    }

    p = c;

  }

  return s;

}

// Converts foo_bar_123baz_456 to foo_bar123_baz456

std::string SnakeToSnake2(const std::string& s) {

  if (s.length() <= 1) return s;

  std::string result;

  result.reserve(s.size());

  for (size_t i = 0; i < s.length() - 1; i++) {

    if (s[i] == '_' && isdigit(s[i + 1])) {

      continue;  // Move the `_` until after the digits.

    }

    result.push_back(s[i]);

    if (isdigit(s[i]) && isalpha(s[i + 1]) && islower(s[i + 1])) {

      result.push_back('_');

    }

  }

  result.push_back(s.back());

  return result;

}

}  // namespace

bool LoadFile(const char* name, bool binary, std::string* buf) {

  FLATBUFFERS_ASSERT(g_load_file_function);

  return g_load_file_function(name, binary, buf);

}

bool FileExists(const char* name) {

  FLATBUFFERS_ASSERT(g_file_exists_function);

  return g_file_exists_function(name);

}

bool DirExists(const char* name) {

  // clang-format off

  #ifdef _WIN32

    #define flatbuffers_stat _stat

    #define FLATBUFFERS_S_IFDIR _S_IFDIR

  #else

    #define flatbuffers_stat stat

    #define FLATBUFFERS_S_IFDIR S_IFDIR

  #endif

  // clang-format on

  struct flatbuffers_stat file_info;

  if (flatbuffers_stat(name, &file_info) != 0) return false;

  return (file_info.st_mode & FLATBUFFERS_S_IFDIR) != 0;

}

LoadFileFunction SetLoadFileFunction(LoadFileFunction load_file_function) {

  LoadFileFunction previous_function = g_load_file_function;

  g_load_file_function = load_file_function ? load_file_function : LoadFileRaw;

  return previous_function;

}

FileExistsFunction SetFileExistsFunction(

    FileExistsFunction file_exists_function) {

  FileExistsFunction previous_function = g_file_exists_function;

  g_file_exists_function =

      file_exists_function ? file_exists_function : FileExistsRaw;

  return previous_function;

}

bool SaveFile(const char* name, const char* buf, size_t len, bool binary) {

  std::ofstream ofs(name, binary ? std::ofstream::binary : std::ofstream::out);

  if (!ofs.is_open()) return false;

  ofs.write(buf, len);

  return !ofs.bad();

}

// We internally store paths in posix format ('/'). Paths supplied

// by the user should go through PosixPath to ensure correct behavior

// on Windows when paths are string-compared.

static const char kPathSeparatorWindows = '\\';

static const char* PathSeparatorSet = "\\/";  // Intentionally no ':'

std::string StripExtension(const std::string& filepath) {

  size_t i = filepath.find_last_of('.');

  return i != std::string::npos ? filepath.substr(0, i) : filepath;

}

std::string GetExtension(const std::string& filepath) {

  size_t i = filepath.find_last_of('.');

  return i != std::string::npos ? filepath.substr(i + 1) : "";

}

std::string StripPath(const std::string& filepath) {

  size_t i = filepath.find_last_of(PathSeparatorSet);

  return i != std::string::npos ? filepath.substr(i + 1) : filepath;

}

std::string StripFileName(const std::string& filepath) {

  size_t i = filepath.find_last_of(PathSeparatorSet);

  return i != std::string::npos ? filepath.substr(0, i) : "";

}

std::string StripPrefix(const std::string& filepath,

                        const std::string& prefix_to_remove) {

  if (!strncmp(filepath.c_str(), prefix_to_remove.c_str(),

               prefix_to_remove.size())) {

    return filepath.substr(prefix_to_remove.size());

  }

  return filepath;

}

std::string ConCatPathFileName(const std::string& path,

                               const std::string& filename) {

  std::string filepath = path;

  if (filepath.length()) {

    char& filepath_last_character = filepath.back();

    if (filepath_last_character == kPathSeparatorWindows) {

      filepath_last_character = kPathSeparator;

    } else if (filepath_last_character != kPathSeparator) {

      filepath += kPathSeparator;

    }

  }

  filepath += filename;

  // Ignore './' at the start of filepath.

  if (filepath[0] == '.' && filepath[1] == kPathSeparator) {

    filepath.erase(0, 2);

  }

  return filepath;

}

std::string PosixPath(const char* path) {

  std::string p = path;

  std::replace(p.begin(), p.end(), '\\', '/');

  return p;

}

std::string PosixPath(const std::string& path) {

  return PosixPath(path.c_str());

}

void EnsureDirExists(const std::string& filepath) {

  auto parent = StripFileName(filepath);

  if (parent.length()) EnsureDirExists(parent);

  // clang-format off

  #ifdef _WIN32

    (void)_mkdir(filepath.c_str());

  #else

    mkdir(filepath.c_str(), S_IRWXU|S_IRGRP|S_IXGRP);

  #endif

  // clang-format on

}

std::string FilePath(const std::string& project, const std::string& filePath,

                     bool absolute) {

  return (absolute) ? AbsolutePath(filePath)

                    : RelativeToRootPath(project, filePath);

}

std::string AbsolutePath(const std::string& filepath) {

  // clang-format off

  #ifdef FLATBUFFERS_NO_ABSOLUTE_PATH_RESOLUTION

    return filepath;

  #else

    #if defined(_WIN32) || defined(__MINGW32__) || defined(__MINGW64__) || defined(__CYGWIN__)

      char abs_path[MAX_PATH];

      return GetFullPathNameA(filepath.c_str(), MAX_PATH, abs_path, nullptr)

    #else

      char *abs_path_temp = realpath(filepath.c_str(), nullptr);

      bool success = abs_path_temp != nullptr;

      std::string abs_path;

      if(success) {

        abs_path = abs_path_temp;

        free(abs_path_temp);

      }

      return success

    #endif

      ? abs_path

      : filepath;

  #endif // FLATBUFFERS_NO_ABSOLUTE_PATH_RESOLUTION

  // clang-format on

}

std::string RelativeToRootPath(const std::string& project,

                               const std::string& filepath) {

  std::string absolute_project = PosixPath(AbsolutePath(project));

  if (absolute_project.back() != '/') absolute_project += "/";

  std::string absolute_filepath = PosixPath(AbsolutePath(filepath));

  // Find the first character where they disagree.

  // The previous directory is the lowest common ancestor;

  const char* a = absolute_project.c_str();

  const char* b = absolute_filepath.c_str();

  size_t common_prefix_len = 0;

  while (*a != '\0' && *b != '\0' && *a == *b) {

    if (*a == '/') common_prefix_len = a - absolute_project.c_str();

    a++;

    b++;

  }

  // the number of ../ to prepend to b depends on the number of remaining

  // directories in A.

  const char* suffix = absolute_project.c_str() + common_prefix_len;

  size_t num_up = 0;

  while (*suffix != '\0')

    if (*suffix++ == '/') num_up++;

  num_up--;  // last one is known to be '/'.

  std::string result = "//";

  for (size_t i = 0; i < num_up; i++) result += "../";

  result += absolute_filepath.substr(common_prefix_len + 1);

  return result;

}

// Locale-independent code.

#if defined(FLATBUFFERS_LOCALE_INDEPENDENT) && \

    (FLATBUFFERS_LOCALE_INDEPENDENT > 0)

// clang-format off

// Allocate locale instance at startup of application.

ClassicLocale ClassicLocale::instance_;

#ifdef _MSC_VER

  ClassicLocale::ClassicLocale()

    : locale_(_create_locale(LC_ALL, "C")) {}

  ClassicLocale::~ClassicLocale() { _free_locale(locale_); }

#else

  ClassicLocale::ClassicLocale()

    : locale_(newlocale(LC_ALL, "C", nullptr)) {}

  ClassicLocale::~ClassicLocale() { freelocale(locale_); }

#endif

// clang-format on

#endif  // !FLATBUFFERS_LOCALE_INDEPENDENT

std::string RemoveStringQuotes(const std::string& s) {

  auto ch = *s.c_str();

  return ((s.size() >= 2) && (ch == '\"' || ch == '\'') && (ch == s.back()))

             ? s.substr(1, s.length() - 2)

             : s;

}

bool SetGlobalTestLocale(const char* locale_name, std::string* _value) {

  const auto the_locale = setlocale(LC_ALL, locale_name);

  if (!the_locale) return false;

  if (_value) *_value = std::string(the_locale);

  return true;

}

bool ReadEnvironmentVariable(const char* var_name, std::string* _value) {

#ifdef _MSC_VER

  __pragma(warning(disable : 4996));  // _CRT_SECURE_NO_WARNINGS

#endif

  auto env_str = std::getenv(var_name);

  if (!env_str) return false;

  if (_value) *_value = std::string(env_str);

  return true;

}

std::string ConvertCase(const std::string& input, Case output_case,

                        Case input_case) {

  if (output_case == Case::kKeep) return input;

  // The output cases expect snake_case inputs, so if we don't have that input

  // format, try to convert to snake_case.

  switch (input_case) {

    case Case::kLowerCamel:

    case Case::kUpperCamel:

      return ConvertCase(CamelToSnake(input), output_case);

    case Case::kDasher:

      return ConvertCase(DasherToSnake(input), output_case);

    case Case::kKeep:

      printf("WARNING: Converting from kKeep case.\n");

      break;

    default:

    case Case::kSnake:

    case Case::kScreamingSnake:

    case Case::kAllLower:

    case Case::kAllUpper:

      break;

  }

  switch (output_case) {

    case Case::kUpperCamel:

      return ToCamelCase(input, true);

    case Case::kLowerCamel:

      return ToCamelCase(input, false);

    case Case::kSnake:

      return input;

    case Case::kScreamingSnake:

      return ToSnakeCase(input, true);

    case Case::kAllUpper:

      return ToAll(input, CharToUpper);

    case Case::kAllLower:

      return ToAll(input, CharToLower);

    case Case::kDasher:

      return ToDasher(input);

    case Case::kSnake2:

      return SnakeToSnake2(input);

    default:

    case Case::kUnknown:

      return input;

  }

}

}  // namespace flatbuffers