// Copyright 2015 The Shaderc Authors. 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.

#include "libshaderc_util/io_shaderc.h"

#include "libshaderc_util/universal_unistd.h"

#if _WIN32

// Need _fileno from stdio.h

// Need _O_BINARY and _O_TEXT from fcntl.h

#include <fcntl.h>

#include <stdio.h>

#endif

#include <errno.h>

#include <cstdio>

#include <cstring>

#include <fstream>

#include <iostream>

namespace {

// Outputs a descriptive message for errno_value to cerr.

// This may be truncated to 1023 bytes on certain platforms.

void OutputFileErrorMessage(int errno_value) {

#ifdef _MSC_VER

  // If the error message is more than 1023 bytes it will be truncated.

  char buffer[1024];

  strerror_s(buffer, errno_value);

  std::cerr << ": " << buffer << std::endl;

#else

  std::cerr << ": " << strerror(errno_value) << std::endl;

#endif

}

}  // anonymous namespace

namespace shaderc_util {

bool IsAbsolutePath(const std::string& path) {

  if (path.empty()) return false;

  // Unix-like OS: /path/to/file

  if (path.front() == '/') return true;

  // Windows: \\server\user\file

  if (path.size() > 1 && path[0] == '\\' && path[1] == '\\') {

    return true;

  }

  // Windows: X:\path\to\file

  if (path.size() > 2 && ::isalpha(path[0]) && path[1] == ':' &&

      path[2] == '\\') {

    return true;

  }

  return false;

}

std::string GetBaseFileName(const std::string& file_path) {

  size_t loc_slash = file_path.find_last_of("/\\");

  std::string base_name =

      file_path.substr((loc_slash == std::string::npos ? -1 : loc_slash) + 1);

  if (base_name == ".." || base_name == ".") {

    base_name = "";

  }

  return base_name;

}

bool ReadFile(const std::string& input_file_name,

              std::vector<char>* input_data) {

  std::istream* stream = &std::cin;

  std::ifstream input_file;

  if (input_file_name != "-") {

    input_file.open(input_file_name, std::ios_base::binary);

    stream = &input_file;

    if (input_file.fail()) {

      std::cerr << "glslc: error: cannot open input file: '" << input_file_name

                << "'";

      if (access(input_file_name.c_str(), R_OK) != 0) {

        OutputFileErrorMessage(errno);

        return false;

      }

      std::cerr << std::endl;

      return false;

    }

  }

  *input_data = std::vector<char>((std::istreambuf_iterator<char>(*stream)),

                                  std::istreambuf_iterator<char>());

  return true;

}

std::ostream* GetOutputStream(const string_piece& output_filename,

                              std::ofstream* file_stream, std::ostream* err) {

  std::ostream* stream = &std::cout;

  if (output_filename != "-") {

    file_stream->open(output_filename.str(), std::ios_base::binary);

    stream = file_stream;

    if (file_stream->fail()) {

      *err << "glslc: error: cannot open output file: '" << output_filename

           << "'";

      if (access(output_filename.str().c_str(), W_OK) != 0) {

        OutputFileErrorMessage(errno);

        return nullptr;

      }

      std::cerr << std::endl;

      return nullptr;

    }

  }

  return stream;

}

bool WriteFile(std::ostream* stream, const string_piece& output_data) {

  if (output_data.size() > 0) {

    stream->write(output_data.data(), output_data.size());

    if (!stream->good()) {

      return false;

    }

  }

  stream->flush();

  return true;

}

void FlushAndSetBinaryModeOnStdout() {

  std::fflush(stdout);

#if _WIN32

  _setmode(_fileno(stdout), _O_BINARY);

#endif

}

void FlushAndSetTextModeOnStdout() {

  std::fflush(stdout);

#if _WIN32

  _setmode(_fileno(stdout), _O_TEXT);

#endif

}

}  // namespace shaderc_util