#ifndef RANG_DOT_HPP
#define RANG_DOT_HPP

#if defined(__unix__) || defined(__unix) || defined(__linux__)
#define OS_LINUX
#elif defined(WIN32) || defined(_WIN32) || defined(_WIN64)
#define OS_WIN
#elif defined(__APPLE__) || defined(__MACH__)
#define OS_MAC
#else
#error Unknown Platform
#endif

#if defined(OS_LINUX) || defined(OS_MAC)
#include <unistd.h>

#elif defined(OS_WIN)

#if defined(_WIN32_WINNT) && (_WIN32_WINNT < 0x0600)
#error                                                                                                       \
    "Please include rang.hpp before any windows system headers or set _WIN32_WINNT at least to _WIN32_WINNT_VISTA"
#elif !defined(_WIN32_WINNT)
#define _WIN32_WINNT _WIN32_WINNT_VISTA
#endif

#include <windows.h>
#include <io.h>
#include <memory>

// Only defined in windows 10 onwards, redefining in lower windows since it
// doesn't gets used in lower versions
// https://docs.microsoft.com/en-us/windows/console/getconsolemode
#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
#endif

#endif

#include <algorithm>
#include <atomic>
#include <cstdlib>
#include <cstring>
#include <iostream>

namespace rang {

/* For better compability with most of terminals do not use any style settings
 * except of reset, bold and reversed.
 * Note that on Windows terminals bold style is same as fgB color.
 */
enum class style {
  reset = 0,
  bold = 1,
  dim = 2,
  italic = 3,
  underline = 4,
  blink = 5,
  rblink = 6,
  reversed = 7,
  conceal = 8,
  crossed = 9
};

enum class fg {
  black = 30,
  red = 31,
  green = 32,
  yellow = 33,
  blue = 34,
  magenta = 35,
  cyan = 36,
  gray = 37,
  reset = 39
};

enum class bg {
  black = 40,
  red = 41,
  green = 42,
  yellow = 43,
  blue = 44,
  magenta = 45,
  cyan = 46,
  gray = 47,
  reset = 49
};

enum class fgB {
  black = 90,
  red = 91,
  green = 92,
  yellow = 93,
  blue = 94,
  magenta = 95,
  cyan = 96,
  gray = 97
};

enum class bgB {
  black = 100,
  red = 101,
  green = 102,
  yellow = 103,
  blue = 104,
  magenta = 105,
  cyan = 106,
  gray = 107
};

enum class control { // Behaviour of rang function calls
  Off = 0,           // toggle off rang style/color calls
  Auto = 1,          // (Default) autodect terminal and colorize if needed
  Force = 2          // force ansi color output to non terminal streams
};
// Use rang::setControlMode to set rang control mode

enum class winTerm { // Windows Terminal Mode
  Auto = 0,          // (Default) automatically detects wheter Ansi or Native API
  Ansi = 1,          // Force use Ansi API
  Native = 2         // Force use Native API
};
// Use rang::setWinTermMode to explicitly set terminal API for Windows
// Calling rang::setWinTermMode have no effect on other OS

namespace rang_implementation {

inline std::atomic<control> &controlMode() noexcept {
  static std::atomic<control> value(control::Auto);
  return value;
}

inline std::atomic<winTerm> &winTermMode() noexcept {
  static std::atomic<winTerm> termMode(winTerm::Auto);
  return termMode;
}

inline bool supportsColor() noexcept {
#if defined(OS_LINUX) || defined(OS_MAC)

  static const bool result = [] {
    const char *Terms[] = {"ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm",    "linux",
                           "msys", "putty", "rxvt",    "screen", "vt100", "xterm",   "alacritty"};

    const char *env_p = std::getenv("TERM");
    if (env_p == nullptr) { return false; }
    return std::any_of(std::begin(Terms), std::end(Terms),
                       [&](const char *term) { return std::strstr(env_p, term) != nullptr; });
  }();

#elif defined(OS_WIN)
  // All windows versions support colors through native console methods
  static constexpr bool result = true;
#endif
  return result;
}

#ifdef OS_WIN

inline bool isMsysPty(int fd) noexcept {
  // Dynamic load for binary compability with old Windows
  const auto ptrGetFileInformationByHandleEx = reinterpret_cast<decltype(&GetFileInformationByHandleEx)>(
      GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")), "GetFileInformationByHandleEx"));
  if (!ptrGetFileInformationByHandleEx) { return false; }

  HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
  if (h == INVALID_HANDLE_VALUE) { return false; }

  // Check that it's a pipe:
  if (GetFileType(h) != FILE_TYPE_PIPE) { return false; }

  // POD type is binary compatible with FILE_NAME_INFO from WinBase.h
  // It have the same alignment and used to avoid UB in caller code
  struct MY_FILE_NAME_INFO {
    DWORD FileNameLength;
    WCHAR FileName[MAX_PATH];
  };

  auto pNameInfo = std::unique_ptr<MY_FILE_NAME_INFO>(new (std::nothrow) MY_FILE_NAME_INFO());
  if (!pNameInfo) { return false; }

  // Check pipe name is template of
  // {"cygwin-","msys-"}XXXXXXXXXXXXXXX-ptyX-XX
  if (!ptrGetFileInformationByHandleEx(h, FileNameInfo, pNameInfo.get(), sizeof(MY_FILE_NAME_INFO))) {
    return false;
  }
  std::wstring name(pNameInfo->FileName, pNameInfo->FileNameLength / sizeof(WCHAR));
  if ((name.find(L"msys-") == std::wstring::npos && name.find(L"cygwin-") == std::wstring::npos) ||
      name.find(L"-pty") == std::wstring::npos) {
    return false;
  }

  return true;
}

#endif

inline bool isTerminal(const std::streambuf *osbuf) noexcept {
  using std::cerr;
  using std::clog;
  using std::cout;
#if defined(OS_LINUX) || defined(OS_MAC)
  if (osbuf == cout.rdbuf()) {
    static const bool cout_term = isatty(fileno(stdout)) != 0;
    return cout_term;
  } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
    static const bool cerr_term = isatty(fileno(stderr)) != 0;
    return cerr_term;
  }
#elif defined(OS_WIN)
  if (osbuf == cout.rdbuf()) {
    static const bool cout_term = (_isatty(_fileno(stdout)) || isMsysPty(_fileno(stdout)));
    return cout_term;
  } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
    static const bool cerr_term = (_isatty(_fileno(stderr)) || isMsysPty(_fileno(stderr)));
    return cerr_term;
  }
#endif
  return false;
}

template <typename T>
using enableStd =
    typename std::enable_if<std::is_same<T, rang::style>::value || std::is_same<T, rang::fg>::value ||
                                std::is_same<T, rang::bg>::value || std::is_same<T, rang::fgB>::value ||
                                std::is_same<T, rang::bgB>::value,
                            std::ostream &>::type;

#ifdef OS_WIN

struct SGR {       // Select Graphic Rendition parameters for Windows console
  BYTE fgColor;    // foreground color (0-15) lower 3 rgb bits + intense bit
  BYTE bgColor;    // background color (0-15) lower 3 rgb bits + intense bit
  BYTE bold;       // emulated as FOREGROUND_INTENSITY bit
  BYTE underline;  // emulated as BACKGROUND_INTENSITY bit
  BOOLEAN inverse; // swap foreground/bold & background/underline
  BOOLEAN conceal; // set foreground/bold to background/underline
};

enum class AttrColor : BYTE { // Color attributes for console screen buffer
  black = 0,
  red = 4,
  green = 2,
  yellow = 6,
  blue = 1,
  magenta = 5,
  cyan = 3,
  gray = 7
};

inline HANDLE getConsoleHandle(const std::streambuf *osbuf) noexcept {
  if (osbuf == std::cout.rdbuf()) {
    static const HANDLE hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
    return hStdout;
  } else if (osbuf == std::cerr.rdbuf() || osbuf == std::clog.rdbuf()) {
    static const HANDLE hStderr = GetStdHandle(STD_ERROR_HANDLE);
    return hStderr;
  }
  return INVALID_HANDLE_VALUE;
}

inline bool setWinTermAnsiColors(const std::streambuf *osbuf) noexcept {
  HANDLE h = getConsoleHandle(osbuf);
  if (h == INVALID_HANDLE_VALUE) { return false; }
  DWORD dwMode = 0;
  if (!GetConsoleMode(h, &dwMode)) { return false; }
  dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
  if (!SetConsoleMode(h, dwMode)) { return false; }
  return true;
}

inline bool supportsAnsi(const std::streambuf *osbuf) noexcept {
  using std::cerr;
  using std::clog;
  using std::cout;
  if (osbuf == cout.rdbuf()) {
    static const bool cout_ansi = (isMsysPty(_fileno(stdout)) || setWinTermAnsiColors(osbuf));
    return cout_ansi;
  } else if (osbuf == cerr.rdbuf() || osbuf == clog.rdbuf()) {
    static const bool cerr_ansi = (isMsysPty(_fileno(stderr)) || setWinTermAnsiColors(osbuf));
    return cerr_ansi;
  }
  return false;
}

inline const SGR &defaultState() noexcept {
  static const SGR defaultSgr = []() -> SGR {
    CONSOLE_SCREEN_BUFFER_INFO info;
    WORD attrib = FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE;
    if (GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &info) ||
        GetConsoleScreenBufferInfo(GetStdHandle(STD_ERROR_HANDLE), &info)) {
      attrib = info.wAttributes;
    }
    SGR sgr = {0, 0, 0, 0, FALSE, FALSE};
    sgr.fgColor = attrib & 0x0F;
    sgr.bgColor = (attrib & 0xF0) >> 4;
    return sgr;
  }();
  return defaultSgr;
}

inline BYTE ansi2attr(BYTE rgb) noexcept {
  static const AttrColor rev[8] = {AttrColor::black, AttrColor::red,     AttrColor::green, AttrColor::yellow,
                                   AttrColor::blue,  AttrColor::magenta, AttrColor::cyan,  AttrColor::gray};
  return static_cast<BYTE>(rev[rgb]);
}

inline void setWinSGR(rang::bg col, SGR &state) noexcept {
  if (col != rang::bg::reset) {
    state.bgColor = ansi2attr(static_cast<BYTE>(col) - 40);
  } else {
    state.bgColor = defaultState().bgColor;
  }
}

inline void setWinSGR(rang::fg col, SGR &state) noexcept {
  if (col != rang::fg::reset) {
    state.fgColor = ansi2attr(static_cast<BYTE>(col) - 30);
  } else {
    state.fgColor = defaultState().fgColor;
  }
}

inline void setWinSGR(rang::bgB col, SGR &state) noexcept {
  state.bgColor = (BACKGROUND_INTENSITY >> 4) | ansi2attr(static_cast<BYTE>(col) - 100);
}

inline void setWinSGR(rang::fgB col, SGR &state) noexcept {
  state.fgColor = FOREGROUND_INTENSITY | ansi2attr(static_cast<BYTE>(col) - 90);
}

inline void setWinSGR(rang::style style, SGR &state) noexcept {
  switch (style) {
  case rang::style::reset:
    state = defaultState();
    break;
  case rang::style::bold:
    state.bold = FOREGROUND_INTENSITY;
    break;
  case rang::style::underline:
  case rang::style::blink:
    state.underline = BACKGROUND_INTENSITY;
    break;
  case rang::style::reversed:
    state.inverse = TRUE;
    break;
  case rang::style::conceal:
    state.conceal = TRUE;
    break;
  default:
    break;
  }
}

inline SGR &current_state() noexcept {
  static SGR state = defaultState();
  return state;
}

inline WORD SGR2Attr(const SGR &state) noexcept {
  WORD attrib = 0;
  if (state.conceal) {
    if (state.inverse) {
      attrib = (state.fgColor << 4) | state.fgColor;
      if (state.bold) attrib |= FOREGROUND_INTENSITY | BACKGROUND_INTENSITY;
    } else {
      attrib = (state.bgColor << 4) | state.bgColor;
      if (state.underline) attrib |= FOREGROUND_INTENSITY | BACKGROUND_INTENSITY;
    }
  } else if (state.inverse) {
    attrib = (state.fgColor << 4) | state.bgColor;
    if (state.bold) attrib |= BACKGROUND_INTENSITY;
    if (state.underline) attrib |= FOREGROUND_INTENSITY;
  } else {
    attrib = state.fgColor | (state.bgColor << 4) | state.bold | state.underline;
  }
  return attrib;
}

template <typename T> inline void setWinColorAnsi(std::ostream &os, T const value) {
  os << "\033[" << static_cast<int>(value) << "m";
}

template <typename T> inline void setWinColorNative(std::ostream &os, T const value) {
  const HANDLE h = getConsoleHandle(os.rdbuf());
  if (h != INVALID_HANDLE_VALUE) {
    setWinSGR(value, current_state());
    // Out all buffered text to console with previous settings:
    os.flush();
    SetConsoleTextAttribute(h, SGR2Attr(current_state()));
  }
}

template <typename T> inline enableStd<T> setColor(std::ostream &os, T const value) {
  if (winTermMode() == winTerm::Auto) {
    if (supportsAnsi(os.rdbuf())) {
      setWinColorAnsi(os, value);
    } else {
      setWinColorNative(os, value);
    }
  } else if (winTermMode() == winTerm::Ansi) {
    setWinColorAnsi(os, value);
  } else {
    setWinColorNative(os, value);
  }
  return os;
}
#else
template <typename T> inline enableStd<T> setColor(std::ostream &os, T const value) {
  return os << "\033[" << static_cast<int>(value) << "m";
}
#endif
} // namespace rang_implementation

template <typename T> inline rang_implementation::enableStd<T> operator<<(std::ostream &os, const T value) {
  const control option = rang_implementation::controlMode();
  switch (option) {
  case control::Auto:
    return rang_implementation::supportsColor() && rang_implementation::isTerminal(os.rdbuf())
               ? rang_implementation::setColor(os, value)
               : os;
  case control::Force:
    return rang_implementation::setColor(os, value);
  default:
    return os;
  }
}

inline void setWinTermMode(const rang::winTerm value) noexcept { rang_implementation::winTermMode() = value; }

inline void setControlMode(const control value) noexcept { rang_implementation::controlMode() = value; }

} // namespace rang

#undef OS_LINUX
#undef OS_WIN
#undef OS_MAC

#endif /* ifndef RANG_DOT_HPP */
