//
// Copyright(c) 2015 Gabi Melman.
// Distributed under the MIT License (http://opensource.org/licenses/MIT)
//
#pragma once

#include "../common.h"

#include <algorithm>
#include <chrono>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <functional>
#include <string>
#include <sys/stat.h>
#include <sys/types.h>
#include <thread>

#ifdef _WIN32

#ifndef NOMINMAX
#define NOMINMAX // prevent windows redefining min/max
#endif

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <io.h>      // _get_osfhandle and _isatty support
#include <process.h> //  _get_pid support
#include <windows.h>

#ifdef __MINGW32__
#include <share.h>
#endif

#else // unix

#include <fcntl.h>
#include <unistd.h>

#ifdef __linux__
#include <sys/syscall.h> //Use gettid() syscall under linux to get thread id

#elif __FreeBSD__
#include <sys/thr.h> //Use thr_self() syscall under FreeBSD to get thread id
#endif

#endif // unix

#ifndef __has_feature      // Clang - feature checking macros.
#define __has_feature(x) 0 // Compatibility with non-clang compilers.
#endif

namespace spdlog {
namespace details {
namespace os {

inline spdlog::log_clock::time_point now() SPDLOG_NOEXCEPT
{

#if defined __linux__ && defined SPDLOG_CLOCK_COARSE
    timespec ts;
    ::clock_gettime(CLOCK_REALTIME_COARSE, &ts);
    return std::chrono::time_point<log_clock, typename log_clock::duration>(
        std::chrono::duration_cast<typename log_clock::duration>(std::chrono::seconds(ts.tv_sec) + std::chrono::nanoseconds(ts.tv_nsec)));

#else
    return log_clock::now();
#endif
}
inline std::tm localtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT
{

#ifdef _WIN32
    std::tm tm;
    localtime_s(&tm, &time_tt);
#else
    std::tm tm;
    localtime_r(&time_tt, &tm);
#endif
    return tm;
}

inline std::tm localtime() SPDLOG_NOEXCEPT
{
    std::time_t now_t = time(nullptr);
    return localtime(now_t);
}

inline std::tm gmtime(const std::time_t &time_tt) SPDLOG_NOEXCEPT
{

#ifdef _WIN32
    std::tm tm;
    gmtime_s(&tm, &time_tt);
#else
    std::tm tm;
    gmtime_r(&time_tt, &tm);
#endif
    return tm;
}

inline std::tm gmtime() SPDLOG_NOEXCEPT
{
    std::time_t now_t = time(nullptr);
    return gmtime(now_t);
}

// eol definition
#if !defined(SPDLOG_EOL)
#ifdef _WIN32
#define SPDLOG_EOL "\r\n"
#else
#define SPDLOG_EOL "\n"
#endif
#endif

SPDLOG_CONSTEXPR static const char *default_eol = SPDLOG_EOL;

// folder separator
#ifdef _WIN32
SPDLOG_CONSTEXPR static const char folder_sep = '\\';
#else
SPDLOG_CONSTEXPR static const char folder_sep = '/';
#endif

inline void prevent_child_fd(FILE *f)
{

#ifdef _WIN32
#if !defined(__cplusplus_winrt)
    auto file_handle = (HANDLE)_get_osfhandle(_fileno(f));
    if (!::SetHandleInformation(file_handle, HANDLE_FLAG_INHERIT, 0))
        throw spdlog_ex("SetHandleInformation failed", errno);
#endif
#else
    auto fd = fileno(f);
    if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
    {
        throw spdlog_ex("fcntl with FD_CLOEXEC failed", errno);
    }
#endif
}

// fopen_s on non windows for writing
inline bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode)
{
#ifdef _WIN32
#ifdef SPDLOG_WCHAR_FILENAMES
    *fp = _wfsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
#else
    *fp = _fsopen((filename.c_str()), mode.c_str(), _SH_DENYNO);
#endif
#else // unix
    *fp = fopen((filename.c_str()), mode.c_str());
#endif

#ifdef SPDLOG_PREVENT_CHILD_FD
    if (*fp != nullptr)
    {
        prevent_child_fd(*fp);
    }
#endif
    return *fp == nullptr;
}

inline int remove(const filename_t &filename) SPDLOG_NOEXCEPT
{
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
    return _wremove(filename.c_str());
#else
    return std::remove(filename.c_str());
#endif
}

inline int rename(const filename_t &filename1, const filename_t &filename2) SPDLOG_NOEXCEPT
{
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
    return _wrename(filename1.c_str(), filename2.c_str());
#else
    return std::rename(filename1.c_str(), filename2.c_str());
#endif
}

// Return if file exists
inline bool file_exists(const filename_t &filename) SPDLOG_NOEXCEPT
{
#ifdef _WIN32
#ifdef SPDLOG_WCHAR_FILENAMES
    auto attribs = GetFileAttributesW(filename.c_str());
#else
    auto attribs = GetFileAttributesA(filename.c_str());
#endif
    return (attribs != INVALID_FILE_ATTRIBUTES && !(attribs & FILE_ATTRIBUTE_DIRECTORY));
#else // common linux/unix all have the stat system call
    struct stat buffer;
    return (stat(filename.c_str(), &buffer) == 0);
#endif
}

// Return file size according to open FILE* object
inline size_t filesize(FILE *f)
{
    if (f == nullptr)
    {
        throw spdlog_ex("Failed getting file size. fd is null");
    }
#if defined(_WIN32) && !defined(__CYGWIN__)
    int fd = _fileno(f);
#if _WIN64 // 64 bits
    __int64 ret = _filelengthi64(fd);
    if (ret >= 0)
    {
        return static_cast<size_t>(ret);
    }

#else // windows 32 bits
    long ret = _filelength(fd);
    if (ret >= 0)
    {
        return static_cast<size_t>(ret);
    }
#endif

#else // unix
    int fd = fileno(f);
// 64 bits(but not in osx or cygwin, where fstat64 is deprecated)
#if !defined(__FreeBSD__) && !defined(__APPLE__) && (defined(__x86_64__) || defined(__ppc64__)) && !defined(__CYGWIN__)
    struct stat64 st;
    if (fstat64(fd, &st) == 0)
    {
        return static_cast<size_t>(st.st_size);
    }
#else // unix 32 bits or cygwin
    struct stat st;

    if (fstat(fd, &st) == 0)
    {
        return static_cast<size_t>(st.st_size);
    }
#endif
#endif
    throw spdlog_ex("Failed getting file size from fd", errno);
}

// Return utc offset in minutes or throw spdlog_ex on failure
inline int utc_minutes_offset(const std::tm &tm = details::os::localtime())
{

#ifdef _WIN32
#if _WIN32_WINNT < _WIN32_WINNT_WS08
    TIME_ZONE_INFORMATION tzinfo;
    auto rv = GetTimeZoneInformation(&tzinfo);
#else
    DYNAMIC_TIME_ZONE_INFORMATION tzinfo;
    auto rv = GetDynamicTimeZoneInformation(&tzinfo);
#endif
    if (rv == TIME_ZONE_ID_INVALID)
        throw spdlog::spdlog_ex("Failed getting timezone info. ", errno);

    int offset = -tzinfo.Bias;
    if (tm.tm_isdst)
    {
        offset -= tzinfo.DaylightBias;
    }
    else
    {
        offset -= tzinfo.StandardBias;
    }
    return offset;
#else

#if defined(sun) || defined(__sun) || defined(_AIX)
    // 'tm_gmtoff' field is BSD extension and it's missing on SunOS/Solaris
    struct helper
    {
        static long int calculate_gmt_offset(const std::tm &localtm = details::os::localtime(), const std::tm &gmtm = details::os::gmtime())
        {
            int local_year = localtm.tm_year + (1900 - 1);
            int gmt_year = gmtm.tm_year + (1900 - 1);

            long int days = (
                // difference in day of year
                localtm.tm_yday -
                gmtm.tm_yday

                // + intervening leap days
                + ((local_year >> 2) - (gmt_year >> 2)) - (local_year / 100 - gmt_year / 100) +
                ((local_year / 100 >> 2) - (gmt_year / 100 >> 2))

                // + difference in years * 365 */
                + (long int)(local_year - gmt_year) * 365);

            long int hours = (24 * days) + (localtm.tm_hour - gmtm.tm_hour);
            long int mins = (60 * hours) + (localtm.tm_min - gmtm.tm_min);
            long int secs = (60 * mins) + (localtm.tm_sec - gmtm.tm_sec);

            return secs;
        }
    };

    auto offset_seconds = helper::calculate_gmt_offset(tm);
#else
    auto offset_seconds = tm.tm_gmtoff;
#endif

    return static_cast<int>(offset_seconds / 60);
#endif
}

// Return current thread id as size_t
// It exists because the std::this_thread::get_id() is much slower(especially
// under VS 2013)
inline size_t _thread_id() SPDLOG_NOEXCEPT
{
#ifdef _WIN32
    return static_cast<size_t>(::GetCurrentThreadId());
#elif __linux__
#if defined(__ANDROID__) && defined(__ANDROID_API__) && (__ANDROID_API__ < 21)
#define SYS_gettid __NR_gettid
#endif
    return static_cast<size_t>(syscall(SYS_gettid));
#elif __FreeBSD__
    long tid;
    thr_self(&tid);
    return static_cast<size_t>(tid);
#elif __APPLE__
    uint64_t tid;
    pthread_threadid_np(nullptr, &tid);
    return static_cast<size_t>(tid);
#else // Default to standard C++11 (other Unix)
    return static_cast<size_t>(std::hash<std::thread::id>()(std::this_thread::get_id()));
#endif
}

// Return current thread id as size_t (from thread local storage)
inline size_t thread_id() SPDLOG_NOEXCEPT
{
#if defined(SPDLOG_NO_TLS)
    return _thread_id();
#else // cache thread id in tls
    static thread_local const size_t tid = _thread_id();
    return tid;
#endif
}

// This is avoid msvc issue in sleep_for that happens if the clock changes.
// See https://github.com/gabime/spdlog/issues/609
inline void sleep_for_millis(int milliseconds) SPDLOG_NOEXCEPT
{
#if defined(_WIN32)
    ::Sleep(milliseconds);
#else
    std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds));
#endif
}

// wchar support for windows file names (SPDLOG_WCHAR_FILENAMES must be defined)
#if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
#define SPDLOG_FILENAME_T(s) L##s
inline std::string filename_to_str(const filename_t &filename)
{
    std::wstring_convert<std::codecvt_utf8<wchar_t>, wchar_t> c;
    return c.to_bytes(filename);
}
#else
#define SPDLOG_FILENAME_T(s) s
inline std::string filename_to_str(const filename_t &filename)
{
    return filename;
}
#endif

inline int pid()
{

#ifdef _WIN32
    return static_cast<int>(::GetCurrentProcessId());
#else
    return static_cast<int>(::getpid());
#endif
}

// Determine if the terminal supports colors
// Source: https://github.com/agauniyal/rang/
inline bool is_color_terminal() SPDLOG_NOEXCEPT
{
#ifdef _WIN32
    return true;
#else
    static constexpr const char *Terms[] = {
        "ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm", "linux", "msys", "putty", "rxvt", "screen", "vt100", "xterm"};

    const char *env_p = std::getenv("TERM");
    if (env_p == nullptr)
    {
        return false;
    }

    static const bool result =
        std::any_of(std::begin(Terms), std::end(Terms), [&](const char *term) { return std::strstr(env_p, term) != nullptr; });
    return result;
#endif
}

// Detrmine if the terminal attached
// Source: https://github.com/agauniyal/rang/
inline bool in_terminal(FILE *file) SPDLOG_NOEXCEPT
{

#ifdef _WIN32
    return _isatty(_fileno(file)) != 0;
#else
    return isatty(fileno(file)) != 0;
#endif
}
} // namespace os
} // namespace details
} // namespace spdlog
