/*
* This file is part of the Omni C++ framework
*
* Copyright (c) 2016, Zeriph Enterprises, LLC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - Neither the name of Zeriph, Zeriph Enterprises, LLC, nor the names
* of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ZERIPH AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL ZERIPH AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <omni/system.hpp>
#include <iostream>
#include <string>
#if !defined(OMNI_WIN_API)
    #if defined(OMNI_OS_WIN)
        #include <direct.h> // _getcwd
    #else
        #include <sys/param.h>
        #include <unistd.h>
    #endif
    #if defined(OMNI_OS_BSD)
        #include <sys/sysctl.h>
    #endif
    #if defined(OMNI_NON_PORTABLE)
        #if defined(OMNI_OS_APPLE)
            #include <mach-o/dyld.h>
            #include <limits.h>
        #elif defined(OMNI_OS_FREEBSD)
            #include <sys/sysctl.h>
        #endif
    #endif
#endif
#include <cerrno>
#include <errno.h>
#include <cstdlib>
#include <cstdio>
#include <climits>
#include <cstring>
#include <omni/constants.hpp>

omni::string_t omni::system::cwd()
{
    omni::char_t* p = new omni::char_t[FILENAME_MAX]();
    #if defined(OMNI_WIN_API)
        bool ret = (::GetCurrentDirectory(FILENAME_MAX, p) != 0);
    #else
        char* tp = new char[FILENAME_MAX]();
        #if defined(OMNI_OS_WIN)
            bool ret = (::_getcwd(tp, FILENAME_MAX) != 0);
        #else
            bool ret = (::getcwd(tp, FILENAME_MAX) != 0);
        #endif
        if (ret) {
            tp[FILENAME_MAX - 1] = '\0';
            #if defined(OMNI_UNICODE)
                std::mbstowcs(p, tp, FILENAME_MAX);
            #else
                std::memcpy(p, tp, FILENAME_MAX);
            #endif
        }
        delete[] tp;
    #endif
    if (!ret) {
        delete[] p;
        OMNI_DBGE(omni::consts::err::PATH_NOT_ACCESSIBLE << ": " << OMNI_GLE)
        return omni::string_t();
    }
    omni::string_t sret(p);
    delete[] p;
    return sret;
}

std::string omni::system::error_str(int code)
{
    #if defined(OMNI_WIN_API)//defined(OMNI_OS_WIN)
        OMNI_CHAR_T *err = NULL;
        // not a direct system message, must use IGNORE_INSERTS
        ::FormatMessage(
            FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS,
            NULL,
            code,
            MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
            err,
            0,
            NULL
        );
        if (err != NULL) {
            OMNI_STRING_T werr(err); // make copy
            ::LocalFree(err); // release memory from FormatMessage
            err = NULL;
            return omni::string::to_string(werr);
        }
        return std::string("Unknown error ").append(omni::string::util::type_cast<int>(code));
    #else
        return std::strerror(code);
    #endif
}

bool omni::system::is_big_endian()
{
    unsigned short test = 0x0001;
    return ((*(reinterpret_cast<char*>(&test))) == 0x00);
}

long omni::system::last_error()
{
    return OMNI_GLE;
}

std::string omni::system::last_error_str()
{
    return omni::system::error_str(OMNI_GLE);
}

#if defined(OMNI_NON_PORTABLE)

omni::string_t omni::system::path()
{
    omni::char_t* p = new omni::char_t[FILENAME_MAX]();
    #if !defined(OMNI_OS_WIN)
        char* tp = new char[FILENAME_MAX]();
    #endif
    #if defined(OMNI_OS_WIN) // windows
        // DEV_NOTE: ifdef OMNI_WIN_API not applicable here
        bool ret = (::GetModuleFileName(0, p, FILENAME_MAX) != 0);
    #elif defined(OMNI_OS_APPLE) // apple
        uint32_t cb = FILENAME_MAX;
        bool ret = (::_NSGetExecutablePath(tp, &cb) == 0);
    #elif defined(OMNI_OS_SOLARIS) // solaris/sun
        bool ret = (std::strncpy(tp, ::getexecname(), FILENAME_MAX) != 0);
    #elif defined(OMNI_OS_BSD) // bsd
        #if defined(OMNI_OS_FREEBSD) // freebsd
            int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
            std::size_t cb = FILENAME_MAX;
            bool ret = (::sysctl(mib, 4, tp, &cb, NULL, 0) == 0);
        #else // other bsd with procfs            
            #if !defined(OMNI_NO_PROC_SYS)
                bool ret = (::readlink("/proc/curproc/file", tp, (FILENAME_MAX - 1)) != -1);
                if (!ret) {
                    std::memset(tp, 0, FILENAME_MAX);
                    char* e = std::getenv("_");
                    ret = (e ? (std::strncpy(tp, e, FILENAME_MAX) != 0) : false);
                }
            #else // copy/pasta but easier to read here
                std::memset(tp, 0, FILENAME_MAX);
                char* e = std::getenv("_");
                bool ret = (e ? (std::strncpy(tp, e, FILENAME_MAX) != 0) : false);
            #endif
        #endif
    #else // *nix
        #if !defined(OMNI_NO_PROC_SYS)
            bool ret = (::readlink("/proc/self/exe", tp, (FILENAME_MAX - 1)) != -1);
            if (!ret) {
                std::memset(tp, 0, FILENAME_MAX);
                char* e = std::getenv("_");
                ret = (e ? (std::strncpy(tp, e, FILENAME_MAX) != 0) : false);
            }
        #else // copy/pasta but easier to read here
            std::memset(tp, 0, FILENAME_MAX);
            char* e = std::getenv("_");
            bool ret = (e ? (std::strncpy(tp, e, FILENAME_MAX) != 0) : false);
        #endif
    #endif
    #if !defined(OMNI_OS_WIN)
        if (ret) {
            #if defined(OMNI_UNICODE)
                ret = (std::mbstowcs(p, tp, FILENAME_MAX) != 0);
            #else
                ret = (std::strncpy(&p[0], tp, FILENAME_MAX) != 0);
            #endif
        }
        delete[] tp;
    #endif
    if (!ret) {
        delete[] p;
        OMNI_DBGE(omni::consts::err::PATH_NOT_ACCESSIBLE << ": " << OMNI_GLE)
        return omni::string_t();
    }
    omni::string_t sret(p);
    delete[] p;
    return sret;
}

std::size_t omni::system::processors()
{
    //may return 0 when not able to detect
    // if C++11, return std::thread::hardware_concurrency();
    #if defined(OMNI_OS_WIN) // windows
        // DEV_NOTE: ifdef OMNI_WIN_API not applicable here
        SYSTEM_INFO si;
        ::GetSystemInfo(&si);
        return si.dwNumberOfProcessors;
    // TODO: can't test on HP-UX or Irix right now
    #elif defined(OMNI_OS_HPUX) // HPUX
        return ::mpctl(MPC_GETNUMSPUS, NULL, NULL);
    #elif defined(OMNI_OS_IRIX) // IRIX
        return ::sysconf(_SC_NPROC_ONLN);
    #elif defined(OMNI_OS_BSD) // bsd
        int mib[4];
        int ret = 0;
        std::size_t len = sizeof(ret);
        /* set the mib for hw.ncpu */
        mib[0] = CTL_HW;
        mib[1] = HW_NCPU;
        /* get the number of CPUs from the system */
        ::sysctl(mib, 2, &ret, &len, NULL, 0);
        if (ret < 1) {
            mib[1] = HW_NCPU;
            ::sysctl(mib, 2, &ret, &len, NULL, 0);
            if (ret < 0) { ret = 0; }
        }
        return ret;
    #else // *nix
        return ::sysconf(_SC_NPROCESSORS_ONLN);
    #endif
}
#endif