#include "FindBlender.hpp"
#include "hecl/SteamFinder.hpp"
#include "hecl/hecl.hpp"

namespace hecl::blender
{

#ifdef __APPLE__
#define DEFAULT_BLENDER_BIN "/Applications/Blender.app/Contents/MacOS/blender"
#elif __linux__
#define DEFAULT_BLENDER_BIN "/usr/bin/blender"
#else
#define DEFAULT_BLENDER_BIN "blender"
#endif

static const std::regex regBlenderVersion(R"(Blender ([0-9]+).([0-9]+) )",
                                          std::regex::ECMAScript|std::regex::optimize);

static bool RegFileExists(const hecl::SystemChar* path)
{
    if (!path)
        return false;
    hecl::Sstat theStat;
    return !hecl::Stat(path, &theStat) && S_ISREG(theStat.st_mode);
}

hecl::SystemString FindBlender(int& major, int& minor)
{
    major = 0;
    minor = 0;

    /* User-specified blender path */
#if _WIN32
    wchar_t BLENDER_BIN_BUF[2048];
    const wchar_t* blenderBin = _wgetenv(L"BLENDER_BIN");
#else
    const char* blenderBin = getenv("BLENDER_BIN");
#endif

    /* Steam blender */
    hecl::SystemString steamBlender;

    /* Child process of blender */
#if _WIN32
    if (!blenderBin || !RegFileExists(blenderBin))
    {
        /* Environment not set; try steam */
        steamBlender = hecl::FindCommonSteamApp(_SYS_STR("Blender"));
        if (steamBlender.size())
        {
            steamBlender += _SYS_STR("\\blender.exe");
            blenderBin = steamBlender.c_str();
        }

        if (!RegFileExists(blenderBin))
        {
            /* No steam; try default */
            wchar_t progFiles[256];
            if (GetEnvironmentVariableW(L"ProgramFiles", progFiles, 256))
            {
                _snwprintf(BLENDER_BIN_BUF, 2048, L"%s\\Blender Foundation\\Blender\\blender.exe", progFiles);
                blenderBin = BLENDER_BIN_BUF;
                if (!RegFileExists(blenderBin))
                    blenderBin = nullptr;
            }
            else
                blenderBin = nullptr;
        }
    }
#else
    if (!RegFileExists(blenderBin))
    {
        /* Try steam */
        steamBlender = hecl::FindCommonSteamApp(_SYS_STR("Blender"));
        if (steamBlender.size())
        {
#ifdef __APPLE__
            steamBlender += "/blender.app/Contents/MacOS/blender";
#else
            steamBlender += "/blender";
#endif
            blenderBin = steamBlender.c_str();
            if (!RegFileExists(blenderBin))
            {
                blenderBin = DEFAULT_BLENDER_BIN;
                if (!RegFileExists(blenderBin))
                {
                    blenderBin = nullptr;
                }
            }
        }
        else
        {
            blenderBin = DEFAULT_BLENDER_BIN;
            if (!RegFileExists(blenderBin))
            {
                blenderBin = nullptr;
            }
        }
    }
#endif

    if (!blenderBin)
        return {};

    hecl::SystemString command = hecl::SystemString(_SYS_STR("\"")) + blenderBin + _SYS_STR("\" --version");
#if _WIN32
    FILE* fp = _wpopen(command.c_str(), _SYS_STR("r"));
#else
    FILE* fp = popen(command.c_str(), "r");
#endif
    char versionBuf[256];
    size_t rdSize = fread(versionBuf, 1, 255, fp);
    versionBuf[rdSize] = '\0';
#if _WIN32
    _pclose(fp);
#else
    pclose(fp);
#endif

    std::cmatch match;
    if (std::regex_search(versionBuf, match, regBlenderVersion))
    {
        major = atoi(match[1].str().c_str());
        minor = atoi(match[2].str().c_str());
        return blenderBin;
    }

    return blenderBin;
}

}