#include <os/process_detail.h>

#include <signal.h>

std::filesystem::path os::process::detail::GetExecutablePath()
{
    char exePath[PATH_MAX] = {};
    if (readlink("/proc/self/exe", exePath, PATH_MAX) > 0)
    {
        return std::filesystem::path(std::u8string_view((const char8_t*)(exePath)));
    }
    else
    {
        return std::filesystem::path();
    }
}

std::filesystem::path os::process::detail::GetWorkingDirectory()
{
    char cwd[PATH_MAX] = {};
    char *res = getcwd(cwd, sizeof(cwd));
    if (res != nullptr)
    {
        return std::filesystem::path(std::u8string_view((const char8_t*)(cwd)));
    }
    else
    {
        return std::filesystem::path();
    }
}

bool os::process::detail::StartProcess(const std::filesystem::path path, const std::vector<std::string> args, std::filesystem::path work)
{
    pid_t pid = fork();
    if (pid < 0)
        return false;

    if (pid == 0)
    {
        setsid();
        
        std::u8string workU8 = work.u8string();
        chdir((const char*)(workU8.c_str())); 
        
        std::u8string pathU8 = path.u8string();
        std::vector<char*> argStrs;
        argStrs.push_back((char*)(pathU8.c_str()));
        for (const std::string& arg : args)
            argStrs.push_back((char *)(arg.c_str()));
        
        argStrs.push_back(nullptr);
        execvp((const char*)(pathU8.c_str()), argStrs.data());
        raise(SIGKILL);
    }

    return true;
}