#pragma once

#include <array>
#include <fstream>
#include <string>
#include <sstream>

#include <detail/include_windows.hpp>

#ifdef __APPLE__
#include <mach-o/dyld.h>
#include <sys/stat.h>
#elif defined(_MSC_VER)
#include <Shlwapi.h>
#elif defined(__linux)
#include <unistd.h>
#include <linux/limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#endif

class path_helper
{
public:
    static std::string read_file(const std::string &filename)
    {
        std::ifstream f(filename);
        std::ostringstream ss;
        ss << f.rdbuf();
        
        return ss.str();
    }
    
    static std::string windows_to_universal_path(const std::string &windows_path)
    {
        std::string fixed;
        std::stringstream ss(windows_path);
        std::string part;

        while(std::getline(ss, part, '\\'))
        {
            if(fixed == "")
            {
                fixed = part;
            }
            else
            {
                fixed += "/" + part;
            }
        }

        return fixed;
    }
    
    static std::string get_executable_directory()
    {
        
#ifdef __APPLE__
        std::array<char, 1024> path;
        uint32_t size = static_cast<uint32_t>(path.size());

        if (_NSGetExecutablePath(path.data(), &size) == 0)
        {
            return std::string(path.begin(), std::find(path.begin(), path.end(), '\0') - 9);
        }

        throw std::runtime_error("buffer too small, " + std::to_string(path.size()) + ", should be: " + std::to_string(size));
#elif defined(_MSC_VER)
        
        std::array<TCHAR, MAX_PATH> buffer;
        DWORD result = GetModuleFileName(nullptr, buffer.data(), (DWORD)buffer.size());
        
        if(result == 0 || result == buffer.size())
        {
            throw std::runtime_error("GetModuleFileName failed or buffer was too small");
        }
        return windows_to_universal_path(std::string(buffer.begin(), buffer.begin() + result - 13)) + "/";
#else
        char arg1[20];
        char exepath[PATH_MAX + 1] = {0};

        sprintf(arg1, "/proc/%d/exe", getpid());
        auto bytes_written = readlink(arg1, exepath, 1024);

        return std::string(exepath).substr(0, bytes_written - 9);
#endif
    }

    static std::string get_working_directory()
    {
#ifdef _WIN32
        TCHAR buffer[MAX_PATH];
        GetCurrentDirectory(MAX_PATH, buffer);
        std::basic_string<TCHAR> working_directory(buffer);
        return windows_to_universal_path(std::string(working_directory.begin(), working_directory.end()));
#else
        char buffer[PATH_MAX];

        if (getcwd(buffer, 2048) == nullptr)
        {
            throw std::runtime_error("getcwd failed");
        }

        return std::string(buffer);
#endif
    }
    
    static std::string get_data_directory(const std::string &append = "")
    {
        return get_executable_directory() + "../../tests/data" + append;
    }
    
    static void copy_file(const std::string &source, const std::string &destination, bool overwrite)
    {
        if(!overwrite && file_exists(destination))
        {
            throw std::runtime_error("destination file already exists and overwrite==false");
        }
        
        std::ifstream src(source, std::ios::binary);
        std::ofstream dst(destination, std::ios::binary);
        
        dst << src.rdbuf();
    }

    static void delete_file(const std::string &path)
    {
      std::remove(path.c_str());
    }
    
    static bool file_exists(const std::string &path)
    {        
#ifdef _MSC_VER
        std::wstring path_wide(path.begin(), path.end());
        return PathFileExists(path_wide.c_str()) && !PathIsDirectory(path_wide.c_str());
#else
        try
        {
            struct stat fileAtt;

            if (stat(path.c_str(), &fileAtt) == 0)
            {
                return S_ISREG(fileAtt.st_mode);
            }
        }
        catch(...) {}

        return false;
#endif
    }
};