#pragma once

#include <modules/OS.h>

#include <iostream>
#include <cstdlib>
#include <ostream>

namespace LXC::Util
{
    // Enum to translate to the Win32 code for the colors //
    enum Color
    {
        DEFAULT         = 0x07,

        BLACK           = 0x00,
        BLUE            = 0x01,
        GREEN           = 0x02,
        AQUA            = 0x03,
        RED             = 0x04,
        PURPLE          = 0x05,
        YELLOW          = 0x06,
        LIGHT_GRAY      = 0x07,
        LIGHT_BLUE      = 0x09,
        LIGHT_GREEN     = 0x0a,
        LIGHT_AQUA      = 0x0b,
        LIGHT_RED       = 0x0c,
        LIGHT_PURPLE    = 0x0d,
        LIGHT_YELLOW    = 0x0e,
        WHITE           = 0x0f
    };
}

namespace LXC::Internal
{
    // Checks if a type can be outputted to std::ostream //
    template<typename T> concept Logable = requires(std::ostream & os, T t)
    {
        // I have no idea what this part does at all //
        { os << t } -> std::same_as<std::ostream&>;
    };

    // Checks if a list of types can be outputted to std::ostream //
    template<typename... Args> concept AllLogable = (Logable<Args> && ...);

    // Checks if the type has a custom log method //
    template <typename T> concept HasLogStrFunc = requires(T obj)
    {
        // Checks the type has a function LogStr that returns a string //
        { obj.LogStr() } -> std::same_as<std::string>;
    };

    // Returns a reference to the log file //
    inline std::ofstream& Log()
    {
        static std::ofstream sLog;
        return sLog;
    }

    #if defined(_WIN32)

    // Base function for all derived Print() functions //
    template<Util::Color col, bool newLine, typename... Args>
    inline void WriteImpl(std::ostream& os, Args&&... args)
    {
        static HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
        if constexpr (col != Util::Color::DEFAULT)
            SetConsoleTextAttribute(hConsole, static_cast<WORD>(col));

        (os << ... << std::forward<Args>(args));

        if constexpr (newLine)
            os << std::endl;

        if constexpr (col != Util::Color::DEFAULT)
            SetConsoleTextAttribute(hConsole, static_cast<WORD>(Util::Color::DEFAULT));
    }

    #elif defined(__unix__)
    
    static const char* GetAnsiCode(Util::Color color)
    {
        switch (color)
        {
            case Util::Color::BLACK:        return "\x1b[30m";
            case Util::Color::BLUE:         return "\x1b[34m";
            case Util::Color::GREEN:        return "\x1b[32m";
            case Util::Color::AQUA:         return "\x1b[36m";
            case Util::Color::RED:          return "\x1b[31m";
            case Util::Color::PURPLE:       return "\x1b[35m";
            case Util::Color::YELLOW:       return "\x1b[33m";
            case Util::Color::LIGHT_GRAY:   return "\x1b[0m";
            case Util::Color::LIGHT_BLUE:   return "\x1b[94m";
            case Util::Color::LIGHT_GREEN:  return "\x1b[92m";
            case Util::Color::LIGHT_AQUA:   return "\x1b[96m";
            case Util::Color::LIGHT_RED:    return "\x1b[91m";
            case Util::Color::LIGHT_PURPLE: return "\x1b[95m";
            case Util::Color::LIGHT_YELLOW: return "\x1b[93m";
            case Util::Color::WHITE:        return "\x1b[97m";
            default:                        return "\x1b[0m";
        }
    }

    template<Util::Color col, bool newLine, typename... Args>
    inline void WriteImpl(std::ostream& os, Args&&... args)
    {
        if constexpr (col != Util::Color::DEFAULT)
            os << GetAnsiCode(col);

        (os << ... << std::forward<Args>(args));

	    if constexpr (newLine)
	        os << std::endl;

        if constexpr (col != Util::Color::DEFAULT)
            os << GetAnsiCode(Util::Color::DEFAULT);
    }

    #endif
}

namespace LXC::Util
{
    // Prints arguments to the console with the given color //
    template<Color col, typename... Args>
        requires Internal::AllLogable<Args...>
    inline void PrintAs(Args&&... args)
    {
        Internal::WriteImpl<col, false>(std::cout, std::forward<Args>(args)...);
    }

    // Prints arguments to the console //
    template<typename... Args>
        requires Internal::AllLogable<Args...>
    inline void Print(Args&&... args)
    {
        Internal::WriteImpl<Util::Color::DEFAULT, false>(std::cout, std::forward<Args>(args)...);
    }

    // Prints arguments to the console with a new-line character at the end //
    template<typename... Args>
        requires Internal::AllLogable<Args...>
    inline void PrintLn(Args&&... args)
    {
        Internal::WriteImpl<Util::Color::DEFAULT, true>(std::cout, std::forward<Args>(args)...);
    }

    // Logs all the arguments to the file (automatically flushes) //
    template<typename... Args>
        requires Internal::AllLogable<Args...> && (sizeof...(Args) > 1)
    inline void Log(Args&&... args)
    {
        std::ofstream& log = Internal::Log();
        if (log.is_open()) _UNLIKELY
            Internal::WriteImpl<Util::Color::DEFAULT, true>(log, R"([LXC] ")", std::forward<Args>(args)..., '"');
    }

    // Logs a singular argument to the log, calls Log() if it can on the object //
    template<typename T>
        requires Internal::HasLogStrFunc<T> || Internal::Logable<T>
    inline void Log(T arg)
    {
        std::ofstream& log = Internal::Log();
        if (log.is_open()) _UNLIKELY
        {
            if constexpr (Internal::HasLogStrFunc<T>)
                Internal::WriteImpl<Util::Color::DEFAULT, true>(log, "[LXC] ", '{', arg.LogStr(), '}');

            else
                Internal::WriteImpl<Util::Color::DEFAULT, true>(log, "[LXC] ", '"', arg, '"');
        }
    }

    // Intitalises the log with the given file name //
    inline void CreateLog(const std::filesystem::path& path)
    {
        // Opens the log file with the given path //
        std::ofstream& log = Internal::Log();
        log.open(path);

        // Assigns a function to close the log file on program exit //
        std::atexit([]()
            {
                std::ofstream& log = Internal::Log();
                log.close();
            });
    }
}