NBEngine/engine/NBCore/Errors.hpp

#pragma once
#include <memory>
#ifndef _NB_ERROR
#define _NB_ERROR

#include <exception>
#include <iostream>
#include <string>
#include <type_traits>
#include "TypeTraits.hpp"
#include <unordered_map>
#include "Utils.hpp"

/* #ifndef THROW_WITH_INFO
    #ifdef CODE_ERROR_LOCATIONS
        #define THROW_WITH_INFO(type, ...) throw type(__VA_ARGS__, __LINE__, __FILE__)
    #else
        #define THROW_WITH_INFO(type, ...) throw type(__VA_ARGS__)
    #endif // CODE_ERROR_LOCATIONS
#endif // THROW_WITH_INFO

#ifndef THROW
    #ifdef LOGGING
        #define THROW_WTIH_INFO(type, ...) throw type(__VA_ARGS__, __LINE__, __FILE__)
    #else
        #define THROW(...) THROW_WITH_INFO(__VA_ARGS__)
    #endif // LOGGING
#endif // THROW */

namespace nb {

typedef std::unordered_map<unsigned int, const char*> ErrorCodeMap;

template <typename T>
using has_type = decltype(T::type);

template<typename StringType, typename ErrorType>
struct NBErrorWhatString;

class ErrorBase_what_str_impl : public std::exception {
    template <typename T>
    T what_str() const;

    template <>
    virtual std::wstring what_str() const;

    template<>
    virtual std::string what_str() const;
};

template<class ErrorType>
class ErrorBase : public ErrorBase_what_str_impl {
public:
    ErrorBase(const ErrorBase&) = default;
    ErrorBase& operator=(const ErrorBase&) = delete;

    template<typename StringType = std::string>
    inline const StringType what_str() const noexcept {
        return NBErrorWhatString<StringType,ErrorType>::what(*this);
    }

    virtual const char* what() const noexcept override final {
        const std::string& ret = what_str();
        return ret.c_str();
    }

    static const std::string type;
    static const ErrorCodeMap ErrorMessages; 

    const unsigned int code;
    const std::string msg;
    const std::shared_ptr<const std::exception> trace;
    const bool traceIsNBError;

protected:
    ErrorBase() = delete;

    template <
        typename TraceType=std::exception,
        std::enable_if_t<std::is_base_of_v<std::exception, TraceType>, bool> = true
    >
    ErrorBase(
        const unsigned int code_,
        std::string msg_,
        const TraceType* trace_=nullptr,
        unsigned int line_=0,
        std::string filename_=""
    ) noexcept :
        code(code_),
        msg(msg_),
        trace{trace_ ? std::make_shared<TraceType>(*trace_) : nullptr},
        traceIsNBError( trace_ ?  is_detected<has_type, TraceType>::value : false)
    {
        static_assert(std::is_same<const std::unordered_map<unsigned int, const char*>, decltype(ErrorType::ErrorMessages)>::value,
            "const std::unordered_map<unsigned int, const char*> ErrorMessages must be "
            "a class member."
        );
        static_assert(std::is_enum_v<typename ErrorType::Codes>, "enum Codes must be a class member.");
        static_assert(std::is_same<std::underlying_type_t<typename ErrorType::Codes>, unsigned int>::value,
            "enum Codes must be of underlying type unsigned int."
        );
        static_assert(std::is_same<const std::string, decltype(ErrorType::type)>::value,
            "const std::string type must be a class member."
        );
        static_assert(std::is_base_of<std::exception, TraceType>::value,
            "`trace_` must be a pointer to a child object of std::exception."
        );
    }

    template <
        typename TraceType,
        std::enable_if_t<std::is_base_of_v<std::exception, TraceType>, bool> = true
    >
    ErrorBase(
        const unsigned int& code_,
        const TraceType& trace_,
        unsigned int line_=0,
        std::string filename_=""
    ) noexcept : ErrorBase(
        code_, 
        ErrorType::ErrorMessages.at(code_),
        &trace_,
        line_,
        filename_
    ) {}

    template <
        typename TraceType,
        std::enable_if_t<std::is_base_of_v<std::exception, TraceType>, bool> = true
    >
    ErrorBase(
        const std::string& msg_,
        const TraceType& trace_,
        unsigned int line_=0,
        std::string filename_=""
    ) noexcept : ErrorBase(
        0, 
        msg_,
        &trace_,
        line_,
        filename_
    ) {}

    ErrorBase(
        const unsigned int& code_,
        unsigned int line_=0,
        std::string filename_=""
    ) noexcept : ErrorBase(
        code_, 
        ErrorType::ErrorMessages.at(code_),
        static_cast<std::exception*>(nullptr),
        line_,
        filename_
    ) {}

    ErrorBase(
        const std::string& msg_,
        unsigned int line_=0,
        std::string filename_=""
    ) noexcept : ErrorBase(
        0, 
        msg_,
        nullptr,
        line_,
        filename_
    ) {}

    std::string (ErrorBase::*_trace_what_str)();
    std::wstring (ErrorBase::*_trace_what_wstr)();
};
template <typename ErrorType>
const std::string ErrorBase<ErrorType>::type = ErrorType::type;
template <typename ErrorType>
const ErrorCodeMap ErrorBase<ErrorType>::ErrorMessages = ErrorType::ErrorMessages;

template<typename ErrorType>
struct NBErrorWhatString<std::wstring, ErrorType> {
    inline static const std::wstring what(const ErrorBase<ErrorType>& err) noexcept {
        std::wstring ret = nb::str_to_wstr(err.msg);
        const std::wstring replace = nb::WNEWLINE + L"┗-";
        if (err.trace) {
            std::wstring trace_msg;
            if (err.traceIsNBError) {
                trace_msg = std::static_pointer_cast<ErrorBase_what_str_impl>(err.trace)->template what_str<std::wstring>();
            } else {
                trace_msg = nb::str_to_wstr(std::string(err.trace->what()));
            }
            trace_msg = find_and_replace<std::wstring>(trace_msg, L"┗", L"-");
            ret += replace + find_and_replace<std::wstring>(
                trace_msg,
                nb::WNEWLINE,
                replace
            );
        }
        return ret;
    }
};

template<typename ErrorType>
struct NBErrorWhatString<std::string, ErrorType> {
    inline static const std::string what(const ErrorBase<ErrorType>& err) noexcept {
        std::string ret = err.msg;
        const std::string replace = nb::NEWLINE+"  ";
        if (err.trace) {
            ret += replace + find_and_replace(
                std::string(err.trace->what()),
                nb::NEWLINE,
                replace
            );
        }
        return ret;
    }
};

template <class ErrorType = NoneType>
class Error;

template<>
class Error<NoneType>;

template <class ErrorType>
class Error : public ErrorBase<ErrorType> {
    using Base = ErrorBase<ErrorType>;
public:    
    template <typename... Args>
    Error(Args... T) : Base(T...) {}

    using Base::what;
    using Base::code;
    using Base::msg;
    using Base::trace;
    using Base::type;
    using Base::ErrorMessages;

    friend ErrorBase<Error>;
};

template<>
class Error<NoneType> : public ErrorBase<Error<NoneType>> {
    using Base = ErrorBase<Error<NoneType>>;
public:
    using Base::Base;
    Error() : Base(0) {}

    enum Codes : unsigned int {
        GENERAL, UNDEFINED, BADERRORCODE
    };

    using Base::what;
    using Base::code;
    using Base::msg;
    using Base::trace;

    static const std::string type;
    static const ErrorCodeMap ErrorMessages;
};

} // namespace nb

#endif // _NB_ERROR