/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: Demangle.cpp
    Date: 2022-3-31
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "Debug.hpp"

#if defined(AURORA_IS_MODERNNT_DERIVED)
    #include <DbgHelp.h>
#endif

#if defined(AURORA_COMPILER_CLANG)
    #include <cxxabi.h>
#endif

namespace Aurora::Debug
{
    AUKN_SYM AuResult<AuString> DemangleName(const AuString &pName)
    {
        // Wine impl:  https://github.com/wine-mirror/wine/blob/master/dlls/msvcrt/undname.c
        // Google impl: idr where i saw it last

        AuResult<AuString> ret;

    #if defined(AURORA_IS_MODERNNT_DERIVED)
        struct win32poll
        {
            const char *ptr;
            char name[4096] = {0};
        } poll;

        poll.ptr = {};

        if (pName.size() >= AuArraySize(poll.name))
        {
            return ret;
        }

        AuMemcpy(poll.name, pName.data(), pName.size());
        auto pInfo = (__std_type_info_data *)&poll;

    #ifdef _M_CEE_PURE
        ret.type = __std_type_info_name((__std_type_info_data *)&poll, static_cast<__type_info_node *>(__type_info_root_node.ToPointer()));
    #else
        ret.type = __std_type_info_name(pInfo, &__type_info_root_node);
    #endif

        // On failure, the undecorated name is assigned the dname docorated name, which is offset by +1 (the '?' or '_' hint)
        if (strcmp(pInfo->_UndecoratedName, pInfo->_DecoratedName + 1) == 0)
        {
            if (pUnDecorateSymbolName)
            {
                auto characters = pUnDecorateSymbolName(pName.c_str(), poll.name, AuArraySize(poll.name), UNDNAME_32_BIT_DECODE);
                if (!characters)
                {
                    return ret;
                }

                ret.type = AuString(poll.name, characters);
            }
            else
            {
                return ret;
            }
        }

    #else 
        int status;
        char *res = abi::__cxa_demangle(pName.c_str(),
                                        nullptr,
                                        nullptr,
                                        &status);

        if (!res)
        {
            return ret;
        }

        if (status != 0)
        {
            free(res);
            return ret;
        }

        ret.type = res;
        free(res);
    #endif

        ret.Complete();
        return ret;
    }
}