#include <Windows.h>
#include <stdio.h>

template< typename Fn >
__forceinline Fn get_vfunc(void* pVmt, int iIndex) {
    return (*(Fn**)pVmt)[iIndex];
}

class CBaseEntity {
public:
    char                __pad[0x64];
    int                 index;
    int                 GetHealth();
};

int CBaseEntity::GetHealth()
{
    return *(int*)((DWORD)this + 0x000000FC);
}

class IClientEntityList {
public:
    CBaseEntity* GetClientEntity(int iIndex)
    {
        // return type  // class to insert // index //args to pass
        return get_vfunc<CBaseEntity*(__thiscall*)(IClientEntityList*, int)>(this, 3)(this, iIndex);
    }
};
class IEngineClient {
public:
    int GetLocalPlayer()
    {
        // return type  // class to insert // index //args to pass
        return get_vfunc<int(__thiscall*)(IEngineClient*)>(this, 12)(this);
    }
};

IClientEntityList* EntList;
IEngineClient* Engine;

typedef void* (*CreateInterfaceFn)(const char *pName, int *pReturnCode);


template< typename Interface >
Interface* GetInterface(const char* pszModule, const char* pszInterfaceName) {
    Interface* pTemp = nullptr;
    char szBuf[64] = { 0 };
    auto Factory = (CreateInterfaceFn)GetProcAddress(GetModuleHandleA(pszModule), "CreateInterface");

    for (int i = 0; i < 100; i++) {
        sprintf_s(szBuf, "%s%03d", pszInterfaceName, i);
        pTemp = (Interface*)Factory(szBuf, 0);

        if (pTemp) break;
    }

    return pTemp;
}

static void Init() {
    auto pEntList = GetInterface<IClientEntityList>("client.dll", "VClientEntityList");
    auto pEngine = GetInterface<IEngineClient>("engine.dll", "VEngineClient");
    Engine = pEngine;
    EntList = pEntList;

    char buf[16];
    sprintf_s(buf, "%d", EntList->GetClientEntity(Engine->GetLocalPlayer())->GetHealth());
    MessageBoxA(NULL, buf, "hi", MB_OK);
}

BOOL WINAPI DllMain(void*, DWORD reason, void*) {
    if (reason == DLL_PROCESS_ATTACH)
        CreateThread(0, 0, (LPTHREAD_START_ROUTINE)Init, 0, 0, 0);

    return TRUE;
}