# 1. Global Auth Middleware
@web.Middleware
async def auth_middleware(request, handler):
    # 1) Initialize auth state in request
    request.update({
        "is_authorized": False,
        "user": None,
        "keypair": None
    })

    # 2) Check if handler requires auth
    if not handler.auth_required:
        return await handler(request)

    # 3) Process authorization and stor info in request obj
    if authenticated:
        request.update({
            "is_authorized": True,
            "user": user_info,
            "keypair": keypair_info
        })

# 2. Pydantic Param handler
def pydantic_params_api_handler(param_model, query_model = None):
    async def wrapped(request):
        try:
            # 1) Validate body/query params
            if request.has_body:
                params = param_model.validate(request.body)
                if query_model:
                    query_model = query_model.validate(request.query)
            else:
                params = param_model.valdiate(request.query)
            
            # 2) Exec handler
            result = await handler(request, params)
        
        # 3) If validation failed make custom msg and raise InvalidAPIParameters error(Custom error)
        except ValidationError as e:
            message = make_custom_msg(e)
            raise InvalidAPIParameters(message)
        
        # 4) Convert Pydantic Response model into aiohttp web.Response
        return web.json_response(result.model_dump(mode="json"))

    return wrapped

# 3. Usage Example
@auth_required  
@pydantic_params_api_handler(RequestModel)
async def handler(request, params):
   user = request["user"]  # Set from auth_middleware
   data = params  # Validated by pydantic