from urllib import parse

class DivaRequestParseException(Exception):
    """
    Exception raised when there is a fault in parsing a diva request,
    either due to a malformed request, or missing required items
    """
    def __init__(self, message: str) -> None:
        self.message = message
        super().__init__(self.message)

class BaseRequest:
    def __init__(self, raw: str) -> None:
        self.raw = dict(parse.parse_qsl(raw))
        
        if 'cmd' not in self.raw:
            raise DivaRequestParseException(f"cmd not in request data {self.raw}")
        self.cmd = raw['cmd']

        if 'req_id' not in self.raw:
            raise DivaRequestParseException(f"req_id not in request data {self.raw}")
        self.req_id = raw['req_id']

class BaseResponse:
    def __init__(self, cmd_id: str, req_id: int) -> None:
        self.cmd = cmd_id
        self.req_id = req_id
        self.stat = "ok"

    def make(self) -> str:
        all_vars = vars(self)
        all_vars.pop('cmd')
        all_vars.pop('req_id')

        ret = f"cmd={self.cmd}&req_id={self.req_id}"
        ret += parse.urlencode(all_vars, doseq=True, quote_via=parse.quote)

        return ret