"""An abstract response"""

from time import time

from MiscUtils import AbstractError

from Message import Message


class Response(Message):
    """The abstract response class.

    Response is a type of Message that offers the following:

      * A time stamp (indicating when the response was finished)
      * An output stream

    Response is an abstract class; developers typically use HTTPResponse.

    FUTURE

      * Consider implementing the buffer/flush logic here
        including buffer size.
      * Also, consider then having a method that doesn't allow
        commitment until the end.
    """


    ## Init ##

    def __init__(self, trans, strmOut):
        Message.__init__(self)
        self._strmOut = strmOut
        self._transaction = trans


    ## End time ##

    def endTime(self):
        return self._endTime

    def recordEndTime(self):
        """Record the end time of the response.

        Stores the current time as the end time of the response. This should
        be invoked at the end of deliver(). It may also be invoked by the
        application for those responses that never deliver due to an error.
        """
        self._endTime = time()


    ## Output ##

    def write(self, string):
        raise AbstractError(self.__class__)

    def isCommitted(self):
        raise AbstractError(self.__class__)

    def deliver(self):
        raise AbstractError(self.__class__)

    def reset(self):
        raise AbstractError(self.__class__)

    def streamOut(self):
        return self._strmOut


    ## Cleanup ##

    def clearTransaction(self):
        del self._transaction


    ## Exception reporting ##

    _exceptionReportAttrNames = Message._exceptionReportAttrNames + ['endTime']
