from functools import partial

from twisted.internet.defer import inlineCallbacks, returnValue 

from ..error import NoRouteForTask, RejectRecipient

from ..model.offer import offers

from ..model.job import exJobs

from .pool  import taskPool

class Task:

    '''one single part of a job.

    a task is one message to one recipient

    '''

    def __init__(self, recipient, job):

        self.recipient = recipient

        self.job = job

    def start(self):

        self.d = taskPool.run(self._run)

        self.d.addCallback(partial(self.job.setStatus,self))

        self.d.addErrback(partial(self.job.setError,self))

        return self.d

    @inlineCallbacks

    def _run(self):

        for offer in self.job.offers:

            try:

                ret = yield offers[offer](self.recipient,self.job.message)

                returnValue(ret)

            except RejectRecipient:

                continue

        else:

            raise NoRouteForTask()

@inlineCallbacks

def createJob(user,recipients, msg, offers, info=None):

    job = yield exJobs.create(user, recipients, msg, offers, info)

    for r in recipients:

        task = Task(r,job)

        job.addTask(task)

        task.start()

    returnValue(job)