# @author Donovan Preston
#
# Copyright (c) 2005-2006, Donovan Preston
# Copyright (c) 2007, Linden Research, Inc.
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

import sys
import traceback

from eventlet import api
from eventlet import timer

from twisted.internet import posixbase
from twisted.internet.interfaces import IReactorFDSet

try:
    from zope.interface import implements
    _working = True
except ImportError:
    _working = False
    def implements(*args, **kw):
        pass


class TwistedTimer(object):
    def __init__(self, timer):
        self.timer = timer

    def cancel(self):
        self.timer.cancel()

    def getTime(self):
        return self.timer.scheduled_time

    def delay(self, seconds):
        hub = api.get_hub()
        new_time = hub.clock() - self.timer_scheduled_time + seconds
        self.timer.cancel()
        cb, args, kw = self.timer.tpl
        self.timer = hub.schedule_call(new_time, cb, *args, **kw)

    def reset(self, new_time):
        self.timer.cancel()
        cb, args, kw = self.timer.tpl
        self.timer = api.get_hub().schedule_call(new_time, cb, *args, **kw)

    def active(self):
        return not self.timer.called


class EventletReactor(posixbase.PosixReactorBase):
    implements(IReactorFDSet)

    def __init__(self, *args, **kw):
        self._readers = {}
        self._writers = {}
        posixbase.PosixReactorBase.__init__(self, *args, **kw)

    def callLater(self, func, *args, **kw):
        return TwistedTimer(api.call_after(func, *args, **kw))

    def run(self):
        self.running = True
        self._stopper = api.call_after(sys.maxint / 1000.0, lambda: None)
        ## schedule a call way in the future, and cancel it in stop?
        api.get_hub().run()

    def stop(self):
        self._stopper.cancel()
        posixbase.PosixReactorBase.stop(self)
        api.get_hub().remove_descriptor(self._readers.keys()[0])
        api.get_hub().abort()

    def addReader(self, reader):
        print "NEW READER", reader.fileno()
        fileno = reader.fileno()
        self._readers[fileno] = reader
        api.get_hub().add_descriptor(fileno, read=self._got_read)

    def _got_read(self, fileno):
        print "got read on", fileno, self._readers[fileno]
        api.get_hub().add_descriptor(fileno, read=self._got_read)
        self._readers[fileno].doRead()

    def addWriter(self, writer):
        print "NEW WRITER", writer.fileno()
        fileno = writer.fileno()
        self._writers[fileno] = writer
        api.get_hub().add_descriptor(fileno, write=self._got_write)

    def _got_write(self, fileno):
        print "got write on", fileno, self._writers[fileno]
        api.get_hub().add_descriptor(fileno, write=self._got_write)
        self._writers[fileno].doWrite()

    def removeReader(self, reader):
        print "removing reader", reader.fileno()
        fileno = reader.fileno()
        if fileno in self._readers:
            self._readers.pop(fileno)
        api.get_hub().remove_descriptor(fileno)

    def removeWriter(self, writer):
        print "removing writer", writer.fileno()
        fileno = writer.fileno()
        if fileno in self._writers:
            self._writers.pop(fileno)
        api.get_hub().remove_descriptor(fileno)

    def removeAll(self):
        return self._removeAll(self._readers.values(), self._writers.values())


def install():
    if not _working:
        raise RuntimeError, "Can't use support.twisted because zope.interface is not installed."
    reactor = EventletReactor()
    from twisted.internet.main import installReactor
    installReactor(reactor)


__all__ = ['install']