'''
Created on 18/01/2010

@author: Claws
'''
from twisted.internet import reactor, defer
from twisted.spread import pb
import datetime

class PluginClient(pb.Referenceable):
    """ Plugin client interface exposed to PluginServer's """
    
    def __init__(self, shutdownCallback):
        self.shutdownHandler = shutdownCallback

    def remote_shutdown(self):
        """ Instruct Plugin to shutdown """
        print "plugin instructed to shutdown"
        d = defer.Deferred()
        self.shutdownHandler(d)
        return d
        
class PluginServer(pb.Root):
    """ Plugin server interface exposed to PluginClient's """

    def remote_set_client_perspective(self, pluginRef):
        print "plugin-runner got client reference"
        reactor.callLater(1.0, self.shutdown_plugin, pluginRef)
    
    def shutdown_plugin(self, pluginRef):
        
        def pluginShutdownCompleted(result, startTime):
            endTime = datetime.datetime.now()
            print "Plugin shutdown took %s to complete." % (endTime - startTime)
            return result
        
        print "plugin-runner asking plugin to shutdown"
        d = pluginRef.callRemote("shutdown")
        d.addCallback(pluginShutdownCompleted, datetime.datetime.now())
        d.addCallback(self.shutdown)
    
    def shutdown(self, _):
        reactor.stop()


def startPluginServer(port):
    """ Start a plugin communications server """
    print "starting server"
    reactor.listenTCP(port=port,
                      factory=pb.PBServerFactory(PluginServer()),
                      interface='localhost')


def startPluginClient(port, shutdownHandler):
    """ Start a plugin communications client """
    
    def gotServerPerspective(serverPerspective, pluginPerspective):
        """ Give the plugin-runner this client's perspective """
        serverPerspective.callRemote("set_client_perspective", pluginPerspective)
        return serverPerspective

    print "starting plugin"
    client = PluginClient(shutdownHandler)
    factory = pb.PBClientFactory()
    reactor.connectTCP(host='localhost', port=port, factory=factory)
    return factory.getRootObject().addCallback(gotServerPerspective, client)

if __name__ == "__main__":
    port = 42155
    
    def longRunningAction(d, countDown=10):
        """ Emulate long running shutdown activities """
        print "shuting down in %i seconds" % countDown
        if countDown == 0:
            d.callback(True)
        else:
            countDown -= 1
            reactor.callLater(1, longRunningAction, d, countDown)

    
    # start plugin-runner
    reactor.callWhenRunning(startPluginServer, port)
    # start plugin
    reactor.callLater(2.0, startPluginClient, port, longRunningAction)
    reactor.run()