'''
Example 3b is identical to ex3_main.py but demonstrates how to do 
the same thing with use pubsub version 3 in "advanced" mode. 
The only difference from Example 3 is that the topic message data 
specification is given, which helps you verify that listeners and 
senders are correct. 

The main constraints are:
- topic message data is sent only via keyword arguments in a 
  sendMessage(). Sending more data is easy compared to pubsub 
  version 1.
- each topic along a topic branch gets only the data specific to it; 
  a subtopic must support all of its parent's data. This is 
  similar to the OO paradigm: "derived" topics "inherit" message data from
  "base" topics. 
- The Topic Message Data Specification (TMDS) is created for a topic
  by looking in a "topic tree definition" that you provide. This sets 
  the keyword arguments that will be allowed/required in a sendMessage()
  for given topics.
- all listeners to subscribe to same topic must follow
  same protocol. E.g. below, first listener is listener1, sets TMDS to be
  msg (required) and extra (optional), so second on to subscribe, i.e. 
  listener2.onTopic1, must have same. 
'''

from pubsub import pub

# -------------- define topic tree --------------

class MyTopicTree:
    class topic1:
        '''Explain when topic1 should be used'''
        def listener(msg, extra=None):
            '''
            - msg: a text string message for recipient
            - extra: something optional
            '''

    class topic2:
        '''Some something useful about topic2'''
        def listener(msg):
            '''
            - msg: a text string
            '''
    
pub.importMyTopicTree( MyTopicTree, format=pub.TOPIC_TREE_FROM_CLASS )

# ------------ create some listeners --------------

def listener1(msg, extra=None):
    print 'Function listener1 received', msg

class Listener:    
    def onTopic1(self, msg, extra=None):
        print 'Method Listener.onTopic1 received', `msg`
    def onTopic2(self, msg):
        print 'Method Listener.onTopic2 received', `msg`
    def __call__(self):
        print 'Listener() called'

# ------------ register listeners ------------------

pub.subscribe(listener1, 'topic1')

listener2 = Listener()
pub.subscribe(listener2, pub.ALL_TOPICS)
pub.subscribe(listener2.onTopic1, 'topic1')
pub.subscribe(listener2.onTopic2, 'topic2')

# ------------ create a couple of senders --------------

def doSomething1():
    print '--- SENDING topic1 message ---'
    pub.sendMessage('topic1', msg='message1', extra='extra')
    print '---- SENT topic1 message ----'
    
def doSomething2():
    print '--- SENDING topic2 message ---'
    pub.sendMessage('topic2', msg=123)
    print '---- SENT topic2 message ----'
    
# --------- define the main part of application --------

def run():
    '''Loop until we get a quit message or user breaks.'''
    doSomething1()
    doSomething2()
    
    from pubsub.utils import printTreeDocs
    print 'done\nTopic tree TMDS:'
    printTreeDocs(extra="DA")
    print '\nTopic tree listeners:'
    printTreeDocs(extra="L")


if __name__ == '__main__':
    run()