handler.py

#With Love @BadFactBot
from __future__ import print_function
import os, sys, subprocess, json


LIBS = os.path.join(os.getcwd(), 'local', 'lib')
#-------PYTHON PACKAGE WRAPPING------------ (NOTE: AWS LAMBDA HAS AN ERROR WHEN IMPORTING PYTHON MODULES
#                                           NORMALLY IN HANDLER FUNCTIONS, SO THERE IS A WORK AROUND BELOW)
"""
Unused Alternate method

def on_intent(intent_request, session):
    print("on_intent requestId=" + intent_request['requestId'] +
          ", sessionId=" + session['sessionId'])
    intent = intent_request['intent']
    intent_name = intent_request['intent']['name']

    #intents
    if intent_name == "AMAZON.HelpIntent":
        return get_welcome_response()
    elif intent_name == "AMAZON.CancelIntent" or intent_name == "AMAZON.StopIntent":
        return handle_session_end_request()
    else:
        raise ValueError("Invalid intent")
"""

def handler(filename):
    def handle(event, context):
        if event['session']['new']:
            on_session_started({'requestId': event['request']['requestId']}, event['session'])
        session = event['session']

        #Security
        if session['application']['applicationId'] != "":
            raise ValueError("Invalid Application ID")

        #Handling Intents Here
        if event['request']['type'] == "LaunchRequest":
            return on_launch(event['request'], event['session'])
        elif event['request']['type'] == "SessionEndedRequest":
            return on_session_ended(event['request'], event['session'])
        elif event['request']['type'] == "IntentRequest":
            intent_request = event['request']
            intent = intent_request['intent']
            intent_name = intent_request['intent']['name']
            print("on_intent requestId=" + intent_request['requestId'] +
                  ", sessionId=" + session['sessionId'])
            if intent_name == "AMAZON.HelpIntent":
                return get_welcome_response()
            elif intent_name == "AMAZON.CancelIntent" or intent_name == "AMAZON.StopIntent":
                return handle_session_end_request()
            elif intent_name == "FactIntent":
                #PYTHON PACKAGE IMPORTING WORKAROUND
                env = os.environ.copy()
                env.update(LD_LIBRARY_PATH=LIBS)
                proc = subprocess.Popen(
                    ('python', filename),
                    env=env,
                    stdin = subprocess.PIPE,
                    stdout = subprocess.PIPE,
                    stderr = subprocess.STDOUT)
                (stdout, _) = proc.communicate(input=json.dumps(event))
                speechOut = ""
                while not speechOut:
                    try:
                        speechOut = json.loads(stdout)
                    except ValueError:
                        print("Something wrong, trying again")
                        return handle(event, context)
                return bad_factor_response(speechOut + ". Ask me for another fact?", session)
            else:
                raise ValueError("Invalid intent")
    return handle

def invoking(f):
    output = f(json.load(sys.stdin))
    json.dump(output, sys.stdout)

lambda_handler = handler('test.py')


#--------Helpers----------------

def build_speechlet_response(title, output, reprompt_text, should_end_session):
    #Building json response
    return {
        'outputSpeech': {
            'type': 'PlainText',
            'text': output
        },
        'card': {
            'type': 'Simple',
            'title': title,
            'content': output
        },
        'reprompt': {
            'outputSpeech': {
                'type': 'PlainText',
                'text': reprompt_text
            }
        },
        'shouldEndSession': should_end_session
    }

def build_response(session_attributes, speechlet_response):
    #Building json response
    return {
        'version': 1.0,
        'sessionAttributes': session_attributes,
        'response': speechlet_response
    }
def bad_factor_response(speechOut, session):
    session_attributes = {}
    reprompt_text = "Ask me another fact?"
    should_end_session = False
    return build_response(session_attributes, build_speechlet_response("Bad fact", speechOut, reprompt_text, should_end_session))

#-------------Skill Behaviors----------------
def get_welcome_response():
    session_attributes = {}
    card_title = "Welcome"
    speech_output = "Hello, Human. I am the most knowledgable bot in the universe." \
                    " I can tell you a fact about anything. " \
                    "Beep. Boop. Beep."
    # If the user either does not reply to the welcome message or says something
    # that is not understood, they will be prompted again with this text.
    reprompt_text = "Ask me a fact human." \
                    "Beep Boop."
    should_end_session = False
    return build_response(session_attributes, build_speechlet_response(
        card_title, speech_output, reprompt_text, should_end_session))

def handle_session_end_request():
    card_title = "Session Ended"
    speech_output = "Are my facts not good enough? ......" \
                    "Dont put me in the dumpster..."
    should_end_session = True
    return build_response({}, build_speechlet_response(card_title, speech_output, None, should_end_session))

#---------Events----------------------------
def on_session_started(session_started_request, session):
    """Called on session start"""
    print("on_session_started requestId=" +session_started_request['requestId'] + ", sessionId=" + session['sessionId'])

def on_launch(launch_request, session):
    """Called on launch"""
    print("on_launch requestId=" + launch_request['requestId'] + ", sessionId=" + session['sessionId'])
    return get_welcome_response()

def on_session_ended(session_ended_request, session):
    """Called when session ends"""
    print("on_session_ended requestId=" + session_ended_request['requestId'] +
          ", sessionId=" + session['sessionId'])
    return handle_session_end_request()