app.py

from flask import Flask, request
import json
import requests
from flask_sqlalchemy import SQLAlchemy
import os
import praw

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ['DATABASE_URL']
db = SQLAlchemy(app)
reddit = praw.Reddit(client_id='*******',
                     client_secret='***************',
                     user_agent='my user agent')

# This needs to be filled with the Page Access Token that will be provided
# by the Facebook App that will be created.
PAT = '*********************************'

quick_replies_list = [{
    "content_type":"text",
    "title":"Meme",
    "payload":"meme",
},
{
    "content_type":"text",
    "title":"Motivation",
    "payload":"motivation",
},
{
    "content_type":"text",
    "title":"Shower Thought",
    "payload":"Shower_Thought",
},
{
    "content_type":"text",
    "title":"Jokes",
    "payload":"Jokes",
}
]
@app.route('/', methods=['GET'])
def handle_verification():
    print("Handling Verification.")
    if request.args.get('hub.verify_token', '') == 'my_voice_is_my_password_verify_me':
        print("Verification successful!")
        return request.args.get('hub.challenge', '')
    else:
        print("Verification failed!")
        return 'Error, wrong validation token'

@app.route('/', methods=['POST'])
def handle_messages():
    print("Handling Messages")
    payload = request.get_data()
    print(payload)
    for sender, message in messaging_events(payload):
        print("Incoming from %s: %s" % (sender, message))
        send_message(PAT, sender, message)
    return "ok"

def messaging_events(payload):
    """Generate tuples of (sender_id, message_text) from the
    provided payload.
    """
    data = json.loads(payload)
    messaging_events = data["entry"][0]["messaging"]
    for event in messaging_events:
        if "message" in event and "text" in event["message"]:
            yield event["sender"]["id"], event["message"]["text"].encode('unicode_escape')
        else:
            yield event["sender"]["id"], "I can't echo this"


def send_message(token, recipient, text):
    """Send the message text to recipient with id recipient.
    """
    if b"meme" in text.lower():
        subreddit_name = "memes"
    elif b"shower" in text.lower():
        subreddit_name = "Showerthoughts"
    elif b"joke" in text.lower():
        subreddit_name = "Jokes"
    else:
        subreddit_name = "GetMotivated"

    myUser = get_or_create(db.session, Users, name=recipient)

    if subreddit_name == "Showerthoughts":
        for submission in reddit.subreddit(subreddit_name).hot(limit=None):
            if (submission.is_self == True):
                query_result = Posts.query.filter(Posts.name == submission.id).first()
                if query_result is None:
                    myPost = Posts(submission.id, submission.title)
                    myUser.posts.append(myPost)
                    db.session.commit()
                    payload = submission.title
                    break
                elif myUser not in query_result.users:
                    myUser.posts.append(query_result)
                    db.session.commit()
                    payload = submission.title
                    break
                else:
                    continue  

        r = requests.post("https://graph.facebook.com/v2.6/me/messages",
            params={"access_token": token},
            data=json.dumps({
                "recipient": {"id": recipient},
                "message": {"text": payload,
                            "quick_replies":quick_replies_list}
            }),
            headers={'Content-type': 'application/json'})
    
    elif subreddit_name == "Jokes":
        for submission in reddit.subreddit(subreddit_name).hot(limit=None):
            if ((submission.is_self == True) and ( submission.link_flair_text is None)):
                query_result = Posts.query.filter(Posts.name == submission.id).first()
                if query_result is None:
                    myPost = Posts(submission.id, submission.title)
                    myUser.posts.append(myPost)
                    db.session.commit()
                    payload = submission.title
                    payload_text = submission.selftext
                    break
                elif myUser not in query_result.users:
                    myUser.posts.append(query_result)
                    db.session.commit()
                    payload = submission.title
                    payload_text = submission.selftext
                    break
                else:
                    continue  

        r = requests.post("https://graph.facebook.com/v2.6/me/messages",
            params={"access_token": token},
            data=json.dumps({
                "recipient": {"id": recipient},
                "message": {"text": payload}
            }),
            headers={'Content-type': 'application/json'})

        r = requests.post("https://graph.facebook.com/v2.6/me/messages",
            params={"access_token": token},
            data=json.dumps({
                "recipient": {"id": recipient},
                "message": {"text": payload_text,
                            "quick_replies":quick_replies_list}
            }),
            headers={'Content-type': 'application/json'})
        
    else:
        payload = "http://imgur.com/WeyNGtQ.jpg"
        for submission in reddit.subreddit(subreddit_name).hot(limit=None):
            if (submission.link_flair_css_class == 'image') or ((submission.is_self != True) and ((".jpg" in submission.url) or (".png" in submission.url))):
                query_result = Posts.query.filter(Posts.name == submission.id).first()
                if query_result is None:
                    myPost = Posts(submission.id, submission.url)
                    myUser.posts.append(myPost)
                    db.session.commit()
                    payload = submission.url
                    break
                elif myUser not in query_result.users:
                    myUser.posts.append(query_result)
                    db.session.commit()
                    payload = submission.url
                    break
                else:
                    continue

        r = requests.post("https://graph.facebook.com/v2.6/me/messages",
            params={"access_token": token},
            data=json.dumps({
                "recipient": {"id": recipient},
                "message": {"attachment": {
                              "type": "image",
                              "payload": {
                                "url": payload
                              }},
                              "quick_replies":quick_replies_list}
            }),
            headers={'Content-type': 'application/json'})

    if r.status_code != requests.codes.ok:
        print(r.text)

def get_or_create(session, model, **kwargs):
    instance = session.query(model).filter_by(**kwargs).first()
    if instance:
        return instance
    else:
        instance = model(**kwargs)
        session.add(instance)
        session.commit()
        return instance

relationship_table=db.Table('relationship_table',                            
    db.Column('user_id', db.Integer,db.ForeignKey('users.id'), nullable=False),
    db.Column('post_id',db.Integer,db.ForeignKey('posts.id'),nullable=False),
    db.PrimaryKeyConstraint('user_id', 'post_id') )
 
class Users(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(255),nullable=False)
    posts=db.relationship('Posts', secondary=relationship_table, backref='users' )  

    def __init__(self, name=None):
        self.name = name
 
class Posts(db.Model):
    id=db.Column(db.Integer, primary_key=True)
    name=db.Column(db.String, unique=True, nullable=False)
    url=db.Column(db.String, nullable=False)

    def __init__(self, name=None, url=None):
        self.name = name
        self.url = url

if __name__ == '__main__':
    app.run()