index.js

var cool = require('cool-ascii-faces');
var request = require('request');
var bodyParser = require('body-parser');
var express = require('express');
var app = express();
var pg = require('pg');
var path = require('path');

let mdb = require('moviedb')('///API_KEY///');

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: false
}));

let FACEBOOK_VERIFY_TOKEN = "?????";
let FACEBOOK_PAGE_ACCESS_TOKEN = "///FACEBOOK_ACCESS_TOKEN///";
let FACEBOOK_SEND_MESSAGE_URL = 'https://graph.facebook.com/v2.6/me/messages?access_token=' + FACEBOOK_PAGE_ACCESS_TOKEN;
let MOVIE_DB_PLACEHOLDER_URL = 'http://image.tmdb.org/t/p/w185/';
let MOVIE_DB_BASE_URL = 'https://www.themoviedb.org/movie/';

//////Change this port according to you////
app.set('port', (process.env.PORT || 5000));

app.use(express.static(__dirname + '/public'));

// views is directory for all template files
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');

app.get('/webhook/', function(req, res) {
  if (req.query['hub.verify_token'] == FACEBOOK_VERIFY_TOKEN) {
    res.send(req.query['hub.challenge'])
  }
  res.send('Error, wrong token')
});

app.post('/webhook', function(req, res) {
  console.log(JSON.stringify(req.body));
  if (req.body.object === 'page') {
    if (req.body.entry) {
      req.body.entry.forEach(function(entry) {
        if (entry.messaging) {
          entry.messaging.forEach(function(messagingObject) {
            var senderId = messagingObject.sender.id;
            if (messagingObject.message) {
              if (!messagingObject.message.is_echo) {
                var movieName = messagingObject.message.text;
                getMovieDetails(senderId, movieName);
              }

            } else if (messagingObject.postback) {
              console.log('Recieved postback');

            }
          });
        } else {
          console.log('no message key found');
        }
      });
    } else {
      console.log('no entry key found');
    }
  } else {

  }
  res.status(200).send();
});

function sendUIMessageToUser(senderId, elementList) {
  request({
    url: FACEBOOK_SEND_MESSAGE_URL,
    method: 'POST',
    json: {
      recipient: {
        id: senderId
      },
      message: {
        attachment: {
          type: 'template',
          payload: {
            template_type: 'generic',
            elements: elementList


          }
        }
      }

    }
  }, function(error, response, body) {
    if (error) {
      console.log('Error sending UIMESSAGE to User ' + error);
    } else if (response.body.error) {
      console.log('Error sending UImessage' + response.body.error);
    }
    //ignore
  });
}

function getElementObject(result) {

  var movieName = result.original_title;
  var overview = result.overview;
  var posterPath = MOVIE_DB_PLACEHOLDER_URL + result.poster_path;
  return {
    title: movieName,
    subtitle: overview,
    image_url: posterPath,
    buttons: [{
      "type": "web_url",
      "url": MOVIE_DB_BASE_URL + result.id,
      "title": "More Details"
    }]
  }
}

function sendMessageToUser(senderId, message) {
  request({
    url: FACEBOOK_SEND_MESSAGE_URL,
    method: 'POST',
    json: {
      recipient: {
        id: senderId
      },
      message: {
        text: message
      }
    }
  }, function(error, response, body) {
    if (error) {
      console.log(error);
    } else if (response.body.error) {
      console.log('Error sending message' + response.body.error);
    }
    //ignore
  });
}

function showTypingIndicatorToUser(senderId, isTyping) {
  var senderAction = isTyping ? 'typing_on' : 'typing_off';
  request({
    url: FACEBOOK_SEND_MESSAGE_URL,
    method: 'POST',
    json: {
      recipient: {
        id: senderId
      },
      sender_action: senderAction
    }

  }, function(error, response, body) {
    if (error) {
      console.log('sending Typing indicator to user ' + error);
    } else if (response.body.error) {
      console.log('Error sending typing indicator' + response.body.error);
    }
  });

}

function getMovieDetails(senderId, movieName) {
  showTypingIndicatorToUser(senderId, true);

  var message = 'Found Details on ' + movieName;
  mdb.searchMovie({
    query: movieName
  }, (err, res) => {
    showTypingIndicatorToUser(senderId, false);
    if (err) {
      console.log('Error found in moviedb' + err);
      sendMessageToUser(senderId, 'Error Finding Movie ' + movieName);
    } else {
      console.log(res);
      if (res.results) {
        if (res.results.length > 0) {
          var elements = []
          var resultCount = res.results.length > 5 ? 5 : res.results.length;
          for (i = 0; i < resultCount; i++) {
            var result = res.results[i];
            elements.push(getElementObject(result));
          }
          sendUIMessageToUser(senderId, elements);

        } else {
          sendMessageToUser(senderId, 'Could not find information on ' + movieName);
        }
      } else {

        sendMessageToUser(senderId, message);
      }
    }
  });

}

app.listen(app.get('port'), function() {
  console.log('Node app is running on port', app.get('port'));
});