index.js

require('dotenv').config();
const fs = require('fs');
const path = require('path');
const Bot = require('slackbots');
const express = require('express');
const Markov = require('markov-strings').default;

const util = require('./util');
const quotes = require('./quotes');

// So that heroku does not stop
const app = express();
const port = process.env.PORT || 3000;
app.get('/', (req, res) => res.send('Hello Tsipras!'));
app.listen(port, () => console.log(`Example app listening on port ${port}!`));

console.log('Generating Markov Chain');
const tsiprasText = fs.readFileSync(path.join(__dirname, 'scrape-twitter', 'atsipras.txt'), 'utf8').split('\n');
const markov = new Markov(tsiprasText, { stateSize: 2 });
markov.buildCorpus();

function nextSentence() {
  const options = {
    maxTries: 20,
    filter: result => result.string.split(' ').length >= 5 && result.string.endsWith('.'),
  };
  return markov.generate(options);
}

const dict = {
  lname: 'tsiprasbot',
  name: 'tsiprasbot',
  botMessage: 'bot_message',
};

const settings = {
  token: process.env.SLACK_BOT_TOKEN,
  name: dict.name,
};

const bot = new Bot(settings);

bot.getUserId(dict.lname).then((data) => {
  console.log('Got user id:', data);
  dict.userId = data;
}, (err) => {
  throw new Error('Couldn\'t retrieve user id :(', err);
});

function closestQuote(quote) {
  return util.entities(quote).then((entities) => {
    const sortedEnts = util.sortedEntities(entities);
    if (sortedEnts.length === 0) {
      return null;
    }
    const rel = quotes.reduce((acc, quo) => {
      const ents1 = quo.entities;
      let match = 0;
      sortedEnts.forEach((e1) => {
        ents1.forEach((e2) => {
          match += (e1.text.toLowerCase() === e2.text.toLowerCase()) * e1.relevance;
        });
      });
      match /= ents1.length;
      return match >= acc[0] ? [match, quo] : acc;
    }, [0, null]);
    console.log('Relevance:', rel[0]);
    if (rel[0] >= 0.3) {
      return rel[1];
    }
    return null;
  }).catch(console.error);
}

bot.on('message', (data) => {
  if (data.type !== 'message' || data.user === undefined || data.text === null || data.user === dict.userId) {
    return;
  }

  let quote;
  closestQuote(data.text).then((q) => {
    if (data.text === 'Local Hack Day') {
      quote = 'Local hack day is the best event of the year 😎';
    } else {
      quote = q ? q.quote : nextSentence().string;
    }
    console.log('Replying to user:', data.user, 'with quote:', quote);
    bot.postMessage(data.channel, quote, { as_user: true, icon_url: 'https://upload.wikimedia.org/wikipedia/commons/f/f0/Alexis_Tsipras_2013.jpg' });
  }).catch((err) => {
    console.error(err);
    bot.postMessage(data.channel, nextSentence().string, {
      as_user: true,
      icon_url: 'https://upload.wikimedia.org/wikipedia/commons/f/f0/Alexis_Tsipras_2013.jpg',
    });
  });
});