app.js

require('dotenv').config();
const express = require('express');
const path = require('path');
const favicon = require('serve-favicon');
const logger = require('morgan');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
const mongoUtil = require('./mongoUtil');
const SubmissionStore = require('./submissionStore');
const Submission = require('./submission');
const config = require('./config');

const index = require('./routes/index');

let graph = require('fbgraph');
let submissionPollster = require('./submissionPollster');
let submissionStore;

let app = express();

mongoUtil.connectToServer(function(err) {
    if (err) { console.error(err); }
    console.log("connected to mongodb. Open app url in browser to authenticate with facebook " +
        "(if you're unsure what to do, try http://localhost:3000 )");

    submissionStore = new SubmissionStore();

    // view engine setup
    app.set('views', path.join(__dirname, 'views'));
    app.set('view engine', 'jade');

    // uncomment after placing your favicon in /public
    //app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
    app.use(logger('dev'));
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({
        extended: false
    }));
    app.use(cookieParser());
    app.use(require('node-sass-middleware')({
        src: path.join(__dirname, 'public'),
        dest: path.join(__dirname, 'public'),
        indentedSyntax: true,
        sourceMap: true
    }));
    app.use(express.static(path.join(__dirname, 'public')));

    app.on('listening', index, function() {
        console.log("Listening on port 3000, boss!")
    });

    // Routes

    app.get('/', function(req, res){
        res.redirect('/auth');
    });

    app.get('/auth', function (req, res) {
        // we have no code yet
        if (!req.query.code) {
            console.log("Performing oauth");

            let authUrl = graph.getOauthUrl({
                "client_id": process.env.FB_APP_ID,
                "redirect_uri": process.env.FB_REDIRECT_URI,
                "scope": config.fb.scope
            });

            if (!req.query.error) {
                res.redirect(authUrl);
            } else {
                res.send('access denied: ' + res.query.error);
            }
        }
        // user is being redirected with code
        else {
            // send code and get access token
            graph.authorize({
                "client_id": process.env.FB_APP_ID,
                "redirect_uri": process.env.FB_REDIRECT_URI,
                "client_secret": process.env.FB_APP_SECRET,
                "code": req.query.code
            }, function (err) {
                if (err) { console.dir(err); }
                graph.setAccessToken(process.env.FB_PAGE_LONG_TOKEN);
                res.redirect('/UserHasLoggedIn');
            });
        }
    });

    // Get new submissions from reddit and save them to mongo
    app.get('/UserHasLoggedIn', updateFromReddit );

    // Render route to browser and then start getting items from queue
    app.get('/UserHasLoggedIn', start );

    // catch 404 and forward to error handler
    app.use(function(req, res, next) {
        let err = new Error('Not Found');
        err.status = 404;
        next(err);
    });

    // error handler
    app.use(function(err, req, res, next) {
        // set locals, only providing error in development
        res.locals.message = err.message;
        res.locals.error = req.app.get('env') === 'development' ? err : {};

        // render the error page
        res.status(err.status || 500);
        res.render('error');
    });

});

let start = function (req, res, next) {
    let time = process.env.MINUTES_BETWEEN_POSTS * 60 * 1000;
    console.log(
        `Starting up: sharing hot submissions from /r/${process.env.REDDIT_SUB_NAME} 
        with > ${process.env.REDDIT_MIN_SCORE} upvotes every ${process.env.MINUTES_BETWEEN_POSTS} minutes.`);
    updateFromReddit();
    setInterval(function () { return updateFromReddit(); }, time);
    shareQueueItem();
    setInterval(shareQueueItem, time);
    res.render("index", { conf: process.env});
};

let shareQueueItem = async function () {
    let item = await submissionStore.queuePop();
    if (item) {
        await submissionStore.queueAck(item.ack);
        console.log(`Sharing submission, title: ${item.payload.title}, domain: ${item.payload.domain}`);
        postToFb(item.payload);
        submissionStore.queueClean();
    } else {
        console.log("The submission queue is empty.")
    }
};

let postToFb = function (item) {
    let fbPost = {
        message: item.title,
        link: item.url
     };

    graph.post(`/${process.env.FB_PAGE_ID}/feed`, fbPost, function (err, res) {
        if (err) { console.dir(err); }
    });
};

let updateFromReddit = function (req, res, next) {
    console.log(`Getting new posts from /r/${process.env.REDDIT_SUB_NAME}`);
    submissionPollster.getHotPosts().then(
        function (result) {
            // save the result to use in routes
            app.set('hotPosts', result);
            result.forEach(function(item) {
                let submission = new Submission (item);
                stripPersonalTitle(submission);
                if (isSubmissionOK(submission))
                    // store new submissions in cold storage and post queue.
                    submissionStore.ifSubmissionNew(submission, function() {
                        submissionStore.addToColdStore(submission);
                        submissionStore.queuePush(submission);
                    });
            });
            if (next) {
                next();
            }
        }
    );
};

// If the reddit submission's title is in the 1st person, remove the title
// for people to not assume authorship incorrectly.
// example "Hi guys, I've recorded an album last month, have a listen!".
function stripPersonalTitle(s) {
    if (s.title.includes(" I ") || s.title.includes("I've")) { s.title = ""; }
}

function isSubmissionOK(submission) {
    // Don't store NSFW or selftext posts
    if (submission.is_nsfw || submission.selftext) { return false; }
    let title = submission.title;
    // for music pages: post from pre-approved hosting (a little hacky)
    if (process.env.MUSICONLY === "true") {
        let domain = submission.domain;
        return domain.includes("youtu") || domain.includes("soundcloud") ||
            domain.includes("bandcamp") || domain.includes("facebook");
    }
    // don't post:
    // x-posts (those link to reddit posts)
    // submissions referencing reddit comments in the title
    if (title.includes("comments") || title.includes("r/") ||
        title.includes("x-post") || title.includes("xpost")) { return false; }
    // otherwise post it
    return true;
}

require('./cleanup').Cleanup(cleanupOnClose);

function cleanupOnClose() {
    console.log("Closing db connection");
    mongoUtil.closeConnection();
}

module.exports = app;