redArc.js

// SN4T14 2014-11-28
// License: WTFPL
// jshint node: true
'use strict'; // Be strict like my math teacher

var redditStream = require('reddit-stream');
var linkHandler = require('./lib/linkHandler.js'); // Outsource all the boring downloading stuff to another file to keep this one nicer
var Promise = require('bluebird');
var fs = Promise.promisifyAll(require('fs'));
var util = require('util');
var moment = require('moment');

var postStream = new redditStream('posts', 'all', 'RedArc.js/0.3.0 by /u/SN4T14'); // Monitor posts on /r/all because keeping up with it is possible, and lets you check all users every 2 seconds instead of having to spend 2*numUsers seconds manually looping through all users.

var usersToArchive = []; // Don't manually add users to this, add them to users.txt!
var subredditsToArchive = []; // Don't manually add subreddits to this, add them to subreddits.txt!

var NoFileError = {code: "ENOENT"};

function savePost (postData) {
	var folderName = postData.over_18 ? "NSFW" : "SFW"; // Save to "./username/NSFW/" or "./username/SFW/" to separate NSFW from SFW pictures (e.g. pics of their puppy)
	linkHandler.saveLink(postData.url, "./posts/" + postData.author + "/" + folderName + "/");
}

function addUser (user) {
	fs.appendFile('users.txt', user, function (err) {
		if (err) {
			throw err;
		}
	});
	usersToArchive.push(user);
}

postStream.on('new', function(posts) {
	posts.forEach(function (post) {
		var save = false;

		if (subredditsToArchive.indexOf("all") !== -1) {
			save = true;
		} else if (usersToArchive.indexOf(post.data.author) !== -1) {
			save = true;
		} else if (subredditsToArchive.indexOf(post.data.subreddit) !== -1) { // else if to avoid adding users that already exist in usersToArchive
			addUser(post.data.author);
			save = true;
		}

		// why do it like this? because when you add more clauses later on, it's still just as easy to read and maintain.
		if (save) {
			console.log("[" + moment().format() + "]", "Found post!", post.data.url, post.data.author);
			savePost(post.data);
		}
	});
});

postStream.on('error', function(err) {
	if (err.error !== 504) {
		console.error(err.message);
		console.error(err.response);
		console.error(err.error);
		console.error("If the problem persists, please copy the above output and paste it in an issue on GitHub");
	}
});

Promise.try(function() {
	return fs.readFileAsync('users.txt');
}).then(function (data) {
	usersToArchive = data.toString().split("\n");

	return fs.readFileAsync('subreddits.txt');
}).then(function (data) {
	subredditsToArchive = data.toString().split("\n");

	if (usersToArchive.length === 0 && subredditsToArchive.length === 0) {
		console.log("Both users.txt and subreddits.txt are empty");
	}

	postStream.start();
	console.log("RedArc.js started!");
}).catch(NoFileError, function (err) {
	fs.appendFile(err.path, "");

	console.log("Created", err.path + ", you might want to put something in there");
});