Quick and dirty script to download Chromecast wallpapers.

castpaperer.js

var https = require('https');
var fs = require('fs');
var request = require('request');
var crypto = require('crypto');

function nothing(){}

function download(uri, filename, callback)
{
	fs.exists(filename, function(exists)
	{
		if(!exists)
		{
			request.head(uri, function(err, res, body)
			{
				request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
			});
		}
	});
}

https.get("https://clients3.google.com/cast/chromecast/home", function(response)
{
	var str = "";

	response.on('data', function(chunk)
	{
		str += chunk;
	});

	response.on('end', function()
	{
		var sub = str.substring(str.indexOf("JSON.parse"));
		sub = sub.substring(0, sub.indexOf(")")+1);

		var pictures = eval(sub);

		fs.mkdir("pictures", function() {});

		for(var i=0;i<pictures[0].length;i++)
		{
			var shasum = crypto.createHash('sha1');
			// Google scales pictures to 1280x720, this will request a 1920x1080 resize
			var url = pictures[0][i][0].replace("s1280-w1280-c-h720-k-no", "s1920-w1920-c-h1080-k-no");
			shasum.update(url);
			download(url, "pictures/"+shasum.digest("hex")+".jpg", nothing);
		}
	});
});