{ 'block height': 420000, hash': '000000000000000002cce816c0ab2c5c269cb081896b7dcb34b8422d6b74ffa1', book number': 3291 }

var request = require('request');
var RNG = require('rng-js');
var blockNumber = 420000;
request({
	url : 'https://bitcoin.toshi.io/api/v0/blocks/' + blockNumber,
	method : 'GET',
}, function (error, response, body) {
	if (response.statusCode == '404') {
		console.log({
			"block height" : "block 420,000 is not yet available",
			"block hash" : "please check in the future",
			"winning book number" : "n/a"
		});
	} else {
		if (error) {
			console.log('Error sending message: ', error);
		} else if (response.body.error) {
			console.log('Error: ', response.body.error);
		} else {
			var blockInfo = JSON.parse(response.body);
			var rng = new RNG(blockInfo.hash);
			console.log({
				"block height" : blockNumber,
				"block hash" : blockInfo.hash,
				"winning book number" : rng.random(1, 5000)
			});
		}
	}
});