(almost) unique order id generator

• Generates order ids in the format xxxx-xxxxxx-xxxx, where x is a digit (0-9). Similar to the format Amazon is using for their order numbers.
• Uses the current unix timestamp (13 digits) plus 1 random digit so it's unique down to the milisecond.
• If your system generates 1,000,000 orders per day (evenly distributed), the probability of collision would be ~1%. The extra padding digit makes it even lower.
• The timestamp is scrambled using a supplied key so the result doesn't appear as a timestamp and is not sequential.
• Bonus: Since it's based on timestamp, we can get the time back from the order id (see api calls).

const orderid = require('order-id')('key');
const id = orderid.generate();
// 3016-734428-7759

orderid.getTime(id);
// 1479812667797

• generate(date) - Generates an order id. date is optional and can be anything that js Date constructor knows how to parse and it will use it as the time for the order id. Otherwise, current date will be used.
• getTime(id) - Use this to get back the time of the order in unix timestamp format. You need to use the same key used to generate the order id.
• key - (Optional) Any string used by the underlying cipher as a seed phrase. Needed if you want to get back the timestamp from an order id.