lindell / JsBarcode

import ITF from './ITF';

// Calculate the checksum digit

const checksum = (data) => {

	const res = data

		.substr(0, 13)

		.split('')

		.map(num => parseInt(num, 10))

		.reduce((sum, n, idx) => sum + (n * (3 - (idx % 2) * 2)), 0);

	return Math.ceil(res / 10) * 10 - res;

};

class ITF14 extends ITF {

	constructor(data, options) {

		// Add checksum if it does not exist

		if (data.search(/^[0-9]{13}$/) !== -1) {

			data += checksum(data);

		}

		super(data, options);

	}

	valid() {

		return (

			this.data.search(/^[0-9]{14}$/) !== -1 &&

			+this.data[13] === checksum(this.data)

		);

	}

}

export default ITF14;