lindell / JsBarcode

import { SIDE_BIN, MIDDLE_BIN } from './constants';

import encode from './encoder';

import Barcode from "../Barcode";

// Calculate the checksum digit

const checksum = (number) => {

	const res = number

		.substr(0, 7)

		.split('')

		.map((n) => +n)

		.reduce((sum, a, idx) => {

			return idx % 2

				? sum + a

				: sum + a * 3;

		}, 0);

	return (10 - (res % 10)) % 10;

};

class EAN8 extends Barcode {

	constructor(data, options) {

		// Add checksum if it does not exist

		if(data.search(/^[0-9]{7}$/) !== -1){

			data += checksum(data);

		}

		super(data, options);

	}

	valid() {

		return (

			this.data.search(/^[0-9]{8}$/) !== -1 &&

			+this.data[7] === checksum(this.data)

		);

	}

	get leftData() {

		return this.data.substr(0, 4);

	}

	get rightData() {

		return this.data.substr(4, 4);

	}

	encode() {

		const data = [

			SIDE_BIN,

			encode(this.leftData, 'LLLL'),

			MIDDLE_BIN,

			encode(this.rightData, 'RRRR'),

			SIDE_BIN,

		];

		return {

			data: data.join(''),

			text: this.text

		};

	}

}

export default EAN8;