// Encoding documentation:
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// https://en.wikipedia.org/wiki/Universal_Product_Code#Encoding
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//
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// UPC-E documentation:
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// https://en.wikipedia.org/wiki/Universal_Product_Code#UPC-E
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import encode from './encoder';
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import Barcode from "../Barcode.js";
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import { checksum } from './UPC.js';
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const EXPANSIONS = [
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"XX00000XXX",
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"XX10000XXX",
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"XX20000XXX",
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"XXX00000XX",
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"XXXX00000X",
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"XXXXX00005",
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"XXXXX00006",
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"XXXXX00007",
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"XXXXX00008",
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"XXXXX00009"
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];
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const PARITIES = [
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["EEEOOO", "OOOEEE"],
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["EEOEOO", "OOEOEE"],
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["EEOOEO", "OOEEOE"],
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["EEOOOE", "OOEEEO"],
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["EOEEOO", "OEOOEE"],
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["EOOEEO", "OEEOOE"],
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["EOOOEE", "OEEEOO"],
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["EOEOEO", "OEOEOE"],
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["EOEOOE", "OEOEEO"],
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["EOOEOE", "OEEOEO"]
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];
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class UPCE extends Barcode{
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constructor(data, options){
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// Code may be 6 or 8 digits;
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// A 7 digit code is ambiguous as to whether the extra digit
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// is a UPC-A check or number system digit.
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super(data, options);
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this.isValid = false;
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if(data.search(/^[0-9]{6}$/) !== -1){
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this.middleDigits = data;
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this.upcA = expandToUPCA(data, "0");
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this.text = options.text ||
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`${this.upcA[0]}${data}${this.upcA[this.upcA.length - 1]}`;
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this.isValid = true;
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}
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else if(data.search(/^[01][0-9]{7}$/) !== -1){
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this.middleDigits = data.substring(1, data.length - 1);
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this.upcA = expandToUPCA(this.middleDigits, data[0]);
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if(this.upcA[this.upcA.length - 1] === data[data.length - 1]){
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this.isValid = true;
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}
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else{
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// checksum mismatch
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return;
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}
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}
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else{
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return;
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}
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this.displayValue = options.displayValue;
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// Make sure the font is not bigger than the space between the guard bars
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if(options.fontSize > options.width * 10){
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this.fontSize = options.width * 10;
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}
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else{
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this.fontSize = options.fontSize;
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}
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// Make the guard bars go down half the way of the text
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this.guardHeight = options.height + this.fontSize / 2 + options.textMargin;
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}
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valid(){
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return this.isValid;
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}
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encode(){
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if(this.options.flat){
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return this.flatEncoding();
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}
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else{
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return this.guardedEncoding();
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}
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}
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flatEncoding(){
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var result = "";
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result += "101";
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result += this.encodeMiddleDigits();
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result += "010101";
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return {
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data: result,
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text: this.text
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};
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}
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guardedEncoding(){
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var result = [];
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// Add the UPC-A number system digit beneath the quiet zone
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if(this.displayValue){
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result.push({
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data: "00000000",
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text: this.text[0],
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options: {textAlign: "left", fontSize: this.fontSize}
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});
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}
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// Add the guard bars
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result.push({
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data: "101",
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options: {height: this.guardHeight}
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});
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// Add the 6 UPC-E digits
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result.push({
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data: this.encodeMiddleDigits(),
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text: this.text.substring(1, 7),
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options: {fontSize: this.fontSize}
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});
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// Add the end bits
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result.push({
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data: "010101",
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options: {height: this.guardHeight}
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});
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// Add the UPC-A check digit beneath the quiet zone
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if(this.displayValue){
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result.push({
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data: "00000000",
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text: this.text[7],
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options: {textAlign: "right", fontSize: this.fontSize}
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});
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}
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return result;
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}
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encodeMiddleDigits() {
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const numberSystem = this.upcA[0];
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const checkDigit = this.upcA[this.upcA.length - 1];
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const parity = PARITIES[parseInt(checkDigit)][parseInt(numberSystem)];
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return encode(this.middleDigits, parity);
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}
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}
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function expandToUPCA(middleDigits, numberSystem) {
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const lastUpcE = parseInt(middleDigits[middleDigits.length - 1]);
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const expansion = EXPANSIONS[lastUpcE];
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let result = "";
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let digitIndex = 0;
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for(let i = 0; i < expansion.length; i++) {
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let c = expansion[i];
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if (c === 'X') {
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result += middleDigits[digitIndex++];
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} else {
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result += c;
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}
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}
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result = `${numberSystem}${result}`;
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return `${result}${checksum(result)}`;
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}
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export default UPCE;
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