lindell / JsBarcode

class ITF14{

	constructor(string){

		this.string = string;

		// Add checksum if it does not exist

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

			this.string += this.checksum(string);

		}

		this.binaryRepresentation = {

			"0":"00110",

			"1":"10001",

			"2":"01001",

			"3":"11000",

			"4":"00101",

			"5":"10100",

			"6":"01100",

			"7":"00011",

			"8":"10010",

			"9":"01010"

		};

	}

	valid(){

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

			this.string[13] == this.checksum();

	}

	encode(){

		var result = "1010";

		// Calculate all the digit pairs

		for(var i = 0; i < 14; i += 2){

			result += this.calculatePair(this.string.substr(i, 2));

		}

		// Always add the same end bits

		result += "11101";

		return {

			data: result,

			text: this.string

		};

	}

	// Calculate the data of a number pair

	calculatePair(numberPair){

		var result = "";

		var number1Struct = this.binaryRepresentation[numberPair[0]];

		var number2Struct = this.binaryRepresentation[numberPair[1]];

		// Take every second bit and add to the result

		for(var i = 0; i < 5; i++){

			result += (number1Struct[i] == "1") ? "111" : "1";

			result += (number2Struct[i] == "1") ? "000" : "0";

		}

		return result;

	}

	// Calulate the checksum digit

	checksum(){

		var result = 0;

		for(var i = 0; i < 13; i++){

			result += parseInt(this.string[i]) * (3 - (i % 2) * 2);

		}

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

	}

}

export {ITF14};