music-codes/dist/gtin.js

Small library for music codes (ISRC, ISWC, UPC)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.GTIN = exports.GtinLengthToFormat = exports.GtinFormatToLength = exports.GtinFormats = void 0;
exports.getGtinFromPrefix = getGtinFromPrefix;
const errors_js_1 = require("./errors.js");
const utils_js_1 = require("./utils.js");
exports.GtinFormats = ['GTIN-8', 'GTIN-12', 'GTIN-13', 'GTIN-14', 'GSIN', 'SSCC'];
exports.GtinFormatToLength = Object.freeze({
    'GTIN-8': 8,
    'GTIN-12': 12,
    'GTIN-13': 13,
    'GTIN-14': 14,
    GSIN: 17,
    SSCC: 18,
});
exports.GtinLengthToFormat = Object.fromEntries(Object.entries(exports.GtinFormatToLength).map(([f, l]) => [l, f]));
class GTIN {
    constructor(gtin, prefix = undefined, verify = true) {
        if (!/^\d+$/.test(gtin)) {
            throw new errors_js_1.ParseError(`Invalid GTIN: ${gtin}`);
        }
        if (!exports.GtinLengthToFormat[gtin.length]) {
            throw new errors_js_1.ParseError(`Unsupported GTIN length: ${gtin.length}`);
        }
        if (prefix && !gtin.startsWith(prefix)) {
            throw new errors_js_1.ParseError(`Invalid prefix '${prefix}' for '${gtin}'`);
        }
        this.length = gtin.length;
        this.code = BigInt(gtin.slice(0, -1));
        this.check = Number.parseInt(gtin.slice(-1), 10);
        this.prefix = prefix;
        if (verify && this.check !== (0, utils_js_1.getLuhnCheckDigit)(this.code)) {
            throw new errors_js_1.ParseError(`Invalid check digit: ${gtin}`);
        }
    }
    get gtinFormat() {
        return exports.GtinLengthToFormat[this.length] ?? (0, utils_js_1.raise)(`Unsupported GTIN length: ${this.length}`);
    }
    get realGtinFormat() {
        let trueLength = `${this.code}${this.check}`.length;
        while (trueLength < this.length) {
            const maybeFormat = exports.GtinLengthToFormat[trueLength];
            if (maybeFormat)
                return maybeFormat;
            trueLength++;
        }
        return exports.GtinLengthToFormat[this.length] ?? (0, utils_js_1.raise)(`Unsupported GTIN length: ${this.length}`);
    }
    first() {
        const code = (this.prefix ?? '1').padEnd(this.length - 1, '0');
        const checkDigit = (0, utils_js_1.getLuhnCheckDigit)(code);
        return new GTIN(`${code}${checkDigit}`, this.prefix, false);
    }
    last() {
        const code = (this.prefix ?? '9').padEnd(this.length - 1, '9');
        const checkDigit = (0, utils_js_1.getLuhnCheckDigit)(code);
        return new GTIN(`${code}${checkDigit}`, this.prefix, false);
    }
    previous() {
        const checkDigit = (0, utils_js_1.getLuhnCheckDigit)(this.code - 1n);
        const prevCode = `${this.code - 1n}${checkDigit}`.padStart(this.length, '0');
        if (this.code === 1n || this.code === BigInt(10n ** BigInt(this.length - 2))) {
            throw new errors_js_1.BoundaryError(`GTIN boundary reached: ${prevCode}`);
        }
        if (this.prefix && !prevCode.startsWith(this.prefix)) {
            throw new errors_js_1.BoundaryError(`GTIN prefix overflow: ${this.prefix}`);
        }
        return new GTIN(prevCode, this.prefix, false);
    }
    next() {
        const checkDigit = (0, utils_js_1.getLuhnCheckDigit)(this.code + 1n);
        const nextCode = `${this.code + 1n}${checkDigit}`.padStart(this.length, '0');
        if (nextCode.length > this.length) {
            throw new errors_js_1.BoundaryError(`GTIN boundary reached: ${nextCode}`);
        }
        if (this.prefix && !nextCode.startsWith(this.prefix)) {
            throw new errors_js_1.BoundaryError(`GTIN prefix overflow: ${this.prefix}`);
        }
        return new GTIN(nextCode, this.prefix, false);
    }
    *iterate(up = true) {
        let gtin = this;
        while (true) {
            yield gtin;
            try {
                gtin = up ? gtin.next() : gtin.previous();
            }
            catch {
                break;
            }
        }
    }
    toString() {
        return `${this.code}${this.check}`.padStart(this.length, '0');
    }
}
exports.GTIN = GTIN;
function getGtinFromPrefix(prefix, length) {
    if (!exports.GtinLengthToFormat[length]) {
        throw new errors_js_1.ParseError(`Unsupported GTIN length: ${length}`);
    }
    if (prefix.length < 1) {
        throw new errors_js_1.ParseError(`Prefix is too short: ${prefix}`);
    }
    if (prefix.length > length - 1) {
        throw new errors_js_1.ParseError(`Prefix is too long: ${prefix}`);
    }
    const code = prefix.padEnd(length - 1, '0');
    const checkDigit = (0, utils_js_1.getLuhnCheckDigit)(code);
    return new GTIN(`${code}${checkDigit}`, prefix, false);
}
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