@adaptabletools/adaptable/src/Utilities/Helpers/Scheduling/CronExpression.js

Powerful AG Grid extension which provides advanced, cutting-edge functionality to meet all DataGrid requirements

const MINUTE_RANGE = [0, 59];
const HOUR_RANGE = [0, 23];
const DAY_OF_MONTH_RANGE = [1, 31];
const MONTH_RANGE = [1, 12];
const FIELD_LABELS = ['minute', 'hour', 'day-of-month', 'month', 'day-of-week'];
export function parseCronExpression(expression) {
    if (!expression || typeof expression !== 'string') {
        throw new Error('Cron expression is empty');
    }
    const parts = expression.trim().split(/\s+/);
    if (parts.length !== 5) {
        throw new Error(`Expected 5 cron fields (minute hour day-of-month month day-of-week) but got ${parts.length}`);
    }
    const minute = parseField(parts[0], MINUTE_RANGE, FIELD_LABELS[0]);
    const hour = parseField(parts[1], HOUR_RANGE, FIELD_LABELS[1]);
    const dayOfMonth = parseField(parts[2], DAY_OF_MONTH_RANGE, FIELD_LABELS[2]);
    const month = parseField(parts[3], MONTH_RANGE, FIELD_LABELS[3]);
    const dayOfWeek = parseDayOfWeekField(parts[4]);
    return {
        minute,
        hour,
        dayOfMonth,
        month,
        dayOfWeek,
        dayOfMonthIsStar: parts[2] === '*',
        dayOfWeekIsStar: parts[4] === '*',
    };
}
export function isCronExpressionValid(expression) {
    try {
        parseCronExpression(expression);
        return true;
    }
    catch {
        return false;
    }
}
export function getNextCronOccurrence(expression, fromDate = new Date()) {
    const cron = parseCronExpression(expression);
    const next = new Date(fromDate.getTime());
    next.setSeconds(0, 0);
    next.setMinutes(next.getMinutes() + 1);
    const horizon = new Date(next.getTime());
    horizon.setFullYear(horizon.getFullYear() + 4);
    while (next < horizon) {
        if (!cron.month.has(next.getMonth() + 1)) {
            next.setDate(1);
            next.setHours(0, 0, 0, 0);
            next.setMonth(next.getMonth() + 1);
            continue;
        }
        if (!matchesDay(cron, next)) {
            next.setHours(0, 0, 0, 0);
            next.setDate(next.getDate() + 1);
            continue;
        }
        if (!cron.hour.has(next.getHours())) {
            next.setMinutes(0, 0, 0);
            next.setHours(next.getHours() + 1);
            continue;
        }
        if (!cron.minute.has(next.getMinutes())) {
            next.setSeconds(0, 0);
            next.setMinutes(next.getMinutes() + 1);
            continue;
        }
        return next;
    }
    return null;
}
function matchesDay(cron, date) {
    const domMatches = cron.dayOfMonth.has(date.getDate());
    const dowMatches = cron.dayOfWeek.has(date.getDay());
    if (cron.dayOfMonthIsStar && cron.dayOfWeekIsStar) {
        return true;
    }
    if (cron.dayOfMonthIsStar) {
        return dowMatches;
    }
    if (cron.dayOfWeekIsStar) {
        return domMatches;
    }
    return domMatches || dowMatches;
}
function parseField(field, range, label) {
    const [min, max] = range;
    const values = new Set();
    const segments = field.split(',');
    for (const raw of segments) {
        const segment = raw.trim();
        if (segment === '') {
            throw new Error(`Invalid ${label} field "${field}"`);
        }
        const [rangePart, stepPart] = segment.split('/');
        const step = stepPart === undefined ? 1 : Number(stepPart);
        if (!Number.isInteger(step) || step <= 0) {
            throw new Error(`Invalid step value in ${label} field "${segment}"`);
        }
        let from;
        let to;
        if (rangePart === '*') {
            from = min;
            to = max;
        }
        else if (rangePart.includes('-')) {
            const [fromStr, toStr] = rangePart.split('-');
            from = Number(fromStr);
            to = Number(toStr);
        }
        else {
            from = Number(rangePart);
            to = from;
        }
        if (!Number.isInteger(from) || !Number.isInteger(to)) {
            throw new Error(`Invalid ${label} field "${segment}"`);
        }
        if (from < min || to > max || from > to) {
            throw new Error(`Out-of-range ${label} field "${segment}" (expected ${min}-${max})`);
        }
        for (let v = from; v <= to; v += step) {
            values.add(v);
        }
    }
    if (values.size === 0) {
        throw new Error(`Empty ${label} field`);
    }
    return values;
}
function parseDayOfWeekField(field) {
    const extended = parseField(field, [0, 7], 'day-of-week');
    const normalised = new Set();
    for (const value of extended) {
        normalised.add(value === 7 ? 0 : value);
    }
    return normalised;
}