import cronParser from 'cron-parser';
/**
* Feed Scheduling Service
*/
export class Scheduler {
/**
* Validate cron expression
*/
static validateCron(expression: string): { valid: boolean; error: string | null } {
try {
cronParser.parseExpression(expression);
return { valid: true, error: null };
} catch (error: any) {
return { valid: false, error: error.message };
}
}
/**
* Calculate next run time
*/
static getNextRun(cronExpression: string): string | null {
try {
const interval = cronParser.parseExpression(cronExpression);
return interval.next().toISOString();
} catch (error) {
return null;
}
}
/**
* Get human-readable schedule description
*/
static getScheduleDescription(cronExpression: string): string {
try {
// Basic patterns
const patterns: { [key: string]: string } = {
'* * * * *': 'Every minute',
'0 * * * *': 'Every hour',
'0 */2 * * *': 'Every 2 hours',
'0 */6 * * *': 'Every 6 hours',
'0 0 * * *': 'Daily at midnight',
'0 9 * * *': 'Daily at 9:00 AM',
'0 0 * * 0': 'Weekly on Sunday',
'0 0 1 * *': 'Monthly on the 1st'
};
if (patterns[cronExpression]) {
return patterns[cronExpression];
}
const parts = cronExpression.split(' ');
if (parts.length === 5) {
const [minute, hour, dayOfMonth, month, dayOfWeek] = parts;
if (hour !== '*' && minute !== '*') {
return `Daily at ${hour}:${minute.padStart(2, '0')}`;
}
if (hour.startsWith('*/')) {
const hours = hour.substring(2);
return `Every ${hours} hours`;
}
}
return `Custom schedule: ${cronExpression}`;
} catch (error) {
return 'Invalid schedule';
}
}
/**
* Check if schedule should run now
*/
static shouldRunNow(lastRun: string | null, cronExpression: string): boolean {
try {
if (!lastRun) return true;
const lastRunTime = new Date(lastRun);
const interval = cronParser.parseExpression(cronExpression, {
currentDate: lastRunTime
});
const nextRun = interval.next().toDate();
const now = new Date();
return now >= nextRun;
} catch (error) {
return false;
}
}
/**
* Get common schedule presets
*/
static getPresets(): { name: string; cron: string; description: string }[] {
return [
{ name: 'Every hour', cron: '0 * * * *', description: 'Updates every hour on the hour' },
{ name: 'Every 2 hours', cron: '0 */2 * * *', description: 'Updates every 2 hours' },
{ name: 'Every 6 hours', cron: '0 */6 * * *', description: 'Updates 4 times daily' },
{ name: 'Every 12 hours', cron: '0 */12 * * *', description: 'Updates twice daily' },
{ name: 'Daily at 9 AM', cron: '0 9 * * *', description: 'Updates once daily at 9:00 AM' },
{ name: 'Daily at midnight', cron: '0 0 * * *', description: 'Updates once daily at midnight' },
{ name: 'Weekly (Monday 9 AM)', cron: '0 9 * * 1', description: 'Updates every Monday at 9:00 AM' }
];
}
}
