import cron from 'node-cron';

class Scheduler {
  constructor() {
    this.jobs = new Map();
  }

  add(id, cronTime, task, options = {}) {
    if (this.jobs.has(id)) this.remove(id);
    const job = cron.createTask(cronTime, task, { ...options, noOverlap: true });
    this.jobs.set(id, { job, cronTime, task, options, status: 'stopped' });
  }

  execute(id) {
    const entry = this.jobs.get(id);
    if (entry && entry.status === 'running') {
      entry.job.execute();
    }
  }

  start(id) {
    const entry = this.jobs.get(id);
    if (entry && entry.status !== 'running') {
      entry.job.start();
      entry.status = 'running';
    }
  }

  stop(id) {
    const entry = this.jobs.get(id);
    if (entry && entry.status === 'running') {
      entry.job.stop();
      entry.status = 'stopped';
    }
  }

  remove(id) {
    const entry = this.jobs.get(id);
    if (entry) {
      entry.job.destroy();
      this.jobs.delete(id);
    }
  }

  updateCronTime(id, newCronTime) {
    const entry = this.jobs.get(id);
    if (entry) {
      this.remove(id);
      this.add(id, newCronTime, entry.task, entry.options);
    }
  }

  list() {
    return Array.from(this.jobs.entries()).map(([id, { cronTime, status }]) => ({
      id, cronTime, status
    }));
  }
}

export default new Scheduler();