import { CronExpressionParser } from 'cron-parser'
import { tryCatch, int, HOUR } from '@welshman/lib'

export type Subscription = {
  id: string
  key: string
  pubkey: string
  email: string
  frequency: string
  created_at: number
  confirmed_at?: number
  unsubscribed_at?: number
  last_digest_at?: number
}

export const getSubscriptionError = (sub: Subscription) => {
  if (!sub.email?.includes('@')) {
    return 'Please provide a valid email address'
  }

  if (!['daily', 'weekly'].includes(sub.frequency)) {
    return 'Frequency must be "daily" or "weekly"'
  }

  // Daily: fire at 17:00 UTC. Weekly: fire Monday at 17:00 UTC.
  // Validation: just ensure frequency is valid, cron is generated internally.
}

export const getCronExpression = (frequency: string, hour = 17, minute = 0) => {
  if (frequency === 'daily') {
    return `0 ${minute} ${hour} * * *`
  }
  // Weekly on Monday
  return `0 ${minute} ${hour} * * 1`
}