import { instrument } from 'succinct-async'
import type { Subscription } from './alert.js'
import { getCronExpression } from './alert.js'
import * as mailer from './mailer.js'
import * as worker from './worker/index.js'
import * as db from './database.js'

export class ActionError extends Error {
  toString() {
    return this.message
  }
}

export type RegisterSubscriptionParams = {
  pubkey: string
  email: string
  frequency: string
}

export const registerSubscription = instrument(
  'actions.registerSubscription',
  async ({ pubkey, email, frequency }: RegisterSubscriptionParams) => {
    const sub = await db.insertSubscription(pubkey, email, frequency)
    const callback = `${process.env.BASE_URL}/notify/${sub.id}`

    // Only send a confirmation when the subscription is new, unconfirmed, or
    // its email address changed. An already-confirmed, unchanged subscription
    // (or one where only the frequency changed) skips it.
    if (!sub.confirmed_at) {
      await mailer.sendConfirm(sub)
    }

    return { key: sub.key, callback }
  },
)

export type ConfirmSubscriptionParams = {
  token: string
}

export const confirmSubscriptionAction = instrument(
  'actions.confirmSubscription',
  async ({ token }: ConfirmSubscriptionParams) => {
    const sub = await db.confirmSubscription(token)

    if (!sub) {
      throw new ActionError('That confirmation code is invalid or has expired.')
    }

    worker.registerSubscription(sub)
  },
)

export type UnsubscribeParams = {
  token: string
}

export const unsubscribeAction = instrument(
  'actions.unsubscribe',
  async ({ token }: UnsubscribeParams) => {
    const sub = await db.unsubscribeSubscription(token)

    if (sub) {
      worker.unregisterSubscription(sub)
    }
  },
)