// Per-user push-notification subscriptions (which streams a user opted into;
// applied to every device they register). The catalog is core's plus every
// installed module's, so it is read back through modules/registries rather than
// from a config file (MODULE_SYSTEM.md §1.8).
//
// **This is now the push PROJECTION of `notification_channel_prefs`**
// (ENGAGEMENT.md Phase 3), and it keeps its exact wire shape on purpose: the
// shipped Android client's DTO is `{ streams: [...] }` and cannot be changed from
// this side. So the general table gained the channel dimension and this one stays
// the answer to "which streams does this user want pushed" — the only question
// that client knows how to ask. Every write here fans out to there; every write
// there that touches push fans out to here. What `utils/pushDispatch` reads did
// not change at all, which is what makes this phase touch no delivery path.

const db = require('./notificationSubs.db')
const { isValidStream } = require('../../modules/registries')

const getForUser = async (userId) => (await db.listByUser(userId)).map((r) => r.stream_id)

// Replace the user's subscription set. Ignores unknown ids and de-dupes, so a
// stale client can't create rows for streams that no longer exist. Returns the
// stored (cleaned) set.
//
// The mirror is required lazily rather than at the top of the file: the channel
// prefs model requires the registries and the channel registry, and this module
// is required by the router at boot. A cycle here would be a silent half-loaded
// module rather than an error, and there is nothing to gain from the eager form.
async function setForUser(userId, streams) {
  const clean = [...new Set((Array.isArray(streams) ? streams : []).filter(isValidStream))]
  await db.replaceForUser(userId, clean)
  // eslint-disable-next-line global-require
  await require('../notificationChannelPrefs/notificationChannelPrefs.model').mirrorPushSet(userId, clean)
  return clean
}

module.exports = { getForUser, setForUser }