// ── Team forum upload sweep ────────────────────────────────────────────────
//
// TEAMS.md §5.5.4's lifecycle half: soft-deleted uploads lose their bytes after a
// retention window, and files uploaded into a composer that was never submitted
// lose theirs after a grace period. The existing admin upload path never deletes
// anything, which is fine at admin volume and is not fine once a community can
// upload.
//
// Same in-process shape as utils/teamActivityPrune — setInterval + unref + stop(),
// wired into server.js start/shutdown. There is no cron in this stack.
//
// **It runs whether or not `teams_forum_images` is `uploads`, and that is the
// point.** An operator who turns uploads off after a problem has files already on
// disk; a sweep that switched itself off with the setting would strand exactly the
// bytes they were trying to be rid of. The admin help text says the same thing in
// the other direction — disabling uploads stops new files, it does not delete old
// ones — and this is the only thing that eventually does.

const uploads = require('../model/teams/teamForumUploads.model')
const log = require('./logger')('teams')

const INTERVAL_MS = Number(process.env.TEAM_FORUM_SWEEP_MS) || 24 * 60 * 60 * 1000
// Later than the activity prune's five minutes, so two table-walking jobs do not
// land on the same boot at the same moment.
const FIRST_RUN_MS = Number(process.env.TEAM_FORUM_SWEEP_DELAY_MS) || 10 * 60 * 1000

let timer = null
let firstRun = null

/** One sweep. Never throws — it runs on a timer with nobody to catch it. */
async function tick() {
  try {
    const result = await uploads.sweep()
    if (result.swept) log.info('team forum upload sweep', result)
    return result
  } catch (err) {
    log.error('team forum upload sweep failed', { message: err.message })
    return null
  }
}

function start() {
  if (timer || firstRun) return timer
  firstRun = setTimeout(() => {
    firstRun = null
    tick()
    timer = setInterval(() => { tick() }, INTERVAL_MS)
    if (timer.unref) timer.unref()
  }, FIRST_RUN_MS)
  if (firstRun.unref) firstRun.unref()
  log.info('team forum upload sweep started', { intervalMs: INTERVAL_MS, firstRunMs: FIRST_RUN_MS })
  return timer
}

function stop() {
  if (firstRun) {
    clearTimeout(firstRun)
    firstRun = null
  }
  if (timer) {
    clearInterval(timer)
    timer = null
  }
}

module.exports = { start, stop, tick, INTERVAL_MS, FIRST_RUN_MS }