import { BaseCommand, flags } from '@adonisjs/core/ace'
import { CommandOptions } from '@adonisjs/core/types/ace'
import env from '#start/env'
import Shutdown from '#services/Shutdown'
import NntpService from '#services/NntpService'
import QueueService from '#services/QueueService'
import DeferredService from '#services/DeferredService'

const IDLE_MS = 60_000

/**
 * Works through `deferred_files` (CONCEPT.md D28): one body per file, and
 * small files completely. Not started by default (compose profile
 * `deferred`); run it when there is bandwidth to spare.
 */
export default class DeferredWorker extends BaseCommand {
  public static commandName = 'worker:deferred'
  public static description = 'Samples deferred files (e.g. ngPost uploads): one article body per file.'

  public static options: CommandOptions = {
    startApp: true,
  }

  @flags.number({ description: 'Stop after this many files (default: keep running)' })
  declare limit?: number

  public async run() {
    const concurrency = env.get('DEFERRED_CONCURRENCY', 4)
    this.logger.info(`Deferred worker started (concurrency ${concurrency}).`)
    const counts: Record<string, number> = {}
    let done = 0
    try {
      while (!Shutdown.requested && (!this.limit || done < this.limit)) {
        try {
          const batch = await DeferredService.claim(Math.min(concurrency * 4, this.limit ? this.limit - done : Infinity))
          if (batch.length === 0) {
            if (this.limit) break
            await Shutdown.sleep(IDLE_MS)
            continue
          }
          let next = 0
          await Promise.all(
            Array.from({ length: concurrency }, async () => {
              while (next < batch.length) {
                const status = await DeferredService.process(batch[next++])
                counts[status] = (counts[status] ?? 0) + 1
              }
            })
          )
          done += batch.length
          this.logger.info(`${done} deferred files processed: ${Object.entries(counts).map(([k, v]) => `${v} ${k}`).join(', ')}.`)
        } catch (err: any) {
          // E.g. Postgres restarting: wait and claim again, instead of ending the loop (LOG.md 2026-10-07 (3)).
          this.logger.error(`Round failed, retrying in 30 s: ${err.message}`)
          await Shutdown.sleep(30_000)
        }
      }
    } finally {
      await NntpService.shutdown()
      await QueueService.closeAll()
    }
  }
}