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 SpotService from '#services/SpotService'

const IDLE_MS = 30_000
/** Spots claimed at a time; most of a history backfill is listed in bulk. */
const BATCH = 500
/** Imported spots whose details are read per idle round. */
const DETAILS_BATCH = 50
/** Listed spots whose article and NZB are read per idle round (passwords, dummies). */
const LISTINGS_BATCH = 50

/**
 * Works through queued Spotnet spots (CONCEPT.md D29): verifies each one,
 * downloads its compressed NZB (a few KB to a few MB) and imports it. When
 * idle, reads what listed spots were listed without: details, passwords.
 */
export default class SpotsWorker extends BaseCommand {
  public static commandName = 'worker:spots'
  public static description = 'Reads Spotnet spots: verifies them and imports their NZBs.'

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

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

  public async run() {
    const concurrency = env.get('SPOT_CONCURRENCY', 4)
    this.logger.info(`Spot worker started (concurrency ${concurrency}).`)
    const counts: Record<string, number> = {}
    let done = 0
    try {
      while (!Shutdown.requested && (!this.limit || done < this.limit)) {
        try {
          const batch = await SpotService.claim(Math.min(BATCH, this.limit ? this.limit - done : Infinity))
          if (batch.length === 0) {
            if (this.limit) break
            // Idle: read the details of imported spots that don't have them yet (newest first), then
            // the article and NZB of listed spots (their passwords; LOG.md 2026-10-08 (10)).
            if ((await SpotService.fillDetails(DETAILS_BATCH)) > 0) continue
            const listings = await SpotService.readListings(LISTINGS_BATCH, concurrency)
            const read = Object.values(listings).reduce((sum, n) => sum + n, 0)
            if (read === 0 || listings.retry === read) await Shutdown.sleep(IDLE_MS)
            continue
          }
          // Old, verified spots are listed in bulk; the rest need their header (and maybe NZB) read.
          const listable = batch.filter((spot) => SpotService.isListable(spot))
          const single = batch.filter((spot) => !SpotService.isListable(spot))
          counts.listed = (counts.listed ?? 0) + (await SpotService.list(listable))
          let next = 0
          await Promise.all(
            Array.from({ length: concurrency }, async () => {
              while (next < single.length) {
                const status = await SpotService.process(single[next++])
                counts[status] = (counts[status] ?? 0) + 1
              }
            })
          )
          done += batch.length
          this.logger.info(`${done} spots: ${Object.entries(counts).map(([k, v]) => `${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()
    }
  }
}