usenet-indexer/app/services/SfvService.ts

import db from '@adonisjs/lucid/services/db'
import logger from '@adonisjs/core/services/logger'
import FileStore from '#services/FileStore'
import { parseSfv, sfvReleaseName } from '#lib/content/index'

/** Releases made by name rules alone; an SFV's listing outranks them. */
const WEAK_SOURCES = ['stem', 'weak-stem', 'subject']
/** Files further apart than this from the SFV in posting time aren't taken. */
const WINDOW_MS = 2 * 24 * 60 * 60 * 1000

/**
 * SFV grouping (CONCEPT.md D34). An uploader that posts every track of an
 * album as its own file (13.5k such releases from one poster on homelab)
 * still posts the album's SFV, which names them all.
 */
class SfvService {
  /**
   * Records an SFV file's listing on its release, moves the listed files that
   * sit in weak releases into it, and names the release after the album when
   * it's still named after a track or the SFV itself. Returns how many files
   * moved, or null when it isn't an SFV.
   */
  async attach(sfvFile: any, text: string): Promise<number | null> {
    const entries = parseSfv(text)
    if (entries.length === 0 || !sfvFile.release_id) return null
    const releaseId = Number(sfvFile.release_id)
    const postedAt = sfvFile.date ? new Date(Number(sfvFile.date)) : null
    await db
      .knexQuery()
      .table('sfv_entries')
      .insert(entries.map((e) => ({ release_id: releaseId, name: e.name, crc: e.crc, poster: sfvFile.poster, posted_at: postedAt })))
      .onConflict(['release_id', 'name'])
      .ignore()
    await FileStore.setDetails(Number(sfvFile.id), { content_type: 'sfv' })

    const candidates = await db
      .from('files as f')
      .join('releases as r', 'r.id', 'f.release_id')
      .whereIn(db.raw('coalesce(f.real_name, f.filename)') as any, entries.map((e) => e.name))
      .whereNot('f.release_id', releaseId)
      .whereIn('r.source', WEAK_SOURCES)
      .select('f.id', 'f.poster', 'f.date')
    const moving = candidates.filter((f) => this.sameUpload(f, sfvFile.poster, postedAt))
    await this.move(moving.map((f) => Number(f.id)), releaseId)

    const release = await db.from('releases').where('id', releaseId).first()
    const album = sfvReleaseName(String(sfvFile.real_name ?? sfvFile.filename))
    if (release && WEAK_SOURCES.includes(release.source) && album !== release.name && /^\d{1,3}-/.test(release.name)) {
      await db.from('releases').where('id', releaseId).update({ name: album })
    }
    logger.info(`SFV "${sfvFile.filename}": ${entries.length} files listed, ${moving.length} moved into release ${releaseId} "${album}".`)
    return moving.length
  }

  /** A new file an SFV already listed joins that SFV's release. Returns the release, or null. */
  /**
   * claim() for a batch of new files: one lookup for all their names, the
   * per-file work only for the few an SFV lists (seeding stores thousands
   * of files per batch; CONCEPT.md D37).
   */
  async claimAll(files: { id: number; name: string; poster?: string | null; date?: number | null; release_id?: number | null }[]): Promise<number> {
    if (files.length === 0) return 0
    const listed = new Set(
      (await db.from('sfv_entries').whereIn('name', [...new Set(files.map((f) => f.name))]).select('name')).map((e) => e.name as string)
    )
    let moved = 0
    for (const file of files) if (listed.has(file.name) && (await this.claim(file)) !== null) moved++
    return moved
  }

  async claim(file: { id: number; name: string; poster?: string | null; date?: number | null; release_id?: number | null }): Promise<number | null> {
    const entries = await db.from('sfv_entries').where('name', file.name)
    const entry = entries.find((e) => this.sameUpload(file, e.poster, e.posted_at ? new Date(e.posted_at) : null))
    if (!entry || Number(entry.release_id) === Number(file.release_id)) return null
    if (file.release_id) {
      const current = await db.from('releases').where('id', file.release_id).first()
      if (current && !WEAK_SOURCES.includes(current.source)) return null
    }
    await this.move([file.id], Number(entry.release_id))
    return Number(entry.release_id)
  }

  private sameUpload(file: { poster?: string | null; date?: number | string | null }, poster: string | null, postedAt: Date | null) {
    if (poster && file.poster && file.poster !== poster) return false
    if (postedAt && file.date && Math.abs(Number(file.date) - postedAt.getTime()) > WINDOW_MS) return false
    return true
  }

  private async move(fileIds: number[], releaseId: number) {
    if (fileIds.length === 0) return
    await db.from('files').whereIn('id', fileIds).update({ release_id: releaseId })
    await db.from('binaries').whereIn('file_id', fileIds).update({ release_id: releaseId })
  }
}

export default new SfvService()