import { NextResponse, type NextRequest } from 'next/server'
import { getPayload } from 'payload'
import config from '@payload-config'
import { downloadAndUploadImage } from '@/lib/utils/media-download'
import { getYouTubeThumbnail } from '@/lib/utils/youtube'

/**
 * POST /api/youtube/thumbnails/bulk
 *
 * Bulk-Download von YouTube-Thumbnails für alle YouTubeContent-Einträge
 * die noch kein Thumbnail haben. Erfordert Super-Admin-Rechte.
 *
 * Query-Parameter:
 * - dryRun=true: Zeigt nur was passieren würde, ohne tatsächlich herunterzuladen
 */
export async function POST(req: NextRequest) {
  try {
    const payload = await getPayload({ config })

    const { user } = await payload.auth({ headers: req.headers })
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    const typedUser = user as { isSuperAdmin?: boolean }
    if (!typedUser.isSuperAdmin) {
      return NextResponse.json({ error: 'Super-Admin erforderlich' }, { status: 403 })
    }

    const dryRun = req.nextUrl.searchParams.get('dryRun') === 'true'

    // Find all YouTubeContent without thumbnail that have a videoId
    const contentWithoutThumbnail = await payload.find({
      collection: 'youtube-content',
      where: {
        thumbnail: { exists: false },
        'youtube.videoId': { exists: true },
      },
      limit: 500,
      depth: 0,
    })

    const results = { processed: 0, downloaded: 0, skipped: 0, errors: 0, dryRun }

    for (const doc of contentWithoutThumbnail.docs) {
      results.processed++
      const videoId = doc.youtube?.videoId
      if (!videoId) {
        results.skipped++
        continue
      }

      if (dryRun) {
        results.downloaded++
        continue
      }

      try {
        const thumbnailUrl = getYouTubeThumbnail(videoId, 'hq')
        const filename = `yt-thumb-${videoId}.jpg`
        const tenantId = typeof doc.tenant === 'object' ? doc.tenant?.id : doc.tenant

        const mediaId = await downloadAndUploadImage(payload, {
          url: thumbnailUrl,
          filename,
          alt: `Thumbnail: ${typeof doc.title === 'string' ? doc.title : doc.title?.de || videoId}`,
          tenantId: tenantId || undefined,
        })

        if (mediaId) {
          await payload.update({
            collection: 'youtube-content',
            id: doc.id,
            data: { thumbnail: mediaId },
            depth: 0,
          })
          results.downloaded++
        } else {
          results.errors++
        }
      } catch {
        results.errors++
      }

      // Rate-limit delay (500ms between downloads)
      await new Promise((resolve) => setTimeout(resolve, 500))
    }

    return NextResponse.json(results)
  } catch (error) {
    console.error('[yt-thumbnail-bulk] Error:', error)
    return NextResponse.json({ error: 'Internal Server Error' }, { status: 500 })
  }
}