import { NextResponse } from 'next/server'
import { navidromeGet } from '@/lib/navidrome'

const OFFLINE_PLAYLIST_NAME = '__soulsync_offline__'

interface SubsonicPlaylist {
  id: string
  name: string
  songCount: number
  coverArt: string
}

interface SubsonicSong {
  id: string
  title: string
  artist: string
  album: string
  albumId: string
  duration: number
  coverArt: string
}

interface PlaylistsResult {
  playlists?: { playlist?: SubsonicPlaylist[] }
}

interface PlaylistResult {
  playlist?: {
    id: string
    name: string
    songCount: number
    entry?: SubsonicSong[]
  }
}

/** Find or create the offline sync playlist, returning its id + songs */
async function getOrCreateOfflinePlaylist() {
  // Find existing
  const data = await navidromeGet<PlaylistsResult>('getPlaylists.view')
  const existing = (data.playlists?.playlist || []).find(
    (p) => p.name === OFFLINE_PLAYLIST_NAME
  )

  if (existing) {
    // Fetch full playlist with entries
    const full = await navidromeGet<PlaylistResult>('getPlaylist.view', { id: existing.id })
    const songs = (full.playlist?.entry || []).map((s) => ({
      id: s.id,
      title: s.title,
      artist: s.artist,
      album: s.album,
      albumId: s.albumId,
      duration: s.duration,
      coverArt: s.coverArt,
    }))
    return { id: existing.id, songs }
  }

  // Create it
  await navidromeGet('createPlaylist.view', { name: OFFLINE_PLAYLIST_NAME })
  // Re-fetch to get its id
  const data2 = await navidromeGet<PlaylistsResult>('getPlaylists.view')
  const created = (data2.playlists?.playlist || []).find(
    (p) => p.name === OFFLINE_PLAYLIST_NAME
  )
  return { id: created?.id || '', songs: [] }
}

/** GET: return offline playlist id + songs */
export async function GET() {
  try {
    const result = await getOrCreateOfflinePlaylist()
    return NextResponse.json(result)
  } catch (error) {
    console.error('Offline playlist error:', error)
    return NextResponse.json({ error: 'Failed to get offline playlist' }, { status: 502 })
  }
}

/** POST: add a song to the offline playlist */
export async function POST(request: Request) {
  try {
    const { songId } = await request.json()
    if (!songId) {
      return NextResponse.json({ error: 'songId required' }, { status: 400 })
    }
    const { id: playlistId } = await getOrCreateOfflinePlaylist()
    await navidromeGet('updatePlaylist.view', {
      playlistId,
      songIdToAdd: songId,
    })
    return NextResponse.json({ success: true })
  } catch (error) {
    console.error('Add to offline playlist error:', error)
    return NextResponse.json({ error: 'Failed to add song' }, { status: 502 })
  }
}

/** DELETE: remove a song from the offline playlist by songId */
export async function DELETE(request: Request) {
  try {
    const { songId } = await request.json()
    if (!songId) {
      return NextResponse.json({ error: 'songId required' }, { status: 400 })
    }
    const { id: playlistId, songs } = await getOrCreateOfflinePlaylist()
    // Subsonic removeFromPlaylist uses songIndexToRemove (0-based index)
    const index = songs.findIndex((s) => s.id === songId)
    if (index === -1) {
      return NextResponse.json({ error: 'Song not in offline playlist' }, { status: 404 })
    }
    await navidromeGet('updatePlaylist.view', {
      playlistId,
      songIndexToRemove: String(index),
    })
    return NextResponse.json({ success: true })
  } catch (error) {
    console.error('Remove from offline playlist error:', error)
    return NextResponse.json({ error: 'Failed to remove song' }, { status: 502 })
  }
}