/**
 * Fanart.tv client. Requires a personal API key (free, no email required
 * but you do need to register at https://fanart.tv/get-an-api-key/ and
 * obtain a "personal" key). The key is stored in user preferences and
 * supplied to every request.
 *
 * Most-useful endpoints for our chrome:
 *   - /v3/movies/{tmdb_or_imdb_id}     movie artwork (logos, clearart, banners)
 *   - /v3/tv/{tvdb_id}                  TV artwork (logos, clearart, banners)
 *
 * Each artwork item carries `lang` so we can pick English versions first
 * when present, falling back to whatever the highest-voted entry is.
 */

const BASE = 'https://webservice.fanart.tv/v3'

export interface FanartImage {
  id: string
  url: string
  lang?: string
  likes?: string
  /* Some artwork types include season number (TV) */
  season?: string
}

export interface FanartMovieResponse {
  name?: string
  tmdb_id?: string
  imdb_id?: string
  hdmovielogo?: FanartImage[]
  hdmovieclearart?: FanartImage[]
  movielogo?: FanartImage[]
  movieart?: FanartImage[]
  movieposter?: FanartImage[]
  moviebackground?: FanartImage[]
  moviedisc?: FanartImage[]
  moviebanner?: FanartImage[]
  moviethumb?: FanartImage[]
}

export interface FanartTvResponse {
  name?: string
  thetvdb_id?: string
  hdtvlogo?: FanartImage[]
  clearlogo?: FanartImage[]
  hdclearart?: FanartImage[]
  clearart?: FanartImage[]
  showbackground?: FanartImage[]
  tvthumb?: FanartImage[]
  tvbanner?: FanartImage[]
  characterart?: FanartImage[]
  seasonposter?: FanartImage[]
  seasonbanner?: FanartImage[]
  seasonthumb?: FanartImage[]
  tvposter?: FanartImage[]
}

async function fetchJson<T>(url: string, apiKey: string): Promise<T | null> {
  if (!apiKey) return null
  try {
    const res = await fetch(url, { headers: { 'api-key': apiKey } })
    if (!res.ok) return null
    return (await res.json()) as T
  } catch {
    return null
  }
}

export function fanartMovie(idTmdbOrImdb: string, apiKey: string): Promise<FanartMovieResponse | null> {
  if (!idTmdbOrImdb) return Promise.resolve(null)
  return fetchJson<FanartMovieResponse>(
    `${BASE}/movies/${encodeURIComponent(idTmdbOrImdb)}`,
    apiKey,
  )
}

export function fanartTv(tvdbId: string, apiKey: string): Promise<FanartTvResponse | null> {
  if (!tvdbId) return Promise.resolve(null)
  return fetchJson<FanartTvResponse>(`${BASE}/tv/${encodeURIComponent(tvdbId)}`, apiKey)
}

/**
 * Pick the best image from a list: prefer English entries, then
 * highest `likes` count, falling back to first in list.
 */
export function pickBestFanartImage(images?: FanartImage[]): FanartImage | null {
  if (!images || images.length === 0) return null
  const eng = images.filter(i => (i.lang || '').toLowerCase() === 'en')
  const pool = eng.length > 0 ? eng : images
  return [...pool].sort((a, b) => Number(b.likes ?? 0) - Number(a.likes ?? 0))[0] || null
}