/**
 * TMDB 富详情与季集详情(MD-1,媒体详情页 / 字段级元数据用)。
 * 迁移来源:MoviePilot app/modules/themoviedb/tmdbapi.py(e6820a8)
 *   __get_movie_detail / __get_tv_detail(append_to_response=credits,alternative_titles,translations,external_ids …)→ fetchRichDetail;
 *   get_tv_season_detail(季名、简介、海报、episodes[]:name/overview/air_date/runtime/still_path/vote_average)→ fetchRichSeason;
 *   请求缓存语义同 client.ts(MP tmdbv3api request 的 @cached:成功才缓存、空结果短 TTL)。
 * 调整:标题 / 简介按语言回退链取(translations.ts);季集在首选语言缺标题(占位名)或缺简介时按链逐个语言补拉,
 *   链走完或全部补齐即停。MD-2:简介 / 标语只按 overviewLanguages(缺省只到中文变体,不回退英文)取,取不到留空。主创只留前 10 位演员 + 导演 / 主创(created_by),头像只存路径(前端经图片代理)。
 */
import type { MediaEntityType, TmdbClient } from "./client.ts";
import {
  DEFAULT_METADATA_LANGUAGES,
  isPlaceholderEpisodeName,
  isPlaceholderSeasonName,
  overviewLanguages,
  parseAltTitles,
  parseTranslations,
  pickChineseTitle,
  pickText,
  pickTitle,
  type TmdbAltTitle,
  type TmdbTranslation,
} from "./translations.ts";

type Json = Record<string, unknown>;
const s = (v: unknown): string | null => (typeof v === "string" && v.trim() !== "" ? v.trim() : null);
const n = (v: unknown): number | null => (typeof v === "number" && Number.isFinite(v) ? v : null);
const int = (v: unknown): number | null => {
  const x = n(v);
  return x === null ? null : Math.round(x);
};
const yearOf = (d: string | null) => (d && /^\d{4}/.test(d) ? Number(d.slice(0, 4)) : null);

export interface TmdbCredit {
  id: number;
  name: string;
  originalName: string | null;
  /** 演员:角色名;幕后:职务 */
  role: string | null;
  profilePath: string | null;
}

export interface TmdbRichSeason {
  seasonNumber: number;
  episodeCount: number;
  name: string | null;
  airDate: string | null;
  overview: string | null;
  posterPath: string | null;
}

export interface TmdbRichDetail {
  entityType: MediaEntityType;
  externalId: string;
  /** 回退链取到的标题及语言(null = 链全落空后用的请求语言值 / 原名) */
  title: string;
  titleLanguage: string | null;
  /** 中文名(链中第一个中文值,zh-CN 优先);没有为 null */
  titleZh: string | null;
  titleZhLanguage: string | null;
  originalTitle: string | null;
  originalLanguage: string | null;
  overview: string | null;
  overviewLanguage: string | null;
  tagline: string | null;
  year: number | null;
  releaseDate: string | null;
  lastAirDate: string | null;
  genres: string[];
  voteAverage: number | null;
  voteCount: number | null;
  /** TMDB status 原文 */
  status: string | null;
  /** 分钟:电影片长 / 剧集单集时长(episode_run_time 首项) */
  runtime: number | null;
  seasonCount: number | null;
  episodeCount: number | null;
  networks: string[];
  originCountry: string[];
  posterPath: string | null;
  backdropPath: string | null;
  cast: TmdbCredit[];
  crew: TmdbCredit[];
  externalIds: { imdb: string | null; tvdb: string | null; wikidata: string | null };
  translations: TmdbTranslation[];
  alternativeTitles: TmdbAltTitle[];
  seasons: TmdbRichSeason[];
  /** 本次使用的语言链 */
  languages: string[];
}

export interface TmdbRichEpisode {
  seasonNumber: number;
  episodeNumber: number;
  name: string | null;
  nameLanguage: string | null;
  overview: string | null;
  overviewLanguage: string | null;
  airDate: string | null;
  runtime: number | null;
  stillPath: string | null;
  voteAverage: number | null;
  voteCount: number | null;
}

export interface TmdbRichSeasonDetail {
  tvId: string;
  seasonNumber: number;
  name: string | null;
  nameLanguage: string | null;
  overview: string | null;
  overviewLanguage: string | null;
  airDate: string | null;
  posterPath: string | null;
  episodes: TmdbRichEpisode[];
  /** 实际请求过的语言(首选 + 补拉) */
  fetchedLanguages: string[];
}

/** MD-2 取值选项 */
export interface RichTextOptions {
  /** 简介 / 标语是否允许回退到非中文(设置 metadata.overviewNonChineseFallback,缺省否) */
  overviewNonChineseFallback?: boolean;
}

const chainOf = (languages?: readonly string[]) =>
  languages?.length ? [...languages] : [...DEFAULT_METADATA_LANGUAGES];

function credits(raw: unknown, type: MediaEntityType, createdBy: unknown): { cast: TmdbCredit[]; crew: TmdbCredit[] } {
  const c = (raw ?? {}) as Json;
  const cast = ((Array.isArray(c.cast) ? c.cast : []) as Json[])
    .filter((x) => n(x.id) !== null && s(x.name))
    .sort((a, b) => (n(a.order) ?? 999) - (n(b.order) ?? 999))
    .slice(0, 10)
    .map((x) => ({
      id: n(x.id)!,
      name: s(x.name)!,
      originalName: s(x.original_name),
      role: s(x.character),
      profilePath: s(x.profile_path),
    }));
  const crew: TmdbCredit[] = [];
  const seen = new Set<number>();
  const push = (x: Json, role: string) => {
    const id = n(x.id);
    if (id === null || seen.has(id) || !s(x.name)) return;
    seen.add(id);
    crew.push({ id, name: s(x.name)!, originalName: s(x.original_name), role, profilePath: s(x.profile_path) });
  };
  if (type === "tv") for (const x of (Array.isArray(createdBy) ? createdBy : []) as Json[]) push(x, "Creator");
  for (const x of (Array.isArray(c.crew) ? c.crew : []) as Json[]) {
    if (x.job === "Director") push(x, "Director");
  }
  return { cast, crew: crew.slice(0, 6) };
}

/**
 * 富详情:一次请求 `/{type}/{id}?language=链首&append_to_response=alternative_titles,credits,external_ids,translations`,
 * 标题 / 简介 / 标语按链从 translations(+ 同地区别名)取。不存在抛 TmdbError(notfound)。
 */
export async function fetchRichDetail(
  client: Pick<TmdbClient, "getJson">,
  type: MediaEntityType,
  id: string | number,
  languages?: readonly string[],
  opts: RichTextOptions = {},
): Promise<TmdbRichDetail> {
  const chain = chainOf(languages);
  const textChain = overviewLanguages(chain, opts.overviewNonChineseFallback);
  const j = await client.getJson<Json>(`/${type}/${id}`, {
    language: chain[0],
    append_to_response: "alternative_titles,credits,external_ids,translations",
  });
  const titleKey = type === "movie" ? "title" : "name";
  const translations = parseTranslations(j.translations, titleKey);
  const altTitles = parseAltTitles(j.alternative_titles);
  const originalTitle = s(type === "movie" ? j.original_title : j.original_name);
  const originalLanguage = s(j.original_language);
  const primary = s(j[titleKey]);
  const titleSrc = { translations, altTitles, originalTitle, originalLanguage, primary };
  const title = pickTitle(chain, titleSrc);
  const zh = pickChineseTitle(chain, titleSrc);
  // 请求语言 = 链首,链首总在 textChain 里(见 overviewLanguages),所以 primary 可以兜底
  const overview = pickText(textChain, translations, "overview", { value: s(j.overview), language: chain[0] ?? null });
  const tagline = pickText(textChain, translations, "tagline", { value: s(j.tagline), language: chain[0] ?? null });
  const date = s(type === "movie" ? j.release_date : j.first_air_date);
  const ext = (j.external_ids ?? {}) as Json;
  const runtimes = Array.isArray(j.episode_run_time) ? (j.episode_run_time as unknown[]) : [];
  const { cast, crew } = credits(j.credits, type, j.created_by);
  return {
    entityType: type,
    externalId: String(id),
    title: title?.value ?? primary ?? originalTitle ?? "",
    titleLanguage: title?.language ?? null,
    titleZh: zh?.value ?? null,
    titleZhLanguage: zh?.language ?? null,
    originalTitle,
    originalLanguage,
    overview: overview?.value ?? null,
    overviewLanguage: overview?.language ?? null,
    tagline: tagline?.value ?? null,
    year: yearOf(date),
    releaseDate: date,
    lastAirDate: s(j.last_air_date),
    genres: ((Array.isArray(j.genres) ? j.genres : []) as Json[]).map((g) => s(g.name)).filter((x): x is string => !!x),
    voteAverage: n(j.vote_average) !== null ? Math.round(n(j.vote_average)! * 10) / 10 : null,
    voteCount: int(j.vote_count),
    status: s(j.status),
    runtime: type === "movie" ? int(j.runtime) : int(runtimes[0]),
    seasonCount: type === "tv" ? int(j.number_of_seasons) : null,
    episodeCount: type === "tv" ? int(j.number_of_episodes) : null,
    networks: ((Array.isArray(j.networks) ? j.networks : []) as Json[])
      .map((x) => s(x.name))
      .filter((x): x is string => !!x),
    originCountry: Array.isArray(j.origin_country)
      ? (j.origin_country as unknown[]).filter((x): x is string => typeof x === "string")
      : [],
    posterPath: s(j.poster_path),
    backdropPath: s(j.backdrop_path),
    cast,
    crew,
    externalIds: {
      imdb: s(ext.imdb_id),
      tvdb: ext.tvdb_id != null && ext.tvdb_id !== "" ? String(ext.tvdb_id) : null,
      wikidata: s(ext.wikidata_id),
    },
    translations,
    alternativeTitles: altTitles,
    seasons: ((Array.isArray(j.seasons) ? j.seasons : []) as Json[]).map((x) => ({
      seasonNumber: int(x.season_number) ?? 0,
      episodeCount: int(x.episode_count) ?? 0,
      name: s(x.name),
      airDate: s(x.air_date),
      overview: s(x.overview),
      posterPath: s(x.poster_path),
    })),
    languages: chain,
  };
}

function episodeOf(e: Json, seasonNumber: number, lang: string): TmdbRichEpisode {
  const num = int(e.episode_number) ?? 0;
  const name = s(e.name);
  const overview = s(e.overview);
  const named = name && !isPlaceholderEpisodeName(name, num);
  return {
    seasonNumber: int(e.season_number) ?? seasonNumber,
    episodeNumber: num,
    name: named ? name : null,
    nameLanguage: named ? lang : null,
    overview,
    overviewLanguage: overview ? lang : null,
    airDate: s(e.air_date),
    runtime: int(e.runtime),
    stillPath: s(e.still_path),
    voteAverage:
      n(e.vote_average) !== null && (int(e.vote_count) ?? 0) > 0 ? Math.round(n(e.vote_average)! * 10) / 10 : null,
    voteCount: int(e.vote_count),
  };
}

/**
 * 季详情:先按链首请求 `/tv/{id}/season/{n}`;有集缺标题(TMDB 占位名"第 N 集")或缺简介时,
 * 按链逐个语言补拉同一端点(各自走请求缓存),补齐即停。补不到标题的集保留链首的占位名。
 */
export async function fetchRichSeason(
  client: Pick<TmdbClient, "getJson">,
  tvId: string | number,
  seasonNumber: number,
  languages?: readonly string[],
  opts: { now?: Date } & RichTextOptions = {},
): Promise<TmdbRichSeasonDetail> {
  const chain = chainOf(languages);
  const first = chain[0]!;
  // MD-2:简介只从这些语言取(缺省只到中文变体);标题仍按完整链
  const textChain = overviewLanguages(chain, opts.overviewNonChineseFallback);
  const j = await client.getJson<Json>(`/tv/${tvId}/season/${seasonNumber}`, { language: first });
  const rawEps = (Array.isArray(j.episodes) ? j.episodes : []) as Json[];
  const eps = rawEps.map((e) => episodeOf(e, seasonNumber, first));
  const placeholders = new Map(rawEps.map((e) => [int(e.episode_number) ?? 0, s(e.name)]));
  let seasonName = s(j.name);
  let seasonNameLang: string | null = seasonName ? first : null;
  let seasonOverview = s(j.overview);
  let seasonOverviewLang: string | null = seasonOverview ? first : null;
  const fetched = [first];
  // 只为已播出的集补拉(未播出的集各语言通常都空,补拉只会白白耗请求);季名"第 N 季"各语言都是占位,不触发补拉
  const today = (opts.now ?? new Date()).toISOString().slice(0, 10);
  const aired = (e: TmdbRichEpisode) => !!e.airDate && e.airDate <= today;
  // 缺简介只在剩下的语言里还有可取简介的语言时才值得补拉
  const missing = (rest: readonly string[]) => {
    const ov = rest.some((l) => textChain.includes(l));
    return eps.some((e) => aired(e) && (!e.name || (ov && !e.overview))) || (ov && !seasonOverview && eps.some(aired));
  };
  for (const [i, lang] of chain.entries()) {
    if (i === 0) continue;
    if (!eps.length || !missing(chain.slice(i))) break;
    const textOk = textChain.includes(lang);
    let k: Json;
    try {
      k = await client.getJson<Json>(`/tv/${tvId}/season/${seasonNumber}`, { language: lang });
    } catch {
      // 补拉失败不影响首选语言结果
      break;
    }
    fetched.push(lang);
    const byNum = new Map(
      ((Array.isArray(k.episodes) ? k.episodes : []) as Json[]).map((e) => [int(e.episode_number) ?? 0, e]),
    );
    for (const e of eps) {
      const alt = byNum.get(e.episodeNumber);
      if (!alt) continue;
      const other = episodeOf(alt, seasonNumber, lang);
      if (!e.name && other.name) {
        e.name = other.name;
        e.nameLanguage = lang;
      }
      if (textOk && !e.overview && other.overview) {
        e.overview = other.overview;
        e.overviewLanguage = lang;
      }
    }
    if (textOk && !seasonOverview && s(k.overview)) {
      seasonOverview = s(k.overview);
      seasonOverviewLang = lang;
    }
    if (
      isPlaceholderSeasonName(seasonName, seasonNumber) &&
      s(k.name) &&
      !isPlaceholderSeasonName(s(k.name), seasonNumber)
    ) {
      seasonName = s(k.name);
      seasonNameLang = lang;
    }
  }
  // 链走完仍没有标题:保留首选语言的占位名(界面显示"第 N 集"比空白好)
  for (const e of eps) {
    if (!e.name) {
      const p = placeholders.get(e.episodeNumber);
      if (p) {
        e.name = p;
        e.nameLanguage = null;
      }
    }
  }
  return {
    tvId: String(tvId),
    seasonNumber: int(j.season_number) ?? seasonNumber,
    name: seasonName,
    nameLanguage: seasonNameLang,
    overview: seasonOverview,
    overviewLanguage: seasonOverviewLang,
    airDate: s(j.air_date),
    posterPath: s(j.poster_path),
    episodes: eps,
    fetchedLanguages: fetched,
  };
}