/**
 * 详情页扩展内容的通用文本规则(NexusPHP HTML 与 M-Team BBCode 共用):MediaInfo 识别、截图过滤、TMDB 链接。
 */
import type { SiteDetailPage } from "./types.ts";
import { extractDoubanId, extractImdbId } from "./util.ts";

/** 表情 / 图标 / 旗帜 / 头像等小图,不算截图 */
const NOT_SCREENSHOT =
  /(smilies|smiley|emoji|\/icons?\/|pic\/(?:trans|cattrans|flag)|\/flags?\/|avatar|\.svg(?:$|\?))/i;

/** 按完整地址排除:豆瓣海报(含站点的豆瓣图片代理 `?https://img…doubanio.com/…poster…`)与站点横幅装饰图 */
const NOT_SCREENSHOT_URL = /(doubanio\.com\/view\/photo\/[a-z_]*poster|\/banners?\/)/i;

export const MAX_SCREENSHOTS = 20;
export const MAX_FILES = 500;

/** MediaInfo / BDInfo 文本:有概览段落 + 视频段落,且至少 5 行「键 : 值」 */
export function looksLikeMediaInfo(text: string): boolean {
  if (!/(^|\n)\s*(General|概览|常规|DISC INFO|Disc Title|Complete name)\b/i.test(text)) return false;
  if (!/(^|\n)\s*(Video|视频)\b/i.test(text)) return false;
  return (text.match(/^[^\n:：]{2,40}[ \t]*[:：][ \t]*\S/gm) ?? []).length >= 5;
}

/** TMDB:themoviedb.org 链接,或 MediaInfo / 简介里的「TMDB : tv/294990」一行 */
export function extractTmdb(text: string | null | undefined): SiteDetailPage["tmdb"] {
  const m = text
    ? (/themoviedb\.org\/(movie|tv)\/(\d+)/.exec(text) ?? /\bTMDB\s*(?:ID)?\s*[:：]\s*(movie|tv)\/(\d+)/i.exec(text))
    : null;
  return m ? { type: m[1]!.toLowerCase() as "movie" | "tv", id: m[2]! } : null;
}

/** 图片地址转绝对 http(s) 地址并过滤非截图;无效返回 null */
export function screenshotUrl(src: string | null | undefined, base: string): string | null {
  if (!src || src.startsWith("data:")) return null;
  let u: URL;
  try {
    u = new URL(src.trim(), base);
  } catch {
    return null;
  }
  if (u.protocol !== "http:" && u.protocol !== "https:") return null;
  if (NOT_SCREENSHOT.test(u.pathname) || NOT_SCREENSHOT_URL.test(u.href)) return null;
  return u.toString();
}

/** 多行文本规整:去 \r、行尾空白,连续空行压成一行 */
export function tidyText(text: string): string {
  return text
    .replace(/\r/g, "")
    .replace(/ /g, " ")
    .split("\n")
    .map((l) => l.replace(/\s+$/, ""))
    .join("\n")
    .replace(/\n{3,}/g, "\n\n")
    .trim();
}

export function emptyDetailPage(): SiteDetailPage {
  return {
    descriptionText: null,
    mediaInfo: null,
    screenshots: [],
    imdbId: null,
    doubanId: null,
    tmdb: null,
    files: [],
    tags: [],
    uploader: null,
    probe: { labels: [], hasDescription: false, imageCount: 0 },
  };
}

/**
 * M-Team 详情(BBCode 简介 + 独立 mediainfo 字段)→ 扩展内容。
 * 截图取 [img] 标签;简介去掉 BBCode 标记与 MediaInfo 引用块。
 */
export function pageFromBbcode(
  descr: string | null | undefined,
  base: string,
  extra: { mediaInfo?: string | null; imdbId?: string | null; doubanId?: string | null; tags?: string[] } = {},
): SiteDetailPage {
  const page = emptyDetailPage();
  const src = descr ?? "";
  const imgs: string[] = [];
  for (const m of src.matchAll(/\[img(?:=([^\]]+))?\]([^[]*)\[\/img\]|\[img=([^\]]+)\]/gi)) {
    const u = screenshotUrl((m[2] || m[1] || m[3] || "").trim(), base);
    if (u && !imgs.includes(u)) imgs.push(u);
  }
  page.probe.imageCount = imgs.length;
  page.screenshots = imgs.slice(0, MAX_SCREENSHOTS);
  let mediaInfo = extra.mediaInfo?.trim() || null;
  let body = src.replace(/\[img(?:=[^\]]+)?\][^[]*\[\/img\]|\[img=[^\]]+\]/gi, "");
  // [quote] / [code] / [mediainfo] 块里的 MediaInfo
  body = body.replace(
    /\[(quote|code|mediainfo|box|hide|spoiler)(=[^\]]*)?\]([\s\S]*?)\[\/\1\]/gi,
    (all, _t, _a, inner) => {
      const text = tidyText(String(inner).replace(/\[\/?[a-z*]+(?:=[^\]]*)?\]/gi, ""));
      if (looksLikeMediaInfo(text)) {
        mediaInfo ??= text;
        return "";
      }
      return all;
    },
  );
  const text = tidyText(body.replace(/\[\/?[a-z*]+(?:=[^\]]*)?\]/gi, ""));
  page.probe.hasDescription = !!src.trim();
  page.descriptionText = text ? text.slice(0, 20_000) : null;
  page.mediaInfo = mediaInfo ? mediaInfo.slice(0, 50_000) : null;
  page.imdbId = extra.imdbId ?? extractImdbId(src) ?? null;
  page.doubanId = extra.doubanId ?? extractDoubanId(src) ?? null;
  page.tmdb = extractTmdb(src);
  page.tags = [...new Set(extra.tags ?? [])].slice(0, 20);
  return page;
}