import { randomUUID } from "node:crypto";
import path from "node:path";
import { logger } from "../logger.js";
import type { Requester, Track } from "../types.js";

const log = logger.child({ mod: "direct" });

const AUDIO_CONTENT_TYPES = [
  "audio/",
  "application/ogg",
  "application/x-mpegurl",
  "application/vnd.apple.mpegurl",
  "video/mp4",
  "video/webm",
];

export interface ProbeResult {
  isMedia: boolean;
  isLive: boolean;
  title: string | null;
}

/** Cheap HEAD probe used to tell "direct media URL" apart from "web page". */
export async function probe(url: string): Promise<ProbeResult> {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), 8000);
  try {
    const res = await fetch(url, {
      method: "HEAD",
      redirect: "follow",
      signal: controller.signal,
      headers: { "user-agent": "stoat-mbot/0.1", icy: "1" },
    });
    const contentType = (res.headers.get("content-type") ?? "").toLowerCase();
    const isMedia = AUDIO_CONTENT_TYPES.some((type) => contentType.startsWith(type));
    // Shoutcast/Icecast expose the station name and never a content length.
    const icyName = res.headers.get("icy-name");
    const isLive = isMedia && !res.headers.get("content-length");
    return { isMedia: isMedia || Boolean(icyName), isLive: isLive || Boolean(icyName), title: icyName };
  } catch (err) {
    log.debug({ err, url }, "probe failed");
    return { isMedia: false, isLive: false, title: null };
  } finally {
    clearTimeout(timer);
  }
}

export function toTrack(url: string, requestedBy: Requester, probed: ProbeResult): Track {
  let title = probed.title;
  if (!title) {
    try {
      const name = path.basename(new URL(url).pathname);
      title = decodeURIComponent(name) || new URL(url).hostname;
    } catch {
      title = url;
    }
  }
  let host: string | null = null;
  try {
    host = new URL(url).hostname;
  } catch {
    host = null;
  }
  return {
    id: randomUUID(),
    title,
    author: host,
    duration: 0,
    isLive: probed.isLive,
    url,
    thumbnail: null,
    source: "direct",
    requestedBy,
  };
}