import type { ReactNode } from "react";
import { useTranslation } from "react-i18next";
import { File, Film, Music } from "lucide-react";
import clsx from "clsx";
import { DOWNLOAD_PHASES } from "../../lib/downloadQueue";
import { api, type DownloadJob } from "../../lib/api";
import { IconButton } from "../../components/ui/IconButton";
import { MediaProgress } from "../../components/ui/MediaCard";
import RemoteImage from "../../components/ui/RemoteImage";

// The small shared primitives of a download (status pill, icon button, the job's picture), all purely
// prop-driven: the admin Storage tab shows the status, the Files list and grid the picture, the
// details dialog the icon button.

const STATUS_CLS: Record<string, string> = {
  queued: "text-muted",
  running: "text-accent",
  paused: "text-warn",
  done: "text-success",
  error: "text-danger",
  canceled: "text-muted",
};

export function StatusPill({ job }: { job: DownloadJob }) {
  const { t } = useTranslation();
  // While downloading, show the concrete phase (video / audio / merging) so the user isn't
  // confused by the bar resetting between the separate video and audio streams.
  if (job.status === "running" && job.phase && DOWNLOAD_PHASES.includes(job.phase)) {
    return (
      <span className="text-sm font-medium text-accent">{t(`downloads.phase.${job.phase}`)}</span>
    );
  }
  return (
    <span className={clsx("text-sm font-medium", STATUS_CLS[job.status] ?? "text-muted")}>
      {t(`downloads.status.${job.status}`)}
    </span>
  );
}

// A picture's box when the caller gives none: a thumbnail-sized 16:9 frame.
const THUMB_BOX =
  "w-28 aspect-video shrink-0 rounded-lg overflow-hidden bg-surface border border-border";

/** A job's picture: its poster, else the source's thumbnail, else a glyph of what it is. `box` sizes
 *  it (the Files list draws a smaller one). */
// An image larger than this keeps the file glyph: a row's thumbnail is the whole file, and a page of
// camera originals would pull hundreds of megabytes for pictures a few rem wide.
const IMAGE_THUMB_MAX_BYTES = 8 * 1024 * 1024;

/** An image file's own picture for its thumbnail, or null (not an image, not readable, too big). */
function imageThumbOf(job: DownloadJob): string | null {
  const a = job.asset;
  if (a?.preview !== "image" || !job.can_download) return null;
  if ((a.size_bytes ?? Infinity) > IMAGE_THUMB_MAX_BYTES) return null;
  return api.previewUrl(job.id);
}

export function JobThumb({ job, box = THUMB_BOX }: { job: DownloadJob; box?: string }) {
  // Prefer OUR self-hosted poster: it's always present on disk, never expires, and is same-origin, so
  // a source-CDN signature expiry (Facebook's fbcdn URLs expire within days) or an ad-blocker/Shields
  // rule on the source domain can't break it. The source's remote thumbnail_url is only a fallback for
  // the rare poster-less asset (a thumbnail-less source whose ffmpeg frame-cut also failed).
  const remote = job.asset?.thumbnail_url ?? null;
  // `job.poster_url` only SIGNALS a poster exists; the <img> src is api.posterImageUrl.
  const poster = job.poster_url ? api.posterImageUrl(job.id) : null;
  // A generic uploaded file (media_kind='file') has no video frame to poster — it's a document/
  // archive, not playable media. An image is its own picture (its sandboxed preview); the rest show
  // a neutral file glyph instead of an (always-empty) thumbnail. A preview that fails is an answer
  // (gone since, or not an image after all), not a hiccup: the glyph at once, no retries.
  if (job.asset?.media_kind === "file") {
    const glyph = <File className="w-8 h-8" aria-hidden="true" />;
    return (
      <div className={`${box} flex items-center justify-center text-muted`}>
        <RemoteImage
          src={imageThumbOf(job)}
          alt=""
          loading="lazy"
          decoding="async"
          className="h-full w-full object-cover"
          retries={0}
          fallback={glyph}
        />
      </div>
    );
  }
  // How far into it the viewer is, the media cards' bar.
  const duration = job.asset?.duration_s ?? 0;
  const pct = duration > 0 ? ((job.position_seconds ?? 0) / duration) * 100 : 0;
  // No picture at all (a link that failed before its details, a poster that never came): a quiet
  // glyph of what it is, like the file glyph above — an empty box read as "still loading".
  const glyph = (
    <div className="flex h-full items-center justify-center text-muted">
      {job.asset?.media_kind === "audio" ? (
        <Music className="w-7 h-7" aria-hidden="true" />
      ) : (
        <Film className="w-7 h-7" aria-hidden="true" />
      )}
    </div>
  );
  // The source's picture, the poster's fallback: retried like any remote picture, then the glyph.
  const remotePicture = (
    <RemoteImage
      src={remote}
      alt=""
      loading="lazy"
      className="w-full h-full object-cover"
      fallback={glyph}
    />
  );
  return (
    <div className={`${box} relative`}>
      <MediaProgress pct={pct} />
      {poster ? (
        // Our own poster failing is an answer (the file is missing), so straight to the source's
        // picture. RemoteImage remembers the failure by URL, so a recycled row never shows one job's
        // fallback over the next one's poster, and forgets it once the row moves on — a poster that
        // 404'd while its file was still being written is asked for again when the row comes back.
        <RemoteImage
          src={poster}
          alt=""
          loading="lazy"
          className="w-full h-full object-cover"
          retries={0}
          fallback={remotePicture}
        />
      ) : (
        remotePicture
      )}
    </div>
  );
}

export function IconBtn({
  onClick,
  title,
  danger,
  open,
  children,
}: {
  onClick: () => void;
  title: string;
  danger?: boolean;
  /** The row's "open" action (play): Enter on a keyboard-walked row (lib/listNav) clicks it. */
  open?: boolean;
  children: ReactNode;
}) {
  return (
    <IconButton
      variant={danger ? "danger" : "ghost"}
      size="md"
      onClick={onClick}
      data-nav-open={open ? "" : undefined}
      label={title}
    >
      {children}
    </IconButton>
  );
}