"use client";

import Link from "next/link";
import { AnimatePresence, motion } from "framer-motion";
import { useMemo, useState, useSyncExternalStore } from "react";

import { useI18n } from "@/lib/i18n";
import { useAppReducedMotion as useReducedMotion } from "@/lib/motion-pref";
import { deletePodcast, podcastMinutes, podcastStore, renamePodcast, sortPodcasts, upsertPodcast } from "@/lib/podcasts";
import { showToast } from "@/lib/toast";
import { EmptyState } from "@/components/ui";
import { ClockIcon, EllipsisIcon, MusicIcon, PlayIcon } from "@/components/icons";
import { cn } from "@/lib/utils";

/**
 * The library's podcasts tab: short episode cards with listen / rename /
 * delete, the same interaction language as the homework cards.
 */
export function PodcastList() {
  const { t, plural } = useI18n();
  const reduceMotion = useReducedMotion();
  const episodes = useSyncExternalStore(
    podcastStore.subscribe,
    podcastStore.getSnapshot,
    podcastStore.getServerSnapshot,
  );
  const sorted = useMemo(() => sortPodcasts(episodes), [episodes]);
  const [menuFor, setMenuFor] = useState<string | null>(null);
  const [renaming, setRenaming] = useState<string | null>(null);
  const [draft, setDraft] = useState("");

  if (sorted.length === 0) {
    return (
      <EmptyState
        title={t("podcast.library.empty")}
        action={
          <Link href="/podcast" className="btn-primary touch-target h-11 px-5 text-sm">
            {t("podcast.library.new")}
          </Link>
        }
      >
        {t("podcast.library.emptyBody")}
      </EmptyState>
    );
  }

  return (
    <ul className="grid list-none grid-cols-[repeat(auto-fill,minmax(280px,1fr))] gap-4 lg:grid-cols-[repeat(auto-fill,minmax(320px,1fr))]">
      <AnimatePresence initial={false}>
        {sorted.map((episode, index) => {
          const minutes = podcastMinutes(episode);
          const progress = episode.progress;
          return (
            <motion.li
              key={episode.id}
              layout={!reduceMotion}
              initial={reduceMotion ? false : { opacity: 0, y: 12 }}
              animate={{ opacity: 1, y: 0 }}
              exit={reduceMotion ? { opacity: 0 } : { opacity: 0, scale: 0.96 }}
              transition={reduceMotion ? { duration: 0 } : { duration: 0.24, delay: Math.min(index * 0.03, 0.18) }}
              className="card card-hover relative flex flex-col gap-3 p-4"
            >
              <div className="flex items-start gap-3">
                <span className="grid size-11 shrink-0 place-items-center rounded-2xl bg-[var(--surface-sunken)] text-accent-600 dark:text-accent-200">
                  <MusicIcon className="size-5" />
                </span>
                <div className="min-w-0 flex-1">
                  {renaming === episode.id ? (
                    <input
                      autoFocus
                      value={draft}
                      onChange={(event) => setDraft(event.target.value)}
                      onKeyDown={(event) => {
                        event.stopPropagation();
                        if (event.key === "Enter") {
                          const title = draft.trim();
                          if (title) {
                            renamePodcast(episode.id, title);
                            showToast({ message: t("podcast.card.renamed") });
                          }
                          setRenaming(null);
                        }
                        if (event.key === "Escape") setRenaming(null);
                      }}
                      maxLength={200}
                      aria-label={t("podcast.card.rename")}
                      className="w-full rounded-lg border border-[var(--hairline)] bg-[var(--surface-strong)] px-2.5 py-1.5 text-[15px] font-semibold text-[var(--text)] outline-none focus:border-accent-400"
                    />
                  ) : (
                    <h2 className="truncate text-[16px] font-bold text-[var(--text)]" title={episode.title}>
                      {episode.title}
                    </h2>
                  )}
                  <p className="mt-0.5 flex flex-wrap items-center gap-x-2 text-[12px] text-[var(--text-subtle)]">
                    <span className="inline-flex items-center gap-1">
                      <ClockIcon className="size-3.5" />
                      {t("podcast.card.minutes", { n: minutes })}
                    </span>
                    <span aria-hidden>·</span>
                    <span>{t("podcast.card.sections", { n: episode.sections.length })}</span>
                    {progress ? (
                      <>
                        <span aria-hidden>·</span>
                        <span>{t("podcast.sectionOf", { n: progress.section + 1, total: episode.sections.length })}</span>
                      </>
                    ) : null}
                  </p>
                </div>
                <button
                  type="button"
                  onClick={() => setMenuFor((current) => (current === episode.id ? null : episode.id))}
                  aria-label={t("podcast.card.actions")}
                  aria-expanded={menuFor === episode.id}
                  className="grid size-9 shrink-0 place-items-center rounded-xl text-[var(--text-subtle)] transition hover:bg-[var(--hover)] hover:text-[var(--text)]"
                >
                  <EllipsisIcon className="size-4" />
                </button>
              </div>

              {episode.summary ? (
                <p className="line-clamp-2 text-[12.5px] leading-relaxed text-[var(--text-muted)]">{episode.summary}</p>
              ) : null}

              {menuFor === episode.id ? (
                <div className="absolute right-3 top-14 z-20 w-44 overflow-hidden rounded-2xl border border-[var(--hairline)] bg-[var(--surface-raised)] p-1 shadow-[var(--shadow-card)]">
                  <button
                    type="button"
                    className="nav-row touch-target"
                    onClick={() => {
                      setDraft(episode.title);
                      setRenaming(episode.id);
                      setMenuFor(null);
                    }}
                  >
                    {t("podcast.card.rename")}
                  </button>
                  <button
                    type="button"
                    className="nav-row touch-target text-rose-600 dark:text-rose-300"
                    onClick={() => {
                      deletePodcast(episode.id);
                      setMenuFor(null);
                      /* Deleting is reversible: no confirm, just an Undo. */
                      showToast({
                        message: t("podcast.card.deleted"),
                        actionLabel: t("toast.undo"),
                        onAction: () => upsertPodcast(episode),
                      });
                    }}
                  >
                    {t("podcast.card.delete")}
                  </button>
                </div>
              ) : null}

              <div className="mt-auto flex items-center gap-2">
                <Link
                  href={`/podcast/${episode.id}`}
                  className={cn("btn-primary touch-target inline-flex h-10 flex-1 items-center justify-center gap-2 text-[13.5px]")}
                >
                  <PlayIcon className="size-4" />
                  {t("podcast.card.open")}
                </Link>
                <span className="shrink-0 text-[11.5px] font-medium text-[var(--text-subtle)]">
                  {plural(episode.sections.length, "podcast.sectionCount")}
                </span>
              </div>
            </motion.li>
          );
        })}
      </AnimatePresence>

      {/* Tapping anywhere else closes an open menu. */}
      {menuFor ? (
        <li aria-hidden className="fixed inset-0 z-10" onClick={() => setMenuFor(null)} />
      ) : null}
    </ul>
  );
}