"use client";

import * as React from "react";
import { motion } from "framer-motion";
import { ArrowLeft, Disc3, Music2 } from "lucide-react";

import { api, type Me, type Track } from "@/lib/api";
import { tint } from "@/lib/colour";
import { cn } from "@/lib/utils";

import { Aurora } from "@/components/aurora";
import { SearchBar } from "@/components/search-bar";
import { TrackRow } from "@/components/track-row";
import { AlbumView } from "@/components/album-view";
import { ArtistView } from "@/components/artist-view";
import { BulkImport } from "@/components/bulk-import";
import { Requests, type JobsSnapshot } from "@/components/requests";
import { Skeletons } from "@/components/skeletons";
import { PlayerProvider } from "@/components/player";
import { ToastProvider } from "@/components/toast";
import { AdminPanel } from "@/components/admin/admin-panel";

type Tab = "search" | "jobs" | "bulk" | "admin";
type View =
  | { k: "welcome" }
  | { k: "results"; q: string }
  | { k: "album"; id: number }
  | { k: "artist"; id: number };

const EXAMPLES = [
  "Radiohead Creep",
  "Kendrick Lamar Money Trees",
  "Fleetwood Mac Dreams",
  "Tame Impala The Less I Know The Better",
  "Frank Ocean Ivy",
];

export default function Page() {
  return (
    <ToastProvider>
      <PlayerProvider>
        <Muse />
      </PlayerProvider>
    </ToastProvider>
  );
}

function Muse() {
  const [tab, setTab] = React.useState<Tab>("search");
  const [view, setView] = React.useState<View>({ k: "welcome" });
  const [history, setHistory] = React.useState<View[]>([]);
  const [results, setResults] = React.useState<Track[] | null>(null);
  const [busy, setBusy] = React.useState(false);
  const [me, setMe] = React.useState<Me | null>(null);
  const [snap, setSnap] = React.useState<JobsSnapshot | null>(null);

  const go = React.useCallback((next: View) => {
    setView((cur) => {
      setHistory((h) => (cur.k === "welcome" ? h : [...h, cur]));
      return next;
    });
    setTab("search");
    window.scrollTo({ top: 0, behavior: "smooth" });
  }, []);

  const back = () => {
    setHistory((h) => {
      const prev = h[h.length - 1];
      if (prev) setView(prev);
      return h.slice(0, -1);
    });
  };

  const doSearch = React.useCallback(
    async (q: string) => {
      if (!q.trim()) return;
      go({ k: "results", q });
      setResults(null);
      setBusy(true);
      try {
        const r = await api.search(q);
        setResults(r.results);
        if (r.results[0]) void tint(r.results[0].cover);
      } catch {
        setResults([]);
      }
      setBusy(false);
    },
    [go],
  );

  const openAlbum = React.useCallback((id: number) => go({ k: "album", id }), [go]);
  const openArtist = React.useCallback((id: number) => go({ k: "artist", id }), [go]);

  const refresh = React.useCallback(async () => {
    try {
      setSnap(await api.jobs());
    } catch {
      /* a 401 here just means the poll outlived the session */
    }
    // Refetched alongside jobs rather than once at mount so the quota chip
    // counts down as you queue, and so a role change or a disable lands within
    // one poll instead of at next sign-in.
    try {
      setMe(await api.me());
    } catch {
      /* ignore */
    }
  }, []);

  React.useEffect(() => {
    void refresh();
    const t = setInterval(refresh, 4000);
    return () => clearInterval(t);
  }, [refresh]);

  const active =
    (snap?.counts.queued ?? 0) +
    (snap?.counts.searching ?? 0) +
    (snap?.counts.downloading ?? 0);

  const isAdmin = me?.role === "admin";
  // Only worth showing when a limit actually exists — a permanent "0 / 0" chip
  // is noise on a single-user install, which is most of them.
  const quotaLeft =
    me?.quota && me.usage ? Math.max(0, me.quota - me.usage.requests) : null;

  return (
    <>
      <Aurora />

      <header
        className="sticky top-0 z-40 border-b border-edge bg-[var(--header)] pt-3.5
                   backdrop-blur-[22px] backdrop-saturate-[1.7]"
      >
        <div className="mx-auto w-full max-w-[940px] px-4">
          <div className="mb-3.5 flex items-center gap-3">
            <motion.div
              whileHover={{ rotate: 12, scale: 1.06 }}
              transition={{ type: "spring", stiffness: 400, damping: 15 }}
              className="grid h-[38px] w-[38px] shrink-0 place-items-center rounded-xl
                         border border-accent-line bg-accent-soft text-accent"
            >
              <Music2 className="h-5 w-5" />
            </motion.div>
            <div className="min-w-0 flex-1">
              <h1 className="text-[19px] font-bold leading-tight tracking-[-0.4px]">muse</h1>
              <p className="text-xs text-dim">search · request · it appears in Navidrome</p>
            </div>
            {me?.user && (
              <div className="flex items-center gap-2 text-[12.5px] text-dim">
                {quotaLeft !== null && (
                  <span
                    title={`${me.usage!.requests} of ${me.quota} requests used this month`}
                    className={cn(
                      "hidden rounded-full border px-2 py-0.5 text-[11px] sm:inline",
                      quotaLeft === 0
                        ? "border-err/50 text-err"
                        : quotaLeft <= 5
                          ? "border-warn/50 text-warn"
                          : "border-edge text-dim",
                    )}
                  >
                    {quotaLeft} left
                  </span>
                )}
                {me.avatar && (
                  /* eslint-disable-next-line @next/next/no-img-element */
                  <img
                    src={me.avatar}
                    alt=""
                    className="h-6 w-6 rounded-full border border-edge"
                  />
                )}
                <span className="hidden font-medium text-ink sm:inline">
                  {me.display || me.user}
                </span>
                {me.role && me.role !== "user" && (
                  <span
                    className="rounded-full border border-accent-line bg-accent-soft px-1.5
                               py-0.5 text-[10.5px] uppercase tracking-[0.6px] text-accent"
                  >
                    {me.role}
                  </span>
                )}
                <a
                  href="/auth/logout"
                  className="border-b border-transparent hover:border-edge-hi hover:text-ink"
                >
                  Log out
                </a>
              </div>
            )}
          </div>

          <SearchBar busy={busy} onSearch={doSearch} onAlbum={openAlbum} onArtist={openArtist} />

          <nav className="flex overflow-x-auto pt-3 no-scrollbar">
            {(
              [
                ["search", "Search"],
                ["jobs", "Requests"],
                ["bulk", "Import list"],
                ...(isAdmin ? ([["admin", "Admin"]] as [Tab, string][]) : []),
              ] as [Tab, string][]
            ).map(([k, label]) => (
              <button
                key={k}
                onClick={() => setTab(k)}
                className={cn(
                  "relative mr-4 cursor-pointer px-1 pb-3 pt-2 text-[13.5px] font-medium transition-colors",
                  tab === k ? "text-ink" : "text-dim hover:text-ink",
                )}
              >
                {label}
                {k === "jobs" && active > 0 && (
                  <span
                    className="ml-1.5 inline-block min-w-[18px] rounded-full border
                               border-accent-line bg-accent-soft px-1.5 text-[11px]
                               font-bold text-accent"
                  >
                    {active}
                  </span>
                )}
                {tab === k && (
                  <motion.i
                    layoutId="tab-underline"
                    className="absolute inset-x-0 bottom-0 h-0.5 rounded-t bg-accent"
                    transition={{ type: "spring", stiffness: 420, damping: 34 }}
                  />
                )}
              </button>
            ))}
          </nav>
        </div>
      </header>

      <main className="mx-auto w-full max-w-[940px] px-4 pb-32 pt-5">
        {/* Keyed on `tab`, so React remounts and Framer replays the entrance.
            Deliberately NOT wrapped in AnimatePresence mode="wait": that holds
            the incoming panel until the outgoing one's exit animation reports
            finished, which makes navigation depend on an animation completing.
            Anything that stalls the frame loop — a backgrounded tab, a browser
            that throttles rAF — then leaves the UI stuck on the old panel with
            no way forward. A cosmetic transition should never gate navigation. */}
        <motion.div
          key={tab}
          initial={{ opacity: 0, y: 8 }}
          animate={{ opacity: 1, y: 0 }}
          transition={{ duration: 0.22 }}
        >
            {tab === "search" && (
              <>
                {history.length > 0 && (
                <motion.button
                  initial={{ opacity: 0, x: -8 }}
                  animate={{ opacity: 1, x: 0 }}
                  onClick={back}
                  className="glass mb-3.5 flex cursor-pointer items-center gap-1.5 rounded-full
                             px-3 py-1.5 text-[13px] text-dim transition hover:border-edge-hi hover:text-ink"
                >
                    <ArrowLeft className="h-3.5 w-3.5" /> Back
                  </motion.button>
                )}

                {view.k === "welcome" && <Welcome onPick={doSearch} />}

                {view.k === "results" &&
                  (results === null ? (
                    <Skeletons />
                  ) : results.length === 0 ? (
                    <div className="py-12 text-center text-dim">
                      No matches. Try adding the artist name.
                    </div>
                  ) : (
                    <motion.div layout className="flex flex-col gap-[7px]">
                      {results.map((t, i) => (
                        <TrackRow
                          key={t.deezer_id}
                          track={t}
                          index={i}
                          onAlbum={openAlbum}
                          onArtist={openArtist}
                          onQueued={refresh}
                        />
                      ))}
                    </motion.div>
                  ))}

                {view.k === "album" && (
                  <AlbumView id={view.id} onArtist={openArtist} onQueued={refresh} />
                )}
                {view.k === "artist" && (
                  <ArtistView id={view.id} onAlbum={openAlbum} onQueued={refresh} />
                )}
              </>
            )}

          {tab === "jobs" && <Requests snap={snap} refresh={refresh} />}
          {tab === "bulk" && <BulkImport onQueued={refresh} />}
          {tab === "admin" && isAdmin && <AdminPanel me={me?.user ?? null} />}
        </motion.div>
      </main>
    </>
  );
}

function Welcome({ onPick }: { onPick: (q: string) => void }) {
  return (
    <motion.div
      initial={{ opacity: 0, y: 12 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{ type: "spring", stiffness: 260, damping: 28 }}
      className="px-5 py-14 text-center"
    >
      <motion.div
        animate={{ y: [0, -7, 0] }}
        transition={{ duration: 4.5, repeat: Infinity, ease: "easeInOut" }}
        className="mx-auto mb-4 grid h-16 w-16 place-items-center rounded-[20px]
                   border border-accent-line bg-accent-soft text-accent"
      >
        <Disc3 className="h-7 w-7" />
      </motion.div>
      <h2 className="mb-2 text-[23px] font-bold tracking-[-0.4px]">Find anything</h2>
      <p className="mx-auto max-w-[46ch] text-sm text-dim">
        Search a song and press{" "}
        <kbd className="rounded-md border border-edge-hi bg-[var(--glass-hi)] px-1.5 py-0.5 text-[11.5px] text-ink">
          Enter
        </kbd>
        . Hit play to hear a 30-second preview before you commit, then <b>Get</b> to pull it into
        your library, tagged.
      </p>
      <div className="mt-5 flex flex-wrap justify-center gap-2">
        {EXAMPLES.map((e, i) => (
          <motion.button
            key={e}
            initial={{ opacity: 0, y: 8 }}
            animate={{ opacity: 1, y: 0 }}
            transition={{ delay: 0.1 + i * 0.05 }}
            whileHover={{ y: -2 }}
            onClick={() => onPick(e)}
            className="glass cursor-pointer rounded-full px-3.5 py-1.5 text-[13px] text-dim
                       transition hover:border-accent-line hover:bg-accent-soft hover:text-ink"
          >
            {e}
          </motion.button>
        ))}
      </div>
    </motion.div>
  );
}