"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 { Review } from "@/components/review";
import { DiscoverPanel } from "@/components/discover";
import { Settings } from "@/components/settings";
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"
  | "discover"
  | "jobs"
  | "review"
  | "bulk"
  | "settings"
  | "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 held = snap?.counts.review ?? 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-title leading-none">muse</h1>
              <p className="mt-0.5 text-caption text-dim">
                search · request · it appears in Navidrome
              </p>
            </div>
            {me?.user && (
              <div className="flex items-center gap-2 text-callout text-dim">
                {quotaLeft !== null && (
                  <span
                    title={`${me.usage!.requests} of ${me.quota} requests used this month`}
                    className={cn(
                      "hidden rounded-pill border px-2 py-0.5 text-caption nums 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-pill border border-accent-line bg-accent-soft px-1.5
                               py-0.5 text-caption uppercase tracking-[0.6px] text-accent"
                  >
                    {me.role}
                  </span>
                )}
                <a
                  href="/auth/logout"
                  className="ring rounded-md px-1 transition-colors hover:text-ink"
                >
                  Log out
                </a>
              </div>
            )}
          </div>

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

          {/* A sliding pill rather than an underline: the moving surface is
              the selection itself, so the eye tracks one object across the
              row instead of watching two things fade. layoutId does the
              interpolation, so it stays correct when tabs appear or vanish
              with a role change. */}
          {/* The mask is the scroll affordance: on a narrow screen the last
              tab fades out at the edge instead of being clipped flat, which
              is the only cue that there is more to the right. */}
          <nav
            className="flex gap-0.5 overflow-x-auto pb-3 pt-2.5 no-scrollbar
                       [mask-image:linear-gradient(to_right,#000_calc(100%-28px),transparent)]
                       sm:[mask-image:none]"
          >
            {(
              [
                ["search", "Search", 0],
                ["discover", "Discover", 0],
                ["jobs", "Requests", active],
                // Only exists when it is actionable. An always-present tab
                // that is empty nine days in ten is chrome; this one appears
                // exactly when something is waiting on you.
                ...(held > 0 || tab === "review"
                  ? ([["review", "Review", held]] as [Tab, string, number][])
                  : []),
                ["bulk", "Import", 0],
                ["settings", "Settings", 0],
                ...(isAdmin ? ([["admin", "Admin", 0]] as [Tab, string, number][]) : []),
              ] as [Tab, string, number][]
            ).map(([k, label, badge]) => (
              <button
                key={k}
                onClick={() => setTab(k)}
                aria-current={tab === k ? "page" : undefined}
                className={cn(
                  "ring relative shrink-0 cursor-pointer rounded-pill px-3 py-1.5",
                  "text-callout font-medium transition-colors duration-200",
                  tab === k ? "text-ink" : "text-dim hover:text-ink",
                )}
              >
                {tab === k && (
                  <motion.span
                    layoutId="tab-pill"
                    className="absolute inset-0 rounded-pill border border-edge-hi bg-[var(--glass-hi)]"
                    transition={{ type: "spring", stiffness: 460, damping: 38 }}
                  />
                )}
                <span className="relative flex items-center gap-1.5">
                  {label}
                  {badge > 0 && (
                    <span
                      className={cn(
                        "min-w-[17px] rounded-pill px-1 text-caption font-bold nums",
                        k === "review"
                          ? "bg-warn/20 text-warn"
                          : "bg-accent-soft text-accent",
                      )}
                    >
                      {badge}
                    </span>
                  )}
                </span>
              </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 === "discover" && <DiscoverPanel onArtist={doSearch} />}
          {tab === "jobs" && <Requests snap={snap} refresh={refresh} />}
          {tab === "review" && <Review onDecided={refresh} />}
          {tab === "bulk" && <BulkImport onQueued={refresh} />}
          {tab === "settings" && me && <Settings me={me} refresh={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-display">Find anything</h2>
      <p className="mx-auto max-w-[46ch] text-body 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-caption 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 ring cursor-pointer rounded-pill px-3.5 py-1.5 text-callout text-dim
                       transition hover:border-accent-line hover:bg-accent-soft hover:text-ink"
          >
            {e}
          </motion.button>
        ))}
      </div>
    </motion.div>
  );
}