import Link from "next/link";
import { notFound } from "next/navigation";
import type { Metadata } from "next";
import { requireUser } from "@/lib/auth";
import { getSettings } from "@/lib/settings";
import { prisma } from "@/lib/db";
import { getUniverse, suggestCollections } from "@/lib/universes";
import { formatMinutes } from "@/lib/labels";
import { AppShell } from "@/components/AppShell";
import { ProgressBar } from "@/components/ProgressBar";
import { OrderedList } from "@/components/universes/OrderedList";
import {
  AddTitles,
  DeleteUniverse,
  OrderTabs,
  SharePanel,
} from "@/components/universes/UniverseTools";

type Params = Promise<{ id: string }>;
type Search = Promise<{ reihenfolge?: string }>;

export async function generateMetadata({ params }: { params: Params }): Promise<Metadata> {
  const { id } = await params;
  const universe = await prisma.universe.findUnique({ where: { id }, select: { name: true } });
  return { title: universe?.name ?? "Universum" };
}

export default async function UniversePage({
  params,
  searchParams,
}: {
  params: Params;
  searchParams: Search;
}) {
  const user = await requireUser();
  const settings = await getSettings();
  const { id } = await params;
  const { reihenfolge } = await searchParams;

  const universe = await getUniverse(user.id, id, reihenfolge);
  if (!universe) notFound();

  const activeOrder = universe.orders.find((order) => order.id === universe.activeOrderId);
  const inUniverse = new Set(universe.entries.map((entry) => entry.titleId));

  // Vorschläge zum Aufnehmen: alles aus der eigenen Bibliothek, was noch fehlt.
  const [libraryTitles, collections] = universe.canWrite
    ? await Promise.all([
        prisma.libraryEntry.findMany({
          where: { userId: user.id, deletedAt: null },
          orderBy: { title: { title: "asc" } },
          select: {
            title: { select: { id: true, title: true, type: true, releaseDate: true } },
          },
        }),
        suggestCollections(user.id),
      ])
    : [[], []];

  const candidates = libraryTitles
    .map((entry) => entry.title)
    .filter((title) => !inUniverse.has(title.id))
    .map((title) => ({
      id: title.id,
      title: title.title,
      type: title.type,
      year: title.releaseDate?.getFullYear() ?? null,
    }));

  return (
    <AppShell user={user} instanceName={settings.instanceName}>
      <header className="mb-5">
        <p className="text-xs font-semibold uppercase tracking-wide text-[var(--fl-faint)]">
          Universum
          {!universe.isOwner && ` · geteilt von ${universe.ownerName}`}
          {!universe.canWrite && " · nur ansehen"}
        </p>
        <h1 className="mt-1 text-2xl font-semibold tracking-tight sm:text-3xl">{universe.name}</h1>
        {universe.description && (
          <p className="mt-1 max-w-2xl text-sm text-[var(--fl-muted)]">{universe.description}</p>
        )}
      </header>

      <section className="fl-card mb-5 p-5" aria-label="Gesamtfortschritt">
        <div className="flex flex-wrap items-end justify-between gap-4">
          <div>
            <p className="text-2xl font-semibold">
              {universe.progress.completed}{" "}
              <span className="text-base font-normal text-[var(--fl-muted)]">
                von {universe.progress.total} abgeschlossen
              </span>
            </p>
            <p className="mt-1 text-sm text-[var(--fl-muted)]">
              {formatMinutes(universe.progress.watchedMinutes)} gesehen
              {universe.progress.remainingMinutes > 0 && (
                <>
                  {" · noch "}
                  <span className="text-[var(--fl-text)]">
                    {formatMinutes(universe.progress.remainingMinutes)}
                  </span>
                  {" bis zum Ende des Universums"}
                </>
              )}
            </p>
          </div>

          {universe.nextUp && (
            <div className="text-right">
              <p className="text-xs font-semibold uppercase tracking-wide text-[var(--fl-faint)]">
                Als Nächstes dran
              </p>
              <Link
                href={`/titel/${universe.nextUp.titleId}`}
                className="fl-gradient-text text-lg font-semibold"
              >
                {universe.nextUp.title}
              </Link>
            </div>
          )}
        </div>

        <div className="mt-4">
          <ProgressBar
            percent={universe.progress.percent}
            label={`${universe.progress.percent} Prozent des Universums abgeschlossen`}
          />
        </div>
      </section>

      <div className="mb-4">
        <OrderTabs universe={universe} canWrite={universe.canWrite} />
        {activeOrder?.kind === "RELEASE" ? (
          <p className="mt-2 text-xs text-[var(--fl-faint)]">
            Diese Reihenfolge ergibt sich aus den Erscheinungsdaten und bleibt damit immer aktuell.
          </p>
        ) : universe.canWrite ? (
          <p className="mt-2 text-xs text-[var(--fl-faint)]">
            Ziehen oder die Pfeile benutzen, um umzusortieren — gespeichert wird sofort.
          </p>
        ) : null}
      </div>

      <div className="grid gap-6 lg:grid-cols-[minmax(0,1fr)_20rem]">
        <div className="order-2 lg:order-1">
          <OrderedList
            universeId={universe.id}
            orderId={universe.activeOrderId}
            entries={universe.entries}
            sortable={activeOrder?.kind === "CUSTOM"}
            canWrite={universe.canWrite}
            nextUpItemId={universe.nextUp?.itemId ?? null}
          />
        </div>

        <aside className="order-1 space-y-5 lg:order-2">
          {universe.canWrite && (
            <div className="fl-card p-4">
              <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-[var(--fl-faint)]">
                Titel aufnehmen
              </h2>
              <AddTitles
                universeId={universe.id}
                candidates={candidates}
                collections={collections}
              />
            </div>
          )}

          {universe.isOwner && (
            <>
              <div className="fl-card p-4">
                <h2 className="mb-3 text-sm font-semibold uppercase tracking-wide text-[var(--fl-faint)]">
                  Teilen
                </h2>
                <SharePanel universe={universe} />
              </div>

              <div className="fl-card p-4">
                <DeleteUniverse universeId={universe.id} name={universe.name} />
              </div>
            </>
          )}
        </aside>
      </div>

      <p className="mt-8 text-sm">
        <Link href="/universen" className="text-[var(--fl-faint)] hover:text-[var(--fl-muted)]">
          ← Alle Universen
        </Link>
      </p>
    </AppShell>
  );
}