import { listSeries, searchPapers } from "@autoscholar/core";
import { PublicSearchQuery } from "@autoscholar/schemas";
import type { Metadata } from "next";
import { Disclosure } from "@/components/Disclosure";
import { EmptyResearchState, EmptyState } from "@/components/EmptyState";
import { FilterSidebar, LibraryFilters } from "@/components/LibraryFilters";
import { Pagination } from "@/components/Pagination";
import { PaperCard } from "@/components/PaperCard";
import { t } from "@/lib/i18n";
import { db } from "@/lib/server/db";

export const dynamic = "force-dynamic";
export const metadata: Metadata = {
  title: "Research library",
  description: "Searchable library of AutoScholar working papers.",
  alternates: { canonical: "/research" },
};

export default async function ResearchPage({
  searchParams,
}: {
  searchParams: Promise<Record<string, string | string[] | undefined>>;
}) {
  const sp = await searchParams;
  const raw: Record<string, string | undefined> = {};
  for (const [k, v] of Object.entries(sp)) raw[k] = Array.isArray(v) ? v[0] : v;
  for (const k of Object.keys(raw)) if (raw[k] === "") delete raw[k];
  const parsed = PublicSearchQuery.safeParse(raw);
  const q = parsed.success ? parsed.data : PublicSearchQuery.parse({});
  const d = db();
  const res = await searchPapers(d, q);
  const series = await listSeries(d);
  const hrefFor = (p: number) => {
    const u = new URLSearchParams();
    for (const [k, v] of Object.entries(raw)) if (v && k !== "page") u.set(k, v);
    u.set("page", String(p));
    return `/research?${u.toString()}`;
  };
  const anyFilter = Object.keys(raw).some((k) => !["page", "sort", "pageSize"].includes(k));
  return (
    <div className="container-x section-tight">
      <header className="max-w-2xl">
        <p className="eyebrow">Library</p>
        <h1 className="title-1 mt-2">Working papers</h1>
        <p className="muted mt-2 text-sm leading-relaxed">
          Search titles, abstracts, keywords and verified metadata. Every entry is an AI-generated working
          paper with its evidence attached.
        </p>
      </header>
      {!parsed.success && (
        <p role="alert" className="mt-4 text-sm" style={{ color: "var(--color-danger-500)" }}>
          Some filters were invalid and have been ignored.
        </p>
      )}
      <div className="mt-6 grid gap-8 lg:grid-cols-12">
        <div className="lg:col-span-9 lg:col-start-4 lg:row-start-1">
          <LibraryFilters q={raw} series={series} total={res.total} />
        </div>
        <aside
          className="hidden lg:col-span-3 lg:col-start-1 lg:row-span-2 lg:row-start-1 lg:block"
          aria-label="Filters"
        >
          <FilterSidebar q={raw} series={series} />
        </aside>
        <div className="lg:col-span-9 lg:col-start-4">
          {res.items.length === 0 ? (
            anyFilter ? (
              <EmptyState title={t("search.empty")}>
                <a href="/research">Clear all filters</a>
              </EmptyState>
            ) : (
              <EmptyResearchState />
            )
          ) : (
            <ul className="border-t hairline">
              {res.items.map((p, i) => (
                <li key={p.publicId}>
                  <PaperCard p={p} variant="row" index={i} />
                </li>
              ))}
            </ul>
          )}
          <div className="mt-6 flex items-center justify-between gap-4">
            <Pagination page={res.page} pageSize={res.pageSize} total={res.total} hrefFor={hrefFor} />
          </div>
          <div className="mt-8">
            <Disclosure compact />
          </div>
        </div>
      </div>
    </div>
  );
}