import { bibtexFor, getPaperBySlug, plainCitationFor, risFor } from "@autoscholar/core";
import { parseBib } from "@autoscholar/qa";
import { publicArtifactKey } from "@autoscholar/storage";
import type { Metadata } from "next";
import Link from "next/link";
import { notFound } from "next/navigation";
import { CopyButton } from "@/components/CopyButton";
import { Disclosure } from "@/components/Disclosure";
import { PaperCard } from "@/components/PaperCard";
import { PdfViewer } from "@/components/PdfViewer";
import { StatusBadge } from "@/components/StatusBadge";
import { Tabs } from "@/components/Tabs";
import { disciplineLabel, fmtBytes, fmtDate, modeLabel, shortHash } from "@/lib/format";
import { t } from "@/lib/i18n";
import { db, storage } from "@/lib/server/db";

export const dynamic = "force-dynamic";

async function load(slug: string) {
  try {
    return await getPaperBySlug(db(), slug);
  } catch {
    return null;
  }
}

export async function generateMetadata({ params }: { params: Promise<{ slug: string }> }): Promise<Metadata> {
  const { slug } = await params;
  const p = await load(slug);
  if (!p) return { title: "Paper not found" };
  const base = process.env.APP_BASE_URL ?? "http://localhost:8470";
  return {
    title: p.version.title,
    description: p.version.abstract.slice(0, 300),
    alternates: { canonical: `/research/${p.paper.slug}` },
    robots: p.paper.synthetic ? { index: false, follow: false } : undefined,
    openGraph: {
      title: p.version.title,
      description: p.version.abstract.slice(0, 300),
      type: "article",
      url: `${base}/research/${p.paper.slug}`,
      publishedTime: p.version.publishedAt.toISOString(),
    },
    other: {
      citation_title: p.version.title,
      citation_publication_date: p.version.publishedAt.toISOString().slice(0, 10),
      citation_technical_report_number: p.paper.publicId,
      citation_technical_report_institution: "AutoScholar.ai",
      citation_pdf_url: `${base}${p.version.pdfPublicPath}`,
    },
  };
}

type ArtifactEntry = {
  path: string;
  kind: string;
  sha256: string;
  bytes: number;
  contentType: string;
  publicPath: string;
};
function Dl({ a }: { a: ArtifactEntry }) {
  return (
    <li className="flex items-center justify-between gap-3 py-1.5 text-sm">
      <a href={`${a.publicPath}?download=1`} className="font-mono text-xs break-all">
        {a.path}
      </a>
      <span className="subtle whitespace-nowrap text-xs">
        {fmtBytes(a.bytes)} · {shortHash(a.sha256, 8)}
      </span>
    </li>
  );
}

export default async function PaperPage({ params }: { params: Promise<{ slug: string }> }) {
  const { slug } = await params;
  const p = await load(slug);
  if (!p) notFound();
  const base = process.env.APP_BASE_URL ?? "http://localhost:8470";
  const v = p.version;
  const meta = v.metadata as Record<string, unknown>;
  const withdrawn = meta.artifactsWithdrawn === true;
  const set = withdrawn ? [] : v.artifactSet;
  const url = `${base}/research/${p.paper.slug}`;
  const pub = new Date(v.publishedAt);
  const cite = {
    publicId: p.paper.publicId,
    title: v.title,
    year: pub.getUTCFullYear(),
    month: pub.getUTCMonth() + 1,
    versionNo: v.versionNo,
    url,
    keywords: v.keywords,
    abstract: v.abstract,
  };
  const figures = set.filter((a) => a.kind === "figure" && /\.(png|svg)$/i.test(a.path));
  const pdfFigures = set.filter((a) => a.kind === "figure" && /\.pdf$/i.test(a.path));
  const tex = set.filter((a) => a.kind === "manuscript" && /\.(tex|bib|cls|sty)$/i.test(a.path));
  const code = set.filter((a) => a.kind === "code");
  const data = set.filter((a) => a.kind === "data");
  const results = set.filter((a) => a.kind === "result" || a.kind === "table");
  const prov = (v.provenance ?? {}) as Record<string, unknown>;
  const qa = (v.qaSummary ?? {}) as {
    gates?: Array<{ gate: string; status: string; severity: string; message: string }>;
    warnings?: string[];
    policyVersion?: string;
    evaluatedAt?: string;
  };
  let bib: ReturnType<typeof parseBib> = [];
  const bibEntry = set.find((a) => a.path === "sources/references.bib");
  if (bibEntry) {
    try {
      bib = parseBib(
        (await storage().get(publicArtifactKey(p.paper.publicId, v.versionNo, bibEntry.path))).toString(
          "utf8",
        ),
      );
    } catch {
      bib = [];
    }
  }
  const jsonLd = {
    "@context": "https://schema.org",
    "@type": "ScholarlyArticle",
    headline: v.title,
    name: v.title,
    abstract: v.abstract,
    keywords: v.keywords.join(", "),
    datePublished: v.publishedAt.toISOString(),
    dateModified: p.paper.updatedAt.toISOString(),
    author: { "@type": "Organization", name: "AutoScholar (AI-generated research)", url: base },
    publisher: { "@type": "Organization", name: "AutoScholar.ai", url: base },
    identifier: p.paper.publicId,
    url,
    isAccessibleForFree: true,
    ...(set.length
      ? {
          encoding: {
            "@type": "MediaObject",
            contentUrl: `${base}${v.pdfPublicPath}`,
            encodingFormat: "application/pdf",
          },
        }
      : {}),
    about: disciplineLabel(p.paper.discipline),
    version: v.versionNo,
    ...(p.retraction ? { creativeWorkStatus: "Retracted" } : {}),
  };
  return (
    <article className="space-y-10">
      {/* biome-ignore lint/security/noDangerouslySetInnerHtml: JSON-LD built from server data */}
      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(jsonLd) }} />
      {p.retraction && (
        <div
          role="alert"
          className="rounded-md border p-4"
          style={{
            borderColor: "var(--color-danger-500)",
            background: "color-mix(in oklab, var(--color-danger-500) 8%, transparent)",
          }}
        >
          <p className="font-semibold">
            This working paper was retracted on {fmtDate(p.retraction.retractedAt)}.
          </p>
          <p className="mt-1 text-sm">{p.retraction.notice}</p>
          {withdrawn && (
            <p className="muted mt-1 text-sm">
              Its artifacts have been withdrawn from delivery. This page remains as a permanent record.
            </p>
          )}
        </div>
      )}
      <header className="grid gap-6 md:grid-cols-12">
        <div className="md:col-span-8">
          <div className="flex flex-wrap items-center gap-2 text-xs">
            <span className="font-mono">{p.paper.publicId}</span>
            <span className="subtle">·</span>
            <span>Version {v.versionNo}</span>
            <StatusBadge status={p.paper.status} />
            {p.paper.synthetic && <span className="badge">staging sample — not a real paper</span>}
          </div>
          <h1 className="serif mt-3 text-3xl font-semibold leading-tight sm:text-4xl">{v.title}</h1>
          <p className="mt-4 text-sm">
            <span className="font-medium">{t("byline")}</span>
            <span className="muted"> · Research computed on MacLustr</span>
          </p>
          <dl className="muted mt-4 grid grid-cols-2 gap-x-6 gap-y-1 text-sm sm:grid-cols-4">
            <div>
              <dt className="label">Released</dt>
              <dd>{fmtDate(p.paper.firstPublishedAt)}</dd>
            </div>
            <div>
              <dt className="label">Revised</dt>
              <dd>{fmtDate(v.publishedAt)}</dd>
            </div>
            <div>
              <dt className="label">Subject</dt>
              <dd>
                <Link href={`/research?discipline=${p.paper.discipline}`}>
                  {disciplineLabel(p.paper.discipline)}
                </Link>
              </dd>
            </div>
            <div>
              <dt className="label">Methodology</dt>
              <dd>{modeLabel(p.paper.researchMode)}</dd>
            </div>
          </dl>
          <ul className="mt-4 flex flex-wrap gap-2" aria-label="Keywords">
            {v.keywords.map((k) => (
              <li key={k}>
                <Link href={`/research?q=${encodeURIComponent(k)}`} className="badge no-underline">
                  {k}
                </Link>
              </li>
            ))}
          </ul>
        </div>
        <aside className="surface p-4 text-sm md:col-span-4">
          <p className="label mb-2">Downloads</p>
          {withdrawn ? (
            <p className="muted">Artifacts withdrawn.</p>
          ) : (
            <ul className="space-y-2">
              <li>
                <a className="btn btn-primary w-full" href={`${v.pdfPublicPath}?download=1`}>
                  PDF
                </a>
              </li>
              {tex.length > 0 && (
                <li>
                  <a
                    className="btn w-full"
                    href={`${set.find((a) => a.path === "manuscript/main.tex")?.publicPath ?? tex[0]!.publicPath}?download=1`}
                  >
                    LaTeX source
                  </a>
                </li>
              )}
              {code.length > 0 && (
                <li>
                  <a className="btn w-full" href="#code">
                    Code ({code.length} files)
                  </a>
                </li>
              )}
              {data.length > 0 && (
                <li>
                  <a className="btn w-full" href="#data">
                    Data ({data.length} files)
                  </a>
                </li>
              )}
            </ul>
          )}
          <div className="mt-4">
            <Disclosure compact />
          </div>
        </aside>
      </header>

      <section aria-labelledby="abstract" className="grid gap-8 md:grid-cols-12">
        <div className="md:col-span-8">
          <h2 id="abstract" className="serif text-xl font-semibold">
            Abstract
          </h2>
          <p className="prose-paper mt-3">{v.abstract}</p>
          {Array.isArray(meta.contributions) && (meta.contributions as string[]).length > 0 && (
            <>
              <h2 className="serif mt-8 text-xl font-semibold">Key contributions</h2>
              <ol className="prose-paper mt-3 list-decimal pl-5">
                {(meta.contributions as string[]).map((c) => (
                  <li key={c}>{c}</li>
                ))}
              </ol>
            </>
          )}
          {typeof meta.methods === "string" && meta.methods && (
            <>
              <h2 className="serif mt-8 text-xl font-semibold">Methods</h2>
              <p className="prose-paper mt-3">{meta.methods}</p>
            </>
          )}
          {typeof meta.mainResults === "string" && meta.mainResults && (
            <>
              <h2 className="serif mt-8 text-xl font-semibold">Main results</h2>
              <p className="prose-paper mt-3">{meta.mainResults}</p>
            </>
          )}
          {typeof meta.limitations === "string" && meta.limitations && (
            <>
              <h2 className="serif mt-8 text-xl font-semibold">Limitations</h2>
              <p className="prose-paper mt-3">{meta.limitations}</p>
            </>
          )}
        </div>
        <div className="space-y-4 md:col-span-4">
          <div className="surface p-4 text-sm">
            <p className="label mb-2">Research status</p>
            <ul className="space-y-1">
              <li>AutoScholar working paper (preprint)</li>
              <li>Produced autonomously by an AI research workflow</li>
              <li>
                Automated critical review; <strong>not</strong> human peer review
              </li>
              <li>
                Deterministic quality gates:{" "}
                {qa.gates
                  ? `${qa.gates.filter((g) => g.status === "pass").length}/${qa.gates.filter((g) => g.status !== "skip").length} passed`
                  : "see provenance"}
              </li>
              <li>DOI: none (not registered)</li>
            </ul>
          </div>
          {p.summary.topics.length > 0 && (
            <div className="surface p-4 text-sm">
              <p className="label mb-2">Topics</p>
              <ul className="flex flex-wrap gap-2">
                {p.summary.topics.map((x) => (
                  <li key={x.slug}>
                    <Link href={`/topics/${x.slug}`} className="badge no-underline">
                      {x.name}
                    </Link>
                  </li>
                ))}
              </ul>
            </div>
          )}
        </div>
      </section>

      {!withdrawn && (
        <section aria-labelledby="pdf">
          <h2 id="pdf" className="serif text-xl font-semibold">
            Read the paper
          </h2>
          <div className="mt-3">
            <PdfViewer
              src={v.pdfPublicPath}
              title={`${p.paper.publicId} v${v.versionNo} — ${v.title}`}
              downloadHref={`${v.pdfPublicPath}?download=1`}
            />
          </div>
        </section>
      )}

      {(figures.length > 0 || pdfFigures.length > 0) && (
        <section aria-labelledby="figures">
          <h2 id="figures" className="serif text-xl font-semibold">
            Figures
          </h2>
          <ul className="mt-3 grid gap-4 sm:grid-cols-2">
            {figures.map((f) => (
              <li key={f.path} className="surface p-3">
                {/* biome-ignore lint/performance/noImgElement: artifact images are served immutable from this origin */}
                <img
                  src={f.publicPath}
                  alt={f.path.split("/").pop() ?? "figure"}
                  className="w-full"
                  loading="lazy"
                />
                <p className="subtle mt-2 font-mono text-xs">{f.path.replace("results/figures/", "")}</p>
              </li>
            ))}
            {pdfFigures.map((f) => (
              <li key={f.path} className="surface p-3 text-sm">
                <a href={`${f.publicPath}?download=1`}>{f.path.replace("results/figures/", "")}</a>{" "}
                <span className="subtle">(vector PDF, {fmtBytes(f.bytes)})</span>
              </li>
            ))}
          </ul>
        </section>
      )}

      {bib.length > 0 && (
        <section aria-labelledby="refs">
          <h2 id="refs" className="serif text-xl font-semibold">
            References ({bib.length})
          </h2>
          <p className="muted mt-1 text-xs">
            Every reference was verified against a scholarly registry before publication; identifiers link to
            the source of record.
          </p>
          <ol className="mt-3 space-y-2 text-sm">
            {bib.map((b) => {
              const f = b.fields;
              const href = f.doi
                ? `https://doi.org/${f.doi.replace(/^https?:\/\/doi\.org\//, "")}`
                : (f.url ?? (f.eprint ? `https://arxiv.org/abs/${f.eprint}` : undefined));
              return (
                <li key={b.key} id={`ref-${b.key}`} className="border-b pb-2 hairline">
                  <span>{f.author ? `${f.author.replace(/\s+and\s+/g, ", ")}. ` : ""}</span>
                  {f.year && <span>({f.year}). </span>}
                  <span className="italic">{f.title?.replace(/[{}]/g, "")}</span>
                  {f.journal && <span>. {f.journal}</span>}
                  {f.booktitle && <span>. In {f.booktitle}</span>}
                  {f.volume && <span>, {f.volume}</span>}
                  {f.pages && <span>, {f.pages}</span>}.{" "}
                  {href && (
                    <a href={href} rel="noopener noreferrer" className="font-mono text-xs break-all">
                      {f.doi ? `doi:${f.doi}` : href}
                    </a>
                  )}
                </li>
              );
            })}
          </ol>
        </section>
      )}

      {(code.length > 0 || data.length > 0 || results.length > 0) && (
        <section aria-labelledby="repro" className="grid gap-6 md:grid-cols-3">
          <h2 id="repro" className="serif text-xl font-semibold md:col-span-3">
            Code, data and results
          </h2>
          {code.length > 0 && (
            <div id="code" className="surface p-4">
              <p className="label mb-1">Code</p>
              <ul>
                {code.map((a) => (
                  <Dl key={a.path} a={a} />
                ))}
              </ul>
            </div>
          )}
          {data.length > 0 && (
            <div id="data" className="surface p-4">
              <p className="label mb-1">Data</p>
              <ul>
                {data.map((a) => (
                  <Dl key={a.path} a={a} />
                ))}
              </ul>
            </div>
          )}
          {results.length > 0 && (
            <div className="surface p-4">
              <p className="label mb-1">Results and tables</p>
              <ul>
                {results.map((a) => (
                  <Dl key={a.path} a={a} />
                ))}
              </ul>
            </div>
          )}
        </section>
      )}

      <section aria-labelledby="reproducibility" className="grid gap-6 md:grid-cols-2">
        <div>
          <h2 id="reproducibility" className="serif text-xl font-semibold">
            Reproducibility
          </h2>
          <dl className="mt-3 grid grid-cols-[max-content_1fr] gap-x-4 gap-y-1 text-sm">
            <dt className="label">Data availability</dt>
            <dd>{(meta.dataAvailability as string) || "Not applicable or not stated."}</dd>
            <dt className="label">Code availability</dt>
            <dd>{(meta.codeAvailability as string) || "Not applicable or not stated."}</dd>
            <dt className="label">Ethics</dt>
            <dd>
              {(meta.ethics as string) ||
                "No restricted activities; public data, mathematics or simulations only."}
            </dd>
            <dt className="label">Toolchain</dt>
            <dd className="font-mono text-xs">
              {prov.toolchain && Object.keys(prov.toolchain as object).length
                ? Object.entries(prov.toolchain as Record<string, string>)
                    .map(([k, val]) => `${k} ${val}`)
                    .join(" · ")
                : "not recorded"}
            </dd>
            <dt className="label">LaTeX source</dt>
            <dd>
              {tex.length
                ? "Released; the PDF was rebuilt from it in a clean environment during verification."
                : "Not released."}
            </dd>
            <dt className="label">Verified</dt>
            <dd>
              {qa.evaluatedAt ? `${fmtDate(qa.evaluatedAt)} under quality policy ${qa.policyVersion}` : "—"}
            </dd>
          </dl>
          {qa.warnings && qa.warnings.length > 0 && (
            <details className="mt-3 text-sm">
              <summary className="cursor-pointer">
                Non-blocking warnings recorded at verification ({qa.warnings.length})
              </summary>
              <ul className="muted mt-2 list-disc pl-5">
                {qa.warnings.map((w) => (
                  <li key={w}>{w}</li>
                ))}
              </ul>
            </details>
          )}
        </div>
        <div>
          <h2 className="serif text-xl font-semibold">Provenance</h2>
          <dl className="mt-3 grid grid-cols-[max-content_1fr] gap-x-4 gap-y-1 text-sm">
            <dt className="label">Model</dt>
            <dd className="font-mono text-xs">{String(prov.model ?? "—")}</dd>
            <dt className="label">Reviewer model</dt>
            <dd className="font-mono text-xs">{String(prov.reviewerModel ?? "—")}</dd>
            <dt className="label">Instruction version</dt>
            <dd className="font-mono text-xs">
              v{String(prov.instructionVersion ?? "?")} · {shortHash(prov.instructionSha256 as string)}
            </dd>
            <dt className="label">Manifest digest</dt>
            <dd className="font-mono text-xs">{shortHash(prov.manifestSha256 as string)}</dd>
            <dt className="label">Execution</dt>
            <dd className="text-xs">
              {prov.startedAt
                ? `${fmtDate(prov.startedAt as string)} → ${prov.completedAt ? fmtDate(prov.completedAt as string) : "?"}`
                : "—"}{" "}
              · {String(prov.infrastructure ?? "MacLustr")}
            </dd>
            <dt className="label">Quality gates</dt>
            <dd>
              {qa.gates && qa.gates.length > 0 ? (
                <details className="text-xs">
                  <summary className="cursor-pointer">{qa.gates.length} gates evaluated</summary>
                  <ul className="mt-1 space-y-0.5">
                    {qa.gates.map((g) => (
                      <li key={g.gate}>
                        <StatusBadge status={g.status} /> <span className="font-mono">{g.gate}</span>{" "}
                        <span className="muted">— {g.message}</span>
                      </li>
                    ))}
                  </ul>
                </details>
              ) : (
                "—"
              )}
            </dd>
          </dl>
          <p className="subtle mt-2 text-xs">
            Artifact digests (SHA-256) are listed with each download; the full list is in
            provenance/checksums.sha256.
          </p>
        </div>
      </section>

      <section aria-labelledby="cite">
        <h2 id="cite" className="serif text-xl font-semibold">
          Cite this working paper
        </h2>
        <div className="mt-3">
          <Tabs
            tabs={[
              {
                label: "BibTeX",
                content: (
                  <div>
                    <pre className="surface overflow-auto p-4 text-xs">{bibtexFor(cite)}</pre>
                    <div className="mt-2 flex gap-2">
                      <CopyButton text={bibtexFor(cite)} />
                      <a className="btn btn-sm" href={`/research/${p.paper.slug}/cite.bib`}>
                        Download .bib
                      </a>
                    </div>
                  </div>
                ),
              },
              {
                label: "RIS",
                content: (
                  <div>
                    <pre className="surface overflow-auto p-4 text-xs">{risFor(cite)}</pre>
                    <div className="mt-2 flex gap-2">
                      <CopyButton text={risFor(cite)} />
                      <a className="btn btn-sm" href={`/research/${p.paper.slug}/cite.ris`}>
                        Download .ris
                      </a>
                    </div>
                  </div>
                ),
              },
              {
                label: "Plain text",
                content: (
                  <div>
                    <p className="surface p-4 text-sm">{plainCitationFor(cite)}</p>
                    <div className="mt-2 flex gap-2">
                      <CopyButton text={plainCitationFor(cite)} />
                      <a className="btn btn-sm" href={`/research/${p.paper.slug}/cite.txt`}>
                        Download .txt
                      </a>
                    </div>
                  </div>
                ),
              },
            ]}
          />
        </div>
      </section>

      <section aria-labelledby="history" className="grid gap-6 md:grid-cols-2">
        <div>
          <h2 id="history" className="serif text-xl font-semibold">
            Version history
          </h2>
          <ol className="mt-3 space-y-2 text-sm">
            {p.versions.map((x) => (
              <li key={x.id} className="surface flex items-start justify-between gap-3 p-3">
                <div>
                  <span className="font-medium">Version {x.versionNo}</span>{" "}
                  <span className="muted">· {fmtDate(x.publishedAt)}</span>
                  <p className="muted mt-1">{x.changelog}</p>
                </div>
                {!withdrawn && (
                  <a className="btn btn-sm" href={`${x.pdfPublicPath}?download=1`}>
                    PDF v{x.versionNo}
                  </a>
                )}
              </li>
            ))}
          </ol>
        </div>
        <div>
          <h2 className="serif text-xl font-semibold">Corrections and notices</h2>
          {p.corrections.length === 0 && !p.retraction ? (
            <p className="muted mt-3 text-sm">No corrections have been issued.</p>
          ) : (
            <ul className="mt-3 space-y-2 text-sm">
              {p.corrections.map((c) => (
                <li key={c.id} className="surface p-3">
                  <span className="font-medium">
                    Correction v{c.fromVersionNo} → v{c.toVersionNo}
                  </span>{" "}
                  <span className="muted">· {fmtDate(c.createdAt)}</span>
                  <p className="mt-1">{c.notice}</p>
                </li>
              ))}
              {p.retraction && (
                <li className="surface p-3">
                  <span className="font-medium">Retraction</span>{" "}
                  <span className="muted">· {fmtDate(p.retraction.retractedAt)}</span>
                  <p className="mt-1">{p.retraction.notice}</p>
                </li>
              )}
            </ul>
          )}
        </div>
      </section>

      {p.related.length > 0 && (
        <section aria-labelledby="related">
          <h2 id="related" className="serif text-xl font-semibold">
            Related working papers
          </h2>
          <p className="muted mt-1 text-xs">
            Selected by shared discipline or keywords recorded in verified metadata.
          </p>
          <ul className="mt-3 grid gap-4 md:grid-cols-2">
            {p.related.map((r) => (
              <li key={r.publicId}>
                <PaperCard p={r} />
              </li>
            ))}
          </ul>
        </section>
      )}
      <Disclosure />
    </article>
  );
}