import { CodeBlock } from '@/components/code-block';
import { JsonLd } from '@/components/json-ld';
import { Logo } from '@/components/logo';
import { type TemplateDetail, fetchTemplate } from '@/lib/templates-server';
import { pageMetadata, templateJsonLd } from '@/lib/seo';
import type { Metadata } from 'next';
import Link from 'next/link';
import { notFound } from 'next/navigation';
import { Activity, ExternalLink, GitFork, ShieldCheck } from 'lucide-react';
import { CollapsibleCode } from './collapsible-code';

// Server-rendered for SEO: per-template <title>, description, OpenGraph and
// SoftwareApplication JSON-LD. The only interactive piece (the code-audit
// toggle) lives in a client island.

interface PageProps {
  params: Promise<{ slug: string }>;
}

export async function generateMetadata({ params }: PageProps): Promise<Metadata> {
  const { slug } = await params;
  const t = await fetchTemplate(slug);
  if (!t) {
    return pageMetadata({
      title: 'Template not found',
      description: 'This MCP server template is not available.',
      path: `/templates/${slug}`,
    });
  }
  return pageMetadata({
    title: `${t.title} — MCP server for Claude, Cursor & ChatGPT`,
    description:
      t.shortDescription.length > 0
        ? t.shortDescription
        : `Fork the ${t.title} MCP server and deploy your own OAuth-protected copy in seconds.`,
    path: `/templates/${slug}`,
  });
}

export default async function TemplateDetailPage({ params }: PageProps) {
  const { slug } = await params;
  const template: TemplateDetail | null = await fetchTemplate(slug);
  if (!template) notFound();

  const forkHref = `/servers/new?template=${template.slug}`;

  return (
    <div className="flex min-h-screen flex-col">
      <JsonLd
        data={templateJsonLd({
          slug: template.slug,
          title: template.title,
          description: template.shortDescription,
          category: template.category,
          tools: template.toolsSchema.map((t) => t.name),
          author: template.ownerName ?? template.ownerOrgName,
        })}
      />
      <header className="sticky top-0 z-50 border-b border-[--color-border] bg-[--color-bg]/85 backdrop-blur-md">
        <div className="mx-auto flex h-12 max-w-5xl items-center justify-between px-6">
          <div className="flex items-center gap-3">
            <Logo />
            <span className="text-[12.5px] text-[--color-fg-subtle]">
              /{' '}
              <Link href="/templates" className="hover:text-[--color-fg]">
                templates
              </Link>{' '}
              / {template.slug}
            </span>
          </div>
          <Link
            href="/login"
            className="rounded-md bg-[--color-accent] px-3 py-1.5 text-[12.5px] font-medium text-white transition-colors duration-200 hover:bg-[#5557e8]"
          >
            Start building
          </Link>
        </div>
      </header>

      <main className="mx-auto w-full max-w-5xl flex-1 px-6 py-10">
        <div className="grid gap-10 lg:grid-cols-[1fr_300px]">
          <div>
            <div className="flex items-center gap-2">
              <span className="mono rounded-full border border-[--color-border] bg-[--color-bg-subtle] px-2 py-0.5 text-[11px] text-[--color-fg-muted]">
                {template.category}
              </span>
              {template.verified && (
                <span className="inline-flex items-center gap-1 rounded-full border border-[--color-accent]/40 bg-[--color-accent]/10 px-2 py-0.5 text-[11px] font-medium text-[--color-accent]">
                  <ShieldCheck size={10} /> verified
                </span>
              )}
            </div>
            <h1 className="mt-3 text-[28px] font-semibold tracking-tight">{template.title}</h1>
            <p className="mt-2 text-[14px] leading-relaxed text-[--color-fg-muted]">
              {template.shortDescription}
            </p>

            {template.longDescription && (
              <p className="mt-4 whitespace-pre-wrap text-[13.5px] leading-relaxed text-[--color-fg]">
                {template.longDescription}
              </p>
            )}

            <section className="mt-10">
              <h2 className="text-[16px] font-semibold tracking-tight">
                Tools ({template.toolsSchema.length})
              </h2>
              <div className="mt-3 space-y-3">
                {template.toolsSchema.map((tool) => {
                  const paramCount = Object.keys(tool.inputSchema ?? {}).length;
                  return (
                    <div key={tool.name} className="panel p-3">
                      <div className="flex items-baseline gap-2">
                        <span className="mono text-[13px] font-semibold">{tool.name}</span>
                        <span className="mono text-[10.5px] text-[--color-fg-subtle]">
                          {paramCount} param{paramCount === 1 ? '' : 's'}
                        </span>
                      </div>
                      <p className="mt-1.5 text-[12.5px] text-[--color-fg-muted]">
                        {tool.description}
                      </p>
                      {paramCount > 0 && (
                        <div className="mt-2">
                          <CodeBlock
                            label="input schema"
                            code={JSON.stringify(tool.inputSchema, null, 2)}
                          />
                        </div>
                      )}
                    </div>
                  );
                })}
              </div>
            </section>

            {template.requiredSecrets.length > 0 && (
              <section className="mt-10">
                <h2 className="text-[16px] font-semibold tracking-tight">
                  Credentials you&apos;ll need
                </h2>
                <p className="mt-1 text-[12.5px] text-[--color-fg-muted]">
                  When you fork, the wizard asks you for these. Your values stay in your container —
                  the template author never sees them.
                </p>
                <div className="mt-3 space-y-2">
                  {template.requiredSecrets.map((s) => (
                    <div key={s.key} className="panel p-3">
                      <div className="flex items-baseline justify-between gap-2">
                        <span className="mono text-[13px] font-semibold">{s.key}</span>
                        {s.howToGetUrl && (
                          <a
                            href={s.howToGetUrl}
                            target="_blank"
                            rel="noreferrer"
                            className="inline-flex items-center gap-1 text-[11.5px] text-[--color-accent] hover:underline"
                          >
                            How to get one <ExternalLink size={10} />
                          </a>
                        )}
                      </div>
                      <p className="mt-1.5 text-[12.5px] text-[--color-fg-muted]">{s.description}</p>
                    </div>
                  ))}
                </div>
              </section>
            )}

            <CollapsibleCode code={template.generatedCode} />
          </div>

          <aside className="space-y-3">
            <div className="panel p-4">
              {template.status === 'public' ? (
                <>
                  <Link
                    href={forkHref}
                    className="inline-flex h-11 w-full items-center justify-center rounded-md bg-[--color-accent] text-[13.5px] font-medium text-white transition-colors duration-200 hover:bg-[#5557e8]"
                  >
                    Fork this template →
                  </Link>
                  <p className="mt-2 text-[11.5px] text-[--color-fg-muted]">
                    One click → your own isolated container.
                  </p>
                </>
              ) : (
                <div className="rounded-md border border-amber-400/30 bg-amber-400/5 p-2.5 text-[12px] text-amber-200/90">
                  This template is <span className="mono">{template.status}</span> — not forkable.
                </div>
              )}
            </div>

            <div className="panel p-3 text-[12px]">
              <Row label="Forks" value={template.forkCount} icon={<GitFork size={11} />} />
              <Row
                label="Live deployments"
                value={template.activeDeployments}
                icon={<Activity size={11} />}
              />
              <Row label="Category" value={template.category} mono />
              <Row label="Published" value={new Date(template.createdAt).toLocaleDateString()} />
              <Row
                label="Author"
                value={template.ownerName ?? template.ownerOrgName ?? 'anonymous'}
              />
            </div>

            <div className="panel p-3 text-[11.5px] leading-relaxed text-[--color-fg-muted]">
              <strong className="text-[--color-fg]">Forking is safe.</strong> Your fork gets its own
              Docker container, its own port, its own AES-256-encrypted secrets. The template author
              has no visibility into your traffic or data.
            </div>
          </aside>
        </div>
      </main>
    </div>
  );
}

function Row({
  label,
  value,
  mono,
  icon,
}: {
  label: string;
  value: string | number;
  mono?: boolean;
  icon?: React.ReactNode;
}) {
  return (
    <div className="flex items-baseline justify-between gap-3 py-1">
      <span className="text-[--color-fg-subtle]">{label}</span>
      <span className={`inline-flex items-center gap-1.5 ${mono ? 'mono' : ''} text-[--color-fg]`}>
        {icon}
        {value}
      </span>
    </div>
  );
}
