/**
 * SEO + agent-discovery routes: robots.txt, sitemap.xml, llms.txt.
 *
 * robots.txt — allow crawlers on public surfaces, disallow admin/settings
 * and API write paths.
 * sitemap.xml — lists the stable public URLs (landing, explore, status,
 * marketplace, graphql explorer, shortcuts, terms). Public repo URLs are
 * not enumerated here — those live behind /explore which crawlers follow.
 * llms.txt — the llmstxt.org convention: a curated map of the platform for
 * AI agents, pointing at the MCP endpoint, API docs, and OAuth discovery so
 * any LLM/agent can orient itself and connect.
 */

import { Hono } from "hono";
import { config } from "../lib/config";

const seo = new Hono();

const ROBOTS = `User-agent: *
Allow: /
Disallow: /admin
Disallow: /settings
Disallow: /api/
Disallow: /login
Disallow: /register
Disallow: /logout
Disallow: /oauth/
Disallow: /*/settings
Disallow: /*.git/

Sitemap: /sitemap.xml
`;
// Note: /llms.txt is intentionally allowed (agent-facing map, public).

seo.get("/robots.txt", (c) => {
  c.header("Content-Type", "text/plain; charset=utf-8");
  c.header("Cache-Control", "public, max-age=3600");
  return c.body(ROBOTS);
});

/**
 * llms.txt (llmstxt.org) — a curated, agent-facing map of the platform.
 * Served at both /llms.txt and /.well-known/llms.txt. Built from the live
 * base URL so links are always absolute + correct for this deployment.
 */
function buildLlmsTxt(): string {
  const b = config.appBaseUrl;
  return `# Gluecron

> AI-native git hosting. Git over HTTPS + SSH, issues, pull requests with AI
> code review and gated auto-merge, CI workflows, package + container
> registries, and a Model Context Protocol (MCP) server so any LLM/agent can
> read and drive repositories directly. Self-hosted-friendly and MCP-native.

## For AI agents

- [MCP server](${b}/mcp): Model Context Protocol endpoint (JSON-RPC 2.0 over HTTP). GET for discovery, POST to call tools. Read tools work anonymously on public repos; write tools require an OAuth/PAT bearer token.
- [OAuth authorization server metadata](${b}/.well-known/oauth-authorization-server): RFC 8414 — how to authenticate (authorize/token endpoints, PKCE S256, scopes).
- [OAuth protected resource metadata](${b}/.well-known/oauth-protected-resource): RFC 9728 — which authorization server guards the MCP resource.

## API

- [REST + GraphQL API docs](${b}/api/docs): endpoints, authentication, and scopes for programmatic access.
- [GraphQL explorer](${b}/api/graphql): read queries over repos, users, issues, and search.

## Get started

- [Sign up](${b}/register): create an account.
- [Explore public repos](${b}/explore): browse what's hosted here.
- [Import from GitHub](${b}/import): mirror an existing repo in one step.
- [Install script](${b}/install): one-line setup for the CLI + Claude Desktop MCP config.

## Conventions

- Personal access tokens are prefixed \`glc_\`; OAuth access tokens \`glct_\`. Pass either as \`Authorization: Bearer <token>\`.
- Repos are addressed as \`${b}/<owner>/<repo>\`; clone over HTTPS at \`${b}/<owner>/<repo>.git\`.
`;
}

seo.get("/llms.txt", (c) => {
  c.header("Content-Type", "text/plain; charset=utf-8");
  c.header("Cache-Control", "public, max-age=3600");
  return c.body(buildLlmsTxt());
});

seo.get("/.well-known/llms.txt", (c) => {
  c.header("Content-Type", "text/plain; charset=utf-8");
  c.header("Cache-Control", "public, max-age=3600");
  return c.body(buildLlmsTxt());
});

const STATIC_PATHS = [
  "/",
  "/explore",
  "/marketplace",
  "/status",
  "/help",
  "/shortcuts",
  "/api/graphql",
  "/terms",
  "/privacy",
  "/acceptable-use",
];

seo.get("/sitemap.xml", (c) => {
  const origin = new URL(c.req.url).origin;
  const lastmod = new Date().toISOString().slice(0, 10);
  const urls = STATIC_PATHS.map(
    (p) =>
      `<url><loc>${origin}${p}</loc><lastmod>${lastmod}</lastmod></url>`
  ).join("\n  ");
  const body = `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  ${urls}
</urlset>
`;
  c.header("Content-Type", "application/xml; charset=utf-8");
  c.header("Cache-Control", "public, max-age=3600");
  return c.body(body);
});

export default seo;