import { defineConfig } from 'astro/config';
import mdx from '@astrojs/mdx';
import sitemap from '@astrojs/sitemap';

// Canonical origin. Drives canonical URLs, OG tags, and the sitemap.
const SITE = process.env.PUBLIC_SITE_URL ?? 'https://adr.smlcompany.ca';

export default defineConfig({
  site: SITE,

  // Static output is the point of this rebuild — see docs/04-seo-spec.md.
  // Do not switch to a server adapter without an AGENTS.md Change Log entry.
  output: 'static',

  // Directory-style URLs with a trailing slash, matched by the CloudFront
  // trailing-slash function. See docs/06-deployment.md.
  trailingSlash: 'always',
  build: { format: 'directory', inlineStylesheets: 'auto' },

  integrations: [
    mdx(),
    sitemap({
      filter: (page) => !page.includes('/legal/'),
      changefreq: 'monthly',
      lastmod: new Date(),
    }),
  ],

  image: {
    // Explicit dimensions everywhere; never base64-inline an image.
    service: { entrypoint: 'astro/assets/services/sharp' },
  },

  // Opt-in only. `prefetchAll: true` with the viewport strategy injects Astro's
  // prefetch script and an IntersectionObserver into EVERY page and speculatively
  // fetches every link that scrolls into view — against CLAUDE.md's "default to
  // zero JS" and AGENTS.md §7's "most pages ship zero JS", with no Change Log
  // entry justifying it. Add data-astro-prefetch to individual links that earn it.
  prefetch: { prefetchAll: false, defaultStrategy: 'hover' },
});