.eleventy.js

module.exports = function (eleventyConfig) {
  // Static files:
  // - `src/public` is copied to the site root (e.g. Google Search Console HTML verification)
  // - `src/static` is copied under `/static/` (icons, misc files)
  eleventyConfig.addPassthroughCopy({ 'src/public': '/' });
  eleventyConfig.addPassthroughCopy({ 'src/static': '/static' });

  eleventyConfig.addGlobalData('buildTime', () => new Date());

  // Blog posts strictly from /src/blog (folder-based, not tag-based)
  eleventyConfig.addCollection('blogPosts', (collectionApi) => {
    // NOTE: In Eleventy v3, getFilteredByGlob is most reliable with a single glob string.
    // We only treat markdown files in /src/blog as posts (avoids including blog/index.njk).
    const items = collectionApi.getFilteredByGlob('./src/blog/**/*.md');
    return items.sort((a, b) => a.date - b.date);
  });

  // Sitemap collection: only HTML pages, excluding anything opted-out via eleventyExcludeFromCollections
  eleventyConfig.addCollection('sitemap', (collectionApi) => {
    return collectionApi
      .getAllSorted()
      .filter((item) => !item.data?.eleventyExcludeFromCollections)
      .filter((item) => typeof item.url === 'string' && typeof item.outputPath === 'string')
      .filter((item) => item.outputPath.endsWith('.html'));
  });

  eleventyConfig.addFilter('dateISO', (value) => {
    const d = value instanceof Date ? value : new Date(value);
    return d.toISOString().slice(0, 10);
  });

  eleventyConfig.addFilter('dateSK', (value) => {
    const d = value instanceof Date ? value : new Date(value);
    return new Intl.DateTimeFormat('sk-SK', {
      day: '2-digit',
      month: '2-digit',
      year: 'numeric',
    }).format(d);
  });

  eleventyConfig.addFilter('year', (value) => {
    const d = value instanceof Date ? value : new Date(value);
    return String(d.getFullYear());
  });

  // Array helper: take first N items (useful in Nunjucks where slice behaves differently)
  eleventyConfig.addFilter('limit', (arr, n) => {
    if (!Array.isArray(arr)) return [];
    return arr.slice(0, n);
  });

  // Transform to ensure sitemap.xml starts with XML declaration (no leading whitespace)
  eleventyConfig.addTransform('trimSitemap', function (content, outputPath) {
    if (outputPath && outputPath.endsWith('/sitemap.xml')) {
      return content.trimStart();
    }
    return content;
  });

  return {
    dir: {
      input: 'src',
      includes: '_includes',
      data: '_data',
      output: '_site',
    },
    markdownTemplateEngine: 'njk',
    htmlTemplateEngine: 'njk',
    templateFormats: ['md', 'njk'],
  };
};