/** @param {import('@11ty/eleventy').UserConfig} eleventyConfig  */
export default function(eleventyConfig) {

  // Markdown and templates go in site-source. They will be converted to HTML.
  eleventyConfig.setInputDirectory('site-source');
  eleventyConfig.setOutputDirectory('slimequest');
  eleventyConfig.setTemplateFormats('md,njk');

  // Everything else goes in site-static. It just gets copied normally.
  eleventyConfig.addPassthroughCopy({ 'site-static': '/' });
  eleventyConfig.addWatchTarget('site-static/*.css');

  // If you want these files to live at, e.g. "example.com/quest", then set pathPrefix to "quest".
  const pathPrefix = 'slimequest';

  // Convenience function for quest images
  // example: {% image '1.jpg' %}
  // Can also add alt text:
  // example: {% image '2.jpg', 'slime dragon with sword piercing its heart' %}
  eleventyConfig.addShortcode('image', (filename, alt) => {
    return `<img src=/${pathPrefix}/${filename} alt="${alt}" title="${alt}">`
  });

  // Fix page sorting. By default this is by file created date? We want it to be by filename.
  eleventyConfig.addCollection('pages', (collection) => (collection
    .getFilteredByGlob(['site-source/index.md', 'site-source/page-*.md'])
    .map(page => {
      let number;
      if (page.fileSlug == 'index') {
        number = 0;
      } else {
        number = Number(page.fileSlug.slice('page-'.length));
      }
      return { page, number };
    })
    .sort((a, b) => a.number - b.number)
    .map(p => p.page)
  ));

  return {
    markdownTemplateEngine: 'njk',
    pathPrefix: pathPrefix,
  }
}