const i18n = require('eleventy-plugin-i18n');
const translations = require('./src/_data/i18n');

module.exports = function (eleventyConfig) {
  // Plugins
  eleventyConfig.addPlugin(i18n, {
    defaultLanguage: 'de',
    localesDirectory: 'src',
    // optional: customize the URL structure
    urlPrefix: locale => (locale === 'de' ? '' : `/${locale}`),
    translations,
    fallbackLocales: {
      '*': 'de'
    }
  });

  // TEMP demo of what could be an i18n-aware plural package?
  eleventyConfig.addFilter('pluralize', function (term, count = 1) {
    // Poorman's pluralize for now...
    return count === 1 ? term : `${term}s`;
  });

  eleventyConfig.addFilter('localizedPermalink', (slug, locale) => {
    const newPath = locale === 'de' ? `${slug.slice(3)}.html` : `${slug}.html`;
    return `${newPath}`;
  });

  // these folders will be copied into webroot
  // e.g. /image => /_site/image
  eleventyConfig.addPassthroughCopy('image');
  eleventyConfig.addPassthroughCopy('css');
  eleventyConfig.addPassthroughCopy('font');

  // contents of public folder will be copied into webroot
  // e.g. /public/something.html => /_site/something.html
  eleventyConfig.addPassthroughCopy({ "public": "." });

  // Browsersync
  // Redirect from root to default language root during --serve
  // Can also be handled by netlify.toml?
  eleventyConfig.setBrowserSyncConfig({
    callbacks: {
      ready: function (err, bs) {
        bs.addMiddleware('*', (req, res) => {
          if (req.url === '/') {
            res.writeHead(302, {
              location: '/en/'
            });
            res.end();
          }
        });
      }
    }
  });

  // Configuration
  return {
    dir: {
      input: 'src'
    },
    markdownTemplateEngine: 'njk'
  };
};