import Dot from 'dot';
import { readFile, writeFile } from 'fs/promises';
import { join } from 'path';
import { debuglog } from 'util';

const internals = {
  debuglog: debuglog('blog'),

  kIndexName: 'index.html'
};

/**
 * Generates the blog index page
 *
 * @name HTMLGenerator
 * @param {string} source the source directory
 * @param {string} target the target directory
 * @param {Array.<Blog.tPost>} posts the list of posts
 */
export default async function HTMLGenerator(source, target, posts) {

  internals.debuglog('Generating HTML');
  const indexTarget = join(target, internals.kIndexName);
  const indexLocation = join(source, internals.kIndexName);

  internals.debuglog(`Reading ${indexLocation}`);
  const indexTemplate = await readFile(indexLocation, { encoding: 'utf8' });

  internals.debuglog('Writing HTML');
  const indexHtml = Dot.template(indexTemplate, {
    ...Dot.templateSettings,
    strip: false
  })({ posts });
  await writeFile(indexTarget, indexHtml);
}