'use strict';

const visiblePostFilter = post => !post.hide;

const createPostQuery = hexo => {
  const query = {};

  if (!hexo.config.future) query.date = { $lte: Date.now() };
  if (!hexo._showDrafts()) query.published = true;

  return query;
};

hexo.extend.filter.register('after_init', () => {
  const getAllPosts = () => hexo.database.model('Post').find(createPostQuery(hexo));
  const getVisiblePosts = () => getAllPosts().filter(visiblePostFilter);

  hexo.locals.set('posts', () => getVisiblePosts());
  hexo.locals.set('categories', () => hexo.model('Category').filter(category => category.posts.length));
  hexo.locals.set('tags', () => hexo.model('Tag').filter(tag => tag.posts.length));

  hexo.extend.generator.register('post', () => {
    const posts = getAllPosts().sort('-date').toArray();
    const visiblePosts = getVisiblePosts().sort('-date').toArray();
    const visibleIndex = new Map(visiblePosts.map((post, index) => [String(post._id), index]));

    return posts.map(post => {
      const { path, layout } = post;
      const index = visibleIndex.get(String(post._id));

      post.prev = null;
      post.next = null;

      if (index !== undefined) {
        post.prev = index > 0 ? visiblePosts[index - 1] : null;
        post.next = index < visiblePosts.length - 1 ? visiblePosts[index + 1] : null;
      }

      if (!layout || layout === 'false') return { path, data: post.content };

      const layouts = ['post', 'page', 'index'];

      if (layout !== 'post') layouts.unshift(layout);

      post.__post = true;

      return { path, layout: layouts, data: post };
    });
  });
});