import { type CollectionEntry, getCollection, getEntry } from 'astro:content';
import getReadingTime, { type ReadTimeResults } from 'reading-time';
import removeMd from 'remove-markdown';
import { siteLocale } from './site';

export type BlogEntry = CollectionEntry<'blog'>;
export type SpecialEntry = CollectionEntry<'special'>;

export type PostEntry = BlogEntry & {
  readingStats: ReadTimeResults;
};

const dateFormatter = new Intl.DateTimeFormat(siteLocale, {
  year: 'numeric',
  month: 'long',
  day: 'numeric',
});

export async function getPosts(
  filter?: (entry: BlogEntry) => boolean,
): Promise<PostEntry[]> {
  let entries: BlogEntry[] = [];
  try {
    entries = await getCollection('blog', (entry) => {
      if (/^\d+$/.test(entry.id)) {
        console.warn(
          `[komorebi-theme] Ignoring blog post with numeric-only id "${entry.id}" because numeric routes are reserved for pagination (/blog/:page).`,
        );
        return false;
      }
      if (import.meta.env.PROD && entry.data.draft) {
        return false;
      }
      return filter ? filter(entry) : true;
    });
  } catch (error) {
    console.error('[komorebi-theme] Failed to load blog collection:', error);
    return [];
  }
  return entries.map((post) => ({
    ...post,
    readingStats: computeReadingTime(post.body ?? ''),
  }));
}

export async function getSortedPosts(
  filter?: (entry: BlogEntry) => boolean,
): Promise<PostEntry[]> {
  const posts = await getPosts(filter);
  sortByPubDate(posts);
  return posts;
}

export async function getSpecialEntry(
  id: string,
): Promise<SpecialEntry | undefined> {
  try {
    return await getEntry('special', id);
  } catch (error) {
    console.error(
      `[komorebi-theme] Failed to load special entry "${id}":`,
      error,
    );
    return undefined;
  }
}

export function sortByPubDate<T extends { data: { pubDate: Date } }>(
  posts: T[],
) {
  posts.sort((a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf());
}

export function getPostUrl(id: string) {
  return `/blog/${id}`;
}

export function computeReadingTime(body: string) {
  const plainText = removeMd(body);
  return getReadingTime(plainText);
}

export function formatDate(date: Date) {
  return dateFormatter.format(date);
}