import _ from 'lodash';
import { readingTime } from 'reading-time-estimator';
import path from 'path';
import { readFile } from 'fs/promises';

const PAGE_SIZE = 10;

export async function load({ params }) {
	const allPostFiles = import.meta.glob<SvelteAllProps>('/src/routes/posts/*.md');
	const iterablePostFiles = Object.entries(allPostFiles);

	const markdownFilesPath = path.resolve(
		process.env.npm_package_json ? path.dirname(process.env.npm_package_json) : '.',
		'src',
		'routes',
		'posts',
	);

	const posts = await Promise.all(
		iterablePostFiles.map(async ([filePath, resolver]) => {
			const { metadata } = await resolver();

			const slug = /[/]([^/]*)[.]md$/.exec(filePath)?.[1];
			if (!slug) throw new Error(`Could not parse slug from path: ${filePath}`);

			const contents = await readFile(path.join(markdownFilesPath, `${slug}.md`), 'utf8');

			return {
				meta: metadata,
				path: slug,
				readingTime: readingTime(contents),
			};
		}),
	);

	// Get the page number, converting it to a 0-based index
	const page = (params.page ? parseInt(params.page, 10) : 1) - 1;

	return {
		posts: _.reverse(_.sortBy(posts, ({ meta }) => meta.date)).slice(
			page * PAGE_SIZE,
			(page + 1) * PAGE_SIZE,
		),
		hasMore: posts.length > (page + 1) * PAGE_SIZE,
		page: page + 1,
		pageCount: Math.ceil(posts.length / PAGE_SIZE),
	};
}
export type Post = Awaited<ReturnType<typeof load>>['posts'][number];