import { promises as fs } from "fs";
import path from "path";
import dateFns from "date-fns";
import slugify from "@sindresorhus/slugify";
import * as util from "../util";
import * as metadata from "../metadata";
import { Page, PostMetadata } from "../metadata";
import * as markdown from "../markdown";
import layout from "../layout";

export default async function posts(): Promise<Page[]> {
	const posts: Page[] = [];

	const files = await fs.readdir("site/posts");
	for (const f of files) {
		const postPath = path.join("site/posts", f);
		let page = await metadata.get(postPath);
		
		if (!(<PostMetadata>page.metadata).permalink) {
			let postMeta = <PostMetadata>page.metadata;
			postMeta.date = dateFns.parse(postMeta.date);
			postMeta.slug = postMeta.slug || slugify(postMeta.title);
			postMeta.permalink = `/${postMeta.category}/${postMeta.date.getFullYear()}/${postMeta.slug}/`;
		}

		page.text = util.render(page.text, { metadata: page.metadata }, postPath);

		if (page.metadata.source && page.metadata.source!.endsWith(".md")) {
			(<PostMetadata>page.metadata).readingTime = util.getReadingTime(page.text);

			page.text = markdown.render(page.text);
		}

		if (!(<PostMetadata>page.metadata).excerpt) {
			const parts = page.text.split("<!-- excerpt-end -->");
			(<PostMetadata>page.metadata).excerpt = parts[0];
		}

		const renderedText = await layout(page.text, page.metadata, page.metadata.layout || "article.html.ejs");

		let dest = page.metadata.permalink;
		if (dest.endsWith("/")) {
			dest += "index.html";
		}

		util.write(dest, renderedText);

		posts.push(page);
	}

	return posts;
}