import ejs from "ejs";
import * as metadata from "../metadata";
import { Page } from "../metadata";
import layout from "../layout";
import * as util from "../util";

async function generateRedirect(oldPermalink: string, newPermalink: string) {
	const page = await metadata.get("site/redirect.html.ejs");

	page.text = ejs.render(page.text, {
		metadata: page.metadata,
		newPermalink
	}, {
		filename: "site/redirect.html.ejs"
	});

	page.text = await layout(page.text, page.metadata, page.metadata.layout!);

	if (oldPermalink.endsWith("/")) {
		oldPermalink += "index.html";
	}
	
	util.write(oldPermalink, page.text);
}

export default async function redirects(posts: Page[]) {
	for (const post of posts) {
		if (post.metadata.oldPermalink) {
			await generateRedirect(post.metadata.oldPermalink, post.metadata.permalink);
		}
	}
}