import { promises as fs } from "fs";
import path from "path";
import hljs from "highlight.js";
import ejs from "ejs";
import formatDate from "date-fns/format";

export async function write(filePath: string, data: any) {
	const dest = path.join("out", filePath);
	await fs.mkdir(path.dirname(dest), {
		recursive: true
	});
	await fs.writeFile(dest, data);
}

export function getReadingTime(text: string): number {
	const avgWPM = 225;
	const words = text.split(/\s+/).length;
	return Math.max(1, Math.round(words / avgWPM))
}

export function highlight(source: string, language?: string): string {
	const res = language ? hljs.highlight(language, source) : hljs.highlightAuto(source);
	const highlighted = res.value;
	return `<pre class="hljs"><code>${highlighted}</code></pre>`;
}

interface Chunk<T> {
	chunk: T[];
	index: number;
}

export function chunk<T>(array: T[], size: number): Chunk<T>[] {
	const chunks: Chunk<T>[] = [];

	for (let i = 0; i < array.length; i += size) {
		chunks.push({
			chunk: array.slice(i, i + size),
			index: i / size
		});
	}

	return chunks;
}

export function fancyLink(text: string, href: string, meta?: string): string {
	return `<a href="${href}" class="fancy-link" ${meta || ""}><span aria-hidden="true">{</span>${text}<span aria-hidden="true">}</span></a>`;
}

export function render(template: string, data: any, filename?: string): string {
	data.fancyLink = fancyLink;
	data.formatDate = formatDate;
	return ejs.render(template, data, {
		filename
	});
}