import { Config } from './conf';
import { render as mustache_render } from 'mustache';
import { promises as fs } from 'fs';
import { resolve as resolve_path } from 'path';
import { glob } from 'glob';

export interface Context {
	env?: Record<string, string>;
	page?: {
		title?: string;
		layout?: string;
		[key: string]: string | number | boolean;
	};
	build_time: {
		iso: string;
		rfc2822: string;
	};
}

export function render_template(template: string, context: Context, layout?: string, partials?: Record<string, string>) {
	partials['.content'] = template;
	return mustache_render(layout || template, context, partials);
}

export async function load_layout(conf: Config, file: string) {
	const path = conf.templates?.layouts;

	if (! path) {
		return null;
	}

	const rel_path = resolve_path('/', file);
	const abs_path = resolve_path(path, '.' + rel_path);
	return await fs.readFile(abs_path, 'utf8');
}

export async function load_partials(conf: Config) {
	const path = conf.templates?.partials;

	if (! path) {
		return { };
	}

	const partials: Record<string, string> = { };
	const partial_files = await glob(path + '/**/*', {
		cwd: path,
		absolute: false,
	});

	for (const file of partial_files) {
		const abs_file = resolve_path(path, file);
		partials[file] = await fs.readFile(abs_file, 'utf8');
	}

	return partials;
}