import { z } from 'astro/zod';

/** Normalize URL to its canonical form */
export function createCanonicalURL(url: string, base?: string): URL {
	let pathname = url.replace(/\/index.html$/, ''); // index.html is not canonical
	pathname = pathname.replace(/\/1\/?$/, ''); // neither is a trailing /1/ (impl. detail of collections)
	if (!getUrlExtension(url)) pathname = pathname.replace(/(\/+)?$/, '/'); // add trailing slash if there’s no extension
	pathname = pathname.replace(/\/+/g, '/'); // remove duplicate slashes (URL() won’t)
	return new URL(pathname, base);
}

/** Check if a URL is already valid */
export function isValidURL(url: string): boolean {
	try {
		new URL(url);
		return true;
	} catch (e) {}
	return false;
}

function getUrlExtension(url: string) {
	const lastDot = url.lastIndexOf('.');
	const lastSlash = url.lastIndexOf('/');
	return lastDot > lastSlash ? url.slice(lastDot + 1) : '';
}

const flattenErrorPath = (errorPath: (string | number)[]) => errorPath.join('.');

export const errorMap: z.ZodErrorMap = (error, ctx) => {
	if (error.code === 'invalid_type') {
		const badKeyPath = JSON.stringify(flattenErrorPath(error.path));
		if (error.received === 'undefined') {
			return { message: `${badKeyPath} is required.` };
		} else {
			return { message: `${badKeyPath} should be ${error.expected}, not ${error.received}.` };
		}
	}
	return { message: ctx.defaultError };
};