import { randomBytes } from "node:crypto";
import {
	bcrypt,
	bcryptVerify,
	md5,
} from "hash-wasm";

import { env } from "@/env";

export async function hashPassword(password: string): Promise<string> {
	const h = await bcrypt({
		password,
		salt: randomBytes(16),
		costFactor: env.BCRYPT_ROUNDS,
		outputType: "encoded",
	});
	return h.replace(/^\$2[ab]\$/, "$2y$");
}

export async function md5Hex(input: string): Promise<string> {
	return await md5(input);
}

export async function isMd5Of(
	password: string,
	stored: string,
): Promise<boolean> {
	return (
		/^[a-f0-9]{32}$/i.test(stored) &&
		(await md5Hex(password)) === stored.toLowerCase()
	);
}

export async function verifyPassword(
	password: string,
	stored: string,
): Promise<boolean> {
	if (/^\$2[aby]\$/.test(stored)) {
		try {
			return await bcryptVerify({ password, hash: stored });
		} catch {
			return false;
		}
	}
	return false;
}

export interface LoginCheck {
	valid: boolean;
	upgradedHash?: string;
}

export async function checkLogin(
	password: string,
	stored: string,
	opts: { convertPasswords: boolean },
): Promise<LoginCheck> {
	if (opts.convertPasswords && (await isMd5Of(password, stored))) {
		return { valid: true, upgradedHash: await hashPassword(password) };
	}
	return { valid: await verifyPassword(password, stored) };
}