import { clsx, type ClassValue } from "clsx";
import { twMerge } from "tailwind-merge";

/** cn merges conditional class names and resolves Tailwind conflicts. */
export function cn(...inputs: ClassValue[]): string {
  return twMerge(clsx(inputs));
}

export function base64urlToBytes(str: string): ArrayBuffer {
  let base64 = str.replace(/-/g, "+").replace(/_/g, "/");
  const pad = base64.length % 4;
  if (pad) {
    base64 += "=".repeat(4 - pad);
  }
  const binary = atob(base64);
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i++) {
    bytes[i] = binary.charCodeAt(i);
  }
  return bytes.buffer;
}

export function bytesToBase64url(bytes: ArrayBuffer): string {
  let binary = "";
  const uint8 = new Uint8Array(bytes);
  const len = uint8.byteLength;
  for (let i = 0; i < len; i++) {
    binary += String.fromCharCode(uint8[i]);
  }
  const base64 = btoa(binary);
  return base64
    .replace(/\+/g, "-")
    .replace(/\//g, "_")
    .replace(/=+$/, "");
}