import { encrypt, decrypt } from "@3t/romulus";
import { DEFAULT_KEY, MessageTypes } from "../common";
import { numberToUint16BE } from "../utilities/number";
import { packOutgoingPacket } from "./packet";

const MESSAGE_TYPE = numberToUint16BE(MessageTypes.Basic);

export interface BasicMessage {
  data: Uint8Array;
}

/**
 * Create an outgoing basic message (0x0001) packet.
 * @param message The plaintext message to send.
 * @param key The key to encrypt the data with.
 * @returns An encrypted outgoing basic message (0x0001) packet.
 */
export function packBasicMessage(
  message: Uint8Array,
  key: Uint8Array = DEFAULT_KEY,
): Uint8Array {
  const data = encrypt(message, MESSAGE_TYPE, key);
  return packOutgoingPacket({
    messageType: MESSAGE_TYPE,
    data: data,
  });
}

/**
 * Unpack the data section of an incoming basic message (0x0001) message.
 * @param data The encrypted data section of an incoming basic message (0x0001) message.
 * @param key The key to decrypt the data with.
 * @returns The decrypted plaintext message.
 */
export function unpackBasicMessage(
  data: Uint8Array,
  key: Uint8Array = DEFAULT_KEY,
): Uint8Array {
  const result = decrypt(data, MESSAGE_TYPE, key);
  if (result.success) {
    return result.plaintext;
  }
  throw new Error("Failed to decrypt basic message");
}