import Color from "color";
import { encrypt } from "@3t/romulus";
import { DEFAULT_KEY, MessageTypes } from "../common";
import { numberToUint16BE } from "../utilities/number";
import { SmartBuffer } from "../utilities/smart-buffer";
import { packOutgoingPacket } from "./packet";

const MESSAGE_TYPE = numberToUint16BE(MessageTypes.UserDataRequest);

export interface UserDataRequestMessage {
  username: string;
  colour: Color;
  clientId: string;
}

/**
 * Create an outgoing user data request (0x0002) packet.
 * @param properties The properties for the message.
 * @param key The key to encrypt the data with.
 * @returns An outgoing user data request (0x0002) packet.
 */
export function packUserDataRequestMessage(
  properties: UserDataRequestMessage,
  key: Uint8Array = DEFAULT_KEY,
): Uint8Array {
  const encoder = new TextEncoder();

  // Prepare data in correct format.
  const username = encoder.encode(properties.username);
  const usernameLength = numberToUint16BE(username.length);
  const colour = new Uint8Array(properties.colour.array());
  const clientId = encoder.encode(properties.clientId);
  const clientIdLength = numberToUint16BE(clientId.length);

  // Pack data.
  const packedData = new SmartBuffer();
  packedData.writeBytes(usernameLength);
  packedData.writeBytes(username);
  packedData.pad(32 - username.length);
  packedData.writeBytes(colour);
  packedData.writeBytes(clientIdLength);
  packedData.writeBytes(clientId);
  packedData.pad(32 - clientId.length);

  // Encrypt the data.
  const data = encrypt(packedData.data, MESSAGE_TYPE, key);

  return packOutgoingPacket({
    messageType: MESSAGE_TYPE,
    data: data,
  });
}

/**
 * Unpack the decrypted data section of an incoming user data request (0x0002) message.
 * @param data The decrypted data section of an incoming user data request (0x0002) message.
 * @returns An unpacked user data request (0x0002) message.
 */
export function unpackUserDataRequestMessage(
  data: Uint8Array,
): UserDataRequestMessage {
  // Unpack and read data in correct format.
  const packedData = SmartBuffer.from(Array.from(data));

  const usernameLength = packedData.readUInt16();
  const username = packedData.readBytes(usernameLength);
  packedData.cursor = 34;
  const colour = packedData.readBytes(3);
  const clientIdLength = packedData.readUInt16();
  const clientId = packedData.readBytes(clientIdLength);

  const decoder = new TextDecoder();

  // Return data in correct format.
  return {
    username: decoder.decode(username),
    colour: Color.rgb(colour),
    clientId: decoder.decode(clientId),
  };
}