import { BufferReader, BufferWriter } from '@node-dlc/bufio';

import { MessageType } from '../MessageType';
import { IWireMessage } from './IWireMessage';

/**
 * This message is defined in BOLT #1 and is used for telling
 * a peer that something is incorrect. The message can indicate
 * which channel is in error, or if channelId is 0, it refers
 * to all channels.
 *
 * These message can indicate protocol violations or internal
 * errors that make channels unusable or that make further
 * communication unusable.
 */
export class ErrorMessage implements IWireMessage {
  /**
   * Deserializes an error message into an ErrorMessage
   * instance.
   */
  public static deserialize(payload: Buffer): ErrorMessage {
    const reader = new BufferReader(payload);
    reader.readUInt16BE(); // read type

    const instance = new ErrorMessage();
    instance.channelId = reader.readUInt32BE();

    const len = reader.readUInt16BE();
    instance.data = reader.readBytes(len);

    return instance;
  }

  /**
   * Message type 17
   */
  public type: MessageType = MessageType.Error;

  /**
   * channelId is used to indicate the failing channel. It
   * can have a value of 0 to indicate there is an error with
   * all channels.
   *
   * All error messsagees sent before (and including) the
   * funding_created messagee should use the temporary_channel_id
   * instead of the channel_id.
   */
  public channelId: any = 0;

  /**
   * Data field may be empty. May contain the raw, hex-encoded
   * transaction in reply to a invalid signature check in
   * funding_created, funding_signed, closing_signed, or
   * commitment_signed messages.
   */
  public data: Buffer = Buffer.alloc(0);

  /**
   * Serialize the ErorrMessage into a Buffer that
   * can be send on the wire.
   */
  public serialize(): Buffer {
    const len =
      2 + // type
      4 + // channel_id
      2 + // len
      this.data.length;

    const writer = new BufferWriter(Buffer.alloc(len));
    writer.writeUInt16BE(this.type);
    writer.writeUInt32BE(this.channelId);
    writer.writeUInt16BE(this.data.length);
    writer.writeBytes(this.data);
    return writer.toBuffer();
  }
}