'use strict';
import { BufferLengthError } from './errors/BufferLengthError';
import { InvalidValueError } from './errors/InvalidValueError';
import { DPT } from './definitions';
import { buffer } from 'stream/consumers';

export class DPT12 implements DPT {
  id = '12';
  name = '4-byte unsigned value';
  bufferLength = 4

  /**
   * Decode a buffer
   *
   * @param buffer the buffer
   * @returns the DPT value
   */
  decoder(buffer: Buffer): number {
    if (buffer.length !== this.bufferLength)
      throw new BufferLengthError(`Invalid buffer length ${buffer.length}/${buffer}.  Expected ${this.bufferLength}.`);

    return buffer.readUInt32BE(0);
  };

  /**
   * Encode a buffer
   *
   * @param value the value to be converted to buffer
   * @returns the buffer
   */
  encoder(value: number): Buffer {
    if (!value)
      throw new InvalidValueError('Cannot write null value');

    let result = Buffer.alloc(this.bufferLength)
    result.writeUInt32BE(value)
    return result;
  }

  subtypes: {
    // 12.001 counter pulses
    "001": {
      "name": "DPT_Value_4_Ucount",
      "desc": "counter pulses"
    }
  };

}