import schemapack from 'schemapack';

export class Packet {

  constructor(data = {}) {
    this.data = data;
  }

  static get builder() {
    if (!this._builder) {
      const schema = this.schema;
      if (!schema._id) {
        throw new Error([
          `No packet id found in '${this.name}.schema'. This is usually due to forgetting to`,
          'inherit from Packet.schema within your packet subclass schema definition.',
        ].join(' '));
      }
      this._builder = schemapack.build(schema);
    }
    return this._builder;
  }

  static pack(packet) {
    return this.builder.encode({
      _id: packet.data[0],
      data: packet.data[1],
    });
  }

  static packPacket(packet) {
    const {idFrom} = require('./registrar');
    const id = idFrom(packet.constructor);
    return packet.constructor.pack({
      data: [id, packet.data],
    });
  }

  static get schema() {
    return {
      _id: 'uint8',
    };
  }

  static unpack(packet) {
    const {data} = this.builder.decode(packet);
    return data;
  }

}