Contrato de transporte

interface HeadbandFrameV1 {
  schemaVersion: "v1";
  source: string;
  sequenceId: number;
  emittedAtMs: number;
  eeg: HeadbandSignalBlock;
  ppgRaw?: HeadbandSignalBlock;
  optics?: HeadbandSignalBlock;
  accgyro?: HeadbandSignalBlock;
  battery?: HeadbandBatteryBlock;
}

interface HeadbandSignalBlock {
  sampleRateHz: number;
  channelNames: string[];
  channelCount: number;
  samples: number[][];
  timestampsMs?: number[];
  clockSource?: "device" | "local";
}

interface HeadbandTransport {
  onFrame?: (frame: HeadbandFrameV1) => void;
  onStatus?: (status: HeadbandTransportStatus) => void;
  connect(): Promise<void>;
  disconnect(): Promise<void>;
  start(): Promise<void>;
  stop(): Promise<void>;
}

interface HeadbandTransportStatus {
  state: HeadbandTransportState;
  atMs: number;
  reason?: string;
  errorCode?: string;
  recoverable?: boolean;
  details?: Record<string, unknown>;
}

const transport: HeadbandTransport = /* BleTransport or another transport */;

transport.onFrame = (frame) => {
  const eegRows = frame.eeg.samples;
  console.log(eegRows.length);
};

transport.onStatus = (status) => {
  console.log(status.state, status.reason ?? "");
};

await transport.connect();
await transport.start();

// ... later
await transport.stop();
await transport.disconnect();