@ledgerhq/live-common/src/ble/hooks/useBleDevicePairing.ts

Common ground for the Ledger Live apps

import { useState, useEffect } from "react";
import { from, throwError, timer } from "rxjs";
import { first, retry } from "rxjs/operators";
import type { FirmwareInfo } from "@ledgerhq/types-live";
import { LockedDeviceError } from "@ledgerhq/errors";
import { withDevice } from "../../hw/deviceAccess";
import { getVersion } from "../../device/use-cases/getVersionUseCase";
import { BleError } from "../types";

export type useBleDevicePairingArgs = {
  deviceId: string;
};

export type PairingError = BleError | null;

export type useBleDevicePairingResult = {
  isPaired: boolean;
  pairingError: PairingError;
};

/**
 * Triggers a BLE pairing with a device
 * @param deviceId A BLE device id
 * @returns An object containing:
 * - isPaired: a boolean set to true if the device has been paired, false otherwise
 * - pairingError: any PairingError that occurred, null otherwise
 *
 * When the device is locked, notify the pairing error and retry
 * until the device is unlocked
 */
export const useBleDevicePairing = ({
  deviceId,
}: useBleDevicePairingArgs): useBleDevicePairingResult => {
  const [isPaired, setIsPaired] = useState<boolean>(false);
  const [pairingError, setPairingError] = useState<PairingError>(null);

  useEffect(() => {
    const requestObservable = withDevice(deviceId)(t => from(getVersion(t))).pipe(
      first(),
      retry({
        delay: (err: BleError) => {
          if (err instanceof LockedDeviceError) {
            setPairingError(err);
            return timer(1000);
          }

          return throwError(() => err);
        },
      }),
    );
    const sub = requestObservable.subscribe({
      next: (_value: FirmwareInfo) => {
        setIsPaired(true);
        setPairingError(null);
      },
      error: (error: BleError) => {
        setIsPaired(false);
        setPairingError(error);
      },
    });

    return () => {
      sub.unsubscribe();
    };
  }, [deviceId]);

  return { isPaired, pairingError };
};