def lambda_handler()

in src/backend/booking/src/reserve-booking/reserve.py [0:0]
17 lines of code
3 McCabe index (conditional complexity)

def lambda_handler(event, context):
    """AWS Lambda Function entrypoint to reserve a booking

    Parameters
    ----------
    event: dict, required
        Step Functions State Machine event

        chargeId: string
            pre-authorization charge ID

        stateExecutionId: string
            Step Functions Process Booking Execution ID

        chargeId: string
            Pre-authorization payment token

        customerId: string
            Customer unique identifier

        bookingOutboundFlightId: string
            Outbound flight unique identifier

    context: object, required
        Lambda Context runtime methods and attributes
        Context doc: https://docs.aws.amazon.com/lambda/latest/dg/python-context-object.html

    Returns
    -------
    bookingId: string
        booking ID generated

    Raises
    ------
    BookingReservationException
        Booking Reservation Exception including error message upon failure
    """
    if not is_booking_request_valid(event):
        metrics.add_metric(name="InvalidReservationRequest", unit=MetricUnit.Count, value=1)
        logger.error({"operation": "input_validation", "details": event})
        raise ValueError("Invalid booking request")

    try:
        logger.debug(f"Reserving booking for customer {event['customerId']}")
        ret = reserve_booking(event)

        metrics.add_metric(name="SuccessfulReservation", unit=MetricUnit.Count, value=1)
        tracer.put_annotation("Booking", ret["bookingId"])
        tracer.put_annotation("BookingStatus", "RESERVED")

        # Step Functions use the return to append `bookingId` key into the overall output
        return ret["bookingId"]
    except BookingReservationException as err:
        metrics.add_metric(name="FailedReservation", unit=MetricUnit.Count, value=1)
        tracer.put_annotation("BookingStatus", "ERROR")
        logger.exception({"operation": "reserve_booking"})
        raise