import struct
import time

import gnuradio
import numpy
import serial


class ArduinoAnalogReadings(gnuradio.gr.sync_block):
    def __init__(self, port="/dev/ttyUSB0", baud_rate=115200, timeout=2):
        gnuradio.gr.sync_block.__init__(
            self, name="Arduino Analog Readings", in_sig=[], out_sig=[numpy.int16]
        )
        self._serial_port = serial.Serial(port, baud_rate, timeout=timeout)
        self._readings_counter = 0
        self._start_timestamp = None

    def work(self, input_items, output_items):
        # pylint: disable=unused-argument
        if not self._start_timestamp:
            self._start_timestamp = time.time()
        output_items[0][0] = struct.unpack(">H", self._serial_port.read(2))[0]
        self._readings_counter += 1
        if self._readings_counter % 1000 == 0:
            print(self._readings_counter / (time.time() - self._start_timestamp), "Hz")
        return 1