#!/usr/bin/env python2
# -*- coding: utf-8 -*-
##################################################
# GNU Radio Python Flow Graph
# Title: Top Block
# Generated: Sun May 12 22:10:45 2019
##################################################


from gnuradio import analog
from gnuradio import audio
from gnuradio import blocks
from gnuradio import eng_notation
from gnuradio import filter
from gnuradio import gr
from gnuradio.eng_option import eng_option
from gnuradio.filter import firdes
from optparse import OptionParser
import osmosdr
import time
import socket
import re

class top_block(gr.top_block):

    def __init__(self):
        gr.top_block.__init__(self, "Top Block")

        ##################################################
        # Variables
        ##################################################
        self.samp_rate = samp_rate = 1536000
        self.frequency = frequency = 96900000

        ##################################################
        # Blocks
        ##################################################
        self.rtlsdr_source_0 = osmosdr.source( args="numchan=" + str(1) + " " + '' )
        self.rtlsdr_source_0.set_sample_rate(samp_rate)
        self.rtlsdr_source_0.set_center_freq(frequency, 0)
        self.rtlsdr_source_0.set_freq_corr(0, 0)
        self.rtlsdr_source_0.set_dc_offset_mode(2, 0)
        self.rtlsdr_source_0.set_iq_balance_mode(2, 0)
        self.rtlsdr_source_0.set_gain_mode(True, 0)
        self.rtlsdr_source_0.set_gain(0, 0)
        self.rtlsdr_source_0.set_if_gain(0, 0)
        self.rtlsdr_source_0.set_bb_gain(0, 0)
        self.rtlsdr_source_0.set_antenna('', 0)
        self.rtlsdr_source_0.set_bandwidth(0, 0)

        self.low_pass_filter_0 = filter.fir_filter_ccf(4, firdes.low_pass(
        	1, samp_rate, 500000, 60000, firdes.WIN_KAISER, 6.76))
        self.blocks_udp_sink_0 = blocks.udp_sink(gr.sizeof_float*1, '127.0.0.1', 7654, 1472, True)
        self.blocks_throttle_0 = blocks.throttle(gr.sizeof_gr_complex*1, samp_rate,True)
        self.analog_wfm_rcv_0 = analog.wfm_rcv(
        	quad_rate=384000,
        	audio_decimation=8,
        )

        ##################################################
        # Connections
        ##################################################
        self.connect((self.analog_wfm_rcv_0, 0), (self.blocks_udp_sink_0, 0))
        self.connect((self.blocks_throttle_0, 0), (self.low_pass_filter_0, 0))
        self.connect((self.low_pass_filter_0, 0), (self.analog_wfm_rcv_0, 0))
        self.connect((self.rtlsdr_source_0, 0), (self.blocks_throttle_0, 0))

    def get_samp_rate(self):
        return self.samp_rate

    def set_samp_rate(self, samp_rate):
        self.samp_rate = samp_rate
        self.rtlsdr_source_0.set_sample_rate(self.samp_rate)
        self.low_pass_filter_0.set_taps(firdes.low_pass(1, self.samp_rate, 500000, 60000, firdes.WIN_KAISER, 6.76))
        self.blocks_throttle_0.set_sample_rate(self.samp_rate)

    def get_frequency(self):
        return self.frequency

    def set_frequency(self, frequency):
        self.frequency = frequency
        self.rtlsdr_source_0.set_center_freq(self.frequency, 0)


def main(top_block_cls=top_block, options=None):
    tb = top_block_cls()
    tb.start()
    HOST = '127.0.0.1' # Loopback Address (Localhost)
    PORT = 65432 # Semi-Random Port that is non-priviledged (> 1023)
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    # Avoid bind() exception: OSError: [Errno 48] Address already in use
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind((HOST, PORT))
    quit = False
    while not quit:
        s.listen(1) # Number of unaccepted connections before it rejects new ones
        conn, addr = s.accept()
        print("Connected by ", addr)
        while not quit:
            data = conn.recv(1024) # Not sure about the bytes argument...
            data = data.strip() # Removes \r\n
            print("DATA: ", data)
            commands = re.split(";", data)
            if data == "":
                break
            for command in commands:
                if command == "":
                    continue
                elif command[0] == '?':
                    # Query Section
                    if command[1:] == "VER":
                        conn.sendall("Version 0.1\n")
                    elif command[1:] == "FREQ":
                        conn.sendall(str(tb.get_frequency()) + '\n')
                    else:
                        print("UNKNOWN COMMAND: ", command)
                elif command[0] == ':':
                    # Setter Section
                    if command[1:5] == "FREQ":
                        print("FREQUENCY SET")
                        frequency = float(command[6:])
                        if frequency >= 87500000 and frequency <= 108000000:
                            tb.set_frequency(frequency)
                        else:
                            print("ERROR: Invalid Frequency ", frequency)
                    elif command[1:] == "QUIT":
                        print("QUITTING")
                        quit = True
                    else:
                        print("UNKNOWN COMMAND: ", command)
                else:
                    print("UNKNOWN COMMAND", command)

        conn.close()
    s.close()


if __name__ == '__main__':
    main()