#!/usr/bin/env python
#
# Copyright 2005,2006,2007,2009 Free Software Foundation, Inc.
# 
# This file is part of GNU Radio
# 
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
# 
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
# 

from gnuradio import gr, gru, modulation_utils
from gnuradio import usrp
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser

import random
import struct
import sys
import time
import binascii
# from current dir
import usrp_receive_path
import operator
# from current dir
import usrp_transmit_path

import usrp_receive_path
#import os 
#print os.getpid()
#raw_input('Attach and press enter')

class my_top_block(gr.top_block):

    def __init__(self, modulator, demodulator, rx_callback, options):
        gr.top_block.__init__(self)
        self.rxpath = usrp_receive_path.usrp_receive_path(demodulator, rx_callback, options)
        self.txpath = usrp_transmit_path.usrp_transmit_path(modulator, options)
        self.connect(self.rxpath)
        self.connect(self.txpath)

# /////////////////////////////////////////////////////////////////////////////
#                                   main
# /////////////////////////////////////////////////////////////////////////////
global n_rcvd, n_right

def main():
    global n_rcvd, n_right, re, a, l, coun

    def send_pkt(payload='', eof=False):
        return tb.txpath.send_pkt(payload, eof)

    def carrier_sensed(self):
        """
    Return True if the receive path thinks there's carrier
        
        """
        return self.rxpath.carrier_sensed()
    a=0

    n_rcvd=0
    n_right=0
    coun=l=0

    def rx_callback(ok, payload):
        global n_rcvd, n_right, coun, l
        (ide,pktno,) = struct.unpack('!cH', payload[0:3])
        n_rcvd += 1
        if ok:
            n_right += 1

        print "ok = %5s  pktno = %4d  n_rcvd = %4d  n_right = %4d ide=%1c" % (
            ok, pktno, n_rcvd, n_right, ide)

        if(ide == 'a' or ide == 'c'):
                print("payload=",payload)
                a =ord(payload[3:options.size])
                abin=bin(a)[2:]
                FILE1.write(payload[3:options.size])
                #a=ord(payload[2:options.size])
                print ('a = ' , a)
                print('abin=',abin)
                x =ord('a')
                #print('x=b=', x)
                t= operator.xor(a,x)
                        #print("t=", t)
                tbin= bin(t)[2:]
                #print('tbin= ',tbin)
                i=0
                l=len(abin)+l

                while i<len(tbin):
                        if tbin[i]=='1':
                                coun=coun+1
                        i=i+1
                print("total error bits so far=",coun)
                print("total bits=", l)
                ber1=float(coun)/float(l)
                print("ber1=",ber1)

#this s the block seen in tx.py, i added it here and it seems to work fine except for the last pkt. sid, please remove the 're' variable and add #the condtion like, (if pkt header=last pkt header)
        if ide=='c':
            nbytes=1250
            n = 0
            pktno = 0
            pkt_size = int(options.size)
           #  c='a'
         #    start_time=0
          #   last_time=0

            while n < nbytes:
                print("in while loop")
                if options.from_file is None:
                    data = (pkt_size - 2) * chr(pktno & 0xff)
                else:
                    data = source_file.read(pkt_size - 2)
                    if data == '':
                       break;

   # if carrier_sensed():
    #    re=1

     #       if re==1:
                print("before payload packing")
                payload = struct.pack('!H', pktno & 0xffff) + data
                send_pkt(payload)
                n += len(payload)
                a=a+1
                sys.stderr.write('.')
                if options.discontinuous and pktno % 5 == 4:
                  time.sleep(1)
                pktno += 1
                send_pkt(eof=True)
                print("pkts hopefully sent", a)


    demods = modulation_utils.type_1_demods()
    mods = modulation_utils.type_1_mods()

    parser = OptionParser(option_class=eng_option, conflict_handler="resolve")
    expert_grp = parser.add_option_group("Expert")

    parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
                      default='gmsk',
                      help="Select modulation from: %s [default=%%default]"
                            % (', '.join(mods.keys()),))

    parser.add_option("-s", "--size", type="eng_float", default=1500,
                      help="set packet size [default=%default]")
    parser.add_option("-M", "--megabytes", type="eng_float", default=1.0,
                      help="set megabytes to transmit [default=%default]")
    parser.add_option("","--discontinuous", action="store_true", default=False,
                      help="enable discontinous transmission (bursts of 5 packets)")
    parser.add_option("","--from-file", default=None,
                      help="use file for packet contents")
  #  expert_grp.add_option("", "--rx-freq", type="eng_float", default=None,
   #                       help="set Rx frequency to FREQ [default=%default]", metavar="FREQ")
   # expert_grp.add_option("", "--tx-freq", type="eng_float", default=None,
    #                      help="set transmit frequency to FREQ [default=%default]", metavar="FREQ")


    usrp_receive_path.add_options(parser, expert_grp)
    usrp_transmit_path.add_options(parser, expert_grp)

    for mod in demods.values():
        mod.add_options(expert_grp)
    for mod in mods.values():
        mod.add_options(expert_grp)

    (options, args) = parser.parse_args ()

    filename1 =args[0];
    FILE1 = open(filename1, "a")

   # if len(args) !=1:
    #    parser.print_help()
     #   sys.exit(1)

  if options.tx_freq is None:
        sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
        parser.print_help(sys.stderr)
        sys.exit(1)

    if options.from_file is not None:
        source_file = open(options.from_file, 'r')


    tb = my_top_block(mods[options.modulation], demods[options.modulation], rx_callback, options)
    print("no of pkts=",a)
    r = gr.enable_realtime_scheduling()
    if r != gr.RT_OK:
        print "Warning: failed to enable realtime scheduling"

    tb.start()                       # start flow graph

    # generate and send packets

    tb.wait()                       # wait for it to finish

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        pass