#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @file
# @author Piotr Krysik <ptrkrysik@gmail.com>
# @author Roman Khassraf <rkhassraf@gmail.com>
# @section LICENSE
#
# Gr-gsm 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.
#
# Gr-gsm 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 gr-gsm; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
#
from gnuradio import blocks
from gnuradio import gr
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from gnuradio.filter import firdes
from gnuradio.filter import pfb
from math import pi
from optparse import OptionParser

import grgsm
import numpy
import os
import osmosdr
import pmt
import time


#from wideband_receiver import *

class receiver_with_decoder(gr.hier_block2):

    def __init__(self, OSR=4, chan_num=0, fc=939.4e6, ppm=0, samp_rate=0.2e6):
        gr.hier_block2.__init__(
            self, "Receiver With Decoder",
            gr.io_signature(1, 1, gr.sizeof_gr_complex*1),
            gr.io_signature(0, 0, 0),
        )
        self.message_port_register_hier_in("bursts")
        self.message_port_register_hier_in("msgs")

        ##################################################
        # Parameters
        ##################################################
        self.OSR = OSR
        self.chan_num = chan_num
        self.fc = fc
        self.ppm = ppm
        self.samp_rate = samp_rate

        ##################################################
        # Variables
        ##################################################
        self.samp_rate_out = samp_rate_out = 1625000.0/6.0*OSR

        ##################################################
        # Blocks
        ##################################################
        self.gsm_receiver_0 = grgsm.receiver(OSR, ([chan_num]), ([]))
        self.gsm_input_0 = grgsm.gsm_input(
            ppm=ppm,
            osr=OSR,
            fc=fc,
            samp_rate_in=samp_rate,
        )
        self.gsm_control_channels_decoder_0 = grgsm.control_channels_decoder()
        self.gsm_clock_offset_control_0 = grgsm.clock_offset_control(fc)
        self.gsm_bcch_ccch_demapper_0 = grgsm.universal_ctrl_chans_demapper(0, ([2,6,12,16,22,26,32,36,42,46]), ([1,2,2,2,2,2,2,2,2,2]))

        ##################################################
        # Connections
        ##################################################
        self.msg_connect(self.gsm_bcch_ccch_demapper_0, 'bursts', self, 'bursts')
        self.msg_connect(self.gsm_bcch_ccch_demapper_0, 'bursts', self.gsm_control_channels_decoder_0, 'bursts')
        self.msg_connect(self.gsm_clock_offset_control_0, 'ppm', self.gsm_input_0, 'ppm_in')
        self.msg_connect(self.gsm_control_channels_decoder_0, 'msgs', self, 'msgs')
        self.msg_connect(self.gsm_receiver_0, 'C0', self.gsm_bcch_ccch_demapper_0, 'bursts')
        self.msg_connect(self.gsm_receiver_0, 'measurements', self.gsm_clock_offset_control_0, 'measurements')
        self.connect((self.gsm_input_0, 0), (self.gsm_receiver_0, 0))    
        self.connect((self, 0), (self.gsm_input_0, 0))    


    def get_OSR(self):
        return self.OSR

    def set_OSR(self, OSR):
        self.OSR = OSR
        self.set_samp_rate_out(1625000.0/6.0*self.OSR)
        self.gsm_input_0.set_osr(self.OSR)

    def get_chan_num(self):
        return self.chan_num

    def set_chan_num(self, chan_num):
        self.chan_num = chan_num

    def get_fc(self):
        return self.fc

    def set_fc(self, fc):
        self.fc = fc
        self.gsm_input_0.set_fc(self.fc)

    def get_ppm(self):
        return self.ppm

    def set_ppm(self, ppm):
        self.ppm = ppm
        self.gsm_input_0.set_ppm(self.ppm)

    def get_samp_rate(self):
        return self.samp_rate

    def set_samp_rate(self, samp_rate):
        self.samp_rate = samp_rate
        self.gsm_input_0.set_samp_rate_in(self.samp_rate)

    def get_samp_rate_out(self):
        return self.samp_rate_out

    def set_samp_rate_out(self, samp_rate_out):
        self.samp_rate_out = samp_rate_out


class wideband_receiver(gr.hier_block2):

    def __init__(self, OSR=4, fc=939.4e6, samp_rate=0.4e6):
        gr.hier_block2.__init__(
            self, "Wideband receiver",
            gr.io_signature(1, 1, gr.sizeof_gr_complex*1),
            gr.io_signature(0, 0, 0),
        )
        self.message_port_register_hier_in("bursts")
        self.message_port_register_hier_in("msgs")
        self.__init(OSR, fc, samp_rate)
    
    def __init(self, OSR=4, fc=939.4e6, samp_rate=0.4e6):
        ##################################################
        # Parameters
        ##################################################
        self.OSR = OSR
        self.fc = fc
        self.samp_rate = samp_rate
        self.channels_num = int(samp_rate/0.2e6)
        self.OSR_PFB = 2
        
        ##################################################
        # Blocks
        ##################################################
        self.pfb_channelizer_ccf_0 = pfb.channelizer_ccf(
            self.channels_num,
            (),
            self.OSR_PFB,
            100)
        self.pfb_channelizer_ccf_0.set_channel_map(([]))
        self.create_receivers()

        ##################################################
        # Connections
        ##################################################
        self.connect((self, 0), (self.pfb_channelizer_ccf_0, 0))
        for chan in xrange(0,self.channels_num):
            self.connect((self.pfb_channelizer_ccf_0, chan), (self.receivers_with_decoders[chan], 0))
            self.msg_connect(self.receivers_with_decoders[chan], 'bursts', self, 'bursts')
            self.msg_connect(self.receivers_with_decoders[chan], 'msgs', self, 'msgs')

    def create_receivers(self):
        self.receivers_with_decoders = {}
        for chan in xrange(0,self.channels_num):
            self.receivers_with_decoders[chan] = receiver_with_decoder(fc=self.fc, OSR=self.OSR, chan_num=chan, samp_rate=self.OSR_PFB*0.2e6)

    def get_OSR(self):
        return self.OSR

    def set_OSR(self, OSR):
        self.OSR = OSR
        self.create_receivers()

    def get_fc(self):
        return self.fc

    def set_fc(self, fc):
        self.fc = fc
        self.create_receivers()

    def get_samp_rate(self):
        return self.samp_rate


class wideband_scanner(gr.top_block):
    
    def __init__(self, rec_len=3, sample_rate=2e6, carrier_frequency=939e6, ppm=0):
        
        gr.top_block.__init__(self, "Wideband Scanner")
        
        self.rec_len = rec_len
        self.sample_rate = sample_rate
        self.carrier_frequency = carrier_frequency
        self.ppm = ppm
        
        # if no file name is given process data from rtl_sdr source
        self.rtlsdr_source = osmosdr.source( args="numchan=" + str(1) + " " + "" )
        
        self.rtlsdr_source.set_sample_rate(sample_rate)
        
        # capture half of GSM channel lower than channel center (-0.1MHz)
        # this is needed when even number of channels is captured in order to process full captured bandwidth
        
        self.rtlsdr_source.set_center_freq(carrier_frequency - 0.1e6, 0)
        
        # correction of central frequency
        # if the receiver has large frequency offset 
        # the value of this variable should be set close to that offset in ppm
        self.rtlsdr_source.set_freq_corr(options.ppm, 0)
        
        self.rtlsdr_source.set_dc_offset_mode(2, 0)
        self.rtlsdr_source.set_iq_balance_mode(0, 0)
        self.rtlsdr_source.set_gain_mode(True, 0)
        self.rtlsdr_source.set_bandwidth(sample_rate, 0)
    
        self.head = blocks.head(gr.sizeof_gr_complex * 1, int(rec_len * sample_rate))
        
        # shift again by -0.1MHz in order to align channel center in 0Hz
        self.blocks_rotator_cc = blocks.rotator_cc(-2 * pi * 0.1e6 / options.samp_rate) 
               
        self.wideband_receiver = wideband_receiver(OSR=4, fc=carrier_frequency, samp_rate=sample_rate)
        self.gsm_extract_system_info = grgsm.extract_system_info()
        
        
        self.connect((self.rtlsdr_source, 0), (self.head, 0))
        self.connect((self.head, 0), (self.blocks_rotator_cc, 0))
        self.connect((self.blocks_rotator_cc, 0), (self.wideband_receiver,0))
        self.msg_connect(self.wideband_receiver, 'msgs', self.gsm_extract_system_info, 'msgs')
        
    def set_carrier_frequency(self, carrier_frequency):
        self.carrier_frequency = carrier_frequency
        self.rtlsdr_source.set_center_freq(carrier_frequency - 0.1e6, 0)

       
class channel_info(object):
    
    def __init__(self, arfcn, freq, cid, lac, mcc, mnc, ccch_conf, power, neighbours, cell_arfcns):
        self.arfcn = arfcn
        self.freq = freq
        self.cid = cid
        self.lac = lac
        self.mcc = mcc
        self.mnc = mnc
        self.ccch_conf = ccch_conf
        self.power = power
        self.neighbours = neighbours
        self.cell_arfcns = cell_arfcns
                
    def get_verbose_info(self):
        i = "  |---- Configuration: %s\n" % self.get_ccch_conf()
        i += "  |---- Cell ARFCNs: " + ", ".join(map(str, self.cell_arfcns)) + "\n"
        i += "  |---- Neighbour Cells: " + ", ".join(map(str, self.neighbours)) + "\n"
        return i
        
    def get_ccch_conf(self):
        if self.ccch_conf == 0:
            return "1 CCCH, not combined"
        elif self.ccch_conf == 1:
            return "1 CCCH, combined"
        elif self.ccch_conf == 2:
            return "2 CCCH, not combined"
        elif self.ccch_conf == 4:
            return "3 CCCH, not combined"
        elif self.ccch_conf == 6:
            return "4 CCCH, not combined"
        else:
            return "Unknown"
        
    def getKey(self):
        return self.arfcn
    
    def __cmp__(self, other):
        if hasattr(other, 'getKey'):
            return self.getKey().__cmp__(other.getKey())
        
    def __repr__(self):
        return "ARFCN: %4u, Freq: %6.1fM, CID: %5u, LAC: %5u, MCC: %3u, MNC: %3u, Pwr: %3i" % (self.arfcn, self.freq/1e6, self.cid, self.lac, self.mcc, self.mnc, self.power)
            

if __name__ == '__main__':
    parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
    bands_list = ", ".join(grgsm.arfcn.get_bands())
    parser.add_option("-b", "--band", dest="band", default="P-GSM",
                      help="Specify the GSM band for the frequency.\nAvailable bands are: " + bands_list)
    parser.add_option("-s", "--samp-rate", dest="samp_rate", type="float", default=2e6,
        help="Set sample rate [default=%default] - allowed values even_number*0.2e6")
    parser.add_option("-p", "--ppm", dest="ppm", type="intx", default=-45,
        help="Set frequency correction in ppm [default=%default]")
    parser.add_option("-g", "--gain", dest="gain", type="eng_float", default=24.0,
        help="Set gain [default=%default]")
    parser.add_option("--speed", dest="speed", type="intx", default=4,
        help="Scan speed [default=%default]. Value range 0-5.")
    parser.add_option("-v", "--verbose", action="store_true", 
                      help="If set, verbose information output is printed: ccch configuration, cell ARFCN's, neighbour ARFCN's")
    
    """
        Dont forget: sudo sysctl kernel.shmmni=32000
    """
        
    (options, args) = parser.parse_args()
    
    if options.band not in grgsm.arfcn.get_bands():
        parser.error("Invalid GSM band\n")
        
    if options.speed < 0 or options.speed > 5:
        parser.error("Invalid scan speed.\n")
        
    if (options.samp_rate / 0.2e6) % 2 != 0:
        parser.error("Invalid sample rate. Sample rate must be an even numer * 0.2e6")
        
    channels_num = int(options.samp_rate/0.2e6)
    
    first_arfcn = grgsm.arfcn.get_first_arfcn(options.band)
    last_arfcn = grgsm.arfcn.get_last_arfcn(options.band)
    last_center_arfcn = last_arfcn - int((channels_num / 2) - 1)
        
    current_freq = grgsm.arfcn.arfcn2downlink(first_arfcn + int(channels_num / 2) - 1, options.band)
    last_freq = grgsm.arfcn.arfcn2downlink(last_center_arfcn, options.band)
    stop_freq = last_freq + 0.2e6 * channels_num
    
    while current_freq < stop_freq:
        
        # silence rtl_sdr output:
        # open 2 fds
        null_fds = [os.open(os.devnull, os.O_RDWR) for x in xrange(2)]
        # save the current file descriptors to a tuple
        save = os.dup(1), os.dup(2)
        # put /dev/null fds on 1 and 2
        os.dup2(null_fds[0], 1)
        os.dup2(null_fds[1], 2)
        
        # instantiate scanner and processor
        scanner = wideband_scanner(rec_len=6-options.speed, 
                            sample_rate=options.samp_rate, 
                            carrier_frequency=current_freq, 
                            ppm=options.ppm)

        # start recording
        scanner.start()
        scanner.wait()
        scanner.stop()
        
        # restore file descriptors so we can print the results
        os.dup2(save[0], 1)
        os.dup2(save[1], 2)
        # close the temporary fds
        os.close(null_fds[0])
        os.close(null_fds[1])
        
        freq_offsets = numpy.fft.ifftshift(numpy.array(range(int(-numpy.floor(channels_num/2)),int(numpy.floor((channels_num+1)/2))))*2e5)
        detected_c0_channels = scanner.gsm_extract_system_info.get_chans()
                
        if detected_c0_channels:
            chans = numpy.array(scanner.gsm_extract_system_info.get_chans())
            found_freqs = current_freq + freq_offsets[(chans)]
            
            cell_ids = numpy.array(scanner.gsm_extract_system_info.get_cell_id())
            lacs = numpy.array(scanner.gsm_extract_system_info.get_lac())
            mccs = numpy.array(scanner.gsm_extract_system_info.get_mcc())
            mncs = numpy.array(scanner.gsm_extract_system_info.get_mnc())
            ccch_confs = numpy.array(scanner.gsm_extract_system_info.get_ccch_conf())
            powers = numpy.array(scanner.gsm_extract_system_info.get_pwrs())
                        
            found_list = []
            for i in range(0, len(chans)):
                cell_arfcn_list = scanner.gsm_extract_system_info.get_cell_arfcns(chans[i])
                neighbour_list = scanner.gsm_extract_system_info.get_neighbours(chans[i])

                info = channel_info(grgsm.arfcn.downlink2arfcn(found_freqs[i], options.band), found_freqs[i], cell_ids[i], lacs[i], mccs[i], mncs[i], ccch_confs[i], powers[i], neighbour_list, cell_arfcn_list)
                found_list.append(info)
                            
            for info in sorted(found_list):
                print info
                if options.verbose:
                    print info.get_verbose_info()
            
        scanner = None
        current_freq += channels_num * 0.2e6