#!/usr/bin/env python
#
# Copyright 2012-2014 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 __future__ import division

from gnuradio import gr, gr_unittest, filter, blocks
import math

def sig_source_c(samp_rate, freq, amp, N):
    t = [float(x) / samp_rate for x in range(N)]
    y = [math.cos(2.*math.pi*freq*x) + \
                1j*math.sin(2.*math.pi*freq*x) for x in t]
    return y

def run_test(tb, channel, fft_rotate, fft_filter):
        N = 1000         # number of samples to use
        M = 5            # Number of channels
        fs = 5000.0      # baseband sampling rate
        ifs = M*fs       # input samp rate to decimator

        taps = filter.firdes.low_pass_2(1, ifs, fs / 2, fs / 10,
                                        attenuation_dB=80,
                                        window=filter.firdes.WIN_BLACKMAN_hARRIS)

        signals = list()
        add = blocks.add_cc()
        freqs = [-230., 121., 110., -513., 203.]
        Mch = ((len(freqs)-1) // 2 + channel) % len(freqs)
        for i in range(len(freqs)):
            f = freqs[i] + (M // 2-M+i+1)*fs
            data = sig_source_c(ifs, f, 1, N)
            signals.append(blocks.vector_source_c(data))
            tb.connect(signals[i], (add,i))

        s2ss = blocks.stream_to_streams(gr.sizeof_gr_complex, M)
        pfb = filter.pfb_decimator_ccf(M, taps, channel, fft_rotate, fft_filter)
        snk = blocks.vector_sink_c()

        tb.connect(add, s2ss)
        for i in range(M):
            tb.connect((s2ss,i), (pfb,i))
        tb.connect(pfb, snk)
        tb.run()

        L = len(snk.data())

        # Adjusted phase rotations for data
        phase = [ 0.11058476216852586,
                  4.5108246571401693,
                  3.9739891674564594,
                  2.2820531095511924,
                  1.3782797467397869]
        phase = phase[channel]

        # Filter delay is the normal delay of each arm
        tpf = math.ceil(len(taps) / float(M))
        delay = -(tpf - 1.0) / 2.0
        delay = int(delay)

        # Create a time scale that's delayed to match the filter delay
        t = [float(x) / fs for x in range(delay, L+delay)]

        # Create known data as complex sinusoids for the baseband freq
        # of the extracted channel is due to decimator output order.
        expected_data = [math.cos(2.*math.pi*freqs[Mch]*x+phase) + \
                                1j*math.sin(2.*math.pi*freqs[Mch]*x+phase) for x in t]
        dst_data = snk.data()

        return (dst_data, expected_data)

class test_pfb_decimator(gr_unittest.TestCase):

    def setUp(self):
        self.tb = gr.top_block()

    def tearDown(self):
        self.tb = None

    def test_000(self):
        Ntest = 50
        dst_data0, expected_data0 = run_test(self.tb, 0, False, False)
        dst_data1, expected_data1 = run_test(self.tb, 0, False, True)
        dst_data2, expected_data2 = run_test(self.tb, 0, True, False)
        dst_data3, expected_data3 = run_test(self.tb, 0, True, True)

        self.assertComplexTuplesAlmostEqual(expected_data0[-Ntest:], dst_data0[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data1[-Ntest:], dst_data1[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data2[-Ntest:], dst_data2[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data3[-Ntest:], dst_data3[-Ntest:], 4)

    def test_001(self):
        Ntest = 50
        dst_data0, expected_data0 = run_test(self.tb, 1, False, False)
        dst_data1, expected_data1 = run_test(self.tb, 1, False, True)
        dst_data2, expected_data2 = run_test(self.tb, 1, True, False)
        dst_data3, expected_data3 = run_test(self.tb, 1, True, True)

        self.assertComplexTuplesAlmostEqual(expected_data0[-Ntest:], dst_data0[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data1[-Ntest:], dst_data1[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data2[-Ntest:], dst_data2[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data3[-Ntest:], dst_data3[-Ntest:], 4)

    def test_002(self):
        Ntest = 50
        dst_data0, expected_data0 = run_test(self.tb, 2, False, False)
        dst_data1, expected_data1 = run_test(self.tb, 2, False, True)
        dst_data2, expected_data2 = run_test(self.tb, 2, True, False)
        dst_data3, expected_data3 = run_test(self.tb, 2, True, True)

        self.assertComplexTuplesAlmostEqual(expected_data0[-Ntest:], dst_data0[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data1[-Ntest:], dst_data1[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data2[-Ntest:], dst_data2[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data3[-Ntest:], dst_data3[-Ntest:], 4)

    def test_003(self):
        Ntest = 50
        dst_data0, expected_data0 = run_test(self.tb, 3, False, False)
        dst_data1, expected_data1 = run_test(self.tb, 3, False, True)
        dst_data2, expected_data2 = run_test(self.tb, 3, True, False)
        dst_data3, expected_data3 = run_test(self.tb, 3, True, True)

        self.assertComplexTuplesAlmostEqual(expected_data0[-Ntest:], dst_data0[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data1[-Ntest:], dst_data1[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data2[-Ntest:], dst_data2[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data3[-Ntest:], dst_data3[-Ntest:], 4)

    def test_004(self):
        Ntest = 50
        dst_data0, expected_data0 = run_test(self.tb, 4, False, False)
        dst_data1, expected_data1 = run_test(self.tb, 4, False, True)
        dst_data2, expected_data2 = run_test(self.tb, 4, True, False)
        dst_data3, expected_data3 = run_test(self.tb, 4, True, True)

        self.assertComplexTuplesAlmostEqual(expected_data0[-Ntest:], dst_data0[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data1[-Ntest:], dst_data1[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data2[-Ntest:], dst_data2[-Ntest:], 4)
        self.assertComplexTuplesAlmostEqual(expected_data3[-Ntest:], dst_data3[-Ntest:], 4)

if __name__ == '__main__':
    gr_unittest.run(test_pfb_decimator, "test_pfb_decimator.xml")
