/*!
 * \file galileo_e5a_noncoherent_iq_acquisition_caf_cc.cc
 * \brief Adapts a PCPS acquisition block to an AcquisitionInterface for
 *  Galileo E5a data and pilot Signals
 * \author Marc Sales, 2014. marcsales92(at)gmail.com
 * \based on work from:
 * 		<ul>
 *          <li> Javier Arribas, 2011. jarribas(at)cttc.es
 *          <li> Luis Esteve, 2012. luis(at)epsilon-formacion.com
 *          <li> Marc Molina, 2013. marc.molina.pena@gmail.com
 *          </ul>
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2015  (see AUTHORS file for a list of contributors)
 *
 * GNSS-SDR is a software defined Global Navigation
 *          Satellite Systems receiver
 *
 * This file is part of GNSS-SDR.
 *
 * GNSS-SDR 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 of the License, or
 * (at your option) any later version.
 *
 * GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
 *
 * -------------------------------------------------------------------------
 */

#include "galileo_e5a_noncoherent_iq_acquisition_caf_cc.h"
#include <sstream>
#include <gnuradio/io_signature.h>
#include <glog/logging.h>
#include <volk/volk.h>
#include <volk_gnsssdr/volk_gnsssdr.h>
#include "control_message_factory.h"

using google::LogMessage;

galileo_e5a_noncoherentIQ_acquisition_caf_cc_sptr galileo_e5a_noncoherentIQ_make_acquisition_caf_cc(
        unsigned int sampled_ms,
        unsigned int max_dwells,
        unsigned int doppler_max, long freq, long fs_in,
        int samples_per_ms, int samples_per_code,
        bool bit_transition_flag,
        gr::msg_queue::sptr queue, bool dump,
        std::string dump_filename,
        bool both_signal_components_,
        int CAF_window_hz_,
        int Zero_padding_)
{

    return galileo_e5a_noncoherentIQ_acquisition_caf_cc_sptr(
            new galileo_e5a_noncoherentIQ_acquisition_caf_cc(sampled_ms, max_dwells, doppler_max, freq, fs_in, samples_per_ms,
                    samples_per_code, bit_transition_flag, queue, dump, dump_filename, both_signal_components_, CAF_window_hz_, Zero_padding_));
}

galileo_e5a_noncoherentIQ_acquisition_caf_cc::galileo_e5a_noncoherentIQ_acquisition_caf_cc(
        unsigned int sampled_ms,
        unsigned int max_dwells,
        unsigned int doppler_max, long freq, long fs_in,
        int samples_per_ms, int samples_per_code,
        bool bit_transition_flag,
        gr::msg_queue::sptr queue, bool dump,
        std::string dump_filename,
        bool both_signal_components_,
        int CAF_window_hz_,
        int Zero_padding_) :
            gr::block("galileo_e5a_noncoherentIQ_acquisition_caf_cc",
                    gr::io_signature::make(1, 1, sizeof(gr_complex)),
                    gr::io_signature::make(0, 0, sizeof(gr_complex)))
{
    d_sample_counter = 0;    // SAMPLE COUNTER
    d_active = false;
    d_state = 0;
    d_queue = queue;
    d_freq = freq;
    d_fs_in = fs_in;
    d_samples_per_ms = samples_per_ms;
    d_samples_per_code = samples_per_code;
    d_max_dwells = max_dwells;
    d_well_count = 0;
    d_doppler_max = doppler_max;
    if (Zero_padding_ > 0)
        {
            d_sampled_ms = 1;
        }
    else
        {
            d_sampled_ms = sampled_ms;
        }
    d_fft_size = sampled_ms * d_samples_per_ms;
    d_mag = 0;
    d_input_power = 0.0;
    d_num_doppler_bins = 0;
    d_bit_transition_flag = bit_transition_flag;
    d_buffer_count = 0;
    d_both_signal_components = both_signal_components_;
    d_CAF_window_hz = CAF_window_hz_;

    d_inbuffer = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
    d_fft_code_I_A = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
    d_magnitudeIA = static_cast<float*>(volk_malloc(d_fft_size * sizeof(float), volk_get_alignment()));

    if (d_both_signal_components == true)
        {
            d_fft_code_Q_A = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
            d_magnitudeQA = static_cast<float*>(volk_malloc(d_fft_size * sizeof(float), volk_get_alignment()));
        }
    else
        {
            d_fft_code_Q_A = 0;
            d_magnitudeQA = 0;
        }
    // IF COHERENT INTEGRATION TIME > 1
    if (d_sampled_ms > 1)
        {
            d_fft_code_I_B = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
            d_magnitudeIB = static_cast<float*>(volk_malloc(d_fft_size * sizeof(float), volk_get_alignment()));
            if (d_both_signal_components == true)
                {
                    d_fft_code_Q_B = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
                    d_magnitudeQB = static_cast<float*>(volk_malloc(d_fft_size * sizeof(float), volk_get_alignment()));
                }
            else
                {
                    d_fft_code_Q_B = 0;
                    d_magnitudeQB = 0;
                }
        }
    else
        {
            d_fft_code_I_B = 0;
            d_magnitudeIB = 0;
            d_fft_code_Q_B = 0;
            d_magnitudeQB = 0;
        }

    // Direct FFT
    d_fft_if = new gr::fft::fft_complex(d_fft_size, true);

    // Inverse FFT
    d_ifft = new gr::fft::fft_complex(d_fft_size, false);

    // For dumping samples into a file
    d_dump = dump;
    d_dump_filename = dump_filename;

    d_doppler_resolution = 0;
    d_threshold = 0;
    d_doppler_step = 250;
    d_grid_doppler_wipeoffs = 0;
    d_gnss_synchro = 0;
    d_code_phase = 0;
    d_doppler_freq = 0;
    d_test_statistics = 0;
    d_CAF_vector = 0;
    d_CAF_vector_I = 0;
    d_CAF_vector_Q = 0;
    d_channel = 0;
    d_gr_stream_buffer = 0;
}

galileo_e5a_noncoherentIQ_acquisition_caf_cc::~galileo_e5a_noncoherentIQ_acquisition_caf_cc()
{
    if (d_num_doppler_bins > 0)
        {
            for (unsigned int i = 0; i < d_num_doppler_bins; i++)
                {
                    volk_free(d_grid_doppler_wipeoffs[i]);
                }
            delete[] d_grid_doppler_wipeoffs;
        }

    volk_free(d_inbuffer);
    volk_free(d_fft_code_I_A);
    volk_free(d_magnitudeIA);
    if (d_both_signal_components == true)
        {
            volk_free(d_fft_code_Q_A);
            volk_free(d_magnitudeQA);
        }
    // IF INTEGRATION TIME > 1
    if (d_sampled_ms > 1)
        {
            volk_free(d_fft_code_I_B);
            volk_free(d_magnitudeIB);
            if (d_both_signal_components == true)
                {
                    volk_free(d_fft_code_Q_B);
                    volk_free(d_magnitudeQB);
                }
        }
    if (d_CAF_window_hz > 0)
        {
            volk_free(d_CAF_vector);
            volk_free(d_CAF_vector_I);
            if (d_both_signal_components == true)
                {
                    volk_free(d_CAF_vector_Q);
                }
        }

    delete d_fft_if;
    delete d_ifft;

    if (d_dump)
        {
            d_dump_file.close();
        }
}


void galileo_e5a_noncoherentIQ_acquisition_caf_cc::set_local_code(std::complex<float> * codeI, std::complex<float> * codeQ )
{
    // DATA SIGNAL
    // Three replicas of data primary code. CODE A: (1,1,1)
    memcpy(d_fft_if->get_inbuf(), codeI, sizeof(gr_complex)*d_fft_size);

    d_fft_if->execute(); // We need the FFT of local code

    //Conjugate the local code
    volk_32fc_conjugate_32fc(d_fft_code_I_A,d_fft_if->get_outbuf(),d_fft_size);

    // SAME FOR PILOT SIGNAL
    if (d_both_signal_components == true)
        {
            // Three replicas of pilot primary code. CODE A: (1,1,1)
            memcpy(d_fft_if->get_inbuf(), codeQ, sizeof(gr_complex)*d_fft_size);

            d_fft_if->execute(); // We need the FFT of local code

            //Conjugate the local code
            volk_32fc_conjugate_32fc(d_fft_code_Q_A,d_fft_if->get_outbuf(),d_fft_size);
        }
    // IF INTEGRATION TIME > 1 code, we need to evaluate the other possible combination
    // Note: max integration time allowed = 3ms (dealt in adapter)
    if (d_sampled_ms > 1)
        {
            // DATA CODE B: First replica is inverted (0,1,1)
            volk_32fc_s32fc_multiply_32fc(&(d_fft_if->get_inbuf())[0],
                    &codeI[0], gr_complex(-1,0),
                    d_samples_per_code);

            d_fft_if->execute(); // We need the FFT of local code

            //Conjugate the local code
            volk_32fc_conjugate_32fc(d_fft_code_I_B,d_fft_if->get_outbuf(),d_fft_size);

            if (d_both_signal_components == true)
                {
                    // PILOT CODE B: First replica is inverted (0,1,1)
                    volk_32fc_s32fc_multiply_32fc(&(d_fft_if->get_inbuf())[0],
                            &codeQ[0], gr_complex(-1,0),
                            d_samples_per_code);
                    d_fft_if->execute(); // We need the FFT of local code

                    //Conjugate the local code
                    volk_32fc_conjugate_32fc(d_fft_code_Q_B,d_fft_if->get_outbuf(),d_fft_size);
                }
        }
}

void galileo_e5a_noncoherentIQ_acquisition_caf_cc::init()
{
    d_gnss_synchro->Flag_valid_acquisition = false;
    d_gnss_synchro->Flag_valid_symbol_output = false;
    d_gnss_synchro->Flag_valid_pseudorange = false;
    d_gnss_synchro->Flag_valid_word = false;
    d_gnss_synchro->Flag_preamble = false;

    d_gnss_synchro->Acq_delay_samples = 0.0;
    d_gnss_synchro->Acq_doppler_hz = 0.0;
    d_gnss_synchro->Acq_samplestamp_samples = 0;
    d_mag = 0.0;
    d_input_power = 0.0;
    const double GALILEO_TWO_PI = 6.283185307179600;

    // Count the number of bins
    d_num_doppler_bins = 0;
    for (int doppler = static_cast<int>(-d_doppler_max);
            doppler <= static_cast<int>(d_doppler_max);
            doppler += d_doppler_step)
        {
            d_num_doppler_bins++;
        }

    // Create the carrier Doppler wipeoff signals
    d_grid_doppler_wipeoffs = new gr_complex*[d_num_doppler_bins];
    for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
        {
            d_grid_doppler_wipeoffs[doppler_index] = static_cast<gr_complex*>(volk_malloc(d_fft_size * sizeof(gr_complex), volk_get_alignment()));
            int doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
            float phase_step_rad = GALILEO_TWO_PI * (d_freq + doppler) / static_cast<float>(d_fs_in);
            float _phase[1];
            _phase[0] = 0;
            volk_gnsssdr_s32f_sincos_32fc(d_grid_doppler_wipeoffs[doppler_index], - phase_step_rad, _phase, d_fft_size);
        }

    /* CAF Filtering to resolve doppler ambiguity. Phase and quadrature must be processed
     * separately before non-coherent integration */
    //    if (d_CAF_filter)
    if (d_CAF_window_hz > 0)
        {
            d_CAF_vector = static_cast<float*>(volk_malloc(d_num_doppler_bins * sizeof(float), volk_get_alignment()));
            d_CAF_vector_I = static_cast<float*>(volk_malloc(d_num_doppler_bins * sizeof(float), volk_get_alignment()));
            if (d_both_signal_components == true)
                {
                    d_CAF_vector_Q = static_cast<float*>(volk_malloc(d_num_doppler_bins * sizeof(float), volk_get_alignment()));
                }
        }
}



void galileo_e5a_noncoherentIQ_acquisition_caf_cc::set_state(int state)
{
    d_state = state;
    if (d_state == 1)
        {
            d_gnss_synchro->Acq_delay_samples = 0.0;
            d_gnss_synchro->Acq_doppler_hz = 0.0;
            d_gnss_synchro->Acq_samplestamp_samples = 0;
            d_well_count = 0;
            d_mag = 0.0;
            d_input_power = 0.0;
            d_test_statistics = 0.0;
        }
    else if (d_state == 0)
        {}
    else
        {
            LOG(ERROR) << "State can only be set to 0 or 1";
        }
}




int galileo_e5a_noncoherentIQ_acquisition_caf_cc::general_work(int noutput_items,
        gr_vector_int &ninput_items, gr_vector_const_void_star &input_items,
        gr_vector_void_star &output_items __attribute__((unused)))
{
    /*
     * By J.Arribas, L.Esteve, M.Molina and M.Sales
     * Acquisition strategy (Kay Borre book + CFAR threshold):
     * 1. Compute the input signal power estimation
     * 2. Doppler serial search loop
     * 3. Perform the FFT-based circular convolution (parallel time search)
     * 4. OPTIONAL: CAF filter to avoid doppler ambiguity
     * 5. Record the maximum peak and the associated synchronization parameters
     * 6. Compute the test statistics and compare to the threshold
     * 7. Declare positive or negative acquisition using a message queue
     */

    int acquisition_message = -1; //0=STOP_CHANNEL 1=ACQ_SUCCEES 2=ACQ_FAIL
    /* States: 	0 Stop Channel
     * 		1 Load the buffer until it reaches fft_size
     * 		2 Acquisition algorithm
     * 		3 Positive acquisition
     * 		4 Negative acquisition
     */
    switch (d_state)
    {
    case 0:
        {
            if (d_active)
                {
                    //restart acquisition variables
                    d_gnss_synchro->Acq_delay_samples = 0.0;
                    d_gnss_synchro->Acq_doppler_hz = 0.0;
                    d_gnss_synchro->Acq_samplestamp_samples = 0;
                    d_well_count = 0;
                    d_mag = 0.0;
                    d_input_power = 0.0;
                    d_test_statistics = 0.0;
                    d_state = 1;
                }
            d_sample_counter += ninput_items[0]; // sample counter
            consume_each(ninput_items[0]);

            break;
        }
    case 1:
        {
            const gr_complex *in = (const gr_complex *)input_items[0]; //Get the input samples pointer
            unsigned int buff_increment;
            if (ninput_items[0] + d_buffer_count <= d_fft_size)
                {
                    buff_increment = ninput_items[0];
                }
            else
                {
                    buff_increment = (d_fft_size - d_buffer_count);
                }
            memcpy(&d_inbuffer[d_buffer_count], in, sizeof(gr_complex) * buff_increment);
            // If buffer will be full in next iteration
            if (d_buffer_count >= d_fft_size - d_gr_stream_buffer)
                {
                    d_state = 2;
                }
            d_buffer_count += buff_increment;
            d_sample_counter += buff_increment; // sample counter
            consume_each(buff_increment);
            break;
        }
    case 2:
        {
            // Fill last part of the buffer and reset counter
            const gr_complex *in = (const gr_complex *)input_items[0]; //Get the input samples pointer
            if (d_buffer_count < d_fft_size)
                {
                    memcpy(&d_inbuffer[d_buffer_count], in, sizeof(gr_complex)*(d_fft_size-d_buffer_count));
                }
            d_sample_counter += d_fft_size-d_buffer_count; // sample counter

            // initialize acquisition algorithm
            int doppler;
            unsigned int indext = 0;
            unsigned int indext_IA = 0;
            unsigned int indext_IB = 0;
            unsigned int indext_QA = 0;
            unsigned int indext_QB = 0;
            float magt = 0.0;
            float magt_IA = 0.0;
            float magt_IB = 0.0;
            float magt_QA = 0.0;
            float magt_QB = 0.0;
            float fft_normalization_factor = static_cast<float>(d_fft_size) * static_cast<float>(d_fft_size);
            d_input_power = 0.0;
            d_mag = 0.0;
            d_well_count++;

            DLOG(INFO) << "Channel: " << d_channel
                    << " , doing acquisition of satellite: " << d_gnss_synchro->System << " "<< d_gnss_synchro->PRN
                    << " ,sample stamp: " << d_sample_counter << ", threshold: "
                    << d_threshold << ", doppler_max: " << d_doppler_max
                    << ", doppler_step: " << d_doppler_step;

            // 1- Compute the input signal power estimation
            volk_32fc_magnitude_squared_32f(d_magnitudeIA, d_inbuffer, d_fft_size);
            volk_32f_accumulator_s32f(&d_input_power, d_magnitudeIA, d_fft_size);
            d_input_power /= static_cast<float>(d_fft_size);

            // 2- Doppler frequency search loop
            for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
                {
                    // doppler search steps

                    doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;

                    volk_32fc_x2_multiply_32fc(d_fft_if->get_inbuf(), d_inbuffer,
                            d_grid_doppler_wipeoffs[doppler_index], d_fft_size);

                    // 3- Perform the FFT-based convolution  (parallel time search)
                    // Compute the FFT of the carrier wiped--off incoming signal
                    d_fft_if->execute();

                    // CODE IA
                    // Multiply carrier wiped--off, Fourier transformed incoming signal
                    // with the local FFT'd code reference using SIMD operations with VOLK library
                    volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
                            d_fft_if->get_outbuf(), d_fft_code_I_A, d_fft_size);

                    // compute the inverse FFT
                    d_ifft->execute();

                    // Search maximum
                    volk_32fc_magnitude_squared_32f(d_magnitudeIA, d_ifft->get_outbuf(), d_fft_size);
                    volk_32f_index_max_16u(&indext_IA, d_magnitudeIA, d_fft_size);
                    // Normalize the maximum value to correct the scale factor introduced by FFTW
                    magt_IA = d_magnitudeIA[indext_IA] / (fft_normalization_factor * fft_normalization_factor);

                    if (d_both_signal_components == true)
                        {
                            // REPEAT FOR ALL CODES. CODE_QA
                            volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
                                    d_fft_if->get_outbuf(), d_fft_code_Q_A, d_fft_size);
                            d_ifft->execute();
                            volk_32fc_magnitude_squared_32f(d_magnitudeQA, d_ifft->get_outbuf(), d_fft_size);
                            volk_32f_index_max_16u(&indext_QA, d_magnitudeQA, d_fft_size);
                            magt_QA = d_magnitudeQA[indext_QA] / (fft_normalization_factor * fft_normalization_factor);
                        }
                    if (d_sampled_ms > 1) // If Integration time > 1 code
                        {
                            // REPEAT FOR ALL CODES. CODE_IB
                            volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
                                    d_fft_if->get_outbuf(), d_fft_code_I_B, d_fft_size);
                            d_ifft->execute();
                            volk_32fc_magnitude_squared_32f(d_magnitudeIB, d_ifft->get_outbuf(), d_fft_size);
                            volk_32f_index_max_16u(&indext_IB, d_magnitudeIB, d_fft_size);
                            magt_IB = d_magnitudeIB[indext_IB] / (fft_normalization_factor * fft_normalization_factor);

                            if (d_both_signal_components == true)
                                {
                                    // REPEAT FOR ALL CODES. CODE_QB
                                    volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(),
                                            d_fft_if->get_outbuf(), d_fft_code_Q_B, d_fft_size);
                                    d_ifft->execute();
                                    volk_32fc_magnitude_squared_32f(d_magnitudeQB, d_ifft->get_outbuf(), d_fft_size);
                                    volk_32f_index_max_16u(&indext_QB, d_magnitudeQB, d_fft_size);
                                    magt_QB = d_magnitudeIB[indext_QB] / (fft_normalization_factor * fft_normalization_factor);
                                }
                        }

                    // Integrate noncoherently the two best combinations (I² + Q²)
                    // and store the result in the I channel.
                    // If CAF filter to resolve doppler ambiguity is needed,
                    // peak is stored before non-coherent integration.
                    if (d_sampled_ms > 1) // T_integration > 1 code
                        {
                            if (magt_IA >= magt_IB)
                                {
                                    // if (d_CAF_filter) {d_CAF_vector_I[doppler_index] = magt_IA;}
                                    if (d_CAF_window_hz > 0) {d_CAF_vector_I[doppler_index] = d_magnitudeIA[indext_IA];}
                                    if (d_both_signal_components)
                                        {
                                            // Integrate non-coherently I+Q
                                            if (magt_QA >= magt_QB)
                                                {
                                                    // if (d_CAF_filter) {d_CAF_vector_Q[doppler_index] = magt_QA;}
                                                    if (d_CAF_window_hz > 0) {d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];}
                                                    for (unsigned int i=0; i<d_fft_size; i++)
                                                        {
                                                            d_magnitudeIA[i] += d_magnitudeQA[i];
                                                        }
                                                }
                                            else
                                                {
                                                    // if (d_CAF_filter) {d_CAF_vector_Q[doppler_index] = magt_QB;}
                                                    if (d_CAF_window_hz > 0) {d_CAF_vector_Q[doppler_index] = d_magnitudeQB[indext_QB];}
                                                    for (unsigned int i=0; i<d_fft_size; i++)
                                                        {
                                                            d_magnitudeIA[i] += d_magnitudeQB[i];
                                                        }
                                                }
                                        }
                                    volk_32f_index_max_16u(&indext, d_magnitudeIA, d_fft_size);
                                    magt = d_magnitudeIA[indext] / (fft_normalization_factor * fft_normalization_factor);
                                }
                            else
                                {
                                    // if (d_CAF_filter) {d_CAF_vector_I[doppler_index] = magt_IB;}
                                    if (d_CAF_window_hz > 0) {d_CAF_vector_I[doppler_index] = d_magnitudeIB[indext_IB];}
                                    if (d_both_signal_components)
                                        {
                                            // Integrate non-coherently I+Q
                                            if (magt_QA >= magt_QB)
                                                {
                                                    //if (d_CAF_filter) {d_CAF_vector_Q[doppler_index] = magt_QA;}
                                                    if (d_CAF_window_hz > 0) {d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];}
                                                    for (unsigned int i=0; i<d_fft_size; i++)
                                                        {
                                                            d_magnitudeIB[i] += d_magnitudeQA[i];
                                                        }
                                                }
                                            else
                                                {
                                                    // if (d_CAF_filter) {d_CAF_vector_Q[doppler_index] = magt_QB;}
                                                    if (d_CAF_window_hz > 0) {d_CAF_vector_Q[doppler_index] = d_magnitudeQB[indext_QB];}
                                                    for (unsigned int i=0; i<d_fft_size; i++)
                                                        {
                                                            d_magnitudeIB[i] += d_magnitudeQB[i];
                                                        }
                                                }
                                        }
                                    volk_32f_index_max_16u(&indext, d_magnitudeIB, d_fft_size);
                                    magt = d_magnitudeIB[indext] / (fft_normalization_factor * fft_normalization_factor);
                                }
                        }
                    else
                        {
                            // if (d_CAF_filter) {d_CAF_vector_I[doppler_index] = magt_IA;}
                            if (d_CAF_window_hz > 0) {d_CAF_vector_I[doppler_index] = d_magnitudeIA[indext_IA];}
                            if (d_both_signal_components)
                                {
                                    // if (d_CAF_filter) {d_CAF_vector_Q[doppler_index] = magt_QA;}
                                    if (d_CAF_window_hz > 0) {d_CAF_vector_Q[doppler_index] = d_magnitudeQA[indext_QA];}
                                    // NON-Coherent integration of only 1 code
                                    for (unsigned int i=0; i<d_fft_size; i++)
                                        {
                                            d_magnitudeIA[i] += d_magnitudeQA[i];
                                        }
                                }
                            volk_32f_index_max_16u(&indext, d_magnitudeIA, d_fft_size);
                            magt = d_magnitudeIA[indext] / (fft_normalization_factor * fft_normalization_factor);
                        }

                    // 4- record the maximum peak and the associated synchronization parameters
                    if (d_mag < magt)
                        {
                            d_mag = magt;
                            // In case that d_bit_transition_flag = true, we compare the potentially
                            // new maximum test statistics (d_mag/d_input_power) with the value in
                            // d_test_statistics. When the second dwell is being processed, the value
                            // of d_mag/d_input_power could be lower than d_test_statistics (i.e,
                            // the maximum test statistics in the previous dwell is greater than
                            // current d_mag/d_input_power). Note that d_test_statistics is not
                            // restarted between consecutive dwells in multidwell operation.
                            if (d_test_statistics < (d_mag / d_input_power) || !d_bit_transition_flag)
                                {
                                    d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % d_samples_per_code);
                                    d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
                                    d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter;

                                    // 5- Compute the test statistics and compare to the threshold
                                    d_test_statistics = d_mag / d_input_power;
                                }
                        }

                    // Record results to file if required
                    if (d_dump)
                        {
                            std::stringstream filename;
                            std::streamsize n = sizeof(float) * (d_fft_size); // noncomplex file write
                            filename.str("");
                            filename << "../data/test_statistics_E5a_sat_"
                                    << d_gnss_synchro->PRN << "_doppler_" <<  doppler << ".dat";
                            d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
                            if (d_sampled_ms > 1) // If integration time > 1 code
                                {
                                    if (magt_IA >= magt_IB)
                                        {
                                            d_dump_file.write((char*)d_magnitudeIA, n);
                                        }
                                    else
                                        {
                                            d_dump_file.write((char*)d_magnitudeIB, n);
                                        }
                                }
                            else
                                {
                                    d_dump_file.write((char*)d_magnitudeIA, n);
                                }
                            d_dump_file.close();
                        }
                }
            // std::cout << "d_mag " << d_mag << ".d_sample_counter " << d_sample_counter << ". acq delay " << d_gnss_synchro->Acq_delay_samples<< " indext "<< indext << std::endl;
            // 6 OPTIONAL: CAF filter to avoid Doppler ambiguity in bit transition.
            if (d_CAF_window_hz > 0)
                {
                    int CAF_bins_half;
                    float* accum = static_cast<float*>(volk_malloc(sizeof(float), volk_get_alignment()));
                    CAF_bins_half = d_CAF_window_hz / (2 * d_doppler_step);
                    float weighting_factor;
                    weighting_factor = 0.5 / static_cast<float>(CAF_bins_half);
                    // weighting_factor = 0;
                    // std::cout << "weighting_factor " << weighting_factor << std::endl;
                    // Initialize first iterations
                    for (int doppler_index = 0; doppler_index < CAF_bins_half; doppler_index++)
                        {
                            d_CAF_vector[doppler_index] = 0;
                            // volk_32f_accumulator_s32f_a(&d_CAF_vector[doppler_index], d_CAF_vector_I, CAF_bins_half+doppler_index+1);
                            for (int i = 0; i < CAF_bins_half + doppler_index + 1; i++)
                                {
                                    d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1 - weighting_factor * static_cast<unsigned int>((doppler_index - i)));
                                }
                            // d_CAF_vector[doppler_index] /= CAF_bins_half+doppler_index+1;
                            d_CAF_vector[doppler_index] /= 1 + CAF_bins_half + doppler_index - weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2 - weighting_factor * doppler_index * (doppler_index + 1) / 2; // triangles = [n*(n+1)/2]
                            if (d_both_signal_components)
                                {
                                    accum[0] = 0;
                                    // volk_32f_accumulator_s32f_a(&accum[0], d_CAF_vector_Q, CAF_bins_half+doppler_index+1);
                                    for (int i = 0; i < CAF_bins_half + doppler_index + 1; i++)
                                        {
                                            accum[0] += d_CAF_vector_Q[i] * (1 - weighting_factor * static_cast<unsigned int>(abs(doppler_index - i)));
                                        }
                                    // accum[0] /= CAF_bins_half+doppler_index+1;
                                    accum[0] /= 1 + CAF_bins_half + doppler_index - weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2 - weighting_factor * doppler_index * (doppler_index + 1) / 2; // triangles = [n*(n+1)/2]
                                    d_CAF_vector[doppler_index] += accum[0];
                                }
                        }
                    // Body loop
                    for (unsigned int doppler_index = CAF_bins_half; doppler_index < d_num_doppler_bins - CAF_bins_half; doppler_index++)
                        {
                            d_CAF_vector[doppler_index] = 0;
                            // volk_32f_accumulator_s32f_a(&d_CAF_vector[doppler_index], &d_CAF_vector_I[doppler_index-CAF_bins_half], 2*CAF_bins_half+1);
                            for (int i = doppler_index - CAF_bins_half; i < static_cast<int>(doppler_index + CAF_bins_half + 1); i++)
                                {
                                    d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1 - weighting_factor * static_cast<unsigned int>((doppler_index - i)));
                                }
                            // d_CAF_vector[doppler_index] /= 2*CAF_bins_half+1;
                            d_CAF_vector[doppler_index] /= 1 + 2 * CAF_bins_half - 2 * weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2;
                            if (d_both_signal_components)
                                {
                                    accum[0] = 0;
                                    // volk_32f_accumulator_s32f_a(&accum[0], &d_CAF_vector_Q[doppler_index-CAF_bins_half], 2*CAF_bins_half);
                                    for (int i = doppler_index-CAF_bins_half; i < static_cast<int>(doppler_index + CAF_bins_half + 1); i++)
                                        {
                                            accum[0] += d_CAF_vector_Q[i] * (1 - weighting_factor * static_cast<unsigned int>((doppler_index - i)));
                                        }
                                    // accum[0] /= 2*CAF_bins_half+1;
                                    accum[0] /= 1 + 2 * CAF_bins_half - 2 * weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2;
                                    d_CAF_vector[doppler_index] += accum[0];
                                }
                        }
                    // Final iterations
                    for (int doppler_index = d_num_doppler_bins - CAF_bins_half; doppler_index < static_cast<int>(d_num_doppler_bins); doppler_index++)
                        {
                            d_CAF_vector[doppler_index] = 0;
                            // volk_32f_accumulator_s32f_a(&d_CAF_vector[doppler_index], &d_CAF_vector_I[doppler_index-CAF_bins_half], CAF_bins_half + (d_num_doppler_bins-doppler_index));
                            for (int i = doppler_index - CAF_bins_half; i < static_cast<int>(d_num_doppler_bins); i++)
                                {
                                    d_CAF_vector[doppler_index] += d_CAF_vector_I[i] * (1 - weighting_factor * (abs(doppler_index - i)));
                                }
                            // d_CAF_vector[doppler_index] /= CAF_bins_half+(d_num_doppler_bins-doppler_index);
                            d_CAF_vector[doppler_index] /= 1 + CAF_bins_half + (d_num_doppler_bins - doppler_index - 1) - weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2 - weighting_factor * (d_num_doppler_bins - doppler_index - 1) * (d_num_doppler_bins - doppler_index) / 2;
                            if (d_both_signal_components)
                                {
                                    accum[0] = 0;
                                    // volk_32f_accumulator_s32f_a(&accum[0], &d_CAF_vector_Q[doppler_index-CAF_bins_half], CAF_bins_half + (d_num_doppler_bins-doppler_index));
                                    for (int i = doppler_index-CAF_bins_half; i < static_cast<int>(d_num_doppler_bins); i++)
                                        {
                                            accum[0] += d_CAF_vector_Q[i] * (1 - weighting_factor * (abs(doppler_index - i)));
                                        }
                                    // accum[0] /= CAF_bins_half+(d_num_doppler_bins-doppler_index);
                                    accum[0] /= 1 + CAF_bins_half + (d_num_doppler_bins - doppler_index - 1) - weighting_factor * CAF_bins_half * (CAF_bins_half + 1) / 2 - weighting_factor * (d_num_doppler_bins - doppler_index - 1) * (d_num_doppler_bins - doppler_index) / 2;
                                    d_CAF_vector[doppler_index] += accum[0];
                                }
                        }

                    // Recompute the maximum doppler peak
                    volk_32f_index_max_16u(&indext, d_CAF_vector, d_num_doppler_bins);
                    doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * indext;
                    d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
                    // Dump if required, appended at the end of the file
                    if (d_dump)
                        {
                            std::stringstream filename;
                            std::streamsize n = sizeof(float) * (d_num_doppler_bins); // noncomplex file write
                            filename.str("");
                            filename << "../data/test_statistics_E5a_sat_" << d_gnss_synchro->PRN << "_CAF.dat";
                            d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
                            d_dump_file.write((char*)d_CAF_vector, n);
                            d_dump_file.close();
                        }
                    volk_free(accum);
                }

            if (d_well_count == d_max_dwells)
                {
                    if (d_test_statistics > d_threshold)
                        {
                            d_state = 3; // Positive acquisition
                        }
                    else
                        {
                            d_state = 4; // Negative acquisition
                        }
                }
            else
                {
                    d_state = 1;
                }

            consume_each(d_fft_size - d_buffer_count);
            d_buffer_count = 0;
            break;
        }
    case 3:
        {
            // 7.1- Declare positive acquisition using a message queue
            DLOG(INFO) << "positive acquisition";
            DLOG(INFO) << "satellite " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN;
            DLOG(INFO) << "sample_stamp " << d_sample_counter;
            DLOG(INFO) << "test statistics value " << d_test_statistics;
            DLOG(INFO) << "test statistics threshold " << d_threshold;
            DLOG(INFO) << "code phase " << d_gnss_synchro->Acq_delay_samples;
            DLOG(INFO) << "doppler " << d_gnss_synchro->Acq_doppler_hz;
            DLOG(INFO) << "magnitude " << d_mag;
            DLOG(INFO) << "input signal power " << d_input_power;

            d_active = false;
            d_state = 0;

            acquisition_message = 1;
            this->message_port_pub(pmt::mp("events"), pmt::from_long(acquisition_message));
            d_sample_counter += ninput_items[0]; // sample counter
            consume_each(ninput_items[0]);
            break;
        }
    case 4:
        {
            // 7.2- Declare negative acquisition using a message queue
            DLOG(INFO) << "negative acquisition";
            DLOG(INFO) << "satellite " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN;
            DLOG(INFO) << "sample_stamp " << d_sample_counter;
            DLOG(INFO) << "test statistics value " << d_test_statistics;
            DLOG(INFO) << "test statistics threshold " << d_threshold;
            DLOG(INFO) << "code phase " << d_gnss_synchro->Acq_delay_samples;
            DLOG(INFO) << "doppler " << d_gnss_synchro->Acq_doppler_hz;
            DLOG(INFO) << "magnitude " << d_mag;
            DLOG(INFO) << "input signal power " << d_input_power;

            d_active = false;
            d_state = 0;

            d_sample_counter += ninput_items[0]; // sample counter
            consume_each(ninput_items[0]);
            acquisition_message = 2;
            this->message_port_pub(pmt::mp("events"), pmt::from_long(acquisition_message));
            break;
        }
    }

    return noutput_items;
}