/*!
 * \file gps_l1_ca_dll_pll_tracking_test_fpga.cc
 * \brief  This class implements a tracking test for Galileo_E5a_DLL_PLL_Tracking
 *  implementation based on some input parameters.
 * \author Marc Majoral, 2017. mmajoral(at)cttc.cat
 * \author Javier Arribas, 2017. jarribas(at)cttc.es
 *
 *
 * -----------------------------------------------------------------------------
 *
 * GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
 * This file is part of GNSS-SDR.
 *
 * Copyright (C) 2012-2020  (see AUTHORS file for a list of contributors)
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * -----------------------------------------------------------------------------
 */

#include "GPS_L1_CA.h"
#include "gnss_block_interface.h"
#include "gnss_synchro.h"
#include "gps_l1_ca_dll_pll_tracking_fpga.h"
#include "in_memory_configuration.h"
#include "interleaved_byte_to_complex_short.h"
#include "signal_generator_flags.h"
#include "tracking_dump_reader.h"
#include "tracking_interface.h"
#include "tracking_true_obs_reader.h"
#include <armadillo>
#include <boost/thread.hpp>  // to test the FPGA we have to create a simultaneous task to send the samples using the DMA and stop the test
#include <gnuradio/analog/sig_source_waveform.h>
#include <gnuradio/blocks/file_source.h>
#include <gnuradio/blocks/interleaved_char_to_complex.h>
#include <gnuradio/blocks/null_sink.h>
#include <gnuradio/blocks/skiphead.h>
#include <gnuradio/top_block.h>
#include <gtest/gtest.h>
#include <pmt/pmt.h>
#include <chrono>
#include <cstdio>  // FPGA read input file
#include <fcntl.h>
#include <iomanip>
#include <iostream>
#include <unistd.h>
#include <utility>

#if USE_GLOG_AND_GFLAGS
#include <gflags/gflags.h>
#include <glog/logging.h>
#else
#include <absl/flags/flag.h>
#include <absl/log/log.h>
#endif
#if HAS_GENERIC_LAMBDA
#else
#include <boost/bind/bind.hpp>
#endif
#ifdef GR_GREATER_38
#include <gnuradio/analog/sig_source.h>
#else
#include <gnuradio/analog/sig_source_c.h>
#endif
#if PMT_USES_BOOST_ANY
namespace wht = boost;
#else
namespace wht = std;
#endif

#define DMA_TRACK_TRANSFER_SIZE 2046  // DMA transfer size for tracking
#define MIN_SAMPLES_REMAINING 20000   // number of remaining samples in the DMA that causes the CPU to stop the flowgraph (it has to be a bit alrger than 2x max packet size)
#define FIVE_SECONDS 5000000          // five seconds in microseconds

void send_tracking_gps_input_samples(FILE *rx_signal_file,
    int num_remaining_samples, const gr::top_block_sptr &top_block)
{
    int num_samples_transferred = 0;   // number of samples that have been transferred to the DMA so far
    static int flowgraph_stopped = 0;  // flag to indicate if the flowgraph is stopped already
    char *buffer_DMA;                  // temporary buffer to store the samples to be sent to the DMA
    int dma_descr;                     // DMA descriptor
    dma_descr = open("/dev/loop_tx", O_WRONLY);
    if (dma_descr < 0)
        {
            std::cerr << "Can't open loop device\n";
            return;
        }

    buffer_DMA = reinterpret_cast<char *>(malloc(DMA_TRACK_TRANSFER_SIZE));
    if (!buffer_DMA)
        {
            std::cerr << "Memory error!\n";
            close(dma_descr);
            return;
        }

    while (num_remaining_samples > 0)
        {
            if (num_remaining_samples < MIN_SAMPLES_REMAINING)
                {
                    if (flowgraph_stopped == 0)
                        {
                            // stop top module
                            top_block->stop();
                            flowgraph_stopped = 1;
                        }
                }
            if (num_remaining_samples > DMA_TRACK_TRANSFER_SIZE)
                {
                    size_t result = fread(buffer_DMA, DMA_TRACK_TRANSFER_SIZE, 1, rx_signal_file);
                    if (result != DMA_TRACK_TRANSFER_SIZE)
                        {
                            std::cerr << "Error reading from DMA\n";
                        }

                    assert(DMA_TRACK_TRANSFER_SIZE == write(dma_descr, &buffer_DMA[0], DMA_TRACK_TRANSFER_SIZE));
                    num_remaining_samples = num_remaining_samples - DMA_TRACK_TRANSFER_SIZE;
                    num_samples_transferred = num_samples_transferred + DMA_TRACK_TRANSFER_SIZE;
                }
            else
                {
                    size_t result = fread(buffer_DMA, num_remaining_samples, 1, rx_signal_file);
                    if (static_cast<int>(result) != num_remaining_samples)
                        {
                            std::cerr << "Error reading from DMA\n";
                        }
                    assert(num_remaining_samples == write(dma_descr, &buffer_DMA[0], num_remaining_samples));
                    num_samples_transferred = num_samples_transferred + num_remaining_samples;
                    num_remaining_samples = 0;
                }
        }

    free(buffer_DMA);
    close(dma_descr);
}


// thread that sends the samples to the FPGA
void sending_thread(const gr::top_block_sptr &top_block, const char *file_name)
{
    // file descriptor
    FILE *rx_signal_file;  // file descriptor
    int file_length;       // length of the file containing the received samples

    rx_signal_file = fopen(file_name, "rb");
    if (!rx_signal_file)
        {
            std::cerr << "Unable to open file!\n";
            return;
        }

    fseek(rx_signal_file, 0, SEEK_END);
    file_length = ftell(rx_signal_file);
    fseek(rx_signal_file, 0, SEEK_SET);

    usleep(FIVE_SECONDS);  // wait for some time to give time to the other thread to program the device

    // send_tracking_gps_input_samples(dma_descr, rx_signal_file, file_length);
    send_tracking_gps_input_samples(rx_signal_file, file_length, top_block);

    fclose(rx_signal_file);
}


// ######## GNURADIO BLOCK MESSAGE RECEIVER #########
class GpsL1CADllPllTrackingTestFpga_msg_rx;

using GpsL1CADllPllTrackingTestFpga_msg_rx_sptr = gnss_shared_ptr<GpsL1CADllPllTrackingTestFpga_msg_rx>;

GpsL1CADllPllTrackingTestFpga_msg_rx_sptr GpsL1CADllPllTrackingTestFpga_msg_rx_make();


class GpsL1CADllPllTrackingTestFpga_msg_rx : public gr::block
{
private:
    friend GpsL1CADllPllTrackingTestFpga_msg_rx_sptr GpsL1CADllPllTrackingTestFpga_msg_rx_make();
    void msg_handler_channel_events(const pmt::pmt_t &msg);
    GpsL1CADllPllTrackingTestFpga_msg_rx();

public:
    int rx_message{0};
    ~GpsL1CADllPllTrackingTestFpga_msg_rx() override;  //!< Default destructor
};


GpsL1CADllPllTrackingTestFpga_msg_rx_sptr GpsL1CADllPllTrackingTestFpga_msg_rx_make()
{
    return GpsL1CADllPllTrackingTestFpga_msg_rx_sptr(
        new GpsL1CADllPllTrackingTestFpga_msg_rx());
}


void GpsL1CADllPllTrackingTestFpga_msg_rx::msg_handler_channel_events(const pmt::pmt_t &msg)
{
    try
        {
            int64_t message = pmt::to_long(msg);
            rx_message = message;
        }
    catch (const wht::bad_any_cast &e)
        {
            LOG(WARNING) << "msg_handler_channel_events Bad any_cast: " << e.what();
            rx_message = 0;
        }
}


GpsL1CADllPllTrackingTestFpga_msg_rx::GpsL1CADllPllTrackingTestFpga_msg_rx()
    : gr::block("GpsL1CADllPllTrackingTestFpga_msg_rx",
          gr::io_signature::make(0, 0, 0),
          gr::io_signature::make(0, 0, 0))
{
    this->message_port_register_in(pmt::mp("events"));
    this->set_msg_handler(pmt::mp("events"),
#if HAS_GENERIC_LAMBDA
        [this](auto &&PH1) { msg_handler_channel_events(std::forward<decltype(PH1)>(PH1)); });
#else
#if USE_BOOST_BIND_PLACEHOLDERS
        boost::bind(&GpsL1CADllPllTrackingTestFpga_msg_rx::msg_handler_channel_events, this, boost::placeholders::_1));
#else
        boost::bind(&GpsL1CADllPllTrackingTestFpga_msg_rx::msg_handler_channel_events, this, _1));
#endif
#endif
}


GpsL1CADllPllTrackingTestFpga_msg_rx::~GpsL1CADllPllTrackingTestFpga_msg_rx() = default;


// ###########################################################

class GpsL1CADllPllTrackingTestFpga : public ::testing::Test
{
public:
    std::string generator_binary;
    std::string p1;
    std::string p2;
    std::string p3;
    std::string p4;
    std::string p5;

#if USE_GLOG_AND_GFLAGS
    const int baseband_sampling_freq = FLAGS_fs_gen_sps;
    std::string filename_rinex_obs = FLAGS_filename_rinex_obs;
    std::string filename_raw_data = FLAGS_filename_raw_data;
#else
    const int baseband_sampling_freq = absl::GetFlag(FLAGS_fs_gen_sps);
    std::string filename_rinex_obs = absl::GetFlag(FLAGS_filename_rinex_obs);
    std::string filename_raw_data = absl::GetFlag(FLAGS_filename_raw_data);
#endif
    int configure_generator();
    int generate_signal();
    void check_results_doppler(arma::vec &true_time_s, arma::vec &true_value,
        arma::vec &meas_time_s, arma::vec &meas_value);
    void check_results_acc_carrier_phase(arma::vec &true_time_s,
        arma::vec &true_value, arma::vec &meas_time_s, arma::vec &meas_value);
    void check_results_codephase(arma::vec &true_time_s, arma::vec &true_value,
        arma::vec &meas_time_s, arma::vec &meas_value);

    GpsL1CADllPllTrackingTestFpga() : item_size(sizeof(gr_complex))
    {
        config = std::make_shared<InMemoryConfiguration>();

        gnss_synchro = Gnss_Synchro();
    }

    ~GpsL1CADllPllTrackingTestFpga() override = default;

    void configure_receiver();

    gr::top_block_sptr top_block;
    std::shared_ptr<InMemoryConfiguration> config;
    Gnss_Synchro gnss_synchro;
    size_t item_size;
};


int GpsL1CADllPllTrackingTestFpga::configure_generator()
{
// Configure signal generator
#if USE_GLOG_AND_GFLAGS
    generator_binary = FLAGS_generator_binary;

    p1 = std::string("-rinex_nav_file=") + FLAGS_rinex_nav_file;
    if (FLAGS_dynamic_position.empty())
        {
            p2 = std::string("-static_position=") + FLAGS_static_position + std::string(",") + std::to_string(FLAGS_duration * 10);
        }
    else
        {
            p2 = std::string("-obs_pos_file=") + std::string(FLAGS_dynamic_position);
        }
    p3 = std::string("-rinex_obs_file=") + FLAGS_filename_rinex_obs;               // RINEX 2.10 observation file output
    p4 = std::string("-sig_out_file=") + FLAGS_filename_raw_data;                  // Baseband signal output file. Will be stored in int8_t IQ multiplexed samples
    p5 = std::string("-sampling_freq=") + std::to_string(baseband_sampling_freq);  // Baseband sampling frequency [MSps]
#else
    generator_binary = absl::GetFlag(FLAGS_generator_binary);

    p1 = std::string("-rinex_nav_file=") + absl::GetFlag(FLAGS_rinex_nav_file);
    if (absl::GetFlag(FLAGS_dynamic_position).empty())
        {
            p2 = std::string("-static_position=") + absl::GetFlag(FLAGS_static_position) + std::string(",") + std::to_string(absl::GetFlag(FLAGS_duration) * 10);
        }
    else
        {
            p2 = std::string("-obs_pos_file=") + std::string(absl::GetFlag(FLAGS_dynamic_position));
        }
    p3 = std::string("-rinex_obs_file=") + absl::GetFlag(FLAGS_filename_rinex_obs);  // RINEX 2.10 observation file output
    p4 = std::string("-sig_out_file=") + absl::GetFlag(FLAGS_filename_raw_data);     // Baseband signal output file. Will be stored in int8_t IQ multiplexed samples
    p5 = std::string("-sampling_freq=") + std::to_string(baseband_sampling_freq);    // Baseband sampling frequency [MSps]
#endif

    return 0;
}


int GpsL1CADllPllTrackingTestFpga::generate_signal()
{
    int child_status;

    char *const parmList[] = {&generator_binary[0], &generator_binary[0], &p1[0], &p2[0], &p3[0],
        &p4[0], &p5[0], nullptr};

    int pid;
    if ((pid = fork()) == -1)
        {
            perror("fork err");
        }
    else if (pid == 0)
        {
            execv(&generator_binary[0], parmList);
            std::cout << "Return not expected. Must be an execv err.\n";
            std::terminate();
        }

    waitpid(pid, &child_status, 0);

    std::cout << "Signal and Observables RINEX and RAW files created.\n";
    return 0;
}


void GpsL1CADllPllTrackingTestFpga::configure_receiver()
{
    gnss_synchro.Channel_ID = 0;
    gnss_synchro.System = 'G';
    std::string signal = "1C";
    signal.copy(gnss_synchro.Signal, 2, 0);
#if USE_GLOG_AND_GFLAGS
    gnss_synchro.PRN = FLAGS_test_satellite_PRN;
#else
    gnss_synchro.PRN = absl::GetFlag(FLAGS_test_satellite_PRN);
#endif

    config->set_property("GNSS-SDR.internal_fs_sps",
        std::to_string(baseband_sampling_freq));
    // Set Tracking
    config->set_property("Tracking_1C.implementation",
        "GPS_L1_CA_DLL_PLL_Tracking_FPGA");
    config->set_property("Tracking_1C.item_type", "cshort");
    config->set_property("Tracking_1C.dump", "true");
    config->set_property("Tracking_1C.dump_filename", "./tracking_ch_");
    config->set_property("Tracking_1C.pll_bw_hz", "30.0");
    config->set_property("Tracking_1C.dll_bw_hz", "2.0");
    config->set_property("Tracking_1C.early_late_space_chips", "0.5");
    config->set_property("Tracking_1C.devicename", "/dev/uio");
    config->set_property("Tracking_1C.device_base", "1");
}


void GpsL1CADllPllTrackingTestFpga::check_results_doppler(arma::vec &true_time_s,
    arma::vec &true_value, arma::vec &meas_time_s, arma::vec &meas_value)
{
    // 1. True value interpolation to match the measurement times
    arma::vec true_value_interp;
    arma::uvec true_time_s_valid = find(true_time_s > 0);
    true_time_s = true_time_s(true_time_s_valid);
    true_value = true_value(true_time_s_valid);
    arma::uvec meas_time_s_valid = find(meas_time_s > 0);
    meas_time_s = meas_time_s(meas_time_s_valid);
    meas_value = meas_value(meas_time_s_valid);
    arma::interp1(true_time_s, true_value, meas_time_s, true_value_interp);

    // 2. RMSE
    arma::vec err;
    err = meas_value - true_value_interp;
    arma::vec err2 = arma::square(err);
    double rmse = sqrt(arma::mean(err2));

    // 3. Mean err and variance
    double error_mean = arma::mean(err);
    double error_var = arma::var(err);

    // 4. Peaks
    double max_error = arma::max(err);
    double min_error = arma::min(err);

    // 5. report
    std::streamsize ss = std::cout.precision();
    std::cout << std::setprecision(10) << "TRK Doppler RMSE=" << rmse
              << ", mean=" << error_mean << ", stdev=" << sqrt(error_var)
              << " (max,min)=" << max_error << "," << min_error << " [Hz]"
              << '\n';
    std::cout.precision(ss);
}


void GpsL1CADllPllTrackingTestFpga::check_results_acc_carrier_phase(
    arma::vec &true_time_s, arma::vec &true_value, arma::vec &meas_time_s,
    arma::vec &meas_value)
{
    // 1. True value interpolation to match the measurement times
    arma::vec true_value_interp;
    arma::uvec true_time_s_valid = find(true_time_s > 0);
    true_time_s = true_time_s(true_time_s_valid);
    true_value = true_value(true_time_s_valid);
    arma::uvec meas_time_s_valid = find(meas_time_s > 0);
    meas_time_s = meas_time_s(meas_time_s_valid);
    meas_value = meas_value(meas_time_s_valid);
    arma::interp1(true_time_s, true_value, meas_time_s, true_value_interp);

    // 2. RMSE
    arma::vec err;

    err = meas_value - true_value_interp;
    arma::vec err2 = arma::square(err);
    double rmse = sqrt(arma::mean(err2));

    // 3. Mean err and variance
    double error_mean = arma::mean(err);
    double error_var = arma::var(err);

    // 4. Peaks
    double max_error = arma::max(err);
    double min_error = arma::min(err);

    // 5. report
    std::streamsize ss = std::cout.precision();
    std::cout << std::setprecision(10) << "TRK acc carrier phase RMSE=" << rmse
              << ", mean=" << error_mean << ", stdev=" << sqrt(error_var)
              << " (max,min)=" << max_error << "," << min_error << " [Hz]"
              << '\n';
    std::cout.precision(ss);
}


void GpsL1CADllPllTrackingTestFpga::check_results_codephase(
    arma::vec &true_time_s, arma::vec &true_value, arma::vec &meas_time_s,
    arma::vec &meas_value)
{
    // 1. True value interpolation to match the measurement times
    arma::vec true_value_interp;
    arma::uvec true_time_s_valid = find(true_time_s > 0);
    true_time_s = true_time_s(true_time_s_valid);
    true_value = true_value(true_time_s_valid);
    arma::uvec meas_time_s_valid = find(meas_time_s > 0);
    meas_time_s = meas_time_s(meas_time_s_valid);
    meas_value = meas_value(meas_time_s_valid);
    arma::interp1(true_time_s, true_value, meas_time_s, true_value_interp);

    // 2. RMSE
    arma::vec err;
    err = meas_value - true_value_interp;
    arma::vec err2 = arma::square(err);
    double rmse = sqrt(arma::mean(err2));

    // 3. Mean err and variance
    double error_mean = arma::mean(err);
    double error_var = arma::var(err);

    // 4. Peaks
    double max_error = arma::max(err);
    double min_error = arma::min(err);

    // 5. report
    std::streamsize ss = std::cout.precision();
    std::cout << std::setprecision(10) << "TRK code phase RMSE=" << rmse
              << ", mean=" << error_mean << ", stdev=" << sqrt(error_var)
              << " (max,min)=" << max_error << "," << min_error << " [Chips]"
              << '\n';
    std::cout.precision(ss);
}


TEST_F(GpsL1CADllPllTrackingTestFpga, ValidationOfResultsFpga)
{
    configure_generator();

    // DO not generate signal raw signal samples and observations RINEX file by default
    // generate_signal();

    std::chrono::time_point<std::chrono::system_clock> start;
    std::chrono::time_point<std::chrono::system_clock> end;
    std::chrono::duration<double> elapsed_seconds(0);

    configure_receiver();

    // open true observables log file written by the simulator
    Tracking_True_Obs_Reader true_obs_data;
#if USE_GLOG_AND_GFLAGS
    int test_satellite_PRN = FLAGS_test_satellite_PRN;
#else
    int test_satellite_PRN = absl::GetFlag(FLAGS_test_satellite_PRN);
#endif
    std::cout << "Testing satellite PRN=" << test_satellite_PRN << '\n';
    std::string true_obs_file = std::string("./gps_l1_ca_obs_prn");
    true_obs_file.append(std::to_string(test_satellite_PRN));
    true_obs_file.append(".dat");
    ASSERT_NO_THROW(
        {
            if (true_obs_data.open_obs_file(true_obs_file) == false)
                {
                    throw std::exception();
                };
        })
        << "Failure opening true observables file";

    top_block = gr::make_top_block("Tracking test");
    // std::shared_ptr<GpsL1CaDllPllCAidTrackingFpga> tracking = std::make_shared<GpsL1CaDllPllCAidTrackingFpga> (config.get(), "Tracking_1C", 1, 1);
    std::shared_ptr<GpsL1CaDllPllTrackingFpga> tracking = std::make_shared<GpsL1CaDllPllTrackingFpga>(config.get(), "Tracking_1C", 1, 1);

    auto msg_rx = GpsL1CADllPllTrackingTestFpga_msg_rx_make();

    // load acquisition data based on the first epoch of the true observations
    ASSERT_NO_THROW(
        {
            if (true_obs_data.read_binary_obs() == false)
                {
                    throw std::exception();
                };
        })
        << "Failure reading true observables file";

    // restart the epoch counter
    true_obs_data.restart();

    std::cout << "Initial Doppler [Hz]=" << true_obs_data.doppler_l1_hz
              << " Initial code delay [Chips]=" << true_obs_data.prn_delay_chips
              << '\n';

    gnss_synchro.Acq_delay_samples = (GPS_L1_CA_CODE_LENGTH_CHIPS - true_obs_data.prn_delay_chips / GPS_L1_CA_CODE_LENGTH_CHIPS) * baseband_sampling_freq * GPS_L1_CA_CODE_PERIOD_S;
    gnss_synchro.Acq_doppler_hz = true_obs_data.doppler_l1_hz;
    gnss_synchro.Acq_samplestamp_samples = 0;

    ASSERT_NO_THROW(
        {
            tracking->set_channel(gnss_synchro.Channel_ID);
        })
        << "Failure setting channel.";

    ASSERT_NO_THROW(
        {
            tracking->set_gnss_synchro(&gnss_synchro);
        })
        << "Failure setting gnss_synchro.";

    ASSERT_NO_THROW(
        {
            tracking->connect(top_block);
        })
        << "Failure connecting tracking to the top_block.";

    ASSERT_NO_THROW(
        {
            gr::blocks::null_sink::sptr sink = gr::blocks::null_sink::make(sizeof(Gnss_Synchro));
            top_block->connect(tracking->get_right_block(), 0, sink, 0);
            top_block->msg_connect(tracking->get_right_block(), pmt::mp("events"), msg_rx, pmt::mp("events"));
        })
        << "Failure connecting the blocks of tracking test.";

    tracking->start_tracking();

    // assemble again the file name in a null terminated string (not available by default in the main program flow)
    std::string file = "./" + filename_raw_data;
    const char *file_name = file.c_str();

    // start thread that sends the DMA samples to the FPGA
    boost::thread t{sending_thread, top_block, file_name};

    EXPECT_NO_THROW(
        {
            start = std::chrono::system_clock::now();
            top_block->run();  // Start threads and wait
            // tracking->reset();  // unlock the channel
            end = std::chrono::system_clock::now();
            elapsed_seconds = end - start;
        })
        << "Failure running the top_block.";

    // wait until child thread terminates
    t.join();

    // check results
    // load the true values
    int64_t nepoch = true_obs_data.num_epochs();
    std::cout << "True observation epochs=" << nepoch << '\n';

    arma::vec true_timestamp_s = arma::zeros(nepoch, 1);
    arma::vec true_acc_carrier_phase_cycles = arma::zeros(nepoch, 1);
    arma::vec true_Doppler_Hz = arma::zeros(nepoch, 1);
    arma::vec true_prn_delay_chips = arma::zeros(nepoch, 1);
    arma::vec true_tow_s = arma::zeros(nepoch, 1);

    int64_t epoch_counter = 0;
    while (true_obs_data.read_binary_obs())
        {
            true_timestamp_s(epoch_counter) = true_obs_data.signal_timestamp_s;
            true_acc_carrier_phase_cycles(epoch_counter) = true_obs_data.acc_carrier_phase_cycles;
            true_Doppler_Hz(epoch_counter) = true_obs_data.doppler_l1_hz;
            true_prn_delay_chips(epoch_counter) = true_obs_data.prn_delay_chips;
            true_tow_s(epoch_counter) = true_obs_data.tow;
            epoch_counter++;
        }

    // load the measured values
    Tracking_Dump_Reader trk_dump;
    ASSERT_NO_THROW(
        {
            if (trk_dump.open_obs_file(std::string("./tracking_ch_0.dat")) == false)
                {
                    throw std::exception();
                };
        })
        << "Failure opening tracking dump file";

    nepoch = trk_dump.num_epochs();
    std::cout << "Measured observation epochs=" << nepoch << '\n';

    arma::vec trk_timestamp_s = arma::zeros(nepoch, 1);
    arma::vec trk_acc_carrier_phase_cycles = arma::zeros(nepoch, 1);
    arma::vec trk_Doppler_Hz = arma::zeros(nepoch, 1);
    arma::vec trk_prn_delay_chips = arma::zeros(nepoch, 1);

    epoch_counter = 0;
    while (trk_dump.read_binary_obs())
        {
            trk_timestamp_s(epoch_counter) = static_cast<double>(trk_dump.PRN_start_sample_count) / static_cast<double>(baseband_sampling_freq);
            trk_acc_carrier_phase_cycles(epoch_counter) = trk_dump.acc_carrier_phase_rad / TWO_PI;
            trk_Doppler_Hz(epoch_counter) = trk_dump.carrier_doppler_hz;

            double delay_chips = GPS_L1_CA_CODE_LENGTH_CHIPS - GPS_L1_CA_CODE_LENGTH_CHIPS * (fmod((static_cast<double>(trk_dump.PRN_start_sample_count) + trk_dump.aux1) / static_cast<double>(baseband_sampling_freq), 1.0e-3) / 1.0e-3);

            trk_prn_delay_chips(epoch_counter) = delay_chips;
            epoch_counter++;
        }

    // Align initial measurements and cut the tracking pull-in transitory
    double pull_in_offset_s = 1.0;
    arma::uvec initial_meas_point = arma::find(trk_timestamp_s >= (true_timestamp_s(0) + pull_in_offset_s), 1, "first");

    trk_timestamp_s = trk_timestamp_s.subvec(initial_meas_point(0), trk_timestamp_s.size() - 1);
    trk_acc_carrier_phase_cycles = trk_acc_carrier_phase_cycles.subvec(initial_meas_point(0), trk_acc_carrier_phase_cycles.size() - 1);
    trk_Doppler_Hz = trk_Doppler_Hz.subvec(initial_meas_point(0), trk_Doppler_Hz.size() - 1);
    trk_prn_delay_chips = trk_prn_delay_chips.subvec(initial_meas_point(0), trk_prn_delay_chips.size() - 1);

    check_results_doppler(true_timestamp_s, true_Doppler_Hz, trk_timestamp_s, trk_Doppler_Hz);
    check_results_codephase(true_timestamp_s, true_prn_delay_chips, trk_timestamp_s, trk_prn_delay_chips);
    check_results_acc_carrier_phase(true_timestamp_s,
        true_acc_carrier_phase_cycles, trk_timestamp_s,
        trk_acc_carrier_phase_cycles);

    std::cout << "Signal tracking completed in " << elapsed_seconds.count() * 1e6 << " microseconds\n";
}
