/*!
 * \file gps_l1_ca_dll_pll_tracking_test.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
 *
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2012-2018  (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 <https://www.gnu.org/licenses/>.
 *
 * -------------------------------------------------------------------------
 */

#include <chrono>
#include <fcntl.h>
#include <iostream>
#include <unistd.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 <stdio.h>// FPGA read input file
#include <gnuradio/top_block.h>
#include <gnuradio/blocks/file_source.h>
#include <gnuradio/analog/sig_source_waveform.h>
#include <gnuradio/analog/sig_source_c.h>
#include <gnuradio/blocks/interleaved_char_to_complex.h>
#include <gnuradio/blocks/null_sink.h>
#include <gnuradio/blocks/skiphead.h>
#include <gflags/gflags.h>
#include <glog/logging.h>
#include <gtest/gtest.h>
#include "GPS_L1_CA.h"
#include "gnss_block_factory.h"
#include "gnss_block_interface.h"
#include "tracking_interface.h"
#include "in_memory_configuration.h"
#include "gnss_synchro.h"
//#include "gps_l1_ca_dll_pll_c_aid_tracking_fpga.h"
#include "gps_l1_ca_dll_pll_tracking_fpga.h"
#include "tracking_true_obs_reader.h"
#include "tracking_dump_reader.h"
#include "signal_generator_flags.h"
#include "interleaved_byte_to_complex_short.h"

#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, 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)
        {
            printf("can't open loop device\n");
            exit(1);
        }

    buffer_DMA = (char *) malloc(DMA_TRACK_TRANSFER_SIZE);
    if (!buffer_DMA)
        {
            fprintf(stderr, "Memory error!");
        }

    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)
                {

                    fread(buffer_DMA, DMA_TRACK_TRANSFER_SIZE, 1,rx_signal_file);

                    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
                {
                    fread(buffer_DMA, num_remaining_samples, 1, rx_signal_file);

                    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 thread(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)
        {
            printf("Unable to open file!");
        }

    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 RECEVER #########
class GpsL1CADllPllTrackingTestFpga_msg_rx;

typedef boost::shared_ptr<GpsL1CADllPllTrackingTestFpga_msg_rx> GpsL1CADllPllTrackingTestFpga_msg_rx_sptr;

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_events(pmt::pmt_t msg);
    GpsL1CADllPllTrackingTestFpga_msg_rx();

public:
    int rx_message;
    ~GpsL1CADllPllTrackingTestFpga_msg_rx(); //!< 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_events(pmt::pmt_t msg)
{
    try
        {
            long int message = pmt::to_long(msg);
            rx_message = message;
        }
    catch (boost::bad_any_cast& e)
        {
            LOG(WARNING) << "msg_handler_telemetry Bad any cast!";
            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"),
            boost::bind(
                    &GpsL1CADllPllTrackingTestFpga_msg_rx::msg_handler_events,
                    this, _1));
    rx_message = 0;
}


GpsL1CADllPllTrackingTestFpga_msg_rx::~GpsL1CADllPllTrackingTestFpga_msg_rx()
{}


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

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;

    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;

    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()
    {
        factory = std::make_shared<GNSSBlockFactory>();
        config = std::make_shared<InMemoryConfiguration>();
        item_size = sizeof(gr_complex);
        gnss_synchro = Gnss_Synchro();
    }

    ~GpsL1CADllPllTrackingTestFpga()
    {
    }

    void configure_receiver();

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


int GpsL1CADllPllTrackingTestFpga::configure_generator()
{
    // Configure signal generator
    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]
    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], NULL };

    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." << std::endl;
            std::terminate();
        }

    waitpid(pid, &child_status, 0);

    std::cout << "Signal and Observables RINEX and RAW files created." << std::endl;
    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);
    gnss_synchro.PRN = FLAGS_test_satellite_PRN;

    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_C_Aid_Tracking_Fpga");
    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.if", "0");
    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);

    // 5. 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]"
              << std::endl;
    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]"
              << std::endl;
    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]"
              << std::endl;
    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, 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;
    int test_satellite_PRN = FLAGS_test_satellite_PRN;
    std::cout << "Testing satellite PRN=" << test_satellite_PRN << std::endl;
    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);

    boost::shared_ptr<GpsL1CADllPllTrackingTestFpga_msg_rx> 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
              << std::endl;

    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;
    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
        { 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
    long int nepoch = true_obs_data.num_epochs();
    std::cout << "True observation epochs=" << nepoch << std::endl;

    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);

    long int 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 << std::endl;

    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 / GPS_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" << std::endl;
}
