/*!
 * \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 Javier Arribas, 2015. jarribas(at)cttc.es
 *
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2012-2015  (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 <unistd.h>
#include <chrono>
#include <exception>
#include <iostream>
#include <string>
#include <armadillo>
#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 <gtest/gtest.h>
#include "GPS_L1_CA.h"
#include "gnss_block_factory.h"
#include "gnss_block_interface.h"
#include "tracking_interface.h"
#include "telemetry_decoder_interface.h"
#include "in_memory_configuration.h"
#include "gnss_synchro.h"
#include "gps_l1_ca_telemetry_decoder.h"
#include "tracking_true_obs_reader.h"
#include "tracking_dump_reader.h"
#include "tlm_dump_reader.h"
#include "gps_l1_ca_dll_pll_tracking.h"
#include "gps_l1_ca_dll_pll_c_aid_tracking.h"
#include "signal_generator_flags.h"


// ######## GNURADIO BLOCK MESSAGE RECEVER FOR TRACKING MESSAGES #########
class GpsL1CADllPllTelemetryDecoderTest_msg_rx;

typedef boost::shared_ptr<GpsL1CADllPllTelemetryDecoderTest_msg_rx> GpsL1CADllPllTelemetryDecoderTest_msg_rx_sptr;

GpsL1CADllPllTelemetryDecoderTest_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_msg_rx_make();

class GpsL1CADllPllTelemetryDecoderTest_msg_rx : public gr::block
{
private:
    friend GpsL1CADllPllTelemetryDecoderTest_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_msg_rx_make();
    void msg_handler_events(pmt::pmt_t msg);
    GpsL1CADllPllTelemetryDecoderTest_msg_rx();

public:
    int rx_message;
    ~GpsL1CADllPllTelemetryDecoderTest_msg_rx(); //!< Default destructor

};

GpsL1CADllPllTelemetryDecoderTest_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_msg_rx_make()
{
    return GpsL1CADllPllTelemetryDecoderTest_msg_rx_sptr(new GpsL1CADllPllTelemetryDecoderTest_msg_rx());
}

void GpsL1CADllPllTelemetryDecoderTest_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;
    }
}

GpsL1CADllPllTelemetryDecoderTest_msg_rx::GpsL1CADllPllTelemetryDecoderTest_msg_rx() :
            gr::block("GpsL1CADllPllTelemetryDecoderTest_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(&GpsL1CADllPllTelemetryDecoderTest_msg_rx::msg_handler_events, this, _1));
    rx_message = 0;
}

GpsL1CADllPllTelemetryDecoderTest_msg_rx::~GpsL1CADllPllTelemetryDecoderTest_msg_rx()
{}


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


// ######## GNURADIO BLOCK MESSAGE RECEVER FOR TLM MESSAGES #########
class GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx;

typedef boost::shared_ptr<GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx> GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_sptr;

GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_make();

class GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx : public gr::block
{
private:
    friend GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_make();
    void msg_handler_events(pmt::pmt_t msg);
    GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx();

public:
    int rx_message;
    ~GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx(); //!< Default destructor

};

GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_sptr GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_make()
{
    return GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_sptr(new GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx());
}

void GpsL1CADllPllTelemetryDecoderTest_tlm_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;
    }
}

GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx::GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx() :
            gr::block("GpsL1CADllPllTelemetryDecoderTest_tlm_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(&GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx::msg_handler_events, this, _1));
    rx_message = 0;
}

GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx::~GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx()
{}


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


class GpsL1CATelemetryDecoderTest: 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(arma::vec & true_time_s,
            arma::vec & true_value,
            arma::vec & meas_time_s,
            arma::vec & meas_value);

    GpsL1CATelemetryDecoderTest()
    {
        factory = std::make_shared<GNSSBlockFactory>();
        config = std::make_shared<InMemoryConfiguration>();
        item_size = sizeof(gr_complex);
        gnss_synchro = Gnss_Synchro();
    }

    ~GpsL1CATelemetryDecoderTest()
    {}

    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 GpsL1CATelemetryDecoderTest::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 GpsL1CATelemetryDecoderTest::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 GpsL1CATelemetryDecoderTest::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.item_type", "gr_complex");
    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", "20.0");
    config->set_property("Tracking_1C.dll_bw_hz", "1.5");
    config->set_property("Tracking_1C.early_late_space_chips", "0.5");

    config->set_property("TelemetryDecoder_1C.dump","true");
}


void GpsL1CATelemetryDecoderTest::check_results(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 + 0.001;
    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) << "TLM TOW RMSE="
              << rmse << ", mean=" << error_mean
              << ", stdev=" << sqrt(error_var)
              << " (max,min)=" << max_error
              << "," << min_error
              << " [Seconds]" << std::endl;
    std::cout.precision (ss);

    ASSERT_LT(rmse, 0.2E-6);
    ASSERT_LT(error_mean, 0.2E-6);
    ASSERT_GT(error_mean, -0.2E-6);
    ASSERT_LT(error_var, 0.2E-6);
    ASSERT_LT(max_error, 0.5E-6);
    ASSERT_GT(min_error, -0.5E-6);
}


TEST_F(GpsL1CATelemetryDecoderTest, ValidationOfResults)
{
    // Configure the signal generator
    configure_generator();

    // Generate signal raw signal samples and observations RINEX file
    if (FLAGS_disable_generator == false)
        {
            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" << std::endl;

    top_block = gr::make_top_block("Telemetry_Decoder test");
    std::shared_ptr<TrackingInterface> tracking = std::make_shared<GpsL1CaDllPllTracking>(config.get(), "Tracking_1C", 1, 1);
    //std::shared_ptr<TrackingInterface> tracking = std::make_shared<GpsL1CaDllPllCAidTracking>(config.get(), "Tracking_1C", 1, 1);

    boost::shared_ptr<GpsL1CADllPllTelemetryDecoderTest_msg_rx> msg_rx = GpsL1CADllPllTelemetryDecoderTest_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" << std::endl;

    //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;

    std::shared_ptr<TelemetryDecoderInterface> tlm(new GpsL1CaTelemetryDecoder(config.get(), "TelemetryDecoder_1C",1, 1));
    tlm->set_channel(0);

    boost::shared_ptr<GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx> tlm_msg_rx = GpsL1CADllPllTelemetryDecoderTest_tlm_msg_rx_make();

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

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

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

    ASSERT_NO_THROW( {
        std::string file =  "./" + filename_raw_data;
        const char * file_name = file.c_str();
        gr::blocks::file_source::sptr file_source = gr::blocks::file_source::make(sizeof(int8_t), file_name, false);
        gr::blocks::interleaved_char_to_complex::sptr  gr_interleaved_char_to_complex = gr::blocks::interleaved_char_to_complex::make();
        gr::blocks::null_sink::sptr sink = gr::blocks::null_sink::make(sizeof(Gnss_Synchro));
        top_block->connect(file_source, 0, gr_interleaved_char_to_complex, 0);
        top_block->connect(gr_interleaved_char_to_complex, 0, tracking->get_left_block(), 0);
        top_block->connect(tracking->get_right_block(), 0, tlm->get_left_block(), 0);
        top_block->connect(tlm->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." << std::endl;

    tracking->start_tracking();

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

    //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
    tlm_dump_reader tlm_dump;
    ASSERT_NO_THROW({
        if (tlm_dump.open_obs_file(std::string("./telemetry0.dat")) == false)
            {
                throw std::exception();
            };
    }) << "Failure opening telemetry dump file" << std::endl;

    nepoch = tlm_dump.num_epochs();
    std::cout << "Measured observation epochs=" << nepoch << std::endl;

    arma::vec tlm_timestamp_s = arma::zeros(nepoch, 1);
    arma::vec tlm_TOW_at_Preamble = arma::zeros(nepoch, 1);
    arma::vec tlm_tow_s = arma::zeros(nepoch, 1);

    epoch_counter = 0;
    while(tlm_dump.read_binary_obs())
    {
        tlm_timestamp_s(epoch_counter) = static_cast<double>(tlm_dump.Tracking_sample_counter) / static_cast<double>(baseband_sampling_freq);
        tlm_TOW_at_Preamble(epoch_counter) = tlm_dump.d_TOW_at_Preamble;
        tlm_tow_s(epoch_counter) = tlm_dump.TOW_at_current_symbol;
        epoch_counter++;
    }

    //Cut measurement initial transitory of the measurements
    arma::uvec initial_meas_point = arma::find(tlm_tow_s >= true_tow_s(0), 1, "first");
    ASSERT_EQ(initial_meas_point.is_empty(), false);
    tlm_timestamp_s = tlm_timestamp_s.subvec(initial_meas_point(0), tlm_timestamp_s.size() - 1);
    tlm_tow_s = tlm_tow_s.subvec(initial_meas_point(0), tlm_tow_s.size() - 1);

    check_results(true_timestamp_s, true_tow_s, tlm_timestamp_s, tlm_tow_s);

    std::cout <<  "Test completed in " << elapsed_seconds.count() * 1e6 << " microseconds" << std::endl;
}