/*!
 * \file kml_printer.cc
 * \brief Implementation of a NMEA 2.1 printer for GNSS-SDR
 * This class provides a implementation of a subset of the NMEA-0183 standard for interfacing
 * marine electronic devices as defined by the National Marine Electronics Association (NMEA).
 * See http://www.nmea.org/ for the NMEA 183 standard
 *
 * \author Javier Arribas, 2012. jarribas(at)cttc.es
 *
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 2010-2014  (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 "nmea_printer.h"
#include <fcntl.h>
#include <termios.h>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <glog/logging.h>
#include <gflags/gflags.h>
#include "GPS_L1_CA.h"


using google::LogMessage;

//DEFINE_string(NMEA_version, "2.1", "Specifies the NMEA version (2.1)");

Nmea_Printer::Nmea_Printer(std::string filename, bool flag_nmea_tty_port, std::string nmea_dump_devname)
{
    nmea_filename = filename;
    nmea_file_descriptor.open(nmea_filename.c_str(), std::ios::out);
    if (nmea_file_descriptor.is_open())
        {
            DLOG(INFO) << "NMEA printer writing on " << nmea_filename.c_str();
        }

    nmea_devname = nmea_dump_devname;
    if (flag_nmea_tty_port == true)
        {
            nmea_dev_descriptor = init_serial(nmea_devname.c_str());
            if (nmea_dev_descriptor != -1)
                {
                    DLOG(INFO) << "NMEA printer writing on " << nmea_devname.c_str();
                }
        }
    else
        {
            nmea_dev_descriptor = -1;
        }
}




Nmea_Printer::~Nmea_Printer()
{
    if (nmea_file_descriptor.is_open())
        {
            nmea_file_descriptor.close();
        }
    close_serial();
}




int Nmea_Printer::init_serial (std::string serial_device)
{
    /*!
     * Opens the serial device and sets the default baud rate for a NMEA transmission (9600,8,N,1)
     */
    int fd = 0;
    struct termios options;
    long BAUD;
    long DATABITS;
    long STOPBITS;
    long PARITYON;
    long PARITY;

    fd = open(serial_device.c_str(), O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1) return fd; //failed to open TTY port

    fcntl(fd, F_SETFL, 0);    // clear all flags on descriptor, enable direct I/O
    tcgetattr(fd, &options);   // read serial port options

    BAUD  = B9600;
    //BAUD  =  B38400;
    DATABITS = CS8;
    STOPBITS = 0;
    PARITYON = 0;
    PARITY = 0;

    options.c_cflag = BAUD | DATABITS | STOPBITS | PARITYON | PARITY | CLOCAL | CREAD;
    // enable receiver, set 8 bit data, ignore control lines
    //options.c_cflag |= (CLOCAL | CREAD | CS8);
    options.c_iflag = IGNPAR;

    // set the new port options
    tcsetattr(fd, TCSANOW, &options);
    return fd;
}



void Nmea_Printer::close_serial ()
{
    if (nmea_dev_descriptor != -1)
        {
            close(nmea_dev_descriptor);
        }
}


bool Nmea_Printer::Print_Nmea_Line(gps_l1_ca_ls_pvt* pvt_data, bool print_average_values)
{
    std::string GPRMC;
    std::string GPGGA;
    std::string GPGSA;
    std::string GPGSV;

    // set the new PVT data
    d_PVT_data = pvt_data;

    // generate the NMEA sentences

    //GPRMC
    GPRMC = get_GPRMC();
    //GPGGA (Global Positioning System Fixed Data)
    GPGGA = get_GPGGA();
    //GPGSA
    GPGSA = get_GPGSA();
    //GPGSV
    GPGSV = get_GPGSV();

    // write to log file
    try
    {
            //GPRMC
            nmea_file_descriptor << GPRMC;
            //GPGGA (Global Positioning System Fixed Data)
            nmea_file_descriptor << GPGGA;
            //GPGSA
            nmea_file_descriptor << GPGSA;
            //GPGSV
            nmea_file_descriptor << GPGSV;
    }
    catch(std::exception ex)
    {
            DLOG(INFO) << "NMEA printer can not write on output file" << nmea_filename.c_str();;
    }

    //write to serial device
    if (nmea_dev_descriptor!=-1)
        {
            try
            {
                    int n_bytes_written;
                    //GPRMC
                    n_bytes_written = write(nmea_dev_descriptor, GPRMC.c_str(), GPRMC.length());
                    //GPGGA (Global Positioning System Fixed Data)
                    n_bytes_written = write(nmea_dev_descriptor, GPGGA.c_str(), GPGGA.length());
                    //GPGSA
                    n_bytes_written = write(nmea_dev_descriptor, GPGSA.c_str(), GPGSA.length());
                    //GPGSV
                    n_bytes_written = write(nmea_dev_descriptor, GPGSV.c_str(), GPGSV.length());
            }
            catch(std::exception ex)
            {
                    DLOG(INFO) << "NMEA printer can not write on serial device" << nmea_filename.c_str();;
            }
        }
    return true;
}



char Nmea_Printer::checkSum(std::string sentence)
{
    char check = 0;
    // iterate over the string, XOR each byte with the total sum:
    for (unsigned int c = 0; c < sentence.length(); c++)
        {
            check = char(check ^ sentence.at(c));
        }
    // return the result
    return check;
}



std::string Nmea_Printer::latitude_to_hm(double lat)
{
    bool north;
    if (lat < 0.0)
        {
            north = false;
            lat = -lat ;
        }
    else
        {
            north = true;
        }

    int deg = (int)lat;
    double mins = lat - (double)deg;
    mins *= 60.0 ;
    std::ostringstream out_string;
    out_string.setf(std::ios::fixed, std::ios::floatfield);
    out_string.fill('0');
    out_string.width(2);
    out_string << deg;
    out_string.width(6);
    out_string.precision(4);
    out_string << mins;

    if (north == true)
        {
            out_string << ",N";
        }
    else
        {
            out_string << ",S";
        }
    return out_string.str();
}



std::string Nmea_Printer::longitude_to_hm(double longitude)
{
    bool east;
    if (longitude < 0.0)
        {
            east = false;
            longitude = -longitude ;
        }
    else
        {
            east = true;
        }
    int deg = (int)longitude;
    double mins = longitude - (double)deg;
    mins *= 60.0 ;
    std::ostringstream out_string;
    out_string.setf(std::ios::fixed, std::ios::floatfield);
    out_string.width(3);
    out_string.fill('0');
    out_string << deg;
    out_string.width(6);
    out_string.precision(4);
    out_string << mins;

    if (east==true)
        {
            out_string << ",E";
        }
    else
        {
            out_string << ",W";
        }
    return out_string.str();
}



std::string Nmea_Printer::get_UTC_NMEA_time(boost::posix_time::ptime d_position_UTC_time)
{
    //UTC Time: hhmmss.sss
    std::stringstream sentence_str;

    boost::posix_time::time_duration td = d_position_UTC_time.time_of_day();
    int utc_hours;
    int utc_mins;
    int utc_seconds;
    int utc_milliseconds;

    utc_hours = td.hours();
    utc_mins = td.minutes();
    utc_seconds = td.seconds();
    utc_milliseconds = td.total_milliseconds() - td.total_seconds()*1000;

    if (utc_hours < 10) sentence_str << "0"; //  two digits for hours
    sentence_str << utc_hours;

    if (utc_mins < 10) sentence_str << "0"; //  two digits for minutes
    sentence_str << utc_mins;

    if (utc_seconds < 10) sentence_str << "0"; //  two digits for seconds
    sentence_str << utc_seconds;

    if (utc_milliseconds < 10)
        {
            sentence_str << ".00"; //  three digits for ms
            sentence_str << utc_milliseconds;
        }
    else if (utc_milliseconds < 100)
        {
            sentence_str << ".0"; //   three digits for ms
            sentence_str << utc_milliseconds;
        }
    else
        {
            sentence_str << "."; //   three digits for ms
            sentence_str << utc_milliseconds;
        }
    return sentence_str.str();
}



std::string Nmea_Printer::get_GPRMC()
{
    // Sample -> $GPRMC,161229.487,A,3723.2475,N,12158.3416,W,0.13,309.62,120598,*10
    bool valid_fix = d_PVT_data->b_valid_position;

    // ToDo: Compute speed and course over ground
    double speed_over_ground_knots = 0;
    double course_over_ground_deg = 0;

    //boost::posix_time::ptime d_position_UTC_time=boost::posix_time::microsec_clock::universal_time();

    std::stringstream sentence_str;

    //GPRMC (RMC-Recommended,Minimum Specific GNSS Data)
    std::string sentence_header;
    sentence_header = "$GPRMC,";
    sentence_str << sentence_header;

    //UTC Time: hhmmss.sss
    sentence_str << get_UTC_NMEA_time(d_PVT_data->d_position_UTC_time);

    //Status: A: data valid, V: data NOT valid

    if (valid_fix == true)
        {
            sentence_str << ",A";
        }
    else
        {
            sentence_str << ",V";
        };

    if (d_PVT_data->d_flag_averaging==true)
        {
            // Latitude ddmm.mmmm,(N or S)
            sentence_str << "," << latitude_to_hm(d_PVT_data->d_avg_latitude_d);
            // longitude dddmm.mmmm,(E or W)
            sentence_str << "," << longitude_to_hm(d_PVT_data->d_avg_longitude_d);
        }
    else
        {
            // Latitude ddmm.mmmm,(N or S)
            sentence_str << "," << latitude_to_hm(d_PVT_data->d_latitude_d);
            // longitude dddmm.mmmm,(E or W)
            sentence_str << "," << longitude_to_hm(d_PVT_data->d_longitude_d);
        }

    //Speed over ground (knots)
    sentence_str << ",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.precision(2);
    sentence_str << speed_over_ground_knots;

    //course over ground (degrees)
    sentence_str << ",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.precision(2);
    sentence_str << course_over_ground_deg;

    // Date ddmmyy
    boost::gregorian::date sentence_date = d_PVT_data->d_position_UTC_time.date();
    unsigned int year = sentence_date.year();
    unsigned int day = sentence_date.day();
    unsigned int month = sentence_date.month();

    sentence_str << ",";
    sentence_str.width(2);
    sentence_str.fill('0');
    sentence_str << day;
    sentence_str.width(2);
    sentence_str.fill('0');
    sentence_str << month;

    std::stringstream year_strs;
    year_strs << std::dec << year;
    sentence_str << std::dec << year_strs.str().substr(2);

    //Magnetic Variation (degrees)
    // ToDo: Implement magnetic compass
    sentence_str << ",";

    //Magnetic Variation (E or W)
    // ToDo: Implement magnetic compass
    sentence_str << ",";

    // Checksum
    char checksum;
    std::string tmpstr;
    tmpstr = sentence_str.str();
    checksum = checkSum(tmpstr.substr(1));
    sentence_str << "*";
    sentence_str.width(2);
    sentence_str.fill('0');
    sentence_str << std::hex << (int)checksum;

    // end NMEA sentence
    sentence_str << "\r\n";
    return sentence_str.str();
}



std::string Nmea_Printer::get_GPGSA()
{
    //$GPGSA,A,3,07,02,26,27,09,04,15, , , , , ,1.8,1.0,1.5*33
    // GSA-GNSS DOP and Active Satellites
    bool valid_fix = d_PVT_data->b_valid_position;
    int n_sats_used = d_PVT_data->d_valid_observations;
    double pdop = d_PVT_data->d_PDOP;
    double hdop = d_PVT_data->d_HDOP;
    double vdop = d_PVT_data->d_VDOP;

    std::stringstream sentence_str;
    std::string sentence_header;
    sentence_header = "$GPGSA,";
    sentence_str << sentence_header;

    // mode1:
    // (M) Manual-forced to operate in 2D or 3D mode
    // (A) Automatic-allowed to automatically switch 2D/3D
    std::string mode1 = "M";
    sentence_str << mode1;

    // mode2:
    // 1 fix not available
    // 2 fix 2D
    // 3 fix 3D
    if (valid_fix==true)
        {
            sentence_str << ",3";
        }
    else
        {
            sentence_str << ",1";
        };

    // Used satellites
    for (int i=0; i<12; i++)
        {
            sentence_str << ",";
            if (i < n_sats_used)
                {
                    sentence_str.width(2);
                    sentence_str.fill('0');
                    sentence_str << d_PVT_data->d_visible_satellites_IDs[i];
                }
        }

    // PDOP
    sentence_str << ",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.width(2);
    sentence_str.precision(1);
    sentence_str.fill('0');
    sentence_str << pdop;
    //HDOP
    sentence_str<<",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.width(2);
    sentence_str.precision(1);
    sentence_str.fill('0');
    sentence_str << hdop;
    //VDOP
    sentence_str << ",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.width(2);
    sentence_str.precision(1);
    sentence_str.fill('0');
    sentence_str << vdop;

    // Checksum
    char checksum;
    std::string tmpstr;
    tmpstr = sentence_str.str();
    checksum = checkSum(tmpstr.substr(1));
    sentence_str << "*";
    sentence_str.width(2);
    sentence_str.fill('0');
    sentence_str << std::hex << (int)checksum;

    // end NMEA sentence
    sentence_str << "\r\n";
    return sentence_str.str();
}




std::string Nmea_Printer::get_GPGSV()
{
    // GSV-GNSS Satellites in View
    // Notice that NMEA 2.1 only supports 12 channels
    int n_sats_used = d_PVT_data->d_valid_observations;
    std::stringstream sentence_str;
    std::stringstream frame_str;
    std::string sentence_header;
    sentence_header = "$GPGSV,";
    char checksum;
    std::string tmpstr;

    // 1st step: How many GPGSV frames we need? (up to 3)
    // Each frame contains up to 4 satellites
    int n_frames;
    n_frames = std::ceil(((double)n_sats_used) / 4.0);

    // generate the frames
    int current_satellite = 0;
    for (int i=1; i<(n_frames+1); i++)
        {
            frame_str.str("");
            frame_str << sentence_header;

            // number of messages
            frame_str << n_frames;

            // message number
            frame_str << ",";
            frame_str << i;

            // total number of satellites in view
            frame_str << ",";
            frame_str.width(2);
            frame_str.fill('0');
            frame_str << std::dec << n_sats_used;

            //satellites info
            for (int j=0; j<4; j++)
                {
                    // write satellite info
                    frame_str << ",";
                    frame_str.width(2);
                    frame_str.fill('0');
                    frame_str << std::dec << d_PVT_data->d_visible_satellites_IDs[current_satellite];

                    frame_str << ",";
                    frame_str.width(2);
                    frame_str.fill('0');
                    frame_str << std::dec << (int)d_PVT_data->d_visible_satellites_El[current_satellite];

                    frame_str << ",";
                    frame_str.width(3);
                    frame_str.fill('0');
                    frame_str << std::dec << (int)d_PVT_data->d_visible_satellites_Az[current_satellite];

                    frame_str << ",";
                    frame_str.width(2);
                    frame_str.fill('0');
                    frame_str << std::dec << (int)d_PVT_data->d_visible_satellites_CN0_dB[current_satellite];

                    current_satellite++;

                    if (current_satellite == n_sats_used)
                        {
                            break;
                        }
                }

            // frame checksum
            tmpstr = frame_str.str();
            checksum = checkSum(tmpstr.substr(1));
            frame_str << "*";
            frame_str.width(2);
            frame_str.fill('0');
            frame_str << std::hex << (int)checksum;

            // end NMEA sentence
            frame_str << "\r\n";

            //add frame to sentence
            sentence_str << frame_str.str();
        }
    return sentence_str.str();
    //$GPGSV,2,1,07,07,79,048,42,02,51,062,43,26,36,256,42,27,27,138,42*71
}





std::string Nmea_Printer::get_GPGGA()
{
    //boost::posix_time::ptime d_position_UTC_time=boost::posix_time::microsec_clock::universal_time();
    bool valid_fix = d_PVT_data->b_valid_position;
    int n_channels = d_PVT_data->d_valid_observations;//d_nchannels
    double hdop = d_PVT_data->d_HDOP;
    double MSL_altitude;

    if (d_PVT_data->d_flag_averaging == true)
        {
            MSL_altitude = d_PVT_data->d_avg_height_m;
        }
    else
        {
            MSL_altitude = d_PVT_data->d_height_m;
        }

    std::stringstream sentence_str;

    //GPGGA (Global Positioning System Fixed Data)
    std::string sentence_header;
    sentence_header = "$GPGGA,";
    sentence_str << sentence_header;

    //UTC Time: hhmmss.sss
    sentence_str << get_UTC_NMEA_time(d_PVT_data->d_position_UTC_time);

    if (d_PVT_data->d_flag_averaging == true)
        {
            // Latitude ddmm.mmmm,(N or S)
            sentence_str << "," << latitude_to_hm(d_PVT_data->d_avg_latitude_d);
            // longitude dddmm.mmmm,(E or W)
            sentence_str << "," << longitude_to_hm(d_PVT_data->d_avg_longitude_d);
        }
    else
        {
            // Latitude ddmm.mmmm,(N or S)
            sentence_str << "," << latitude_to_hm(d_PVT_data->d_latitude_d);
            // longitude dddmm.mmmm,(E or W)
            sentence_str << "," << longitude_to_hm(d_PVT_data->d_longitude_d);
        }

    // Position fix indicator
    // 0 - Fix not available or invalid
    // 1 - GPS SPS Mode, fix valid
    // 2 - Differential GPS, SPS Mode, fix valid
    // 3-5 - Not supported
    // 6 - Dead Reckoning Mode, fix valid
    // ToDo: Update PVT module to identify the fix mode

    if (valid_fix == true)
        {
            sentence_str << ",1";
        }
    else
        {
            sentence_str << ",0";
        }

    // Number of satellites used in PVT
    sentence_str << ",";
    if (n_channels < 10)
        {
            sentence_str << '0' << n_channels;
        }
    else
        {
            sentence_str << n_channels;
        }

    // HDOP
    sentence_str << ",";
    sentence_str.setf(std::ios::fixed, std::ios::floatfield);
    sentence_str.width(2);
    sentence_str.precision(1);
    sentence_str.fill('0');
    sentence_str << hdop;

    // MSL Altitude
    sentence_str << ",";
    sentence_str.precision(1);
    sentence_str << MSL_altitude;
    sentence_str << ",M";

    // Geoid-to-ellipsoid separation. Ellipsoid altitude = MSL Altitude + Geoid Separation.
    // ToDo: Compute this value
    sentence_str << ",";
    sentence_str << "0.0";
    sentence_str << ",M";

    // Age of Diff. Corr.  (Seconds) Null fields when DGPS is not used
    // Diff. Ref. Station ID (0000)
    // ToDo: Implement this fields for Differential GPS
    sentence_str << ",";
    sentence_str << "0.0,0000";

    // Checksum
    char checksum;
    std::string tmpstr;
    tmpstr = sentence_str.str();
    checksum = checkSum(tmpstr.substr(1));
    sentence_str << "*";
    sentence_str.width(2);
    sentence_str.fill('0');
    sentence_str << std::hex <<(int)checksum;

    // end NMEA sentence
    sentence_str << "\r\n";
    return sentence_str.str();
    //$GPGGA,104427.591,5920.7009,N,01803.2938,E,1,05,3.3,78.2,M,23.2,M,0.0,0000*4A
}