//
// Copyright 2010 Ettus Research LLC
//
// This program 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.
//
// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
//

#include "gps_ctrl.hpp"
#include <uhd/utils/assert.hpp>
#include <boost/cstdint.hpp>
#include <string>
#include <boost/date_time/posix_time/posix_time.hpp>

using namespace uhd;
using namespace boost::gregorian;
using namespace boost::posix_time;

/*!
 * A usrp2 GPS control for Jackson Labs devices
 */

//TODO: multiple baud rate support (requires mboard_impl changes for poking UART registers), NMEA support, better autodetection
class usrp2_gps_ctrl_impl : public usrp2_gps_ctrl{
public:
  usrp2_gps_ctrl_impl(usrp2_iface::sptr iface){
    _iface = iface;
    //do init here
    //so the Jackson Labs Firefly (and Fury) don't acknowledge successful commands -- only invalid ones.
    //first we test to see if there's a Firefly/Fury connected by sending an invalid packet and listening for the response

    std::string reply;

    //TODO: try multiple baud rates (many GPS's are set up for 4800bps, you're fixed at 115200bps 8N1 right now)
    //you have to poke registers in order to set baud rate, there's no dude/bro interface for it
    _iface->write_uart(GPS_UART, "HAAAY GUYYYYS\n"); 
    try {
      reply = _iface->read_uart(GPS_UART, 20);
    } catch (std::runtime_error err) {
      if(err.what() != std::string("usrp2 no control response")) throw; //sorry can't cope with that
      else { //we don't actually have a GPS installed
        gps_type = GPS_TYPE_NONE;
      }
    }

    if(reply == "Command Error") gps_type = GPS_TYPE_JACKSON_LABS;
    else gps_type = GPS_TYPE_NONE; //we'll add NMEA support later

    switch(gps_type) {
    case GPS_TYPE_JACKSON_LABS:
      //issue some setup stuff so it quits spewing data out when not asked to
      //none of these should issue replies so we don't bother looking for it
      _iface->write_uart(GPS_UART, "SYST:COMM:SER:");
      _iface->write_uart(GPS_UART, "ECHO OFF\n"); //we split lines before 20 chars right now -- TODO: fix driver to split writes/reads for you
      _iface->write_uart(GPS_UART, "SYST:COMM:SER:");
      _iface->write_uart(GPS_UART, "PRO OFF\n");
      _iface->write_uart(GPS_UART, "GPS:GPGGA 0\n");
      _iface->write_uart(GPS_UART, "GPS:GGAST 0\n");
      break;

    case GPS_TYPE_GENERIC_NMEA:
    case GPS_TYPE_NONE:
    default:

      break;
    }
  }

  ~usrp2_gps_ctrl_impl(void){

  }

  ptime get_time(void) {
    std::string reply;
    ptime now;
    switch(gps_type) {
    case GPS_TYPE_JACKSON_LABS:
      _iface->write_uart(GPS_UART, "PTIME:TIME\n");
      reply = _iface->read_uart(GPS_UART, 20);
      now = ptime(get_date(), duration_from_string(reply));
      break;
    case GPS_TYPE_GENERIC_NMEA:
    case GPS_TYPE_NONE:
    default:
      throw std::runtime_error("get_time(): Unsupported GPS or no GPS detected\n");
      break;
    }
    return now;
  }

  date get_date(void) {
    std::string reply;
    date today;
    switch(gps_type) {
    case GPS_TYPE_JACKSON_LABS:
      _iface->write_uart(GPS_UART, "PTIME:DATE\n");
      reply = _iface->read_uart(GPS_UART, 20);
      today = from_string(reply);
      break;
    case GPS_TYPE_GENERIC_NMEA:
    case GPS_TYPE_NONE:
    default:
      throw std::runtime_error("get_date(): Unsupported GPS or no GPS detected\n");
      break;
    }
    return today;
  }

  bool gps_detected(void) {
    return (gps_type != GPS_TYPE_NONE);
  }

private:
  usrp2_iface::sptr _iface;

  enum {
    GPS_TYPE_JACKSON_LABS,
    GPS_TYPE_GENERIC_NMEA,
    GPS_TYPE_NONE
  } gps_type;

  static const int GPS_UART = 2; //TODO: this should be plucked from fw_common.h or memory_map.h or somewhere in common with the firmware

};

/***********************************************************************
 * Public make function for the GPS control
 **********************************************************************/
usrp2_gps_ctrl::sptr usrp2_gps_ctrl::make(usrp2_iface::sptr iface){
    return sptr(new usrp2_gps_ctrl_impl(iface));
}