#! /usr/bin/python

 
import os
from gps import *
from time import *
import time
import threading
import socket
import subprocess
import fcntl
import struct
import datetime

gpsd = None #seting the global variable

class GpsPoller(threading.Thread):
  def __init__(self):
    threading.Thread.__init__(self)
    global gpsd #bring it in scope
    gpsd = gps(mode=WATCH_ENABLE) #starting the stream of info
    self.current_value = None
    self.running = True #setting the thread running to true

  def run(self):
    global gpsd
    while gpsp.running:
      gpsd.next() #this will continue to loop and grab EACH set of gpsd info to clear the buffer

def logData(data):
  time = datetime.datetime.now()
  fileName = "/home/dsu/data.csv"
  logFile = open(fileName,"a")
#  logFile.write(time.isoformat() +",")
  logFile.write(data+"\n")
  logFile.close()

def recovergpsd():
  logData("Trying to recover gpsd service...")
  process = subprocess.Popen(["service gpsd restart"], stdout = subprocess.PIPE)
  out, err = process.communicate()
  logData(out)

def isGpsRunning():
  process = subprocess.Popen(["ps", "-A"], stdout = subprocess.PIPE)
  out, err = process.communicate()
  if("gpsd" in out):
    return True
  else:
    logData("gpsd service unavailable")
    return False

def sendPacket(data):
  port = 81
  ip = "127.0.0.1"
  packet = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
  packet.sendto(data,(ip,port))

if __name__ == '__main__':
	gpsp = GpsPoller() # create the thread

	try:
		loopCount = 0 #how many times did we have to try before we got valid data?
		gpsp.start() # start it up

		while(True):
			time.sleep(2) #wait for a wee bit before polling again
			if isGpsRunning():
				currentTime = datetime.datetime.now()

				#determine the current latitude and store it
				latitude = gpsd.fix.latitude
				if( latitude > 0 ):
					latitude = str(abs(latitude)) + " N"
				else:
					latitude = str(abs(latitude)) + " S"

				#same story with longtitude
				longitude = gpsd.fix.longitude
				if( longitude > 0 ):
					longitude = str(abs(longitude)) + " E"
				else:
					longitude = str(abs(longitude)) + " W"

				#what's the altitude?
				altFt = str(gpsd.fix.altitude * 3.28084) + " ft"

				if ("nan" not in str(altFt)):
					print("Time:\t" + " " + str(currentTime.isoformat()))
					print("Latitude:\t" + " " + str(latitude))
					print("Longitude:\t" + " " + str(longitude))
					print("Altitude:\t" + " " + str(altFt))

					gpsData = str(gpsd.fix.latitude) + "," + str(gpsd.fix.longitude)
					logData(str(gpsData))
					#gpsData = str(gpsd.fix.latitude) + ",\n" + str(gpsd.fix.longitude)+",\n"+str(loopCount)+",\n"+str(gpsd.fix.time)
					#logData(str(gpsData)+str(gpsd.fix.altitude)+",\n"+str(gpsd.fix.eps)+",\n"+str(gpsd.fix.epx)+",\n"+str(gpsd.fix.epv)+",\n"+str(gpsd.fix.ept)+",\n"+str(gpsd.fix.speed)+",\n"+str(gpsd.fix.climb))

				else:
					print("Time: \t" + str(currentTime.isoformat()))
					print("Unable to obtain GPS lock")
			else:
				recovergpsd()

 	except (KeyboardInterrupt, SystemExit): #when you press ctrl+c
	    gpsp.running = False
	    print ("Closing down...")
    	gpsp.join() # wait for the thread to finish what it's doing