#----------------------------------------------------------------------
# Includes
#----------------------------------------------------------------------

import gps, os, time, shlex, sys, subprocess, re, math

from datetime import datetime
from dateutil import zoneinfo

#----------------------------------------------------------------------
# Global Variables / Constants
#----------------------------------------------------------------------

# Global debug to output console
DEBUG = True

# Global to write the date and column headers
WRITE_FILE_HEADER = True

# Automatically connect even when disconnected
AUTO_CONNECT = True

# Global for which data set to get
RUN_RSSI = True
RUN_IPERF = False

# Pause through loop
PRESS_ANY_KEY = False

# Directory constants - The name of the file is the date and time
RSSI_DIRECTORY = "./rssi/"
MBPS_DIRECTORY = "./mbps/"
CREATE_DIRS_IF_NOT_EXIST = False

# wimaxcu constants
SCAN_RSSI_STRING = "RSSI        : "
STATUS_LINK_RSSI_STRING = "RSSI      : "

# Iperf server
IPERF_SERVER = "iperf.wiscnet.net"

#----------------------------------------------------------------------
# Function:         iperf_from_server()
# Parameters:       none.
# Returns:          Overall value (mbps) from the command or -1
# Description:      Runs iperf tcp test with the server address in the global variable.
#  With the current command the output interval is set to every 2 seconds.  The first
#  "0.0-" that is output from the iperf command is going to be 0.0-2.0 and the overall
#  will be output by 0.0-10.x.  An example output of the average is below:
#  [1860]  0.0-10.1 sec  1.43 MBytes  1.19 Mbits/sec
#  So after we find the second "0.0-" we look for "Mbits/sec" and work backwards to
#  get the overall throughput
#----------------------------------------------------------------------
def iperf_from_server():

	# Local Variables
	isSecond = False
	mbps = -1

	# Try running an iperf test and grab the overall Mbits/sec
	p = subprocess.Popen(["iperf", "-c", IPERF_SERVER, "-i2"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

	try:
		for line in p.stdout.readlines():

			# Command outputs 0.0- twice, 2nd one contains the overall average
			if re.search("0.0-",line) and not isSecond:
				isSecond = True
			elif re.search("0.0-",line) and isSecond:

				# Found the second one, get the Mbits/sec and work backwards for the value
				idx = line.index("Mbits/sec")
				mbps = line[idx-5:idx-1]
	except:
		print 'Waiting for subprocess to end before exiting...'
		p.communicate()
		sys.exit()
	return mbps

#----------------------------------------------------------------------
# Function:         rssi_wimaxcu_connected()
# Parameters:       none.
# Returns:          Overall rssi value from the "wimaxcu status link" command or -1
# Description:      Runs the "wimaxcu status link" command and searches for the
#  rssi output value.
#----------------------------------------------------------------------
def rssi_wimaxcu_connected():

	# Local Variables
	# Default return value if failed
	rssi = -1

	# Run wimaxcu status link
	p = subprocess.Popen(["wimaxcu", "status", "link"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

	for line in p.stdout.readlines():

		# Look for the RSSI line
		if re.search(STATUS_LINK_RSSI_STRING,line):

			# Found the rssi line, now have to find the index of the value
			idx = line.index(STATUS_LINK_RSSI_STRING) + len(STATUS_LINK_RSSI_STRING)

			# Only get the number, disregard the dB on the end of the output
			rssi = line[idx:idx+3]
	return rssi

#----------------------------------------------------------------------
# Function:         get_rssi_from_scan(x)
# Parameters:       x - String to search for the RSSI value
# Returns:          RSSI value or -1
# Description:      Searches x, a single line, for the output of the RSSI value.  The format it
#  searches for is the output of the "wimaxcu scan" command.
#----------------------------------------------------------------------
def get_rssi_from_scan(x):

	# Local Variables
	rssi = -1

	if re.search(SCAN_RSSI_STRING,x):
		idx = x.index(SCAN_RSSI_STRING) + len(SCAN_RSSI_STRING)
		rssi = x[idx:idx+3]
	return rssi;

#----------------------------------------------------------------------
# Function:         wimaxcu_scan_geni()
# Parameters:       None.
# Returns:          RSSI value of the GENI network or -1
# Description:      Runs the wimaxcu_scan command and searches the output for
#  the GENI network.  If the GENI network is found, the RSSI value is returned.
#  This is useful when multiple networks are listed under the scan.
#----------------------------------------------------------------------
def wimaxcu_scan_geni():

	# Local Variables
	rssi = -1
	is_geni = False;
	nsp = "";
	ID = "";
	signal = "";
	rssi = "";
	cinr = "";
	NetworkType = "";
	Activated = "";

	# Run wimaxcu scan
	p = subprocess.Popen(["wimaxcu", "scan"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

	try:
		while not is_geni:
			line = p.stdout.readline()
			if re.search("Network found.", line):
				nsp = p.stdout.readline()
				ID = p.stdout.readline()
				signal = p.stdout.readline()
				rssi = p.stdout.readline()
				cinr = p.stdout.readline()
				NetworkType = p.stdout.readline()
				Activated = p.stdout.readline()
				print '\tNetwork found:  ', nsp
			if re.search("NSP : GENI 4G", nsp):
				is_geni = True
			if not line:
				return -1;
	except:
		print 'Waiting for subprocess to end before exiting...'
		p.communicate()
		sys.exit()

	p.communicate()
	return get_rssi_from_scan(rssi)

#----------------------------------------------------------------------
# Function:         is_connected()
# Parameters:       None.
# Returns:          True or False if is connected to GENI network
# Description:      Checks to see if rssi returned from the connected
#  function returns -1 -> which means it is not connected
#----------------------------------------------------------------------
def is_connected():
	return (rssi_wimaxcu_connected() != -1)

#----------------------------------------------------------------------
# Function:         wimaxcu_connect()
# Parameters:       None.
# Returns:          True or False if is connected to GENI network	
# Description:      Checks to see if rssi returned from the connected
#  function returns -1 -> which means it is not connected
#----------------------------------------------------------------------
def wimaxcu_connect():

	# Local Variables
	geni_network_found = False

	while not geni_network_found:
		print 'Scanning for GENI network...'
		if wimaxcu_scan_geni() != -1:
			geni_network_found = True

	# Run wimaxcu connect
	print 'Connecting to GENI network...'
	p = subprocess.Popen(["wimaxcu", "connect", "network", "51"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
	output = p.communicate()
	print output[0]
	print 'GENI network connected'

#----------------------------------------------------------------------
# Function:         is_dir()
# Parameters:       x - Path to check if it is a directory.
# Returns:          None.
# Description:      Checks to see if the path is a directory and prompts
#  the user to create the directory if it is not already created.
#----------------------------------------------------------------------
def is_dir(x):
	if not os.path.isdir(x):
		print x + ' does not exist.'
		if CREATE_DIRS_IF_NOT_EXIST:
			print 'Creating ' + x + 'directory.'
			os.makedirs(x)
			if os.path.isdir(x):
				return True
			else:
				return False
	else:
		return True;
	return False

#---------------------------------
# Main Program Entrance
#---------------------------------

# Get the date and time
now = datetime.now()

# Initialize main program variables
rssi_filename = RSSI_DIRECTORY + "{0}.txt".format(now.strftime("%Y-%m-%d_%H:%M"))
mbps_filename = MBPS_DIRECTORY + "{0}.txt".format(now.strftime("%Y-%m-%d_%H:%M"))
iperf_header_written = False
rssi_header_written = False

# Verify the RSSI and MBPS directory exist
if not is_dir(RSSI_DIRECTORY):
	sys.exit("Rssi directory does not exist and could not be created.")
if not is_dir(MBPS_DIRECTORY):
	sys.exit("Mbps directory does not exist and could not be created.")

while 1:
	if AUTO_CONNECT:
		while not is_connected():
			wimaxcu_connect()
	else:
		if not is_connected():
			sys.exit('Please connect to the GENI network or enable AUTO_CONNECT.  Exiting...')

	# Setup communication to GPS daemon
	lat = 0
	lon = 0
	session = gps.gps(mode=gps.WATCH_NEWSTYLE)
	session.poll()
	session.stream()

	# Wait until we get location information, takes a little bit of time
	print 'Getting gps signal...'
	while session.fix.latitude == lat:
		session.poll(),time.sleep(1)
	while session.fix.longitude == lon:
		session.poll(),time.sleep(1)

	lat = session.fix.latitude
	lon = session.fix.longitude

	# Check for valid signal, had nan once
	if math.isnan(lat) or math.isnan(lon):
		print 'Error getting GPS signal.'
		sys.exit(lat)

	session.poll()
	lat = session.fix.latitude
	lon = session.fix.longitude

	if RUN_RSSI:
		rssi = rssi_wimaxcu_connected()
		# Write lat,long,dbm to a file
		with open(rssi_filename, mode='a') as f:
			if WRITE_FILE_HEADER:
				if not rssi_header_written:
					f.write("latitude,longitude,RSSI\n")
					rssi_header_written = True
			f.write('{0},{1},{2}\n'.format(lat,lon,rssi))

	session.poll()
	lat = session.fix.latitude
	lon = session.fix.longitude

	if RUN_IPERF:
		mbps = iperf_from_server()
		# Write lat,long,dbm to a file
		with open(mbps_filename, mode='a') as f:
			if WRITE_FILE_HEADER:
				if not iperf_header_written:
					f.write("latitude,longitude,Mbps\n")
					iperf_header_written = True
			f.write('{0},{1},{2}\n'.format(lat,lon,mbps))

	# Print output to the console
	if DEBUG:
		print '------------------------------------'
		print now.strftime("%Y-%m-%d %H:%M")
		print 'latitude   ' , lat
		print 'longitude  ' , lon
		if RUN_RSSI:
			print 'rssi       ' , rssi
		if RUN_IPERF:
			print 'mbps       ' , mbps
		print '------------------------------------\n\n'

	if PRESS_ANY_KEY:
		raw_input('Hit enter for next location')

	# Close the GPS session
	session.close()