""" Copyright (c) 2015, Swedish Institute of Computer Science
  All rights reserved.
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:
	  * Redistributions of source code must retain the above copyright
		notice, this list of conditions and the following disclaimer.
	  * Redistributions in binary form must reproduce the above copyright
		notice, this list of conditions and the following disclaimer in the
		documentation and/or other materials provided with the distribution.
	  * Neither the name of The Swedish Institute of Computer Science nor the
		names of its contributors may be used to endorse or promote products
		derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED. IN NO EVENT SHALL THE SWEDISH INSTITUTE OF COMPUTER SCIENCE BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Authors: ljjm@sics.se
Testers:
"""

import os
import sys
import json
import urllib2
import uuid
import time
import md5
import argparse
import multiprocessing
import platform
import netifaces
from subprocess import call

import cheesepi as cp
from cheesepi.tasks import *

logger = cp.config.get_logger(__name__)


def console_script():
	"""Command line tool, installed through setup.py"""
	commands = ['start','stop','status','reset','upgrade']
	options  = ['dispatcher','storage','influxdb','dashboard','all']

	parser = argparse.ArgumentParser(prog='cheesepi')
	parser.add_argument('command', metavar='COMMAND', choices=commands, nargs='?', help="'start' or 'stop' one of the CheesePi components")
	parser.add_argument('option',  metavar='OPTION', choices=options, nargs='?', help='Options to the command')
	args = parser.parse_args()

	# single parameter commands
	if   args.command=="status":  show_status()
	elif args.command=="reset":   reset_install()
	elif args.command=="upgrade": upgrade_install()
	elif args.command=="list": list_data(args.option)
	else: # both command and option required
		if   args.option=='dispatcher': control_dispatcher(args.command)
		elif args.option=='storage' or args.option=='influxdb': control_storage(args.command)
		elif args.option=='dashboard':  control_dashboard(args.command)
		elif args.option=='all':        control_all(args.command)
		else:
			print "Error: unknown OPTION: %s" % args.option


def show_status():
	"""Just print the location of important CheesePi dirs/files"""
	schedule_file = os.path.join(cp.config.cheesepi_dir, cp.config.get('schedule'))
	print "Status of CheesePi install (version %s):" % cp.config.version()
	print "Install dir:\t%s"   % cp.config.cheesepi_dir
	print "Log file:\t%s"      % cp.config.log_file
	print "Config file:\t%s"   % cp.config.config_file
	print "Schedule file:\t%s" % schedule_file

def list_data(task="ping"):
	dao = cp.config.get_dao()
	print dao.read_op(task)

def control_dispatcher(action):
	"""Start or stop the dispatcher"""
	if action=='start':
		print "Starting the dispatcher..."
		cp.dispatcher.start()
	else:
		print "Error: action not yet implemented!"

def copy_influx_config(influx_config):
	"""Copy the default influx config to a local copt (probably in $HOME)"""
	print "Warning: making local config: %s" % influx_config
	storage_dir = "/var/lib/influxdb"
	if not os.path.exists(storage_dir):
		print "Warning: Default InfluxDB storage dir %s does not exist!" % storage_dir
	influx_dir = cp.config.cheesepi_dir+"/bin/tools/influxdb"
	default_config  = os.path.join(influx_dir,"config.toml")
	print "Warning: copying from default config: %s" % default_config
	cp.config.copyfile(default_config, influx_config, replace={"INFLUX_DIR":influx_dir} )

def test_execute(cmd_array):
	"""Return true if cmd_array can execute"""
	try:
		call(cmd_array)
		return True
	except:
		return False

def find_influx_exe():
	"""See which influxdb we should use"""
	config_path = cp.config.get("database_exe")
	if config_path: # if database exectable was set in config file
		print "set it configfile"
		return config_path
	elif (test_execute(["influxdb","-h"])):
		print "system influx"
		return "influxdb"
	else:
		if isARM():
			print "cheesepi influx"
			return cp.config.cheesepi_dir+"/bin/tools/influxdb/influxdb.arm"
		else:
			print "Error: Can't find InfluxDB binary, set 'database_exe' in the config file"
			sys.exit(1)

def control_storage(action):
	"""Start or stop InfluxDB, either the bundled or the system version"""
	storage_dir = "/var/lib/influxdb"
	if not os.path.exists(storage_dir):
		print "Warning: Default InfluxDB storage dir %s does not exist!" % storage_dir

	if action=='start':
		print "Starting InfluxDB..."
		home_dir = os.path.expanduser("~")
		influx_config = os.path.join(home_dir,".influxconfig.toml")
		# test if we have already made the local config file
		if not os.path.isfile(influx_config):
			copy_influx_config(influx_config)
		influx=find_influx_exe()
		# start the influx server
		print "Running: "+influx+" -config="+influx_config
		try:
			call([influx, "-config="+influx_config])
		except Exception as e:
			msg = "Problem executing influxdb command %s -config=%s: %s" % (influx,influx_config,e)
			msg += "\nCheck PATH inclusion of system and python 'bin' directories"
			print msg
			logger.error(msg)
	else:
		print "Error: action not yet implemented!"

def control_dashboard(action):
	"""Start or stop the webserver that hosts the dashboard"""
	if action=='start':
		print "Starting the dashboard..."
		cp.bin.webserver.webserver.setup_server()
	else:
		print "Error: action not yet implemented!"

def control_all(action):
	pool = multiprocessing.Pool(processes=3)
	pool.apply_async(control_storage,  [action])
	time.sleep(3) # allow spoolup and config generation
	pool.apply_async(control_dispatcher,[action])
	pool.apply_async(control_dashboard, [action])
	pool.close()
	pool.join()

def reset_install():
	"""Wipe all local changes to schedule, config"""
	home_dir = os.path.expanduser("~")
	influx_config = os.path.join(home_dir,".influxconfig.toml")
	copy_influx_config(influx_config)
	cp.config.ensure_default_config(True)

def upgrade_install():
	"""Try and pull new version of the code from PyPi"""
	upgrade_task = cp.tasks.Upgradecode()
	upgrade_task.run()




def make_series():
	"""Ensure that database contains series grafana and cheesepi"""
	dao = cp.config.get_dao()
	# TODO: dont make if already exists
	dao.make_database("cheesepi")
	dao.make_database("grafana")

def build_json(dao, json_str):
	"""Build a Task object out of a JSON string spec"""
	spec = json.loads(json_str)
	return build_task(dao, spec)

def build_task(dao, spec):
	if not 'taskname' in spec:
		logger.error("No 'taskname' specified!")
		return None

	spec['taskname'] = spec['taskname'].lower()
	if spec['taskname']=='ping':
		return Ping(dao, spec)
	elif spec['taskname']=='httping':
		return Httping(dao, spec)
	elif spec['taskname']=='traceroute':
		return Traceroute(dao, spec)
	elif spec['taskname']=='dash':
		return Dash(dao, spec)
	elif spec['taskname']=='dns':
		return DNS(dao, spec)
	elif spec['taskname']=='throughput':
		return Throughput(dao, spec)
	elif spec['taskname']=='iperf':
		return iPerf(dao, spec)
	elif spec['taskname']=='beacon':
		return Beacon(dao, spec)
	elif spec['taskname']=='upload':
		return Upload(dao, spec)
	elif spec['taskname']=='status':
		return Status(dao, spec)
	elif spec['taskname']=='wifi':
		return Wifi(dao, spec)
	elif spec['taskname']=='dummy':
		return Dummy(dao, spec)
	elif spec['taskname']=='upload':
		return Upload(dao, spec)
	elif spec['taskname']=='upgradecode':
		return Upgradecode(dao, spec)
	elif spec['taskname']=='updatetasks':
		return Updatetasks(dao, spec)
	else:
		raise Exception('Task name not specified! '+str(spec))


# time functions
def now():
	return time.time()
	#return int(datetime.datetime.utcnow().strftime("%s"))

def isARM():
	if "arm" in platform.machine():
		return True
	return False

# logging facilities
def write_file(ret, start_time, ethmac):
	filename = "./"+ethmac+str(start_time)+".txt"
	fd = open(filename, 'w')
	fd.write(ret)
	fd.close()


def get_MAC():
	"""Return the MAC of this device's first NIC"""
	return str(hex(uuid.getnode()))[2:]

def get_host_id():
	"""Return this host's ID"""
	return str(md5.new(get_MAC()).hexdigest())


#get our currently used MAC address
def getCurrMAC():
	ret =':'.join(['{:02x}'.format((uuid.getnode() >> i) & 0xff) for i in range(0,8*6,8)][::-1])
	return ret


def resolve_if(interface):
	"""Get the IP address of an interface"""
	addr_type = 2 # 2=AF_INET, 30=AF_INET6
	try:
		addr = netifaces.ifaddresses(interface)[addr_type][0]['addr']
	except Exception as e:
		# failed to resolve
		return None
	return addr

def get_IP():
	"""Try to get this host's active address"""
	interfaces = ["eth0","en0","wlan0"]
	# apppend all interfaces on this host
	#interfaces.append(netifaces.interfaces())
	for interface in interfaces:
		ip = resolve_if(interface)
		if ip!=None: # we have a valid IP
			return ip
	# unknown IP
	return "127.0.0.1"

def get_SA():
	"""get our percieved remote source address"""
	try:
		ret = urllib2.urlopen('http://ip.42.pl/raw').read()
	except Exception as e: # We may be offline
		logger.error("Unable to request ip.42.pl server's view of our IP, we may be offline: %s" % e)
		return "0.0.0.0"
	return ret

def get_temperature():
	"""Return the current temperature sensor, if possible"""
	filename = "/sys/class/thermal/thermal_zone0/temp"
	try:
		f = open(filename, 'r')
		data = f.read()
		return float(data.strip())
	except:
		pass
	return None

#
# Simple statistics to avoid numpy
#
def mean(data):
	"""Return the sample arithmetic mean of data."""
	n = len(data)
	if n < 1:
		raise ValueError('mean requires at least one data point')
	return sum(data)/n # in Python 2 use sum(data)/float(n)


def sumsq(data):
	"""Return sum of square deviations of sequence data."""
	c = mean(data)
	ss = sum((x-c)**2 for x in data)
	return ss


def stdev(data):
	"""Calculates the population standard deviation."""
	n = len(data)
	if n < 2:
		raise ValueError('variance requires at least two data points')
	ss = sumsq(data)
	pvar = ss/n # the population variance
	return pvar**0.5


