#!/usr/bin/python2
print "" # python2.7 is required to run OpenWebRX instead of python3. Please run me by: python2 openwebrx.py
"""

	This file is part of OpenWebRX, 
	an open-source SDR receiver software with a web UI.
	Copyright (c) 2013-2015 by Andras Retzler <randras@sdr.hu>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero 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 Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
sw_version="v0.12+"

import os
import code
import importlib
import plugins
import plugins.dsp
import thread
import time
import subprocess
import os 
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
from SocketServer import ThreadingMixIn
import fcntl
import time
import md5
import random
import threading
import sys
import traceback
from collections import namedtuple
import Queue
import ctypes

#import rtl_mus
import rxws
import uuid
import config_webrx as cfg
import signal
import socket

try: import sdrhu
except: sdrhu=False
avatar_ctime=""

#pypy compatibility
try: import dl
except: pass
try: import __pypy__
except: pass
pypy="__pypy__" in globals()

def import_all_plugins(directory):
	for subdir in os.listdir(directory):
		if os.path.isdir(directory+subdir) and not subdir[0]=="_":
			exact_path=directory+subdir+"/plugin.py"
			if os.path.isfile(exact_path):
				importname=(directory+subdir+"/plugin").replace("/",".")
				print "[openwebrx-import] Found plugin:",importname
				importlib.import_module(importname)

class MultiThreadHTTPServer(ThreadingMixIn, HTTPServer):
    pass 

def handle_signal(signal, frame):
	print "[openwebrx] Ctrl+C: aborting."
	os._exit(1) #not too graceful exit

def main():
	global clients, clients_mutex, pypy, lock_try_time, avatar_ctime
	print
	print "OpenWebRX - Open Source SDR Web App for Everyone!  | for license see LICENSE file in the package"
	print "_________________________________________________________________________________________________"
	print 
	print "Author contact info:    Andras Retzler, HA7ILM <randras@sdr.hu>"
	print 

	#Set signal handler
	signal.signal(signal.SIGINT, handle_signal) #http://stackoverflow.com/questions/1112343/how-do-i-capture-sigint-in-python

	#Load plugins
	import_all_plugins("plugins/dsp/")

	#Pypy
	if pypy: print "pypy detected (and now something completely different: a c code is expected to run at a speed of 3*10^8 m/s?)"

	#Change process name to "openwebrx" (to be seen in ps)
	try:
		for libcpath in ["/lib/i386-linux-gnu/libc.so.6","/lib/libc.so.6"]:
			if os.path.exists(libcpath):
				libc = dl.open(libcpath)
				libc.call("prctl", 15, "openwebrx", 0, 0, 0)
				break
	except:
		pass

	#Start rtl thread
	if cfg.start_rtl_thread:
		rtl_thread=threading.Thread(target = lambda:subprocess.Popen(cfg.start_rtl_command, shell=True), args=())
		rtl_thread.start()
		print "[openwebrx-main] Started rtl thread: "+cfg.start_rtl_command

	#Run rtl_mus.py in a different OS thread
	python_command="pypy" if pypy else "python2"
	rtl_mus_thread=threading.Thread(target = lambda:subprocess.Popen(python_command+" rtl_mus.py config_rtl", shell=True), args=())
	rtl_mus_thread.start() # The new feature in GNU Radio 3.7: top_block() locks up ALL python threads until it gets the TCP connection.
	print "[openwebrx-main] Started rtl_mus."
	time.sleep(1) #wait until it really starts	

	#Initialize clients
	clients=[]
	clients_mutex=threading.Lock()
	lock_try_time=0

	#Start watchdog thread
	print "[openwebrx-main] Starting watchdog threads."
	mutex_test_thread=threading.Thread(target = mutex_test_thread_function, args = ())
	mutex_test_thread.start()
	mutex_watchdog_thread=threading.Thread(target = mutex_watchdog_thread_function, args = ())
	mutex_watchdog_thread.start()
	

	#Start spectrum thread
	print "[openwebrx-main] Starting spectrum thread."
	spectrum_thread=threading.Thread(target = spectrum_thread_function, args = ())
	spectrum_thread.start()

	get_cpu_usage()
	bcastmsg_thread=threading.Thread(target = bcastmsg_thread_function, args = ())
	bcastmsg_thread.start()
	
	#threading.Thread(target = measure_thread_function, args = ()).start()

	#Start sdr.hu update thread
	if sdrhu and cfg.sdrhu_key and cfg.sdrhu_public_listing: 
		print "[openwebrx-main] Starting sdr.hu update thread..."
		sdrhu_thread=threading.Thread(target = sdrhu.run, args = ())
		sdrhu_thread.start()
		avatar_ctime=str(os.path.getctime("htdocs/gfx/openwebrx-avatar.png"))
	
	#Start HTTP thread
	httpd = MultiThreadHTTPServer(('', cfg.web_port), WebRXHandler)
	print('[openwebrx-main] Starting HTTP server.')
	httpd.serve_forever()


# This is a debug function below:
measure_value=0
def measure_thread_function():
	global measure_value
	while True:	
		print "[openwebrx-measure] value is",measure_value
		measure_value=0
		time.sleep(1)

def bcastmsg_thread_function():
	global clients
	while True:
		time.sleep(3)
		try: cpu_usage=get_cpu_usage()
		except: cpu_usage=0
		cma("bcastmsg_thread")
		for i in range(0,len(clients)):
			clients[i].bcastmsg="MSG cpu_usage={0} clients={1}".format(int(cpu_usage*100),len(clients))
		cmr()

def mutex_test_thread_function():
	global clients_mutex, lock_try_time
	while True:
		time.sleep(0.5)
		lock_try_time=time.time()
		clients_mutex.acquire()
		clients_mutex.release()
		lock_try_time=0

def cma(what): #clients_mutex acquire
	global clients_mutex
	global clients_mutex_locker
	if not clients_mutex.locked(): clients_mutex_locker = what
	clients_mutex.acquire()

def cmr():
	global clients_mutex
	global clients_mutex_locker
	clients_mutex_locker = None
	clients_mutex.release()

def mutex_watchdog_thread_function():
	global lock_try_time
	global clients_mutex_locker
	global clients_mutex
	while True:
		if lock_try_time != 0 and time.time()-lock_try_time > 3.0: 
			#if 3 seconds pass without unlock
			print "[openwebrx-watchdog] Mutex unlock timeout. Locker: \""+str(clients_mutex_locker)+"\" Now unlocking..." 
			clients_mutex.release()
		time.sleep(0.5)	
		
def spectrum_thread_function():
	global clients
	dsp=getattr(plugins.dsp,cfg.dsp_plugin).plugin.dsp_plugin()
	dsp.set_demodulator("fft")
	dsp.set_samp_rate(cfg.samp_rate)
	dsp.set_fft_size(cfg.fft_size)
	dsp.set_fft_fps(cfg.fft_fps)
	dsp.set_fft_compression(cfg.fft_compression)
	dsp.set_format_conversion(cfg.format_conversion)
	sleep_sec=0.87/cfg.fft_fps
	print "[openwebrx-spectrum] Spectrum thread initialized successfully."
	dsp.start()
	print "[openwebrx-spectrum] Spectrum thread started." 
	bytes_to_read=int(dsp.get_fft_bytes_to_read())
	while True:
		data=dsp.read(bytes_to_read)
		#print "gotcha",len(data),"bytes of spectrum data via spectrum_thread_function()"
		cma("spectrum_thread")
		correction=0
		for i in range(0,len(clients)):
			i-=correction
			if (clients[i].ws_started):
				if clients[i].spectrum_queue.full():
					print "[openwebrx-spectrum] client spectrum queue full, closing it."
					close_client(i, False)
					correction+=1
				else:
					clients[i].spectrum_queue.put([data]) # add new string by "reference" to all clients
		cmr()
	
def get_client_by_id(client_id, use_mutex=True):
	global clients
	output=-1
	if use_mutex: cma("get_client_by_id")
	for i in range(0,len(clients)):
		if(clients[i].id==client_id):
			output=i
			break
	if use_mutex: cmr()
	if output==-1:
		raise ClientNotFoundException
	else:
		return output

def log_client(client, what):
	print "[openwebrx-httpd] client {0}#{1} :: {2}".format(client.ip,client.id,what)

def cleanup_clients():
	# if client doesn't open websocket for too long time, we drop it
	global clients
	cma("cleanup_clients")
	correction=0
	for i in range(0,len(clients)):
		i-=correction
		#print "cleanup_clients:: len(clients)=", len(clients), "i=", i
		if (not clients[i].ws_started) and (time.time()-clients[i].gen_time)>45:
			print "[openwebrx] cleanup_clients :: client timeout to open WebSocket"
			close_client(i, False)
			correction+=1
	cmr()

def generate_client_id(ip):
	#add a client
	global clients
	new_client=namedtuple("ClientStruct", "id gen_time ws_started sprectum_queue ip closed bcastmsg dsp")	
	new_client.id=md5.md5(str(random.random())).hexdigest()
	new_client.gen_time=time.time()
	new_client.ws_started=False # to check whether client has ever tried to open the websocket
	new_client.spectrum_queue=Queue.Queue(1000)
	new_client.ip=ip
	new_client.bcastmsg=""
	new_client.closed=[False] #byref, not exactly sure if required
	new_client.dsp=None
	cma("generate_client_id")
	clients.append(new_client)
	log_client(new_client,"client added. Clients now: {0}".format(len(clients)))
	cmr()
	cleanup_clients()
	return new_client.id

def close_client(i, use_mutex=True):
	global clients
	log_client(clients[i],"client being closed.")
	if use_mutex: cma("close_client")
	try:
		clients[i].dsp.stop()
	except:
		exc_type, exc_value, exc_traceback = sys.exc_info()
		print "[openwebrx] close_client dsp.stop() :: error -",exc_type,exc_value
		traceback.print_tb(exc_traceback)
	clients[i].closed[0]=True
	del clients[i]
	if use_mutex: cmr()

# http://www.codeproject.com/Articles/462525/Simple-HTTP-Server-and-Client-in-Python
# some ideas are used from the artice above

class WebRXHandler(BaseHTTPRequestHandler):    
	def proc_read_thread():
		pass

	def send_302(self,what):
		self.send_response(302)
		self.send_header('Content-type','text/html')
		self.send_header("Location", "http://{0}:{1}/{2}".format(cfg.server_hostname,cfg.web_port,what))
		self.end_headers()
		self.wfile.write("<html><body><h1>Object moved</h1>Please <a href=\"/{0}\">click here</a> to continue.</body></html>".format(what))


	def do_GET(self):
		self.connection.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
		global dsp_plugin, clients_mutex, clients, avatar_ctime, sw_version
		rootdir = 'htdocs' 
		self.path=self.path.replace("..","")
		path_temp_parts=self.path.split("?")
		self.path=path_temp_parts[0]
		request_param=path_temp_parts[1] if(len(path_temp_parts)>1) else "" 
		try:
			if self.path=="/":
				self.path="/index.wrx"
			# there's even another cool tip at http://stackoverflow.com/questions/4419650/how-to-implement-timeout-in-basehttpserver-basehttprequesthandler-python
			#if self.path[:5]=="/lock": cma("do_GET /lock/") # to test mutex_watchdog_thread. Do not uncomment in production environment!
			if self.path[:4]=="/ws/":
				try:
					# ========= WebSocket handshake  =========
					ws_success=True
					try:				
						rxws.handshake(self)
						cma("do_GET /ws/")				
						client_i=get_client_by_id(self.path[4:], False)
						myclient=clients[client_i]
					except rxws.WebSocketException: ws_success=False
					except ClientNotFoundException: ws_success=False
					finally:
						if clients_mutex.locked(): cmr()
					if not ws_success:
						self.send_error(400, 'Bad request.')
						return

					# ========= Client handshake =========
					if myclient.ws_started:
						print "[openwebrx-httpd] error: second WS connection with the same client id, throwing it."
						self.send_error(400, 'Bad request.') #client already started
						return
					rxws.send(self, "CLIENT DE SERVER openwebrx.py")
					client_ans=rxws.recv(self, True)
					if client_ans[:16]!="SERVER DE CLIENT":
						rxws.send("ERR Bad answer.")
						return
					myclient.ws_started=True
					#send default parameters
					rxws.send(self, "MSG center_freq={0} bandwidth={1} fft_size={2} fft_fps={3} audio_compression={4} fft_compression={5} max_clients={6} setup".format(str(cfg.shown_center_freq),str(cfg.samp_rate),cfg.fft_size,cfg.fft_fps,cfg.audio_compression,cfg.fft_compression,cfg.max_clients))

					# ========= Initialize DSP =========
					dsp=getattr(plugins.dsp,cfg.dsp_plugin).plugin.dsp_plugin()
					dsp.set_samp_rate(cfg.samp_rate)
					dsp.set_demodulator("nfm")
					dsp.set_offset_freq(0)
					dsp.set_bpf(-4000,4000)
					dsp.set_audio_compression(cfg.audio_compression)
					dsp.set_format_conversion(cfg.format_conversion)
					dsp.start()
					myclient.dsp=dsp
					
					while True:
						if myclient.closed[0]: 
							print "[openwebrx-httpd:ws] client closed by other thread"
							break

						# ========= send audio =========
						temp_audio_data=dsp.read(256)
						rxws.send(self, temp_audio_data, "AUD ")

						# ========= send spectrum =========
						while not myclient.spectrum_queue.empty():
							spectrum_data=myclient.spectrum_queue.get()
							#spectrum_data_mid=len(spectrum_data[0])/2
							#rxws.send(self, spectrum_data[0][spectrum_data_mid:]+spectrum_data[0][:spectrum_data_mid], "FFT ") 
							# (it seems GNU Radio exchanges the first and second part of the FFT output, we correct it)
							rxws.send(self, spectrum_data[0],"FFT ")

						# ========= send bcastmsg =========
						if myclient.bcastmsg!="":
							rxws.send(self,myclient.bcastmsg)
							myclient.bcastmsg=""

						# ========= process commands =========
						while True:
							rdata=rxws.recv(self, False)
							if not rdata: break
							#try:
							elif rdata[:3]=="SET":
								print "[openwebrx-httpd:ws,%d] command: %s"%(client_i,rdata)
								pairs=rdata[4:].split(" ")
								bpf_set=False
								new_bpf=dsp.get_bpf()
								filter_limit=dsp.get_output_rate()/2
								for pair in pairs:
									param_name, param_value = pair.split("=")
									if param_name == "low_cut" and -filter_limit <= float(param_value) <= filter_limit:
										bpf_set=True
										new_bpf[0]=int(param_value)
									elif param_name == "high_cut" and -filter_limit <= float(param_value) <= filter_limit:
										bpf_set=True
										new_bpf[1]=int(param_value)
									elif param_name == "offset_freq" and -cfg.samp_rate/2 <= float(param_value) <= cfg.samp_rate/2:
										dsp.set_offset_freq(int(param_value))
									elif param_name=="mod":
										if (dsp.get_demodulator()!=param_value):
											dsp.stop()
											dsp.set_demodulator(param_value)
											dsp.start()
									else:
										print "[openwebrx-httpd:ws] invalid parameter"
								if bpf_set:
									dsp.set_bpf(*new_bpf)
								#code.interact(local=locals())
				except:
					exc_type, exc_value, exc_traceback = sys.exc_info()
					if exc_value[0]==32: #"broken pipe", client disconnected
						pass
					elif exc_value[0]==11: #"resource unavailable" on recv, client disconnected	
						pass
					else:	
						print "[openwebrx-httpd] error in /ws/ handler: ",exc_type,exc_value
						traceback.print_tb(exc_traceback)

				#stop dsp for the disconnected client				
				try:
					dsp.stop()
					del dsp
				except:
					print "[openwebrx-httpd] error in dsp.stop()"

				#delete disconnected client
				try:
					cma("do_GET /ws/ delete disconnected")
					id_to_close=get_client_by_id(myclient.id,False)
					close_client(id_to_close,False)
				except:
					exc_type, exc_value, exc_traceback = sys.exc_info()
					print "[openwebrx-httpd] client cannot be closed: ",exc_type,exc_value
					traceback.print_tb(exc_traceback)
				finally:
					cmr()
				return
			elif self.path in ("/status", "/status/"):
				#self.send_header('Content-type','text/plain')
				getbands=lambda: str(int(cfg.shown_center_freq-cfg.samp_rate/2))+"-"+str(int(cfg.shown_center_freq+cfg.samp_rate/2))
				self.wfile.write("status=active\nname="+cfg.receiver_name+"\nsdr_hw="+cfg.receiver_device+"\nop_email="+cfg.receiver_admin+"\nbands="+getbands()+"\nusers="+str(len(clients))+"\navatar_ctime="+avatar_ctime+"\ngps="+str(cfg.receiver_gps)+"\nasl="+str(cfg.receiver_asl)+"\nloc="+cfg.receiver_location+"\nsw_version="+sw_version+"\nantenna="+cfg.receiver_ant+"\n")
				print "[openwebrx-httpd] GET /status/ from",self.client_address[0]			
			else:
				f=open(rootdir+self.path)
				data=f.read()
				extension=self.path[(len(self.path)-4):len(self.path)]
				extension=extension[2:] if extension[1]=='.' else extension[1:]
				if extension == "wrx" and ((self.headers['user-agent'].count("Chrome")==0 and self.headers['user-agent'].count("Firefox")==0 and (not "Googlebot" in self.headers['user-agent'])) if 'user-agent' in self.headers.keys() else True) and (not request_param.count("unsupported")):
					self.send_302("upgrade.html")
					return
				if extension == "wrx" and cfg.max_clients<=len(clients):
					self.send_302("retry.html")
					return
				self.send_response(200)
				if(("wrx","html","htm").count(extension)):
					self.send_header('Content-type','text/html')
				elif(extension=="js"):
					self.send_header('Content-type','text/javascript')
				elif(extension=="css"):
					self.send_header('Content-type','text/css')
				self.end_headers()		
				if extension == "wrx":
					replace_dictionary=(
						("%[RX_PHOTO_DESC]",cfg.photo_desc),
						("%[CLIENT_ID]", generate_client_id(self.client_address[0])) if "%[CLIENT_ID]" in data else "",
						("%[WS_URL]","ws://"+cfg.server_hostname+":"+str(cfg.web_port)+"/ws/"),
						("%[RX_TITLE]",cfg.receiver_name),
						("%[RX_LOC]",cfg.receiver_location),
						("%[RX_QRA]",cfg.receiver_qra),
						("%[RX_ASL]",str(cfg.receiver_asl)),
						("%[RX_GPS]",str(cfg.receiver_gps[0])+","+str(cfg.receiver_gps[1])),
						("%[RX_PHOTO_HEIGHT]",str(cfg.photo_height)),("%[RX_PHOTO_TITLE]",cfg.photo_title),
						("%[RX_ADMIN]",cfg.receiver_admin),
						("%[RX_ANT]",cfg.receiver_ant),
						("%[RX_DEVICE]",cfg.receiver_device),
						("%[AUDIO_BUFSIZE]",str(cfg.client_audio_buffer_size))
					)
					for rule in replace_dictionary:
						while data.find(rule[0])!=-1:
							data=data.replace(rule[0],rule[1])
				self.wfile.write(data)
				f.close()
			return
		except IOError:
			self.send_error(404, 'Invalid path.')
		except:
			exc_type, exc_value, exc_traceback = sys.exc_info()
			print "[openwebrx-httpd] error (@outside):", exc_type, exc_value
			traceback.print_tb(exc_traceback)
			

class ClientNotFoundException(Exception):
	pass

last_worktime=0
last_idletime=0

def get_cpu_usage():
	global last_worktime, last_idletime
	f=open("/proc/stat","r")
	line=""
	while not "cpu " in line: line=f.readline()
	f.close()
	spl=line.split(" ")
	worktime=int(spl[2])+int(spl[3])+int(spl[4])
	idletime=int(spl[5])
	dworktime=(worktime-last_worktime)
	didletime=(idletime-last_idletime)
	rate=float(dworktime)/(didletime+dworktime)
	last_worktime=worktime
	last_idletime=idletime
	if(last_worktime==0): return 0
	return rate


if __name__=="__main__":
	main()