#!/usr/bin/python3
#
# Tiny SAT>IP client which activates multicast streaming.
#
# Use command line parameters of
# Create /etc/sysconfig/multicast file with syntax:
#
# <mport>:<satip-params>
#
# You can modify this file when the program is active and
# reload the configuration using the SIGHUP signal.
#
# Configuration Example:
#
# # Channel 1 on multicast port 5554, using first orbital position
# 5554:src=1&freq=11347&pol=v&ro=0.35&msys=dvbs2&\
#      mtype=8psk&plts=on&sr=22000&fec=23&\
#      pids=0,17,18,6600,6610,6620,6630
#
# The SAT>IP parameters should match the SAT>IP specification:
#   http://www.satip.info/resources
#
# Note: The multicast address must be specified through minisatip
# option -r <ipv4_mcast> or --remote-rtp <ipv4_mcast>. By default,
# this address is 239.255.255.250.
#
# Command-line example:
#
# ./multicast-rtp \
#   -s 192.168.1.100:554 -d 239.0.0.1 -p 5554 \
#   -u "src=1&freq=11347&pol=v&ro=0.35&msys=dvbs2&mtype=8psk&plts=on&sr=22000&fec=23&pids=0,17,18,6600,6610,6620,6630"
#
# Note: The SAT>IP server needs to support "target" spoofing
# and multicast address as "unicast" (minisatip project does it)
#

import os
import signal
import functools
import asyncio
import syslog
import argparse,sys
import signal

VERSION='0.2'
SYSLOG=False
SERVER='127.0.0.1:554'
CONFIG=''
REQUEST=''
TARGET_ADDR=''
TARGET_PORT=0
USE_CONFIG=True
QUIET=False

#
# Command line parameters
#

parser = argparse.ArgumentParser(description='Request multicast streaming from a SAT>IP server.')
parser.add_argument('-q', '--quiet', dest='quiet',
  action='store_true',
  help='quiet display option')
parser.add_argument('-l', '--syslog', dest='syslog',
  action='store_true',
  help='enable System LOG')
parser.add_argument('-s', '--server', dest='server',
  required=True,
  help='server to connect')
parser.add_argument('-d', '--destination', dest='addr',
  default='',
  help='target address  (Note: Only if server accept it!)')
parser.add_argument('-p', '--port', dest='port', type=int,
  default=10000,
  help='target port  (default: 10000)')
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument('-u', '--uri', dest='uri',
  default='',
  help='URI to request')
group.add_argument('-c', '--config', dest='config',
  default='/etc/sysconfig/multicast',
  help='config file with static multicast streams  (default: /etc/sysconfig/multicast)')

args = parser.parse_args()

SYSLOG = args.syslog

if args.port > 0 and args.port < 65536 :
  TARGET_PORT = args.port
else :
  parser.print_help()
  sys.exit()

if len(args.server) > 0 :
  SERVER = args.server
else :
  parser.print_help()
  sys.exit()

if len(args.uri) > 0 :
  REQUEST = args.uri
elif len(args.config) > 0 :
  CONFIG = args.config
else :
  parser.print_help()
  sys.exit()

TARGET_ADDR = args.addr
QUIET = args.quiet

if len(REQUEST) > 0 :
  USE_CONFIG = False

#
#
#


def log(msg):
  if QUIET :
    return
  if SYSLOG:
    syslog.syslog(msg)
  else:
    print('LOG:', msg)

#
# Basic RTSP Protocol class
#

class RTSP_Protocol:

  def __init__(self, client, params):
    self.mport = 0
    try:
      self.client = client
      client.protocol = self
      self.mport, self.params = params.split(':')[:2]
      self.mport = int(self.mport) & ~1
      self.params = self.params.strip().rstrip()
      self.action = 'SETUP'
    except:
      log('Invalid parameters: %s' % params)
      client.fatal()
    self.timeout = 30
    self.session = ''
    self.streamID = 0
    self.transport = None
    self.cseq = 0

  def connection_made(self, transport):
    self.transport = transport
    peer = transport._sock.getpeername()
    if self.action == 'SETUP':
      s = 'rtsp://%s:%d/?%s' % (peer[0], peer[1], self.params)
      log('%d (open): %s' % (self.mport, s))
      msg = 'SETUP ' + s + ' RTSP/1.0\r\n'
      if len(REQUEST) > 0 :
        msg += 'Transport: RTP/AVP;unicast;destination=%s;client_port=%d-%d\r\n' % (TARGET_ADDR, self.mport, self.mport + 1)
      else :
        msg += 'Transport: RTP/AVP;multicast;port=%d-%d\r\n' % (self.mport, self.mport + 1)
      msg += 'CSeq: 1\r\n\r\n'
      log(' -----> : %s' % msg)
      transport.write(msg.encode())
      self.action = 'PLAY'

  def data_received(self, data):
    if not self.transport:
      return
    log(' <----- : %s' % data)
    lines = data.decode("utf-8").splitlines()
    if lines[0] != 'RTSP/1.0 200 OK':
      return self.retry()
    try:
      cseq = 0
      streamID = 0
      session = ''
      timeout = 0
      for line in lines[1:]:
        if line == '':
          break
        pos = line.find(':')
        if pos >= 0:
          header = line[:pos].lower()
          data = line[pos+1:].strip().lstrip()
          if header == 'cseq':
            cseq = int(data)
          elif header == 'com.ses.streamid':
            streamID = int(data)
          elif header == 'session':
            a = data.split(';')
            session = a[0]
            for b in a[1:]:
              if b.startswith('timeout='):
                timeout = int(b[8:])
      if timeout: self.timeout = timeout
      if session: self.session = session
      if streamID: self.streamID = streamID
    except:
      self.retry()
      return
    peer = self.transport._sock.getpeername()
    if self.action == 'PLAY':
      log('%d (setup): Session %s, streamID %d' % (self.mport, self.session, self.streamID))
      self.action = 'OPTIONS'
      msg = 'PLAY rtsp://%s:%d/stream=%d RTSP/1.0\r\n' % (peer[0], peer[1], self.streamID)
      msg += 'Session: %s\r\n' % self.session
      msg += 'CSeq: 2\r\n\r\n'
      self.transport.write(msg.encode())
      self.client.loop.call_at(loop.time() + self.timeout/2, self.options)
      self.cseq = 2
    elif self.action == 'OPTIONS' and self.cseq == 2:
      log('%d (play): OK' % self.mport)
    elif self.action == 'TEARDOWN':
      log('%d (close): OK' % self.mport)
      self.retry()
      return

  def options(self):
    if not self.transport:
      return
    peer = self.transport._sock.getpeername()
    if self.action == 'OPTIONS':
      self.cseq += 1
      msg = 'OPTIONS rtsp://%s:%d/stream=%d RTSP/1.0\r\n' % (peer[0], peer[1], self.streamID)
      msg += 'Session: %s\r\n' % self.session
      msg += 'CSeq: %d\r\n\r\n' % self.cseq
      self.transport.write(msg.encode())
      self.client.loop.call_at(loop.time() + self.timeout/2, self.options)

  def teardown(self):
    self.action = 'TEARDOWN'
    if not self.transport:
      return
    peer = self.transport._sock.getpeername()
    log('%d (teardown): Session %s, streamID %d' % (self.mport, self.session, self.streamID))
    self.cseq += 1
    msg = 'TEARDOWN rtsp://%s:%d/stream=%d RTSP/1.0\r\n' % (peer[0], peer[1], self.streamID)
    msg += 'Session: %s\r\n' % self.session
    msg += 'CSeq: %d\r\n\r\n' % self.cseq
    self.transport.write(msg.encode())
    self.client.loop.call_at(loop.time() + 1, self.retry)

  def eof_received(self):
    self.connection_lost(None)

  def connection_lost(self, exc):
    if self.transport:
      log('%d (connection lost)' % self.mport)
      self.client.connection_lost()
      self.transport = None

  def retry(self):
    if self.transport:
      self.transport.close()

  def fatal(self):
    if self.transport:
      self.teardown()
    self.client.protocol = None
    self.client.fatal()

#
# Basic RTSP Client class
#

class RTSP_Client:

  def __init__(self, clients, params):
    self.clients = clients
    self.loop = clients.loop
    self.protocol = None
    self.params = params
    self.dead = False
    self.deleteme = False
    log('New multicast client: %s' % (params))
    self.create_connection()

  def create_connection(self):
    srv = SERVER.split(':')
    coro = self.loop.create_connection(lambda: RTSP_Protocol(self, self.params),
                                       srv[0], srv[1] and int(srv[1]) or 554)
    asyncio.async(coro, loop=self.loop)

  def connection_lost(self):
    self.protocol = None
    self.loop.call_at(loop.time() + 30, self.create_connection)

  def fatal(self):
    if self.dead:
      return
    log("Remove multicast client: %s" % self.params)
    self.dead = True
    if self.protocol:
      self.protocol.teardown()
    self.clients.remove_client(self)

#
# RTSP clients
#

class RTSP_Clients:

  def __init__(self, loop):
    self.loop = loop
    self.clients = []
    if USE_CONFIG :
      self.parse_config_file()
      hupfcn = lambda: self.parse_config_file()
    else :
      self.parse_request()
      hupfcn = lambda: self.parse_request()
    loop.add_signal_handler(signal.SIGHUP,
                            functools.partial(hupfcn))

  def remove_client(self, client):
    if client in self.clients:
      self.clients.remove(client)
      client.fatal()

  def add_client(self, params):
    for c in self.clients:
      if c.params == params:
        c.deleteme = False
        return
    self.clients.append(RTSP_Client(self, params))

  async def close_all(self):
    for c in self.clients:
      c.fatal()

  def parse_request(self):
    # mark clients
    for c in self.clients:
      c.deleteme = True
    # parse command line
    l = str(TARGET_PORT) + ':' + REQUEST
    #print("parse_request: " + l)
    self.add_client(l)
    # remove marked clients
    for c in self.clients:
      if c.deleteme:
        self.remove_client(c)

  def parse_config_file(self):
    # mark clients
    for c in self.clients:
      c.deleteme = True
    # parse config
    lines = []
    try:
      a = open(CONFIG)
      lines = a.readlines()
      a.close()
    except:
      pass
    prev = ''
    for l in lines:
      l = prev + l.strip().rstrip()
      prev = ''
      if not l or (l[0] in ['#', ';']): continue
      if l[-1] == '\\':
        prev = l[:-1].rstrip()
      else:
        self.add_client(l)
    # remove marked clients
    for c in self.clients:
      if c.deleteme:
        self.remove_client(c)

#
# configuration
#

if SYSLOG:
  syslog.openlog('multicast-rtp', 0, syslog.LOG_LOCAL7)

silent = QUIET
if QUIET :
  QUIET = False
log('Version %s' % VERSION)
log('SERVER: %s' % SERVER)
log('CONFIG: %s' % CONFIG)
log('TARGET: %s:%d' % (TARGET_ADDR, TARGET_PORT))
log('REQUEST: %s' % REQUEST)
log('------------')
if silent :
  log(' Start.')
  QUIET = True

loop = asyncio.get_event_loop()
loop.add_signal_handler(signal.SIGTERM, signal.getsignal(signal.SIGINT))

clients = RTSP_Clients(loop)

try:
    loop.run_forever()
except (KeyboardInterrupt, SystemExit) as e:
##  Send TEARDOWN before exit!
    log(' Closing.')
    loop.run_until_complete(clients.close_all())
    loop.run_until_complete(asyncio.sleep(1.0))
except:
    print('*******')
finally:
    QUIET = False
    log(' Stop.')
    loop.close()
if SYSLOG:
  syslog.closelog()
sys.exit(0)