#!/usr/bin/python
import subprocess
import os
import re
import sys
import json


TINC_NETWORK =os.environ.get("TINC_NETWORK","retiolum")

# is_legacy is the parameter which defines if the tinc config files are handled old fashioned (parse from syslog), 
# or if the new and hip tincctl should be used


# Tags and Delimiters
TINC_TAG="tinc.%s" % TINC_NETWORK
BEGIN_NODES = "Nodes:"
END_NODES = "End of nodes."
BEGIN_SUBNET = "Subnet list:"
END_SUBNET = "End of subnet list"
BEGIN_EDGES = "Edges:"
END_EDGES = "End of edges."
def usage():
  from sys import argv,exit
  print("""usage: %s
This tool dumps all tinc node informations as json

ENVIRONMENT VARIABLES:
  TINC_NETWORK   The tinc network to dump 
                      (default: retiolum)
  LOG_FILE       If legacy tinc is used, defines the log file where tinc stats are dumped in
                      (default: /var/log/everything.log)
""" % argv[0])
  exit(1)
def debug(func):
  from functools import wraps
  @wraps(func)
  def with_debug(*args,**kwargs):
    print( func.__name__ + " (args: %s | kwargs %s)"% (args,kwargs))
    return func(*args,**kwargs)
  return with_debug


def parse_tinc_stats():
  import subprocess
  from time import sleep
  from distutils.spawn import find_executable as which
  #newest tinc
  if which("tinc"):
    return parse_new_input("tinc")
  #new tinc
  elif which("tincctl"):
    return parse_new_input("tincctl")
  #old tinc
  else:
    raise Exception("no tinc executable found!")
  
#@debug
def get_tinc_block(log_file):
  """ returns an iterateable block from the given log file (syslog) 
      This function became obsolete with the introduction of tincctl
  """
  from BackwardsReader import BackwardsReader
  tinc_block = []
  in_block = False
  bf = BackwardsReader(log_file)
  BOL = re.compile(".*tinc.%s\[[0-9]+\]: " % TINC_NETWORK)
  while True:
    line = bf.readline()
    if not line:
      raise Exception("end of file at log file? This should not happen!")
    line = BOL.sub('',line).strip()

    if END_SUBNET in line:
      in_block = True

    if not in_block:
      continue
    tinc_block.append(line)

    if BEGIN_NODES in line:
      break
  return reversed(tinc_block)

def parse_new_input(tinc_bin):
  nodes = {} 
  pnodes = subprocess.Popen(
          [tinc_bin,"-n",TINC_NETWORK,"dump","reachable","nodes"],
          stdout=subprocess.PIPE).communicate()[0].decode()
  #pnodes = subprocess.check_output(["tincctl","-n",TINC_NETWORK,"dump","reachable","nodes"])
  for line in pnodes.split('\n'):
    if not line: continue
    l = line.split()
    nodes[l[0]]= { 'external-ip': l[2], 'external-port' : l[4] }
  psubnets = subprocess.check_output(
          [tinc_bin,"-n",TINC_NETWORK,"dump","subnets"]).decode()
  for line in psubnets.split('\n'):
    if not line: continue
    l = line.split()
    try:
      if not nodes[l[2]].get('internal-ip',False):
         nodes[l[2]]['internal-ip'] = []
      nodes[l[2]]['internal-ip'].append(l[0].split('#')[0])
    except KeyError:
      pass # node does not exist (presumably)
  pedges = subprocess.check_output(
          [tinc_bin,"-n",TINC_NETWORK,"dump","edges"]).decode()
  for line in pedges.split('\n'):
    if not line: continue
    l = line.split()
    try:
      if not 'to' in nodes[l[0]] :
        nodes[l[0]]['to'] = []
      nodes[l[0]]['to'].append(
          {'name':l[2],'addr':l[4],'port':l[6],'weight' : l[10] })
    except KeyError:
      pass #node does not exist
  return nodes

if __name__ == '__main__':
  from sys import argv
  if len(argv) > 1:
    usage()
  else:
    print (json.dumps(parse_tinc_stats()))