#!/usr/bin/python
#
# 'router', 'host' and 'device' are used interchangably in this script

configsDir   = "/store/rancid/nordunet/configs"
outputDir    = "/home/vlanscrape/git/git.nordu.net/vlanscrape-data"
routerDBFile = "/store/rancid/nordunet/router.db"
routerDB     = dict()

# populate 'routerDB' with the contents of routerDBFile
f = open(routerDBFile, 'r')
for line in f:
  hostname, vendor, state = line.split(";")
  # ignore 'state' as it is of no consequence for the purpose of this script
  routerDB[hostname]=vendor
f.close()

import os
import errno
import re
import shutil
import time

# populate 'hostList'
hostList = os.listdir(configsDir)
if 'CVS' in hostList:
  hostList.remove('CVS')
if '.cvsignore' in hostList:
  hostList.remove('.cvsignore')

def is_arista(hostName):
  vlanDict=dict()
# print "arista:   ", hostName
  inFile = configsDir + "/" + hostName
  outFile = outputDir + "/" + hostName
  f = open(inFile)
  hostConfig=f.readlines()
  f.close()
  for i, l in enumerate(hostConfig):
    if re.match("^vlan", hostConfig[i]):
      # The config allows a comma separated list of multiple vlan ids,
      # with the same name, and it also allows vlans to be unnamed.
      # The simplest way to handle this is to grab the (lack of) name first
      # and apply it to the (list of) vlan(s) after.
      j = 1
      while True:
        if re.match(".*name ", hostConfig[i + j]):
          name = re.sub(".*name ", "", hostConfig[i + j].rstrip())
          break
        elif re.match('^!', hostConfig[i + j]):
          name = ""
          break
        else:
          j += 1

      vlan = re.sub(".*vlan ", "", hostConfig[i].rstrip())
      if "," in vlan:
        for v in vlan.split(","):
          vlanDict[v] = name
      elif "-" in vlan:
        first, last = vlan.split("-")
        for v in range(int(first),(int(last) + 1)):
          vlanDict[v] = name
      else:
        vlanDict[vlan] = name

  vlanList=vlanDict.items()
  check_out_vs_dst(hostName,vlanList)

def look_in_juniper_vlans_section(hostName, hostConfig):
  # Since vlans in the 'vlans' section (of a switch config) can only exist
  # once per 'device', using a dict here makes sense, as it ensures there will
  # only be one instance.
  vlanDict=dict()
  vBegin = 0
  vEnd = 0
  for i, l in enumerate(hostConfig):
    if re.match('^vlans {', l):
      vBegin = i
    if (vBegin != 0) and re.match('^}', l):
      vEnd = i
      break

  for i in range(int(vBegin) + 1,int(vEnd) + 1):
    # match: four spaces, the vlan 'name', one space, curly brace
    if re.match('^    [\S]+ {', hostConfig[i]):
      name=re.sub('{','',hostConfig[i]).strip()
      j = 1
      while True:
        if 'vlan-id' in hostConfig[i + j]:
          vlan=re.sub('vlan-id', '', hostConfig[i + j]).strip()
          vlan=re.sub(';', '', vlan)
          break
        else:
          j += 1
        if (i + j) >= len(hostConfig):
          vlan="none"
          break
      vlanDict[vlan] = name

  vlanList=vlanDict.items()
  return(vlanList)

def look_in_juniper_interfaces(hostName, hostConfig):
  # This is different from the 'vlans' section, as we have to keep track
  # of the interfaces too. Also, the same vlan-id may exist under different
  # names on different interfaces. For this reason the 'vlanList' data
  # structure in this def: is a list of lists
  vlanList=[]
  iBegin = 0
  for i, l in enumerate(hostConfig):
    if re.match('^interfaces {', l):
      iBegin = i
    if (iBegin != 0) and re.match('^}', l):
      iEnd = i
      break

  for i in range(int(iBegin) + 1, int(iEnd) +1):
    if re.match("^    [\S]+[\s]*[\S]+ {", hostConfig[i]):
      iFace=re.sub('{','',hostConfig[i]).strip()
      inUnit = 0
      name = ''
      while ( not (re.match('^    }',hostConfig[i]))):
        i += 1
        if re.match("^        .*unit", hostConfig[i]):
          unit=re.sub("^        .*unit ",'', hostConfig[i]).strip()
          unit=re.sub('{', '', unit).strip()
          inUnit = 1
        if (re.match('^        }', hostConfig[i])) and (inUnit == 1):
          inUnit = 0

        if (inUnit ==1):
          if "description" in hostConfig[i]:
            name=re.sub('[\s]+description','',hostConfig[i]).strip()
            name=re.sub('[";]','',name)
          if "vlan-id" in hostConfig[i]:
            vlan=re.sub('[\s]+vlan-id', '', hostConfig[i]).strip()
            vlan=re.sub(';', '', vlan)

            if "-range" in vlan:
              vBegin = re.sub('^-range ','', vlan)
              vBegin = re.sub('-[0-9]+$', '', vBegin)
              vEnd   = re.sub('-range [0-9]+-', '', vlan)
              for v in range(int(vBegin), int(vEnd) +1):
                vlanList.append([v,name,iFace])
            else:
              vlanList.append([vlan,name,iFace])
  return(vlanList)

def write_list_to_file(outFile, outList):
  f = open(outFile, "w")
  for l in outList:
    f.write(l)
  f.close

def check_out_vs_dst(hostName, vlanList):
  outFile = outputDir + "/" + hostName
  outList = []
  if (len(vlanList) == 1) and ("none" in vlanList[0]):
    #print "no vlans in", hostName
    pass
  else:
    for l in sorted(vlanList, key=lambda x: int(x[0])):
      o=''
      for i, sl in enumerate(l):
        if o == '':
          o = str(sl)
        else:
          o = o + ";" + str(sl)
      # we want the resulting 'csv' to have the same number of fields, whether
      # or not the source config has 'interface' for the vlan:
      if i == 1:
        o = o + ";"
      o = o + "\n"
      outList.append(o)
    if os.path.isfile(outFile):
      dstList = open(outFile, 'r').readlines()
      compare = set(sorted(outList)) & set(sorted(dstList))
      if (len(compare) != len(dstList)) or (len(compare) != len(outList)):
        write_list_to_file(outFile, outList)
    else:
      write_list_to_file(outFile, outList)


def is_juniper(hostName):
# print "juniper:  ", host
  vlanList=dict()
  inFile = configsDir + "/" + hostName
  outFile = outputDir + "/" + hostName
  f = open(inFile)
  hostConfig=f.readlines()
  f.close()
  if len(hostConfig) == 0:
    check_out_vs_dst(hostName, '')
  else:
    # find device model
    model = "unset"
    for l in hostConfig:
      if re.match('^# Chassis', l):
        l = re.sub('[\s]+', ':', l)
        ll = l.split(':')
        model = ll[3]

    if "EX" in model:
      vlanList=look_in_juniper_vlans_section(hostName, hostConfig)
      check_out_vs_dst(hostName,vlanList)
    elif "MX" in model:
      vlanList=look_in_juniper_interfaces(hostName, hostConfig)
      check_out_vs_dst(hostName, vlanList)
    elif "JNP204" in model:
      vlanList=look_in_juniper_interfaces(hostName, hostConfig)
      check_out_vs_dst(hostName, vlanList)
    elif "SRX" in model:
      vlanListInterfaces=look_in_juniper_interfaces(hostName, hostConfig)
      vlanListVlanSection=look_in_juniper_vlans_section(hostName, hostConfig)
      vlanList=vlanListInterfaces + vlanListVlanSection
      check_out_vs_dst(hostName, vlanList)
    elif "Virtual" in model:
      vlanList=look_in_juniper_vlans_section(hostName, hostConfig)
      check_out_vs_dst(hostName, vlanList)
    elif "unset" in model:
      print "Model info missing for", hostName, "- skipping"
    else:
      print "model", model, "not recognized, skipping:", hostName


try:
  os.makedirs(outputDir)
except OSError as e:
  if e.errno != errno.EEXIST:
    raise

for host in hostList:
  if host in routerDB:
    if routerDB[host] == 'arista':
      is_arista(host)
    elif routerDB[host] == 'juniper':
      is_juniper(host)
    else:
      print "unknown:  ", host