#!/usr/bin/python

import urllib2
import json
import socket
import datetime
import sys
import time
import smtplib
import atexit
import socket
import signal
from email.mime.text import MIMEText


def dump(obj):
  for attr in dir(obj):
    print "obj.%s = %s" % (attr, getattr(obj, attr))


def testurl(url, timeout):
  """
  returns a list, which first item is status, and optional second item is extra information, like:
    ['ok']
  of
    ['other', 'overheating']
  status:
    'ok'  - check ok
    'head too old': arg = time diff in seconds
    'connection refused'
    'connection timeout'
    'response timeout'
    'other': arg = error string - other unknown errors
  
  """

  try:
    f = urllib2.urlopen(url, timeout=timeout)
    now = datetime.datetime.utcnow()
    obj = json.load(f)
    if 'timestamp' in obj:
      x = datetime.datetime.utcfromtimestamp(obj['timestamp'] / 1000) + datetime.timedelta(milliseconds = obj['timestamp'] % 1000)
      secs = (now - x).total_seconds()
      if secs > 7200:
        return ['head too old', secs]
      return ['ok']
    return ['other', 'no timestamp in reply']
    
  except urllib2.URLError as e:
    #print 'except urllib2.URLError'
    #print repr(e.reason)

    reason_type = type(e.reason).__name__

    if reason_type == 'error':
      err_str = e.args[0].strerror
      if err_str == 'Connection refused':
        return ['connection refused']
      else:
        return ['other', str(e)]

    elif reason_type == 'timeout':
      # timeout when connecting
      return ['connection timeout']

    else:
      return ['other', str(e)]

  except IOError as e:
    #print 'except IOError'
    
    if type(e).__name__ == 'timeout':
      # timeout when reading
      return ['response timeout']

    else:
      return ['other', str(e)]

  except:
    return ['other', str(sys.exc_info()[0])]
    

"""
    print repr(type(e.reason).__name__)
    print 'repr(e) ', repr(e)
    print 'e ', e
    print 'e.args ', e.args
    print 'e.errno ', e.errno
    print 'e.strerror ', e.strerror
    dump(e)
    print 'repr(e.args[0]) ', repr(e.args[0])
    dump (e.args[0])


"""

myhostname = None

def sendmsg(newstate, state, l, lastchange, adminonly=False):
  global myhostname
  if not myhostname:
    myhostname = socket.gethostname()

  txt = 'checkflimsy on %s\n' % (myhostname)
  txt += 'state: %s\n' % newstate
  if newstate == 'head too old':
    txt += 'head too old: %f seconds\n' % l[1]
  if newstate == 'other':
    txt += 'message: %s\n' % str(l[1])
  txt += 'last state change: %s\n' % lastchange.replace(microsecond=0).isoformat(' ')
  delta = datetime.datetime.now().replace(microsecond=0) - lastchange.replace(microsecond=0)
  txt += 'time since last state change: %s\n' % str(delta)
  txt += '(previous state: %s)\n' % state

  print txt # XXX

  msg = MIMEText(txt)

  fromaddr = 'foo-admin@example.net'
  toaddrs = ['foo@example.net']
  if adminonly:
    toaddrs = ['foo@example.net']
    

  subj = '%s flimsy status: %s' % (myhostname, newstate)
  if newstate == 'other':
    subj += ' - %s' % str(l[1])
  if newstate not in ['ok', 'starting']:
    subj += ' - WARNING'
  msg['Subject'] = subj
  msg['From'] = fromaddr
  msg['To'] = ', '.join(toaddrs)

  # Send the message via our own SMTP server, but don't include the
  # envelope header.
  s = smtplib.SMTP('localhost')
  s.sendmail(fromaddr, toaddrs, msg.as_string())
  s.quit()


lastchange = None
state = None

def runloop(url):
  timeout = 10
  sleeptime = 30
  repeattime = 7200
  lasttold = None
  global lastchange
  global state

  while True:
    #print '.' # XXX
    l = testurl(url, timeout)
    newstate = l[0]

    now = datetime.datetime.now()
    
    if state != newstate:
      lastchange = now
      lasttold = now
      if state == None:
        # starting
        print 'check-flimsy started at %s' % (str(now))
        sendmsg('starting', state, l, lastchange, adminonly=True)
      else:
        sendmsg(newstate, state, l, lastchange)
      state = newstate
    elif state != 'ok' and (now - lasttold) > datetime.timedelta(seconds=repeattime):
      lasttold = now
      sendmsg(newstate, state, l, lastchange)

    time.sleep(sleeptime)


"""    
    'ok'  - check ok
    'head too old': arg = time diff in seconds
    'connection refused'
    'connection timeout'
    'response timeout'
    'other': arg = error string - other unknown errors
"""


def exitproc():
  sendmsg('EXITING', state, ['-'], lastchange, adminonly=True)


def main():
  url = 'https://flimsy.ct.nordu.net:8080/ct/v1/get-sth'
  #url = 'http://127.0.0.1:8080'

  while True:
    try:
      atexit.register(exitproc)
      signal.signal(signal.SIGHUP, exitproc)

      runloop(url)
    except:
      print "Unexpected error from runloop():", sys.exc_info()[0]
      raise # XXX


main()