#!/usr/local/bin/python

import os
import re
import sys
import yaml
import pushover
import email.header
import email.parser

try:
  # Use argv[1] as path to config file if specified
  cfg = sys.argv[1]
except IndexError:
  # Fall back to push.cfg in the same direcetory
  cfg = os.path.dirname(os.path.realpath(__file__)) + '/push.cfg'

with open(cfg, 'r') as fh:
  maps = yaml.load(fh)

try:
  sender_map    = maps['senders']
except KeyError:
  print >>sys.stderr, "Found no senders."
  sys.exit(1)

try:
  recipient_map = maps['recipients']
except KeyError:
  print >>sys.stderr, "Found no recipients."
  sys.exit(1)

try:
  recipient = os.environ['RECIPIENT']
except KeyError:
  print >>sys.stderr, "Recipient missing."
  sys.exit(1)

try:
  sender    = os.environ['SENDER']
except KeyError:
  print >>sys.stderr, "Sender missing."
  sys.exit(1)

# Select api key from map based on sender
for s in sender_map:
  try:
    if re.match(s['re'], sender):
      try:
        api_token = s['key']
      except KeyError:
        print >>sys.stderr, "Found no key for sender."
        sys.exit(1)
      else:
        break
  except KeyError:
    next
else:
  print >>sys.stderr, "Found no matching sender."
  sys.exit(1)

# Select user key(s) from map based on sender
for r in recipient_map:
  try:
    if re.match(r['re'], recipient):
      try:
        user_tokens = r['keys']
      except KeyError:
        print >>sys.stderr, "Found no key(s) for recipient."
        sys.exit(1)
      else:
        break
  except KeyError:
    next
else:
  print >>sys.stderr, "Found no matching receiver."
  sys.exit(1)

# Read an email from stdin
parser = email.parser.Parser()
mail = parser.parse(sys.stdin)

# Try to get the subject from the email and recode to utf-8 if possible
title, encoding = email.header.decode_header(mail.get('subject'))[0]
try:
  title = title.decode(encoding).encode('utf-8')
except (NameError, TypeError):
  pass

# Lets at least try to handle mime multipart
if mail.is_multipart():
  # Try to find something plain text
  for current in mail.walk():
    if current.get_content_type() == 'text/plain':
      payload  = current.get_payload(decode=True)
      encoding = current.get_charsets()[0]
      break
  else:
    # A realy stupid fallback
    payload  = mail.get_payload(0)
    encoding = mail.get_charsets()[0]

else:
  # Hurray no multipart
  payload = mail.get_payload(decode=True)
  encoding = mail.get_charsets()[0]

# Recode payload to utf-8 if possible
try:
  payload = payload.decode(encoding).encode('utf-8')
except (NameError, TypeError):
  pass

msg = payload.strip()

# Send notification to each user key
for user_token in user_tokens:
  if type(user_token) is dict:
    k = user_token.keys()[0]
    device = user_token.get(k, None)
    user_token = k
  else:
    device = None

  p = pushover.Client(user_token, api_token=api_token)
  p.send_message(msg, title=title, device=device)