#!/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)

sender_map    = maps.get('senders', [])
recipient_map = maps.get('recipients', [])

recipient = os.environ.get('RECIPIENT', '')
sender    = os.environ.get('SENDER', '')
api_token   = None
user_tokens = None

# Make sure we got a sender and a recipient
if len(recipient) == 0 or len(sender) == 0:
  print >>sys.stderr, "recipient or sender missing."
  sys.exit(1)

# Select api key from map based on sender
for s in sender_map:
  if re.match(s.get('re', r'^$'), sender):
    api_token = s.get('key', None)
    break

# Select user key(s) from map based on sender
for r in recipient_map:
  if re.match(r.get('re', r'^$'), recipient):
    user_tokens = r.get('keys', None)
    break

# Make sure we have both user and api keys
if api_token is None or user_tokens is None:
  print >>sys.stderr, "found no matching keys for sender or recipient."
  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]
if title is not None and encoding is not None:
  title = title.decode(encoding).encode('utf-8')

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

else:
  # Hurray no multipart
  payload = mail.get_payload(decode=True)

# Recode payload to utf-8 if possible
encoding = payload.get_charsets()[0]
if payload is not None and encoding is not None:
  payload = payload.decode(encoding).encode('utf-8')

msg = payload.strip()

# Check for multiple user keys
if type(user_tokens) is list:
  # Send notification to each user key
  for user_token in user_tokens:
    p = pushover.Client(user_token, api_token=api_token)
    p.send_message(msg, title=title)
else:
  # Send notification to the only user key
  p = pushover.Client(user_tokens, api_token=api_token)
  p.send_message(msg, title=title)