#!/usr/bin/python
# Copyright 2015 (c) Anna Schumaker.
#

import slack
import sys
from email.parser import Parser


headers = Parser().parsestr(sys.stdin.read())


#
# Only allow replies that come from the slack user's email address.
#
sender = headers["sender"].replace(".", "")
target = slack.user().email().replace(".", "")
if sender != target:
    print("Reply not from user!")
    sys.exit(1)


#
# Look for our marker text to help find thread id
#
reply  = "--- Reply above this line ---"
payload = headers.get_payload()
if payload.find(reply) == -1:
    print("Reply line missing!")
    sys.exit(1)
split = headers.get_payload().split(reply)


#
# We should have a two element list.  The thread id
# is in the text at the start of the second element.
#
thread_id = split[-1].split()[0]
if thread_id.find("thread=") == -1:
    print("Thread ID missing!")
    sys.exit(1)
thread_id = thread_id[7:]


#
# Loop over each line of the reply, strip out special characters,
# and remove any "Reply sent on <whenever>" text.  Note that we
# make the following assumptions:
#
#  - The email reply will always have "Reply sent on <whenever>" text
#  - There will always be a blank line between content and replied-on text
#
lines = []
for line in split[0].split("\n"):
    lines += [ line.strip() ]
while lines[-1] != "":
    lines.pop(len(lines) - 1)
text = ' '.join(lines).strip()
print(text)


thread = slack.find_thread(thread_id)
if thread == None:
    print("No such thread!")
    sys.exit(1)

channel.post(text)