#!/usr/bin/env python2

# -*- coding: utf-8 -*-

# Milter calls methods of your class at milter events.

# Return REJECT,TEMPFAIL,ACCEPT to short circuit processing for a message.

# You can also add/del recipients, replacebody, add/del headers, etc.

import base64

import email

import hashlib

import os

import urlparse

import StringIO

import sys

import time

from socket import AF_INET, AF_INET6

from multiprocessing import Process as Thread, Queue

import Milter

import requests

from Milter.utils import parse_addr

logq = Queue(maxsize=4)

if 'PAGURE_CONFIG' not in os.environ \

        and os.path.exists('/etc/pagure/pagure.cfg'):

    os.environ['PAGURE_CONFIG'] = '/etc/pagure/pagure.cfg'

import pagure

def get_email_body(emailobj):

    ''' Return the body of the email, preferably in text.

    '''

    body = None

    if emailobj.is_multipart():

        for payload in emailobj.get_payload():

            body = payload.get_payload()

            if payload.get_content_type() == 'text/plain':

                break

    else:

        body = emailobj.get_payload()

    enc = emailobj['Content-Transfer-Encoding']

    if enc == 'base64':

        body = base64.decodestring(body)

    return body

def clean_item(item):

    ''' For an item provided as <item> return the content, if there are no</item>

    <> then return the string.

    '''

    if '<' in item:

        item = item.split('<')[1]

    if '>' in item:

        item = item.split('>')[0]

    return item

class PagureMilter(Milter.Base):

    def __init__(self):  # A new instance with each new connection.

        self.id = Milter.uniqueID()  # Integer incremented with each call.

        self.fp = None

    def log(self, message):

        print(message)

        sys.stdout.flush()

    def envfrom(self, mailfrom, *str):

        self.log("mail from: %s  -  %s" % (mailfrom, str))

        self.fromparms = Milter.dictfromlist(str)

        # NOTE: self.fp is only an *internal* copy of message data.  You

        # must use addheader, chgheader, replacebody to change the message

        # on the MTA.

        self.fp = StringIO.StringIO()

        self.canon_from = '@'.join(parse_addr(mailfrom))

        self.fp.write('From %s %s\n' % (self.canon_from, time.ctime()))

        return Milter.CONTINUE

    @Milter.noreply

    def header(self, name, hval):

        ''' Headers '''

        # add header to buffer

        self.fp.write("%s: %s\n" % (name, hval))

        return Milter.CONTINUE

    @Milter.noreply

    def eoh(self):

        ''' End of Headers '''

        self.fp.write("\n")

        return Milter.CONTINUE

    @Milter.noreply

    def body(self, chunk):

        ''' Body '''

        self.fp.write(chunk)

        return Milter.CONTINUE

    @Milter.noreply

    def envrcpt(self, to, *str):

        rcptinfo = to, Milter.dictfromlist(str)

        print rcptinfo

        return Milter.CONTINUE

    def eom(self):

        ''' End of Message '''

        self.fp.seek(0)

        msg = email.message_from_file(self.fp)

        msg_id = msg.get('In-Reply-To', None)

        if msg_id is None:

            self.log('No In-Reply-To, keep going')

            return Milter.CONTINUE

        # Ensure we don't get extra lines in the message-id

        msg_id = msg_id.split('\n')[0].strip()

        self.log('msg-ig %s' % msg_id)

        self.log('To %s' % msg['to'])

        self.log('From %s' % msg['From'])

        # Ensure the user replied to his/her own notification, not that

        # they are trying to forge their ID into someone else's

        salt = pagure.APP.config.get('SALT_EMAIL')

        m = hashlib.sha512('%s%s%s' % (msg_id, salt, clean_item(msg['From'])))

        tohash= msg['to'].split('@')[0].split('+')[-1]

        if m.hexdigest() != tohash:

            self.log('hash: %s' % m.hexdigest())

            self.log('tohash:   %s' % tohash)

            self.log('Hash does not correspond to the destination')

            return Milter.CONTINUE

        if msg['From'] and msg['From'] == pagure.APP.config.get('FROM_EMAIL'):

            self.log("Let's not process the email we send")

            return Milter.CONTINUE

        msg_id = clean_item(msg_id)

        if msg_id and '-ticket-' in msg_id:

            self.log('Processing issue')

            return self.handle_ticket_email(msg, msg_id)

        elif msg_id and '-pull-request-' in msg_id:

            self.log('Processing pull-request')

            return self.handle_request_email(msg, msg_id)

        else:

            self.log('Not a pagure ticket or pull-request email, let it go')

            return Milter.CONTINUE

    def handle_ticket_email(self, emailobj, msg_id):

        ''' Add the email as a comment on a ticket. '''

        uid  = msg_id.split('-ticket-')[-1].split('@')[0]

        parent_id = None

        if '-' in uid:

            uid, parent_id = uid.rsplit('-', 1)

        if '/' in uid:

            uid = uid.split('/')[0]

        self.log('uid %s' % uid)

        self.log('parent_id %s' % parent_id)

        data = {

            'objid': uid,

            'comment': get_email_body(emailobj),

            'useremail': clean_item(emailobj['From']),

        }

        url = pagure.APP.config.get('APP_URL')

        if url.endswith('/'):

            url = url[:-1]

        url = '%s/pv/ticket/comment/' % url

        req = requests.put(url, data=data)

        if req.status_code == 200:

            self.log('Comment added')

            return Milter.ACCEPT

        self.log('Could not add the comment to pagure')

        return Milter.CONTINUE

    def handle_request_email(self, emailobj, msg_id):

        ''' Add the email as a comment on a request. '''

        uid  = msg_id.split('-pull-request-')[-1].split('@')[0]

        parent_id = None

        if '-' in uid:

            uid, parent_id = uid.rsplit('-', 1)

        if '/' in uid:

            uid = uid.split('/')[0]

        self.log('uid %s' % uid)

        self.log('parent_id %s' % parent_id)

        data = {

            'objid': uid,

            'comment': get_email_body(emailobj),

            'useremail': clean_item(emailobj['From']),

        }

        url = pagure.APP.config.get('APP_URL')

        if url.endswith('/'):

            url = url[:-1]

        url = '%s/pv/pull-request/comment/' % url

        req = requests.put(url, data=data)

        return Milter.ACCEPT

def background():

    while True:

        t = logq.get()

        if not t: break

        msg,id,ts = t

        print "%s [%d]" % (time.strftime('%Y%b%d %H:%M:%S',time.localtime(ts)),id),

        # 2005Oct13 02:34:11 [1] msg1 msg2 msg3 ...

        for i in msg: print i,

        print

def main():

    bt = Thread(target=background)

    bt.start()

    socketname = "/var/run/pagure/paguresock"

    timeout = 600

    # Register to have the Milter factory create instances of your class:

    Milter.factory = PagureMilter

    print "%s pagure milter startup" % time.strftime('%Y%b%d %H:%M:%S')

    sys.stdout.flush()

    Milter.runmilter("paguremilter", socketname, timeout)

    logq.put(None)

    bt.join()

    print "%s pagure milter shutdown" % time.strftime('%Y%b%d %H:%M:%S')

if __name__ == "__main__":

    main()