#!/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.

from __future__ import print_function, unicode_literals

import base64

import email

import hashlib

import os

import sys

import time

from io import BytesIO

from multiprocessing import Process as Thread, Queue

import Milter

import requests

from Milter.utils import parse_addr

import pagure.config

import pagure.lib

if 'PAGURE_CONFIG' not in os.environ \

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

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

logq = Queue(maxsize=4)

_config = pagure.config.reload_config()

def get_email_body(emailobj):

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

    '''

    def _get_body(emailobj):

        """ Return the first text/plain body found if the email is multipart

        or just the regular payload otherwise.

        """

        if emailobj.is_multipart():

            for payload in emailobj.get_payload():

                # If the message comes with a signature it can be that this

                # payload itself has multiple parts, so just return the

                # first one

                if payload.is_multipart():

                    return _get_body(payload)

                body = payload.get_payload()

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

                    return body

        else:

            return emailobj.get_payload()

    body = _get_body(emailobj)

    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 = BytesIO()

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

        from_txt = 'From %s %s\n' % (self.canon_from, time.ctime())

        self.fp.write(from_txt.encode('utf-8'))

        return Milter.CONTINUE

    @Milter.noreply

    def header(self, name, hval):

        ''' Headers '''

        # add header to buffer

        header_txt = "%s: %s\n" % (name, hval)

        self.fp.write(header_txt.encode('utf-8'))

        return Milter.CONTINUE

    @Milter.noreply

    def eoh(self):

        ''' End of Headers '''

        self.fp.write(b"\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('Cc %s' % msg.get('cc'))

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

        # Check the email was sent to the right address

        email_address = msg['to']

        if 'reply+' in msg.get('cc', ''):

            email_address = msg['cc']

        if 'reply+' not in email_address:

            self.log(

                'No valid recipient email found in To/Cc: %s'

                % email_address)

            return Milter.CONTINUE

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

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

        salt = _config.get('SALT_EMAIL')

        from_email = clean_item(msg['From'])

        session = pagure.lib.create_session(_config['DB_URL'])

        try:

            user = pagure.lib.get_user(session, from_email)

        except:

            self.log(

                "Could not find an user in the DB associated with %s" %

                from_email)

            session.remove()

            return Milter.CONTINUE

        hashes = []

        for email_obj in user.emails:

            m = hashlib.sha512('%s%s%s' % (msg_id, salt, email_obj.email))

            hashes.append(m.hexdigest())

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

        if tohash not in hashes:

            self.log('hash list: %s' % hashes)

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

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

            session.remove()

            return Milter.CONTINUE

        if msg['From'] and msg['From'] == _config.get('FROM_EMAIL'):

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

            session.remove()

            return Milter.CONTINUE

        msg_id = clean_item(msg_id)

        if msg_id and '-ticket-' in msg_id:

            self.log('Processing issue')

            session.remove()

            return self.handle_ticket_email(msg, msg_id)

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

            self.log('Processing pull-request')

            session.remove()

            return self.handle_request_email(msg, msg_id)

        else:

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

            session.remove()

            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 = _config.get('APP_URL')

        if url.endswith('/'):

            url = url[:-1]

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

        self.log('Calling URL: %s' % 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 ticket to pagure')

        self.log(req.text)

        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 = _config.get('APP_URL')

        if url.endswith('/'):

            url = url[:-1]

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

        self.log('Calling URL: %s' % url)

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

        if req.status_code == 200:

            self.log('Comment added on PR')

            return Milter.ACCEPT

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

        self.log(req.text)

        return Milter.CONTINUE

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()