#!/usr/bin/python
"""
Jutda Helpdesk - A Django powered ticket tracker for small enterprise.

(c) Copyright 2008 Jutda. All Rights Reserved. See LICENSE for details.

scripts/get_email.py - Designed to be run from cron, this script checks the
                       POP and IMAP boxes defined for the queues within a
                       helpdesk, creating tickets from the new messages (or
                       adding to existing tickets if needed)
"""

import email
import imaplib
import mimetypes
import poplib
import re
from datetime import datetime, timedelta
from email.Utils import parseaddr

from django.core.files.base import ContentFile
from django.core.management.base import BaseCommand
from django.db.models import Q
from django.utils.translation import ugettext as _

from helpdesk.lib import send_templated_mail
from helpdesk.models import Queue, Ticket, FollowUp, Attachment, IgnoreEmail


class Command(BaseCommand):
    def handle(self, *args, **options):
        process_email()


def process_email():
    for q in Queue.objects.filter(
            email_box_type__isnull=False,
            allow_email_submission=True):

        if not q.email_box_last_check:
            q.email_box_last_check = datetime.now()-timedelta(minutes=30)

        if not q.email_box_interval:
            q.email_box_interval = 0


        queue_time_delta = timedelta(minutes=q.email_box_interval)

        if (q.email_box_last_check + queue_time_delta) > datetime.now():
            continue

        process_queue(q)

        q.email_box_last_check = datetime.now()
        q.save()


def process_queue(q):
    print "Processing: %s" % q
    if q.email_box_type == 'pop3':
        
        if q.email_box_ssl:
            if not q.email_box_port: q.email_box_port = 995
            server = poplib.POP3_SSL(q.email_box_host, q.email_box_port)
        else:
            if not q.email_box_port: q.email_box_port = 110
            server = poplib.POP3(q.email_box_host, q.email_box_port)

        server.getwelcome()
        server.user(q.email_box_user)
        server.pass_(q.email_box_pass)

        messagesInfo = server.list()[1]

        for msg in messagesInfo:
            msgNum = msg.split(" ")[0]
            msgSize = msg.split(" ")[1]

            full_message = "\n".join(server.retr(msgNum)[1])
            ticket = ticket_from_message(message=full_message, queue=q)
            
            if ticket:
                server.dele(msgNum)

        server.quit()

    elif q.email_box_type == 'imap':
        if q.email_box_ssl:
            if not q.email_box_port: q.email_box_port = 993
            server = imaplib.IMAP4_SSL(q.email_box_host, q.email_box_port)
        else:
            if not q.email_box_port: q.email_box_port = 143
            server = imaplib.IMAP4(q.email_box_host, q.email_box_port)

        server.login(q.email_box_user, q.email_box_pass)
        server.select(q.email_box_imap_folder)
        status, data = server.search(None, 'ALL')
        for num in data[0].split():
            status, data = server.fetch(num, '(RFC822)')
            ticket = ticket_from_message(message=data[0][1], queue=q)
            if ticket:
                server.store(num, '+FLAGS', '\\Deleted')

        server.expunge()
        server.close()
        server.logout()


def decodeUnknown(charset, string):
    if not charset:
        try:
            string = string.decode('utf-8')
        except:
            string = string.decode('iso8859-1')
    string = unicode(string)
    return string
   

def ticket_from_message(message, queue):
    # 'message' must be an RFC822 formatted message.
    msg = message
    message = email.message_from_string(msg)
    subject = message.get('subject', _('Created from e-mail'))
    subject = decodeUnknown(message.get_charset(), subject)
    subject = subject.replace("Re: ", "").replace("Fw: ", "").replace("RE: ", "").replace("FW: ", "").strip()

    sender = message.get('from', _('Unknown Sender'))
    sender = decodeUnknown(message.get_charset(), sender)

    sender_email = parseaddr(sender)[1]

    for ignore in IgnoreEmail.objects.filter(Q(queues=queue) | Q(queues__isnull=True)):
        if ignore.test(sender_email):
            return False

    regex = re.compile("^\[[A-Za-z0-9]+-\d+\]")
    if regex.match(subject):
        # This is a reply or forward.
        ticket = re.match(r"^\[(?P<queue>[A-Za-z0-9]+)-(?P<id>\d+)\]", subject).group('id')
    else:
        ticket = None

    counter = 0
    files = []

    for part in message.walk():
        if part.get_content_maintype() == 'multipart':
            continue

        name = part.get_param("name")

        if part.get_content_maintype() == 'text' and name == None:
            body = part.get_payload(decode=True)
            body = decodeUnknown(part.get_charset(), body)
        else:
            if not name:
                ext = mimetypes.guess_extension(part.get_content_type())
                name = "part-%i%s" % (counter, ext)

            files.append({
                'filename': name,
                'content': part.get_payload(decode=True),
                'type': part.get_content_type()},
                )

        counter += 1

    now = datetime.now()

    if ticket:
        try:
            t = Ticket.objects.get(id=ticket)
            new = False
        except Ticket.DoesNotExist:
            ticket = None

    priority = 3

    smtp_priority = message.get('priority', '')
    smtp_importance = message.get('importance', '')

    high_priority_types = ('high', 'important', '1', 'urgent')

    if smtp_priority in high_priority_types or smtp_importance in high_priority_types:
        priority = 2

    if ticket == None:
        t = Ticket(
            title=subject,
            queue=queue,
            submitter_email=sender_email,
            created=now,
            description=body,
            priority=priority,
        )
        t.save()
        new = True
        update = ''

    context = {
        'ticket': t,
        'queue': queue,
    }

    if new:

        if sender_email:
            send_templated_mail(
                'newticket_submitter',
                context,
                recipients=sender_email,
                sender=queue.from_address,
                fail_silently=True,
                )

        if queue.new_ticket_cc:
            send_templated_mail(
                'newticket_cc',
                context,
                recipients=queue.new_ticket_cc,
                sender=queue.from_address,
                fail_silently=True,
                )

        if queue.updated_ticket_cc and queue.updated_ticket_cc != queue.new_ticket_cc:
            send_templated_mail(
                'newticket_cc',
                context,
                recipients=queue.updated_ticket_cc,
                sender=queue.from_address,
                fail_silently=True,
                )

    else:
        update = _(' (Updated)')

        if t.assigned_to:
            send_templated_mail(
                'updated_owner',
                context,
                recipients=t.assigned_to.email,
                sender=queue.from_address,
                fail_silently=True,
                )

        if queue.updated_ticket_cc:
            send_templated_mail(
                'updated_cc',
                context,
                recipients=queue.updated_ticket_cc,
                sender=queue.from_address,
                fail_silently=True,
                )

    f = FollowUp(
        ticket = t,
        title = _('E-Mail Received from %(sender_email)s' % {'sender_email': sender_email}),
        date = datetime.now(),
        public = True,
        comment = body,
    )
    f.save()

    print " [%s-%s] %s%s" % (t.queue.slug, t.id, t.title, update)

    for file in files:
        filename = file['filename'].replace(' ', '_')
        if file['content']:
            a = Attachment(
                followup=f,
                filename=filename,
                mime_type=file['type'],
                size=len(file['content']),
                )
            a.file.save(file['filename'], ContentFile(file['content']))
            a.save()
            print "    - %s" % file['filename']

    return t


if __name__ == '__main__':
    process_email()