#!/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)
"""
from __future__ import print_function

import email
import imaplib
import mimetypes
import poplib
import re
import socket

from datetime import timedelta
from email.header import decode_header
from email.Utils import parseaddr, collapse_rfc2231_value
from optparse import make_option

from email_reply_parser import EmailReplyParser

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 import settings

try:
    from django.utils import timezone
except ImportError:
    from datetime import datetime as timezone

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


class Command(BaseCommand):
    def __init__(self):
        BaseCommand.__init__(self)

        self.option_list += (
            make_option(
                '--quiet', '-q',
                default=False,
                action='store_true',
                help='Hide details about each queue/message as they are processed'),
            )

    help = 'Process Jutda Helpdesk queues and process e-mails via POP3/IMAP as required, feeding them into the helpdesk.'

    def handle(self, *args, **options):
        quiet = options.get('quiet', False)
        process_email(quiet=quiet)


def process_email(quiet=False):
    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 = timezone.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) > timezone.now():
            continue

        process_queue(q, quiet=quiet)

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


def process_queue(q, quiet=False):
    if not quiet:
        print("Processing: %s" % q)

    if q.socks_proxy_type and q.socks_proxy_host and q.socks_proxy_port:
        try:
            import socks
        except ImportError:
            raise ImportError("Queue has been configured with proxy settings, but no socks library was installed. Try to install PySocks via pypi.")

        proxy_type = {
            'socks4': socks.SOCKS4,
            'socks5': socks.SOCKS5,
        }.get(q.socks_proxy_type)

        socks.set_default_proxy(proxy_type=proxy_type, addr=q.socks_proxy_host, port=q.socks_proxy_port)
        socket.socket = socks.socksocket
    else:
        socket.socket = socket._socketobject

    email_box_type = settings.QUEUE_EMAIL_BOX_TYPE if settings.QUEUE_EMAIL_BOX_TYPE else q.email_box_type

    if email_box_type == 'pop3':

        if q.email_box_ssl or settings.QUEUE_EMAIL_BOX_SSL:
            if not q.email_box_port: q.email_box_port = 995
            server = poplib.POP3_SSL(q.email_box_host or settings.QUEUE_EMAIL_BOX_HOST, int(q.email_box_port))
        else:
            if not q.email_box_port: q.email_box_port = 110
            server = poplib.POP3(q.email_box_host or settings.QUEUE_EMAIL_BOX_HOST, int(q.email_box_port))

        server.getwelcome()
        server.user(q.email_box_user or settings.QUEUE_EMAIL_BOX_USER)
        server.pass_(q.email_box_pass or settings.QUEUE_EMAIL_BOX_PASSWORD)


        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, quiet=quiet)

            if ticket:
                server.dele(msgNum)

        server.quit()

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

        server.login(q.email_box_user or settings.QUEUE_EMAIL_BOX_USER, q.email_box_pass or settings.QUEUE_EMAIL_BOX_PASSWORD)
        server.select(q.email_box_imap_folder)

        status, data = server.search(None, 'NOT', 'DELETED')
        if data:
            msgnums = data[0].split()
            for num in msgnums:
                status, data = server.fetch(num, '(RFC822)')
                ticket = ticket_from_message(message=data[0][1], queue=q, quiet=quiet)
                if ticket:
                    server.store(num, '+FLAGS', '\\Deleted')
        
        server.expunge()
        server.close()
        server.logout()


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

def decode_mail_headers(string):
    decoded = decode_header(string)
    return u' '.join([unicode(msg, charset or 'utf-8') for msg, charset in decoded])

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

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

    sender_email = parseaddr(sender)[1]

    body_plain, body_html = '', ''

    for ignore in IgnoreEmail.objects.filter(Q(queues=queue) | Q(queues__isnull=True)):
        if ignore.test(sender_email):
            if ignore.keep_in_mailbox:
                # By returning 'False' the message will be kept in the mailbox,
                # and the 'True' will cause the message to be deleted.
                return False
            return True

    matchobj = re.match(r".*\["+queue.slug+"-(?P<id>\d+)\]", subject)
    if matchobj:
        # This is a reply or forward.
        ticket = matchobj.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 name:
            name = collapse_rfc2231_value(name)

        if part.get_content_maintype() == 'text' and name == None:
            if part.get_content_subtype() == 'plain':
                body_plain = EmailReplyParser.parse_reply(decodeUnknown(part.get_content_charset(), part.get_payload(decode=True)))
            else:
                body_html = part.get_payload(decode=True)
        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

    if body_plain:
        body = body_plain
    else:
        body = _('No plain-text email body available. Please see attachment email_html_body.html.')

    if body_html:
        files.append({
            'filename': _("email_html_body.html"),
            'content': body_html,
            'type': 'text/html',
        })

    now = timezone.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 = ''

    elif t.status == Ticket.CLOSED_STATUS:
        t.status = Ticket.REOPENED_STATUS
        t.save()

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

    if t.status == Ticket.REOPENED_STATUS:
        f.new_status = Ticket.REOPENED_STATUS
        f.title = _('Ticket Re-Opened by E-Mail Received from %(sender_email)s' % {'sender_email': sender_email})
    
    f.save()

    if not quiet:
        print((" [%s-%s] %s" % (t.queue.slug, t.id, t.title,)).encode('ascii', 'replace'))

    for file in files:
        if file['content']:
            filename = file['filename'].encode('ascii', 'replace').replace(' ', '_')
            filename = re.sub('[^a-zA-Z0-9._-]+', '', filename)
            a = Attachment(
                followup=f,
                filename=filename,
                mime_type=file['type'],
                size=len(file['content']),
                )
            a.file.save(filename, ContentFile(file['content']), save=False)
            a.save()
            if not quiet:
                print("    - %s" % filename)


    context = safe_template_context(t)

    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:
        context.update(comment=f.comment)

        if t.status == Ticket.REOPENED_STATUS:
            update = _(' (Reopened)')
        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,
                )

    return t


if __name__ == '__main__':
    process_email()