import datetime
import email
import os
import imaplib
from time import sleep
from threading import Thread
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.application import MIMEApplication
from email.mime.text import MIMEText

#Fri May 24 15:51:32 2019

class EmailSniffer():

    def __init__(self,
                 email_account,
                 username=None, pw=None,
                 check_rate_min=1,
                 imap_svr=None, imap_port=None,
                 smtp_svr=None, smtp_port=None,
                 imei=None,
                 arrival_email_filt=None,
                 attachment_ext_filt=None):
        self.IMEI = imei
        self.SENDER = arrival_email_filt
        self.FROM = email_account
        self.email_username = username
        self.email_pw = pw
        self.email_check_rate = check_rate_min
        self.email_incoming_svr = imap_svr
        self.email_outgoing_svr = smtp_svr
        self.email_incoming_port = imap_port
        self.email_outgoing_port = smtp_port
        self.attachment_ext_filt = attachment_ext_filt

        self.EMAILTEXT = "MOMSN: {0}\nMTMSN: 0\nTime of Session (UTC): {1}\nSession Status: 00 - Transfer OK\nMessage Size (bytes): {2}"
        self.momsn = 900000

        self.incoming_attachment_queues = []

        #self.last_read = datetime.datetime.now()
        self.last_read = datetime.datetime.utcnow()
        self.alive = True

        self._threadL = Thread(target=self._listen)
        self._threadL.setDaemon(True)
        self._threadL.start()

    def _listen(self):
        print('Listen thread started')
        while self.alive:
            try:
                date = (datetime.datetime.now() - datetime.timedelta(hours=1)).strftime("%d-%b-%Y")

                M = imaplib.IMAP4(self.email_incoming_svr)

                response, details = M.login(self.email_username, self.email_pw)
                M.select('INBOX')

                print('Checking INBOX')
                #Search for messages in the past hour with subject line specified and from sender specified
                response, items = M.search(None,
                                           '(UNSEEN SENTSINCE {date} HEADER Subject "{subject}" FROM "{sender}")'.format(
                                               date=date,
                                               subject=self.IMEI,
                                               sender=self.SENDER
                                           ))

                for emailid in items[0].split():
                    response, data = M.fetch(emailid, '(RFC822)')

                    mail = email.message_from_string((data[0][1]).decode('utf-8'))

                    if not mail.is_multipart():
                        continue
                    for part in mail.walk():
                        if part.is_multipart():
                            continue
                        if part.get('Content-Disposition') is None:
                            continue
                        file_nm = part.get_filename()
                        if file_nm is None:
                            continue
                        filename, fileext = os.path.splitext(file_nm)
                        if self.attachment_ext_filt is not None:
                            if fileext != self.attachment_ext_filt:
                                continue
                        msg = part.get_payload(decode=True)

                        print('Found msg in INBOX')
                        print(msg)
                        for q in self.incoming_attachment_queues:
                            q.put_nowait(msg)


                        temp = M.store(emailid, '+FLAGS', '\\Seen')

                M.close()
                M.logout()
                sleep(self.email_check_rate * 10)
            except:
                # Could probably handle this better, but just so we don't kill the thread...
                pass

    def write(self, msg):
        print('Writing e-mail')
        email_msg = MIMEMultipart()
        email_msg['Subject'] = "SBD Msg From Unit: " + "{0}".format(self.IMEI)
        email_msg['To'] = self.SENDER
        email_msg['From'] = self.FROM

       #part = MIMEText(self.EMAILTEXT.format(self.momsn, datetime.datetime.now().ctime(), len(msg)))
        part = MIMEText(self.EMAILTEXT.format(self.momsn, datetime.datetime.utcnow().ctime(), len(msg)))

        email_msg.attach(part)

        attachment = MIMEApplication(msg)

        attachment.add_header('Content-Disposition', 'attachment',
                              filename="{0}_{1}{2}".format(self.IMEI, self.momsn,
                                                            self.attachment_ext_filt))
        email_msg.attach(attachment)
        print('SMTP connect')
        print(self.email_outgoing_svr)
        print(self.email_outgoing_port)
        smtp = smtplib.SMTP('outbox.whoi.edu', self.email_outgoing_port)
        smtp.ehlo()
        smtp.starttls()
        smtp.login(self.email_username, self.email_pw)
        print('SMTP send')
        smtp.sendmail(self.FROM, [email_msg['To'], self.FROM], email_msg.as_string())
        print('SMTP quit')
        smtp.quit()

        self.momsn = self.momsn + 1

    def close(self):
        self.alive = False

    def append_incoming_attachment_queue(self, queue_to_append):
        self.incoming_attachment_queues.append(queue_to_append)