__author__ = "Akshen Doke"

from django.core.mail import send_mail
from textwrap import dedent
from random import randint
from smtplib import SMTP
import hashlib 
from django.utils.crypto import get_random_string
from string import punctuation, digits
try:
    from string import letters
except ImportError:
    from string import ascii_letters as letters
from workshop_portal.settings import (
                    EMAIL_HOST, 
                    EMAIL_PORT, 
                    EMAIL_HOST_USER, 
                    EMAIL_HOST_PASSWORD,
                    EMAIL_USE_TLS,
                    PRODUCTION_URL, 
                    SENDER_EMAIL
                    )
from django.core.mail import EmailMultiAlternatives
from django.conf import settings
from os import listdir, path
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders
from time import sleep
from .models import WorkshopType

def generate_activation_key(username):
	"""Generates hashed secret key for email activation"""
	chars = letters + digits + punctuation
	secret_key = get_random_string(randint(10,40), chars)
	return hashlib.sha256((secret_key + username).encode('utf-8')).hexdigest()

def send_smtp_email(request=None, subject=None, message=None,
				user_position=None, workshop_date=None,
				workshop_title=None, user_name=None,
				other_email=None, phone_number=None,
				institute=None, attachment=None):
	'''
		Send email using SMTPLIB
	'''

	msg = MIMEMultipart()
	msg['From'] = EMAIL_HOST_USER
	msg['To'] = other_email
	msg['Subject'] = subject
	body = message
	msg.attach(MIMEText(body, 'plain'))

	if attachment:
		from django.conf import settings
		from os import listdir, path
		files = listdir(settings.MEDIA_ROOT)
		for f in files:
			attachment = open(path.join(settings.MEDIA_ROOT,f), 'rb')
			part = MIMEBase('application', 'octet-stream')
			part.set_payload((attachment).read())
			encoders.encode_base64(part)
			part.add_header('Content-Disposition', "attachment; filename= %s " % f)
			msg.attach(part)
	
	
	server = SMTP(EMAIL_HOST, EMAIL_PORT)
	server.ehlo()
	server.starttls()
	server.ehlo()
	server.esmtp_features['auth']='LOGIN DIGEST-MD5 PLAIN'
	server.login(EMAIL_HOST_USER, EMAIL_HOST_PASSWORD)
	text = msg.as_string()
	server.sendmail(EMAIL_HOST_USER, other_email, text)
	server.close()


def send_email(	request, call_on,
			user_position=None, workshop_date=None,
			workshop_title=None, user_name=None,
			other_email=None, phone_number=None,
			institute=None, key=None
			):
	'''
	Email sending function while registration and 
	booking confirmation.
	'''

	if call_on == "Registration":
		if user_position == "instructor":
			message = dedent("""\
					Your request as an Instructor at FOSSEE, IIT Bombay 
					has been received. Please click on the below link to 
					activate your account
					{0}/activate_user/{1}

					You will be notified via email on
					approval of your instructor account
					within 3 working days.

					In case of queries regarding the same revert to this 
					email.""".format(PRODUCTION_URL, key))

			try:
				send_mail(
					"Instructor Registration - FOSSEE, IIT Bombay", message, 
					SENDER_EMAIL, [request.user.email], fail_silently=False
					)
			except Exception: 
				send_smtp_email(request=request, 
					subject="Instructor Registration - FOSSEE, IIT Bombay", 
					message=message, other_email=request.user.email,
					)
			

			#Send a mail to admin as well.
			message = dedent("""\
					A new instructor request has been received.

					Instructor name: {0}
					Instructor email: {1}

					Please verify the profile and mail the user within 2
					working days.""".format(request.user, request.user.email))

			try:
				send_mail("New Instructor Registration - FOSSEE, IIT Bombay", 
					message, SENDER_EMAIL, ['workshops@fossee.in'], 
					fail_silently=False)
			except Exception:
				send_smtp_email(request=request, 
					subject="Instructor Registration - FOSSEE, IIT Bombay", 
					message=message, other_email='workshops@fossee.in',
					)
			
		else:
			message = dedent("""\
						Thank you for registering as a coordinator with us. 

						Please click on the below link to 
						activate your account
						{0}/activate_user/{1}
						
						After activation you can proceed to book your dates for 
						the workshop(s).

						In case of queries regarding workshop booking(s), 
						revert to this email.""".format(PRODUCTION_URL, key))

			try:
				send_mail(
					"Coordinator Registration at FOSSEE, IIT Bombay", message, SENDER_EMAIL, 
					[request.user.email, 'workshops@fossee.in'], fail_silently=False
					)
			except Exception:
				send_smtp_email(request=request, 
					subject="Coordinator Registration - FOSSEE, IIT Bombay", 
					message=message, other_email=request.user.email,
					)

	elif call_on == "Booking":
		if user_position == "instructor":
			message = dedent("""\
					Coordinator name:{0}
					Coordinator email: {1}
					Contact number:{2}
					Institute:{3}
					Workshop date:{4}
					Workshop title:{5}

					You may accept or reject this booking 
					{6}/my_workshops/ .""".format(
					user_name, request.user.email, 
					request.user.profile.phone_number,
					request.user.profile.institute,
					workshop_date, workshop_title, 
					PRODUCTION_URL
					))

			try:
				send_mail(
			 		"New FOSSEE Workshop booking on {0}".format(workshop_date),
			 		message, SENDER_EMAIL, [other_email], 
			 		fail_silently=False
			 		)
			except Exception:
				send_smtp_email(request=request, 
					subject="New FOSSEE Workshop booking on {0}"
					.format(workshop_date),
					message=message, other_email=other_email,
					)
		else:
			message = dedent("""\
					Thank You for New FOSSEE Workshop booking. 

					Workshop date:{0}
					Workshop title:{1}

					Your request has been received and is awaiting instructor 
					approval/disapproval. You will be notified about the status
					via email and on {2}/my_workshops/

					Please Note: Unless you get a confirmation email for this workshop with 
					the list of instructions, your workshop shall be in the waiting list.
					 
					In case of queries regarding workshop booking(s), revert
					to this email.""".format(
					workshop_date, workshop_title, PRODUCTION_URL
					))

			try:
				send_mail(
					"Pending Request for New FOSSEE Workshop booking on {0}"
					.format(workshop_date), message, SENDER_EMAIL, 
					[request.user.email], fail_silently=False
					)
			except Exception:
				send_smtp_email(request=request, 
					subject="Pending Request for New FOSSEE Workshop booking \
					on {0}".format(workshop_date),
					message=message, other_email=request.user.email,
					)

	elif call_on == "Booking Confirmed":
		if user_position == "instructor":
			message = dedent("""\
			Coordinator name:{0}
			Coordinator email: {1}
			Contact number:{2}
			Institute:{3}
			Workshop date:{4}
			Workshop title:{5}

			You have accepted this booking.  Detailed instructions have
			been sent to the coordinator. """.format(user_name, other_email, 
				phone_number, institute, workshop_date, workshop_title))


			subject = "FOSSEE Workshop booking confirmation  on {0}".\
				format(workshop_date)
			msg = EmailMultiAlternatives(subject, message, SENDER_EMAIL, [request.user.email])
			attachment_paths = path.join(settings.MEDIA_ROOT, workshop_title.replace(" ","_"))
			files = listdir(attachment_paths)
			for f in files:
				attachment = open(path.join(attachment_paths, f), 'rb')
				part = MIMEBase('application', 'octet-stream')
				part.set_payload((attachment).read())
				encoders.encode_base64(part)
				part.add_header('Content-Disposition', "attachment; filename= %s " % f)
				msg.attach(part)
				sleep(1)
			msg.send()

		else:
			message = dedent("""\
				Instructor name:{0}
				Instructor email: {1}
				Contact number:{2}
				Workshop date:{3}
				Workshop title:{4}

				Your workshop booking has been accepted. Detailed 
				instructions are attached below.  

				In case of queries regarding the workshop 
				instructions/schedule revert to this email.""".format(
				request.user.username, request.user.email, 
				phone_number, workshop_date, workshop_title
				))

			subject = "FOSSEE Workshop booking confirmation  on {0}".\
				format(workshop_date)
			msg = EmailMultiAlternatives(subject, message, SENDER_EMAIL, [other_email])
			attachment_paths = path.join(settings.MEDIA_ROOT, workshop_title.replace(" ","_"))
			files = listdir(attachment_paths)
			for f in files:
				attachment = open(path.join(attachment_paths, f), 'rb')
				part = MIMEBase('application', 'octet-stream')
				part.set_payload((attachment).read())
				encoders.encode_base64(part)
				part.add_header('Content-Disposition', "attachment; filename= %s " % f)
				msg.attach(part)
			msg.send()


	elif call_on == "Booking Request Rejected":
		if user_position == "instructor":
			message = dedent("""\
					Coordinator name:{0}
					Coordinator email: {1}
					Contact number:{2}
					Institute:{3}
					Workshop date:{4}
					Workshop title:{4}

					You have rejected this booking.  The coordinator has
					been notified.""".format(user_name, other_email,
					phone_number, institute,
					workshop_date, workshop_title))

			try:
				send_mail("FOSSEE Workshop booking rejected for {0}"
					.format(workshop_date), message, SENDER_EMAIL, 
					[request.user.email], fail_silently=False)
			except Exception:
				send_smtp_email(request=request, 
					subject="FOSSEE Workshop booking rejected for {0}".
					format(workshop_date), message=message,
					other_email=request.user.email
					)
		else:
			message = dedent("""\
					Workshop date:{0}
					Workshop title:{1}

					We regret to inform you that your workshop booking
					has been rejected due to unavailability of the
					instructor. You may try booking other available 
					slots {2}/book/ """
					.format(workshop_date, workshop_title, PRODUCTION_URL))

			try:
				send_mail("FOSSEE Workshop booking rejected for {0}".
					format(workshop_date), message, SENDER_EMAIL, 
					[other_email], fail_silently=False)
			except Exception:
				send_smtp_email(request=request, 
					subject="FOSSEE Workshop booking rejected for {0}".
					format(workshop_date), message=message,
					other_email=other_email
					)

	elif call_on =='Workshop Deleted':
		message = dedent("""\
				You have deleted a Workshop.

				Workshop date:{0}
				Workshop title:{1}"""
				.format(workshop_date, workshop_title))
		try:
			send_mail("FOSSEE workshop deleted for {0}".format(workshop_date),
				message, SENDER_EMAIL, [request.user.email], 
				fail_silently=False)
		except Exception:
			send_smtp_email(request=request, 
				subject="FOSSEE Workshop deleted for {0}".
				format(workshop_date), message=message,
				other_email=request.user.email
				)