#    Society Self-Service
#    Copyright © 2018-2019  Yingtong Li (RunasSudo)
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <https://www.gnu.org/licenses/>.

import boto3
from botocore.exceptions import ClientError
import premailer

from django.core.management.base import BaseCommand, CommandError

from django.conf import settings
from django.template import loader
from django.urls import reverse

from ssmembership.monboard import get_members, set_emailed_by_email

import hmac
import logging
import time
import urllib.parse

class Command(BaseCommand):
	help = 'Send emails for membership onboarding'
	
	def add_arguments(self, parser):
		parser.add_argument('ids', nargs='*', type=int, help='Members with ID numbers equal to these values will be emailed (default all)')
		parser.add_argument('--render', action='store_true', help='Render to stdout instead of sending emails')
	
	def handle(self, *args, **options):
		template_html = loader.get_template('ssmembership/email/onboard.html')
		template_txt = loader.get_template('ssmembership/email/onboard.txt')
		
		members = get_members()
		
		if len(options['ids']) > 0:
			members = [member for member in members if member[0] in options['ids']]
		else:
			raise Exception('Must provide IDs')
		
		client = boto3.client('ses', aws_access_key_id=settings.AWS_KEY_ID, aws_secret_access_key=settings.AWS_SECRET, region_name=settings.AWS_REGION)
		
		def send_mail(**kwargs):
			for i in range(0, 10):
				try:
					client.send_email(**kwargs)
					return
				except ClientError as e:
					if e['Error']['Code'] == 'Throttling' and e['Error']['Message'] == 'Maximum sending rate exceeded.':
						wait_time = max(10*(2**i), 5000)
						self.stdout.write(self.style.NOTICE('Reached maximum sending rate, waiting {} ms'.format(wait_time)))
						time.sleep(wait_time/1000)
					else:
						raise e
			raise Exception('Reached maximum number of retries')
		
		for member in members:
			#_id, student_id, email, first_name, last_name, year, is_msa, phone, date, purchased, imported, emailed
			if member[10] or member[11]:
				continue
			
			sig = hmac.new(settings.SECRET_KEY_MEMBERSIG.encode('utf-8'), member[2].encode('utf-8'), 'sha256').hexdigest()
			renew_url = reverse('monboard_signed') + '?' + urllib.parse.urlencode({'email': member[2], 'sig': sig})
			
			template_args = {
				'name': member[3].strip() + ' ' + member[4].strip(),
				'renew_url': renew_url,
				'baseurl': 'https://' + settings.ALLOWED_HOSTS[0],
				'purchased': member[10]
			}
			
			content_html = premailer.Premailer(template_html.render(template_args), cssutils_logging_level=logging.ERROR).transform()
			content_txt = template_txt.render(template_args)
			
			if options['render']:
				self.stdout.write('Content-Type: multipart/alternative; boundary=boundary\n\n--boundary\nContent-Type: text/html; charset=utf-8\n\n' + content_html + '\n--boundary\nContent-Type: text/plain; charset=utf-8\n\n' + content_txt + '\n--boundary')
			else:
				self.stdout.write('Emailing {} at {}'.format(member[0], member[2]))
				send_mail(
					Destination={
						'ToAddresses': [member[2]],
					},
					Message={
						'Body': {
							'Html': {
								'Charset': 'utf-8',
								'Data': content_html,
							},
							'Text': {
								'Charset': 'utf-8',
								'Data': content_txt,
							},
						},
						'Subject': {
							'Charset': 'utf-8',
							'Data': 'Activate your ' + settings.ORG_NAME + ' membership',
						},
					},
					Source='{} <{}>'.format(settings.ORG_NAME, settings.AWS_SENDER_EMAIL),
				)
				set_emailed_by_email(member[2])