#    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/>.

from ssmembership.models import Member

from django.contrib.auth.models import User

from django.conf import settings
from django.db import models
from jsonfield import JSONField

class Group(models.Model):
	name = models.CharField(max_length=1000)
	subscribable = models.BooleanField()
	order = models.IntegerField(null=True, blank=True)
	hidden = models.BooleanField()
	
	managers = JSONField(default=[], blank=True)
	
	class Meta:
		ordering = ['order', 'id']
	
	def __str__(self):
		return self.name
	
	def can_user_access(self, user):
		if user.is_superuser:
			return True
		if user.email in self.managers:
			return True
		for email in self.managers:
			manager = User.objects.get(email=email)
			if hasattr(manager, 'userprofile') and user.email in manager.userprofile.delegates:
				return True
		return False
	
	def contains_member(self, member):
		if self.subscribable:
			return GroupSubscription.objects.filter(member=member, group=self).count() > 0
		
		if self.name in settings.PROMO_GROUPS_MANDATORY:
			return True
		if next(v for k, v in Member.YEARS if k == member.year) in self.name.split('/'):
			# Year level group
			return True
		return False
	
	def subscribe_member(self, member, subscribe):
		if not self.subscribable:
			raise Exception('Cannot subscribe to an unsubscribable group')
		
		if subscribe:
			if GroupSubscription.objects.filter(member=member, group=self).count() == 0:
				subscription = GroupSubscription(member=member, group=self)
				subscription.save()
		else:
			GroupSubscription.objects.filter(member=member, group=self).delete()
	
	@staticmethod
	def get_member_groups(member):
		# Subscribable groups
		subscriptions = GroupSubscription.objects.filter(member=member)
		groups = set(subscription.group for subscription in subscriptions.all())
		
		# Non-subscribable groups
		for group in Group.objects.filter(subscribable=False):
			if group.contains_member(member):
				groups.add(group)
		
		groups = list(groups)
		groups.sort(key=lambda group: group.order)
		
		return groups

class BulletinItem(models.Model):
	author = models.ForeignKey(User, on_delete=models.CASCADE)
	group = models.ForeignKey(Group, on_delete=models.CASCADE)
	also_limit = JSONField(default=[])
	title = models.CharField(max_length=1000)
	link = models.CharField(max_length=1000, null=True)
	image = models.ImageField(upload_to='promo_uploads/%Y/%m/%d/', null=True)
	content = models.TextField()
	date = models.DateField()
	
	def can_user_access(self, user):
		if self.group.can_user_access(user):
			return True
		if user == self.author:
			return True
		if hasattr(self.author, 'userprofile') and user.email in self.author.userprofile.delegates:
			return True
		return False

class BulletinSubscription(models.Model):
	member = models.ForeignKey(Member, on_delete=models.CASCADE)
	subscribed = models.BooleanField()
	
	@staticmethod
	def is_member_subscribed(member):
		return BulletinSubscription.objects.filter(member=member, subscribed=True).count() > 0
	
	@staticmethod
	def set_member_subscribed(member, subscribed):
		if BulletinSubscription.objects.filter(member=member).count() > 0:
			subscription = BulletinSubscription.objects.get(member=member)
		else:
			subscription = BulletinSubscription(member=member)
		subscription.subscribed = subscribed
		subscription.save()

class GroupSubscription(models.Model):
	member = models.ForeignKey(Member, on_delete=models.CASCADE)
	group = models.ForeignKey(Group, on_delete=models.CASCADE)