#    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 django.contrib.auth.models import User

from django.db import models
from jsonfield import JSONField

from enum import Enum

class DescriptionEnum(Enum):
	def __new__(cls, value, description):
		obj = object.__new__(cls)
		obj._value_ = value
		obj.description = description
		return obj

class Budget(models.Model):
	pass

class BudgetComment(models.Model):
	budget = models.ForeignKey(Budget, on_delete=models.CASCADE)
	author = models.ForeignKey(User, on_delete=models.PROTECT, related_name='+')
	time = models.DateTimeField()
	content = models.TextField()
	
	class Meta:
		ordering = ['id']

class BudgetState(DescriptionEnum):
	DRAFT = 10, 'Draft'
	RESUBMIT = 20, 'Returned for redrafting'
	AWAIT_REVIEW = 30, 'Awaiting Treasury review'
	ENDORSED = 40, 'Endorsed by Treasury, awaiting committee approval'
	APPROVED = 50, 'Approved'
	#CANCELLED = 60, 'Cancelled'

class BudgetAction(DescriptionEnum):
	CREATE = 5, 'Created'
	EDIT = 10, 'Edited'
	UPDATE_STATE = 20, 'Updated state'

class BudgetRevision(models.Model):
	budget = models.ForeignKey(Budget, on_delete=models.CASCADE)
	name = models.CharField(max_length=100)
	date = models.DateField()
	contributors = models.ManyToManyField(User, related_name='+')
	comments = models.TextField()
	
	author = models.ForeignKey(User, on_delete=models.PROTECT, related_name='+')
	time = models.DateTimeField()
	
	state = models.IntegerField(choices=[(v.value, v.description) for v in BudgetState])
	
	revenue = JSONField(default=[])
	revenue_comments = models.TextField()
	
	expense = JSONField(default=[])
	expense_no_emergency_fund = models.BooleanField()
	expense_comments = models.TextField()
	
	action = models.IntegerField(choices=[(v.value, v.description) for v in BudgetAction])
	
	def copy(self):
		contributors = list(self.contributors.all())
		self.pk, self.id = None, None
		self.save()
		self.contributors.add(*contributors)
	
	def can_view(self, user):
		if user == self.author:
			return True
		if user in self.contributors.all():
			return True
		if user.groups.filter(name='Treasury').exists():
			return True
		if (self.state == BudgetState.ENDORSED or self.state == BudgetState.APPROVED) and user.groups.filter(name='Committee').exists():
			return True
		return False
	
	class Meta:
		ordering = ['id']

class ClaimState(DescriptionEnum):
	DRAFT = 10, 'Draft'
	RESUBMIT = 20, 'Returned for redrafting'
	AWAIT_REVIEW = 30, 'Awaiting Treasury approval'
	APPROVED = 40, 'Approved by Treasury, awaiting payment'
	PAID = 50, 'Paid'

class ClaimAction(DescriptionEnum):
	CREATE = 5, 'Created'
	EDIT = 10, 'Edited'
	UPDATE_STATE = 20, 'Updated state'

class ReimbursementClaim(models.Model):
	purpose = models.CharField(max_length=100)
	date = models.DateField()
	budget_id = models.CharField(max_length=20)
	comments = models.TextField()
	
	author = models.ForeignKey(User, on_delete=models.PROTECT, related_name='+')
	time = models.DateTimeField()
	
	state = models.IntegerField(choices=[(v.value, v.description) for v in ClaimState])
	
	items = JSONField(default=[])
	
	def can_view(self, user):
		if user == self.author:
			return True
		if user.groups.filter(name='Treasury').exists():
			return True
		return False

class ClaimReceipt(models.Model):
	claim = models.ForeignKey(ReimbursementClaim, on_delete=models.CASCADE)
	uploaded_file = models.FileField()

class ClaimComment(models.Model):
	claim = models.ForeignKey(ReimbursementClaim, on_delete=models.CASCADE)
	author = models.ForeignKey(User, on_delete=models.PROTECT, related_name='+')
	time = models.DateTimeField()
	content = models.TextField()
	
	class Meta:
		ordering = ['id']

class ClaimHistory(models.Model):
	claim = models.ForeignKey(ReimbursementClaim, on_delete=models.CASCADE)
	author = models.ForeignKey(User, on_delete=models.PROTECT, related_name='+')
	state = models.IntegerField(choices=[(v.value, v.description) for v in ClaimState])
	time = models.DateTimeField()
	action = models.IntegerField(choices=[(v.value, v.description) for v in ClaimAction])