"""
external library imports
"""
import datetime 
import uuid

from django.utils.http import urlquote
import logging

from decimal import Decimal

from jsonfield import JSONField

"""
django imports
"""
from django.conf import settings
from django.contrib.auth.models import User
from django.db import models
from django.db.models import Q
from django.contrib.sites.models import Site
from django.db.models.signals import post_save, post_delete, pre_save

"""
django module imports
"""
from notification import models as notification


"""
regluit imports
"""
from regluit.payment.parameters import *
from regluit.payment.signals import credit_balance_added, pledge_created
from regluit.utils.localdatetime import now, date_today

logger = logging.getLogger(__name__)

# in fitting stripe -- here are possible fields to fit in with Transaction
# c.id, c.amount, c.amount_refunded, c.currency, c.description, datetime.fromtimestamp(c.created, tz=utc), c.paid,
# c.fee, c.disputed, c.amount_refunded, c.failure_message,
# c.card.fingerprint, c.card.type, c.card.last4, c.card.exp_month, c.card.exp_year

# promising fields

class Transaction(models.Model):
    
    # type e.g., PAYMENT_TYPE_INSTANT or PAYMENT_TYPE_AUTHORIZATION -- defined in parameters.py
    type = models.IntegerField(default=PAYMENT_TYPE_NONE, null=False)
    
    # host: the payment processor.  Named after the payment module that hosts the payment processing functions
    host = models.CharField(default=PAYMENT_HOST_NONE, max_length=32, null=False)
        
    #execution: e.g. EXECUTE_TYPE_CHAINED_INSTANT, EXECUTE_TYPE_CHAINED_DELAYED, EXECUTE_TYPE_PARALLEL
    execution = models.IntegerField(default=EXECUTE_TYPE_NONE, null=False)
    
    # status: general status constants defined in parameters.py
    status = models.CharField(max_length=32, default=TRANSACTION_STATUS_NONE, null=False)
    
    # local_status: status code specific to the payment processor
    local_status = models.CharField(max_length=32, default='NONE', null=True)
    
    # amount & currency -- amount of money and its currency involved for transaction
    amount = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    max_amount = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    currency = models.CharField(max_length=10, default='USD', null=True)
    
    # a unique ID that can be passed to PayPal to track a transaction
    secret = models.CharField(max_length=64, null=True)
    
    # a paykey that PayPal generates to identify this transaction
    pay_key = models.CharField(max_length=128, null=True)
    
    # a preapproval key that Paypal generates to identify this transaction
    preapproval_key = models.CharField(max_length=128, null=True)
    
    # (RY is not sure what receipt is for; t4u has hijacked this to be an email address for user.is_anonymous to send a receipt to)
    receipt = models.CharField(max_length=256, null=True)
    
    # whether a Preapproval has been approved or not
    approved = models.NullBooleanField(null=True)
    
    # error message from a transaction
    error = models.CharField(max_length=256, null=True)
    
    # IPN.reason_code
    reason = models.CharField(max_length=64, null=True)
    
    # creation and last modified timestamps
    date_created = models.DateTimeField(auto_now_add=True, db_index=True,)
    date_modified = models.DateTimeField(auto_now=True)
    
    # date_payment: when an attempt is made to make the primary payment
    date_payment = models.DateTimeField(null=True)
    
    # date_executed: when an attempt is made to send money to non-primary chained receivers
    date_executed = models.DateTimeField(null=True)
    
    # datetime for creation of preapproval and for its expiration
    date_authorized = models.DateTimeField(null=True)
    date_expired = models.DateTimeField(null=True)
    
    # associated User, Campaign, and Premium for this Transaction
    user = models.ForeignKey(settings.AUTH_USER_MODEL, null=True)
    campaign = models.ForeignKey('core.Campaign', null=True)
    premium = models.ForeignKey('core.Premium', null=True)
    offer = models.ForeignKey('core.Offer', null=True)
    extra = JSONField(null=True, default={})
    
    # whether the user wants to be not listed publicly
    anonymous = models.BooleanField(default=False)

    @property
    def tier(self):
        if self.amount < 25:
            return 0
        if self.amount < 50:
            return 1
        if self.amount < 100:
            return 2
        else:
            return 3

    @property
    def needed_amount(self):
        if self.user == None or self.user.is_anonymous():
            return self.max_amount
        if self.user.credit.available >= self.max_amount:
            return 0
        else:
            return self.max_amount - self.user.credit.available

    @property
    def credit_amount(self):
        if self.user == None or self.user.is_anonymous():
            return 0
        if self.user.credit.available >= self.max_amount:
            return self.max_amount
        return self.user.credit.available
            
    @property
    def ack_link(self):
        return 'https://unglue.it/supporter/%s' % urlquote(self.user.username) if not self.anonymous else ''
        
    def save(self, *args, **kwargs):
        if not self.secret:
            self.secret = str(uuid.uuid1())
        super(Transaction, self).save(*args, **kwargs) # Call the "real" save() method.
    
    def __unicode__(self):
        return u"-- Transaction:\n \tstatus: %s\n \t amount: %s\n \terror: %s\n" % (self.status, str(self.amount),  self.error)
    
    def create_receivers(self, receiver_list):
        
        primary = True
        for r in receiver_list:
            receiver = Receiver.objects.create(email=r['email'], amount=r['amount'], currency=self.currency, status="None", primary=primary, transaction=self)
            primary = False
            
    def get_payment_class(self):
        '''
            Returns the specific payment processor that implements this transaction
        '''
        if self.host == PAYMENT_HOST_NONE:
            return None
        else:
            mod = __import__("regluit.payment." + self.host, fromlist=[str(self.host)])
            return mod.Processor()
    
    def set_executed(self):
        self.date_executed = now()
        self.save()

    def set_payment(self):      
        self.date_payment = now()
        self.save() 
    
    def set_credit_approved(self, amount):
        self.amount=amount
        self.host = PAYMENT_HOST_CREDIT
        self.type = PAYMENT_TYPE_AUTHORIZATION
        self.status=TRANSACTION_STATUS_ACTIVE
        self.approved=True
        now_val = now()
        self.date_authorized = now_val
        self.date_expired = now_val + datetime.timedelta( days=settings.PREAPPROVAL_PERIOD )
        self.save()
        pledge_created.send(sender=self, transaction=self)
        
    def set_pledge_extra(self, pledge_extra):
        if pledge_extra:
            self.anonymous = pledge_extra.anonymous
            self.premium = pledge_extra.premium
            self.offer = pledge_extra.offer
            self.extra.update( pledge_extra.extra)

    def get_pledge_extra(self):
        class pe:
            anonymous=self.anonymous
            premium=self.premium
            offer=self.offer
            extra=self.extra
        return pe

    @classmethod
    def create(cls,amount=0.00, host=PAYMENT_HOST_NONE, max_amount=0.00, currency='USD',
                status=TRANSACTION_STATUS_NONE,campaign=None, user=None, pledge_extra=None):
        if user and user.is_anonymous():
            user = None
        if pledge_extra:
            t = cls.objects.create(amount=amount,
                                host=host,
                                max_amount=max_amount, 
                                currency=currency,
                                status=status,
                                campaign=campaign,
                                user=user,
                                )
            t.set_pledge_extra(pledge_extra)
            return t
        else:
            return cls.objects.create(amount=amount, host=host, max_amount=max_amount, currency=currency,status=status,
                                campaign=campaign, user=user)
                            
class PaymentResponse(models.Model):
    # The API used
    api = models.CharField(max_length=64, null=False)
    
    # The correlation ID
    correlation_id = models.CharField(max_length=512, null=True)
    
    # the paypal timestamp
    timestamp = models.CharField(max_length=128, null=True)
    
    # extra info we want to store if an error occurs such as the response message
    info = models.CharField(max_length=1024, null=True)
    
    # local status specific to the api call
    status = models.CharField(max_length=32, null=True)
    
    transaction = models.ForeignKey(Transaction, null=False)

    def __unicode__(self):
        return u"PaymentResponse -- api: {0} correlation_id: {1} transaction: {2}".format(self.api, self.correlation_id, unicode(self.transaction))
        
    
class Receiver(models.Model):
    
    email = models.CharField(max_length=64)
    
    amount = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    currency = models.CharField(max_length=10)

    status = models.CharField(max_length=64)
    local_status = models.CharField(max_length=64, null=True)
    reason = models.CharField(max_length=64)
    primary = models.BooleanField(default=True)
    txn_id = models.CharField(max_length=64)
    transaction = models.ForeignKey(Transaction)
    
    def __unicode__(self):
        return u"Receiver -- email: {0} status: {1} transaction: {2}".format(self.email, self.status, unicode(self.transaction))

class CreditLog(models.Model):
    # a write only record of Gift Credit Transactions
    user = models.ForeignKey(settings.AUTH_USER_MODEL, null=True) 
    amount = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    timestamp = models.DateTimeField(auto_now=True)
    action = models.CharField(max_length=16)
    # used to record the sent id when action = 'deposit'
    sent=models.IntegerField(null=True)
    
class Credit(models.Model):
    user = models.OneToOneField(settings.AUTH_USER_MODEL, related_name='credit')
    balance = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    pledged = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    last_activity = models.DateTimeField(auto_now=True)
    
    @property
    def available(self):
        return self.balance - self.pledged
    
    def add_to_balance(self, num_credits):
        if self.pledged - self.balance >  num_credits :  # negative to withdraw
            return False
        else:
            self.balance = self.balance + num_credits
            self.save()
            try: # bad things can happen here if you don't return True
                CreditLog(user = self.user, amount = num_credits, action="add_to_balance").save()
            except:
                logger.exception("failed to log add_to_balance of %s", num_credits)
            try: 
                credit_balance_added.send(sender=self, amount=num_credits)
            except:
                logger.exception("credit_balance_added failed  of %s", num_credits)
            return True
    
    def add_to_pledged(self, num_credits):
        num_credits=Decimal(num_credits)
        if num_credits is Decimal('NaN'):
            return False
        if self.balance - self.pledged <  num_credits :
            return False
        else:
            self.pledged=self.pledged + num_credits
            self.save()
            try: # bad things can happen here if you don't return True
                CreditLog(user = self.user, amount = num_credits, action="add_to_pledged").save()
            except:
                logger.exception("failed to log add_to_pledged of %s", num_credits)
            return True
 
    def use_pledge(self, num_credits):
        num_credits=Decimal(num_credits)
        if num_credits is Decimal('NaN'):
            return False
        if self.pledged <  num_credits :
            return False
        else:
            self.pledged=self.pledged - num_credits
            self.balance = self.balance - num_credits
            self.save()
            try:
                CreditLog(user = self.user, amount = - num_credits, action="use_pledge").save()
            except:
                logger.exception("failed to log use_pledge of %s", num_credits)
            return True
            
    def transfer_to(self, receiver, num_credits):
        num_credits=Decimal(num_credits)
        if num_credits is Decimal('NaN') or not isinstance( receiver, User):
            logger.info('fail: %s, %s' % (num_credits,receiver))
            return False
        if self.add_to_balance(-num_credits):
            if receiver.credit.add_to_balance(num_credits):
                return True
            else:
                # unwind transfer
                self.add_to_balance(num_credits)
                return False
        else:
            return False

class Sent(models.Model):
    '''used by gift view to record gifts it has sent'''
    user = models.CharField(max_length=32, null=True)
    amount = models.DecimalField(default=Decimal('0.00'), max_digits=14, decimal_places=2) # max 999,999,999,999.99
    timestamp = models.DateTimeField(auto_now=True)
           
class Account(models.Model):
    """holds references to accounts at third party payment gateways, especially for representing credit cards"""
    
    # the following fields from stripe Customer might be relevant to Account -- we need to pick good selection
    # c.id, c.description, c.email, datetime.fromtimestamp(c.created, tz=utc), c.account_balance, c.delinquent,
    # c.active_card.fingerprint, c.active_card.type, c.active_card.last4, c.active_card.exp_month, c.active_card.exp_year,
    # c.active_card.country
    
    # ACTIVE, DEACTIVATED, EXPIRED, EXPIRING, or ERROR
    STATUS_CHOICES = ( 
            ('ACTIVE','ACTIVE'), 
            ('DEACTIVATED','DEACTIVATED'), 
            ('EXPIRED','EXPIRED'), 
            ('EXPIRING','EXPIRING'),
            ( 'ERROR','ERROR')
        )
    
    # host: the payment processor.  Named after the payment module that hosts the payment processing functions
    host = models.CharField(default=PAYMENT_HOST_NONE, max_length=32, null=False)
    account_id = models.CharField(max_length=128, null=True)
    
    # card related info
    card_last4 = models.CharField(max_length=4, null=True)
    
    # Visa, American Express, MasterCard, Discover, JCB, Diners Club, or Unknown
    card_type = models.CharField(max_length=32, null=True)
    card_exp_month = models.IntegerField(null=True)
    card_exp_year = models.IntegerField(null=True)
    card_fingerprint = models.CharField(max_length=32, null=True)
    card_country = models.CharField(max_length=2, null=True)
    
    # creation and last modified timestamps
    date_created = models.DateTimeField(auto_now_add=True)
    date_modified = models.DateTimeField(auto_now=True)
    date_deactivated = models.DateTimeField(null=True)
    
    # associated User if any
    user = models.ForeignKey(settings.AUTH_USER_MODEL, null=True)
    
    # status variable
    status = models.CharField(max_length=11, choices=STATUS_CHOICES, null=False, default='ACTIVE')
    
    def deactivate(self):
        """Don't allow more than one active Account of given host to be associated with a given user"""
        self.date_deactivated = now()
        self.status = 'DEACTIVATED'
        self.save()
        
    def calculated_status(self):
        """returns ACTIVE, DEACTIVATED, EXPIRED, EXPIRING, or ERROR"""
                
    # is it deactivated?
    
        today = date_today()
        
        if self.date_deactivated is not None:
            return 'DEACTIVATED'
    
    # is it expired?
    
        elif self.card_exp_year < today.year or (self.card_exp_year == today.year and self.card_exp_month < today.month):
            return 'EXPIRED'
        
    # about to expire?  do I want to distinguish from 'ACTIVE'?
    
        elif (self.card_exp_year == today.year and self.card_exp_month == today.month):
            return 'EXPIRING'        
    
    # any transactions w/ errors after the account date?
    # Transaction.objects.filter(host='stripelib', status='Error', approved=True).count()
    
        elif Transaction.objects.filter(host='stripelib', 
                 status='Error', approved=True, user=self.user).filter(date_payment__gt=self.date_created):
            return 'ERROR'
        else:
            return 'ACTIVE'
                
 
    def update_status( self, value=None, send_notice_on_change_only=True):
        """set Account.status = value unless value is None, in which case, we set Account.status=self.calculated_status()
        fire off associated notifications
        
        By default, send notices only if the status is *changing*.  Set send_notice_on_change_only = False to
        send notice based on new_status regardless of old status.  (Useful for initialization)
        """
        old_status = self.status
        
        if value is None:
            new_status = self.calculated_status()
        else:
            new_status = value

        self.status = new_status
        self.save()
        
        if not send_notice_on_change_only or (old_status != new_status):

            logger.info( "Account status change: %d %s %s", self.pk, old_status, new_status)
            
            if new_status == 'EXPIRING':
                
                logger.info( "EXPIRING.  send to instance.user: %s  site: %s", self.user,
                            Site.objects.get_current())
                
                # fire off an account_expiring notice -- might not want to do this immediately
                
                notification.queue([self.user], "account_expiring", {
                    'user': self.user,
                    'site':Site.objects.get_current()
                }, True)

            elif new_status == 'EXPIRED':
                logger.info( "EXPIRING.  send to instance.user: %s  site: %s", self.user,
                            Site.objects.get_current())
                
                notification.queue([self.user], "account_expired", {
                    'user': self.user,
                    'site':Site.objects.get_current()
                }, True)
                
            elif new_status == 'ERROR':
                # TO DO:  we need to figure out notice needs to be sent out if we get an ERROR status.
                pass

            elif new_status == 'DEACTIVATED':
                # nothing needs to happen here
                pass

    def recharge_failed_transactions(self):
        """When a new Account is saved, check whether this is the new active account for a user.  If so, recharge any
        outstanding failed transactions
        """
        transactions_to_recharge = self.user.transaction_set.filter((Q(status=TRANSACTION_STATUS_FAILED) | Q(status=TRANSACTION_STATUS_ERROR)) & Q(campaign__status='SUCCESSFUL')).all()

        if transactions_to_recharge:
            from regluit.payment.manager import PaymentManager
            pm = PaymentManager()
            for transaction in transactions_to_recharge:
                # check whether we are still within the window to recharge
                if (now() - transaction.campaign.deadline_or_now) < datetime.timedelta(settings.RECHARGE_WINDOW):
                    logger.info("Recharging transaction {0} w/ status {1}".format(transaction.id, transaction.status))
                    pm.execute_transaction(transaction, [])

    
# handle any save, updates to a payment.Transaction

def handle_transaction_change(sender, instance, created, **kwargs):
    campaign = instance.campaign
    if campaign:
        campaign.update_left()
    return True

# handle any deletes of payment.Transaction

def handle_transaction_delete(sender, instance, **kwargs):
    campaign = instance.campaign
    if campaign:
        campaign.update_left()
    return True

post_save.connect(handle_transaction_change,sender=Transaction)
post_delete.connect(handle_transaction_delete,sender=Transaction)

# handle recharging failed transactions