# -*- coding: utf-8 -*-

from django.db import models
from django.core.urlresolvers import reverse
from django.core.validators import RegexValidator
from django.contrib.auth.models import User
from gestioncof.models import CofProfile
from django.utils.six.moves import reduce
from django.utils import timezone
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _
from django.db import transaction
from django.db.models import F
from datetime import date
import re

from .auth import KFET_GENERIC_TRIGRAMME
from .auth.models import GenericTeamToken  # noqa

from .config import kfet_config
from .utils import to_ukf

def choices_length(choices):
    return reduce(lambda m, choice: max(m, len(choice[0])), choices, 0)

def default_promo():
    now = date.today()
    return now.month <= 8 and now.year-1 or now.year


class AccountManager(models.Manager):
    """Manager for Account Model."""

    def get_queryset(self):
        """Always append related data to this Account."""
        return super().get_queryset().select_related('cofprofile__user',
                                                     'negative')

    def get_generic(self):
        """
        Get the kfet generic account instance.
        """
        return self.get(trigramme=KFET_GENERIC_TRIGRAMME)

    def get_by_password(self, password):
        """
        Get a kfet generic account by clear password.

        Raises Account.DoesNotExist if no Account has this password.
        """
        from .auth.utils import hash_password
        if password is None:
            raise self.model.DoesNotExist
        return self.get(password=hash_password(password))


class Account(models.Model):
    objects = AccountManager()

    cofprofile = models.OneToOneField(
        CofProfile, on_delete = models.PROTECT,
        related_name = "account_kfet")
    trigramme = models.CharField(
        unique     = True,
        max_length = 3,
        validators = [RegexValidator(regex='^[^a-z]{3}$')],
        db_index   = True)
    balance = models.DecimalField(
        max_digits = 6, decimal_places = 2,
        default = 0)
    is_frozen = models.BooleanField("est gelé", default = False)
    created_at = models.DateTimeField(default=timezone.now)
    # Optional
    PROMO_CHOICES = [(r,r) for r in range(1980, date.today().year+1)]
    promo = models.IntegerField(
        choices = PROMO_CHOICES,
        blank = True, null = True, default = default_promo())
    nickname = models.CharField(
        "surnom(s)",
        max_length = 255,
        blank = True, default = "")
    password = models.CharField(
        max_length = 255,
        unique = True,
        blank = True, null = True, default = None)

    class Meta:
        permissions = (
            ('is_team', 'Is part of the team'),
            ('manage_perms', 'Gérer les permissions K-Fêt'),
            ('manage_addcosts', 'Gérer les majorations'),
            ('edit_balance_account', "Modifier la balance d'un compte"),
            ('change_account_password',
                "Modifier le mot de passe d'une personne de l'équipe"),
            ('special_add_account',
                "Créer un compte avec une balance initiale"),
            ('can_force_close', "Fermer manuellement la K-Fêt"),
            ('see_config', "Voir la configuration K-Fêt"),
            ('change_config', "Modifier la configuration K-Fêt"),
        )

    def __str__(self):
        return '%s (%s)' % (self.trigramme, self.name)

    # Propriétés pour accéder aux attributs de cofprofile et user
    @property
    def user(self):
        return self.cofprofile.user
    @property
    def username(self):
        return self.cofprofile.user.username
    @property
    def first_name(self):
        return self.cofprofile.user.first_name
    @property
    def last_name(self):
        return self.cofprofile.user.last_name
    @property
    def email(self):
        return self.cofprofile.user.email
    @property
    def departement(self):
        return self.cofprofile.departement
    @property
    def is_cof(self):
        return self.cofprofile.is_cof

    # Propriétés supplémentaires
    @property
    def balance_ukf(self):
        return to_ukf(self.balance, is_cof=self.is_cof)

    @property
    def real_balance(self):
        if hasattr(self, 'negative') and self.negative.balance_offset:
            return self.balance - self.negative.balance_offset
        return self.balance

    @property
    def name(self):
        return self.user.get_full_name()

    @property
    def is_cash(self):
        return self.trigramme == 'LIQ'

    @property
    def need_comment(self):
        return self.trigramme == '#13'

    @property
    def readable(self):
        return self.trigramme != 'GNR'

    @property
    def is_team(self):
        return self.has_perm('kfet.is_team')

    @staticmethod
    def is_validandfree(trigramme):
        data = { 'is_valid' : False, 'is_free' : False }
        pattern = re.compile("^[^a-z]{3}$")
        data['is_valid'] = pattern.match(trigramme) and True or False
        try:
            account = Account.objects.get(trigramme=trigramme)
        except Account.DoesNotExist:
            data['is_free'] = True
        return data

    def perms_to_perform_operation(self, amount):
        overdraft_duration_max = kfet_config.overdraft_duration
        overdraft_amount_max = kfet_config.overdraft_amount
        perms = set()
        stop_ope = False
        # Checking is cash account
        if self.is_cash:
            # Yes, so no perms and no stop
            return set(), False
        if self.need_comment:
            perms.add('kfet.perform_commented_operations')
        # Checking is frozen account
        if self.is_frozen:
            perms.add('kfet.override_frozen_protection')
        new_balance = self.balance + amount
        if new_balance < 0 and amount < 0:
            # Retrieving overdraft amount limit
            if (hasattr(self, 'negative')
                and self.negative.authz_overdraft_amount is not None):
                overdraft_amount = - self.negative.authz_overdraft_amount
            else:
                overdraft_amount = - overdraft_amount_max
            # Retrieving overdraft datetime limit
            if (hasattr(self, 'negative')
                    and self.negative.authz_overdraft_until is not None):
                overdraft_until = self.negative.authz_overdraft_until
            elif hasattr(self, 'negative'):
                overdraft_until = \
                    self.negative.start + overdraft_duration_max
            else:
                overdraft_until = timezone.now() + overdraft_duration_max
            # Checking it doesn't break 1 rule
            if new_balance < overdraft_amount or timezone.now() > overdraft_until:
                stop_ope = True
            perms.add('kfet.perform_negative_operations')
        return perms, stop_ope

    # Surcharge Méthode save() avec gestions de User et CofProfile
    # Args:
    # - data : datas pour User et CofProfile
    # Action:
    # - Enregistre User, CofProfile à partir de "data"
    # - Enregistre Account
    def save(self, data = {}, *args, **kwargs):

        if self.pk and data:
            # Account update

            # Updating User with data
            user = self.user
            user.first_name = data.get("first_name", user.first_name)
            user.last_name  = data.get("last_name", user.last_name)
            user.email      = data.get("email", user.email)
            user.save()
            # Updating CofProfile with data
            cof = self.cofprofile
            cof.departement = data.get("departement", cof.departement)
            cof.save()
        elif data:
            # New account

            # Checking if user has already an account
            username = data.get("username")
            try:
                user = User.objects.get(username=username)
                if hasattr(user.profile, "account_kfet"):
                    trigramme = user.profile.account_kfet.trigramme
                    raise Account.UserHasAccount(trigramme)
            except User.DoesNotExist:
                pass

            # Creating or updating User instance
            (user, _) = User.objects.get_or_create(username=username)
            if "first_name" in data:
                user.first_name = data['first_name']
            if "last_name" in data:
                user.last_name = data['last_name']
            if "email" in data:
                user.email = data['email']
            user.save()
            # Creating or updating CofProfile instance
            (cof, _) = CofProfile.objects.get_or_create(user=user)
            if "login_clipper" in data:
                cof.login_clipper = data['login_clipper']
            if "departement" in data:
                cof.departement = data['departement']
            cof.save()
        if data:
            self.cofprofile = cof
        super(Account, self).save(*args, **kwargs)

    def change_pwd(self, clear_password):
        from .auth.utils import hash_password
        self.password = hash_password(clear_password)

    # Surcharge de delete
    # Pas de suppression possible
    # Cas à régler plus tard
    def delete(self, *args, **kwargs):
        pass

    def update_negative(self):
        if self.real_balance < 0:
            if hasattr(self, 'negative') and not self.negative.start:
                self.negative.start = timezone.now()
                self.negative.save()
            elif not hasattr(self, 'negative'):
                self.negative = (
                    AccountNegative.objects.create(
                        account=self, start=timezone.now(),
                    )
                )
        elif hasattr(self, 'negative'):
            # self.real_balance >= 0
            balance_offset = self.negative.balance_offset
            if balance_offset:
                (
                    Account.objects
                    .filter(pk=self.pk)
                    .update(balance=F('balance')-balance_offset)
                )
                self.refresh_from_db()
            self.negative.delete()

    class UserHasAccount(Exception):
        def __init__(self, trigramme):
            self.trigramme = trigramme


class AccountNegativeManager(models.Manager):
    """Manager for AccountNegative model."""

    def get_queryset(self):
        return (
            super().get_queryset()
            .select_related('account__cofprofile__user')
        )


class AccountNegative(models.Model):
    objects = AccountNegativeManager()

    account = models.OneToOneField(
        Account, on_delete=models.PROTECT,
        related_name="negative",
    )
    start = models.DateTimeField(blank=True, null=True, default=None)
    balance_offset = models.DecimalField(
        "décalage de balance",
        help_text="Montant non compris dans l'autorisation de négatif",
        max_digits=6, decimal_places=2,
        blank=True, null=True, default=None,
    )
    authz_overdraft_amount = models.DecimalField(
        "négatif autorisé",
        max_digits=6, decimal_places=2,
        blank=True, null=True, default=None,
    )
    authz_overdraft_until = models.DateTimeField(
        "expiration du négatif",
        blank=True, null=True, default=None,
    )
    comment = models.CharField("commentaire", max_length=255, blank=True)

    class Meta:
        permissions = (
            ('view_negs', 'Voir la liste des négatifs'),
        )

    @property
    def until_default(self):
        return self.start + kfet_config.overdraft_duration


class Checkout(models.Model):
    created_by = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "+")
    name = models.CharField(max_length = 45)
    valid_from = models.DateTimeField()
    valid_to   = models.DateTimeField()
    balance = models.DecimalField(
        max_digits = 6, decimal_places = 2,
        default = 0)
    is_protected = models.BooleanField(default = False)

    def get_absolute_url(self):
        return reverse('kfet.checkout.read', kwargs={'pk': self.pk})

    class Meta:
        ordering = ['-valid_to']

    def __str__(self):
        return self.name

class CheckoutTransfer(models.Model):
    from_checkout = models.ForeignKey(
        Checkout, on_delete = models.PROTECT,
        related_name = "transfers_from")
    to_checkout = models.ForeignKey(
        Checkout, on_delete = models.PROTECT,
        related_name = "transfers_to")
    amount = models.DecimalField(
        max_digits = 6, decimal_places = 2)

@python_2_unicode_compatible
class CheckoutStatement(models.Model):
    by = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "+")
    checkout = models.ForeignKey(
        Checkout, on_delete = models.PROTECT,
        related_name = "statements")
    balance_old  = models.DecimalField("ancienne balance",
                                       max_digits = 6, decimal_places = 2)
    balance_new  = models.DecimalField("nouvelle balance",
                                       max_digits = 6, decimal_places = 2)
    amount_taken = models.DecimalField("montant pris",
                                       max_digits = 6, decimal_places = 2)
    amount_error = models.DecimalField("montant de l'erreur",
                                       max_digits = 6, decimal_places = 2)
    at = models.DateTimeField(auto_now_add = True)
    not_count = models.BooleanField("caisse non comptée", default=False)

    taken_001 = models.PositiveSmallIntegerField("pièces de 1¢", default=0)
    taken_002 = models.PositiveSmallIntegerField("pièces de 2¢", default=0)
    taken_005 = models.PositiveSmallIntegerField("pièces de 5¢", default=0)
    taken_01 = models.PositiveSmallIntegerField("pièces de 10¢", default=0)
    taken_02 = models.PositiveSmallIntegerField("pièces de 20¢", default=0)
    taken_05 = models.PositiveSmallIntegerField("pièces de 50¢", default=0)
    taken_1 = models.PositiveSmallIntegerField("pièces de 1€", default=0)
    taken_2 = models.PositiveSmallIntegerField("pièces de 2€", default=0)
    taken_5 = models.PositiveSmallIntegerField("billets de 5€", default=0)
    taken_10 = models.PositiveSmallIntegerField("billets de 10€", default=0)
    taken_20 = models.PositiveSmallIntegerField("billets de 20€", default=0)
    taken_50 = models.PositiveSmallIntegerField("billets de 50€", default=0)
    taken_100 = models.PositiveSmallIntegerField("billets de 100€", default=0)
    taken_200 = models.PositiveSmallIntegerField("billets de 200€", default=0)
    taken_500 = models.PositiveSmallIntegerField("billets de 500€", default=0)
    taken_cheque = models.DecimalField(
        "montant des chèques",
        default=0, max_digits=6, decimal_places=2)

    def __str__(self):
        return '%s %s' % (self.checkout, self.at)

    def save(self, *args, **kwargs):
        if not self.pk:
            checkout_id = self.checkout_id
            self.balance_old = (Checkout.objects
                .values_list('balance', flat=True).get(pk=checkout_id))
            if self.not_count:
                self.balance_new = self.balance_old - self.amount_taken
            self.amount_error = (
                    self.balance_new + self.amount_taken - self.balance_old)
            with transaction.atomic():
                Checkout.objects.filter(pk=checkout_id).update(balance=self.balance_new)
                super(CheckoutStatement, self).save(*args, **kwargs)
        else:
            self.amount_error = (
                self.balance_new + self.amount_taken - self.balance_old)
            # Si on modifie le dernier relevé d'une caisse et que la nouvelle
            # balance est modifiée alors on modifie la balance actuelle de la caisse
            last_statement = (CheckoutStatement.objects
                    .filter(checkout=self.checkout)
                    .order_by('at')
                    .last())
            if (last_statement.pk == self.pk
                    and last_statement.balance_new != self.balance_new):
                Checkout.objects.filter(pk=self.checkout_id).update(
                    balance=F('balance') - last_statement.balance_new + self.balance_new)
            super(CheckoutStatement, self).save(*args, **kwargs)


@python_2_unicode_compatible
class ArticleCategory(models.Model):
    name = models.CharField("nom", max_length=45)
    has_addcost = models.BooleanField("majorée", default=True,
                                      help_text="Si oui et qu'une majoration "
                                                "est active, celle-ci sera "
                                                "appliquée aux articles de "
                                                "cette catégorie.")

    def __str__(self):
        return self.name


@python_2_unicode_compatible
class Article(models.Model):
    name     = models.CharField("nom", max_length = 45)
    is_sold  = models.BooleanField("en vente", default = True)
    hidden   = models.BooleanField("caché",
                                   default=False,
                                   help_text="Si oui, ne sera pas affiché "
                                             "au public ; par exemple "
                                             "sur la carte.")
    price    = models.DecimalField(
        "prix",
        max_digits = 6, decimal_places = 2,
        default = 0)
    stock    = models.IntegerField(default = 0)
    category = models.ForeignKey(
        ArticleCategory, on_delete = models.PROTECT,
        related_name = "articles", verbose_name='catégorie')
    BOX_TYPE_CHOICES = (
        ("caisse", "caisse"),
        ("carton", "carton"),
        ("palette", "palette"),
        ("fût", "fût"),
    )
    box_type = models.CharField(
        "type de contenant",
        choices    = BOX_TYPE_CHOICES,
        max_length = choices_length(BOX_TYPE_CHOICES),
        blank = True, null = True, default = None)
    box_capacity = models.PositiveSmallIntegerField(
        "capacité du contenant",
        blank = True, null = True, default = None)

    def __str__(self):
        return '%s - %s' % (self.category.name, self.name)

    def get_absolute_url(self):
        return reverse('kfet.article.read', kwargs={'pk': self.pk})

    def price_ukf(self):
        return to_ukf(self.price)


class ArticleRule(models.Model):
    article_on = models.OneToOneField(
        Article, on_delete = models.PROTECT,
        related_name = "rule_on")
    article_to = models.OneToOneField(
        Article, on_delete = models.PROTECT,
        related_name = "rule_to")
    ratio = models.PositiveSmallIntegerField()

class Inventory(models.Model):
    articles = models.ManyToManyField(
        Article,
        through      = 'InventoryArticle',
        related_name = "inventories")
    by = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "+")
    at = models.DateTimeField(auto_now_add = True)
    # Optional
    order = models.OneToOneField(
        'Order', on_delete = models.PROTECT,
        related_name = "inventory",
        blank = True, null = True, default = None)

    class Meta:
        ordering = ['-at']
        permissions = (
            ('order_to_inventory', "Générer un inventaire à partir d'une commande"),
        )


class InventoryArticle(models.Model):
    inventory = models.ForeignKey(
        Inventory, on_delete = models.PROTECT)
    article = models.ForeignKey(
        Article, on_delete = models.PROTECT)
    stock_old   = models.IntegerField()
    stock_new   = models.IntegerField()
    stock_error = models.IntegerField(default = 0)

    def save(self, *args, **kwargs):
        # S'il s'agit d'un inventaire provenant d'une livraison, il n'y a pas
        # d'erreur
        if not self.inventory.order:
            self.stock_error = self.stock_new - self.stock_old
        super(InventoryArticle, self).save(*args, **kwargs)


class Supplier(models.Model):
    articles = models.ManyToManyField(
        Article,
        verbose_name=_("articles vendus"),
        through='SupplierArticle',
        related_name='suppliers',
    )
    name = models.CharField(_("nom"), max_length=45)
    address = models.TextField(_("adresse"), blank=True)
    email = models.EmailField(_("adresse mail"), blank=True)
    phone = models.CharField(_("téléphone"), max_length=20, blank=True)
    comment = models.TextField(_("commentaire"), blank=True)

    def __str__(self):
        return self.name


class SupplierArticle(models.Model):
    supplier = models.ForeignKey(
        Supplier, on_delete = models.PROTECT)
    article = models.ForeignKey(
        Article, on_delete = models.PROTECT)
    at = models.DateTimeField(auto_now_add = True)
    price_HT = models.DecimalField(
        max_digits = 7, decimal_places = 4,
        blank = True, null = True, default = None)
    TVA = models.DecimalField(
        max_digits = 4, decimal_places = 2,
        blank = True, null = True, default = None)
    rights = models.DecimalField(
        max_digits = 7, decimal_places = 4,
        blank = True, null = True, default = None)

class Order(models.Model):
    supplier = models.ForeignKey(
        Supplier, on_delete = models.PROTECT,
        related_name = "orders")
    articles = models.ManyToManyField(
        Article,
        through        = "OrderArticle",
        related_name   = "orders")
    at = models.DateTimeField(auto_now_add = True)
    amount = models.DecimalField(
        max_digits = 6, decimal_places = 2, default = 0)

    class Meta:
        ordering = ['-at']

class OrderArticle(models.Model):
    order = models.ForeignKey(
        Order, on_delete = models.PROTECT)
    article = models.ForeignKey(
        Article, on_delete = models.PROTECT)
    quantity_ordered = models.IntegerField()
    quantity_received = models.IntegerField(default = 0)

class TransferGroup(models.Model):
    at = models.DateTimeField(default=timezone.now)
    # Optional
    comment = models.CharField(
        max_length = 255,
        blank = True, default = "")
    valid_by = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "+",
        blank = True, null = True, default = None)


class Transfer(models.Model):
    group = models.ForeignKey(
        TransferGroup, on_delete=models.PROTECT,
        related_name="transfers")
    from_acc = models.ForeignKey(
        Account, on_delete=models.PROTECT,
        related_name="transfers_from")
    to_acc = models.ForeignKey(
        Account, on_delete=models.PROTECT,
        related_name="transfers_to")
    amount = models.DecimalField(max_digits=6, decimal_places=2)
    # Optional
    canceled_by = models.ForeignKey(
        Account, on_delete=models.PROTECT,
        null=True, blank=True, default=None,
        related_name="+")
    canceled_at = models.DateTimeField(
        null=True, blank=True, default=None)

    def __str__(self):
        return '{} -> {}: {}€'.format(self.from_acc, self.to_acc, self.amount)


class OperationGroup(models.Model):
    on_acc = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "opesgroup")
    checkout = models.ForeignKey(
        Checkout, on_delete = models.PROTECT,
        related_name = "opesgroup")
    at = models.DateTimeField(default=timezone.now)
    amount = models.DecimalField(
        max_digits = 6, decimal_places = 2,
        default = 0)
    is_cof = models.BooleanField(default = False)
    # Optional
    comment = models.CharField(
        max_length = 255,
        blank = True, default = "")
    valid_by = models.ForeignKey(
        Account, on_delete = models.PROTECT,
        related_name = "+",
        blank = True, null = True, default = None)

    def __str__(self):
        return ', '.join(map(str, self.opes.all()))


class Operation(models.Model):
    PURCHASE = 'purchase'
    DEPOSIT = 'deposit'
    WITHDRAW = 'withdraw'
    INITIAL = 'initial'
    EDIT = 'edit'

    TYPE_ORDER_CHOICES = (
        (PURCHASE, 'Achat'),
        (DEPOSIT, 'Charge'),
        (WITHDRAW, 'Retrait'),
        (INITIAL, 'Initial'),
        (EDIT, 'Édition'),
    )

    group = models.ForeignKey(
        OperationGroup, on_delete=models.PROTECT,
        related_name="opes")
    type = models.CharField(
        choices=TYPE_ORDER_CHOICES,
        max_length=choices_length(TYPE_ORDER_CHOICES))
    amount = models.DecimalField(
        max_digits=6, decimal_places=2,
        blank=True, default=0)
    # Optional
    article = models.ForeignKey(
        Article, on_delete=models.PROTECT,
        related_name="operations",
        blank=True, null=True, default=None)
    article_nb = models.PositiveSmallIntegerField(
        blank=True, null=True, default=None)
    canceled_by = models.ForeignKey(
        Account, on_delete=models.PROTECT,
        related_name="+",
        blank=True, null=True, default=None)
    canceled_at = models.DateTimeField(
        blank=True, null=True, default=None)
    addcost_for = models.ForeignKey(
        Account, on_delete=models.PROTECT,
        related_name="addcosts",
        blank=True, null=True, default=None)
    addcost_amount = models.DecimalField(
        max_digits=6, decimal_places=2,
        blank=True, null=True, default=None)

    class Meta:
        permissions = (
            ('perform_deposit', 'Effectuer une charge'),
            ('perform_negative_operations',
                'Enregistrer des commandes en négatif'),
            ('override_frozen_protection', "Forcer le gel d'un compte"),
            ('cancel_old_operations', 'Annuler des commandes non récentes'),
            ('perform_commented_operations',
                'Enregistrer des commandes avec commentaires'),
        )

    @property
    def is_checkout(self):
        return (self.type == Operation.DEPOSIT or
                self.type == Operation.WITHDRAW or
                (self.type == Operation.PURCHASE and self.group.on_acc.is_cash)
                )

    def __str__(self):
        templates = {
                self.PURCHASE: "{nb} {article.name} ({amount}€)",
                self.DEPOSIT: "charge ({amount}€)",
                self.WITHDRAW: "retrait ({amount}€)",
                self.INITIAL: "initial ({amount}€)",
                self.EDIT: "édition ({amount}€)",
            }
        return templates[self.type].format(nb=self.article_nb,
                                           article=self.article,
                                           amount=self.amount)