import re
from datetime import date
from functools import reduce

from django.contrib.auth.models import User
from django.core.validators import RegexValidator
from django.db import models, transaction
from django.db.models import F
from django.urls import reverse
from django.utils import timezone
from django.utils.translation import ugettext_lazy as _

from gestioncof.models import CofProfile

from .auth import KFET_GENERIC_TRIGRAMME
from .auth.models import GenericTeamToken, Group, Permission  # 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.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().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 CheckoutQuerySet(models.QuerySet):
    def is_valid(self):
        now = timezone.now()
        return self.filter(valid_from__lte=now, valid_to__gte=now)


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)

    objects = CheckoutQuerySet.as_manager()

    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

    def save(self, *args, **kwargs):
        created = self.pk is None

        ret = super().save(*args, **kwargs)

        if created:
            self.statements.create(
                amount_taken=0,
                balance_old=self.balance,
                balance_new=self.balance,
                by=self.created_by,
            )

        return ret


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)


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().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().save(*args, **kwargs)


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


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().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
        )