from django.db import models


class Client(models.Model):
    class Meta:
        verbose_name = "Client"
        verbose_name_plural = "Clients"

    name = models.CharField(max_length=255, verbose_name="Nom")
    address = models.CharField(max_length=255, verbose_name="Adresse")
    postal_code = models.IntegerField(verbose_name="Code postal")
    city = models.CharField(max_length=255, verbose_name="Ville")
    contact = models.CharField(max_length=255, verbose_name="Personne de contact")
    is_company = models.BooleanField(blank=True, default=True)
    company_number = models.CharField(max_length=50, verbose_name="N° BCE", blank=True, null=True)

    def __str__(self):
        return "%s" % (self.name)


class Contract(models.Model):
    class Meta:
        verbose_name = "Contrat"
        verbose_name_plural = "Contrats"

    title = models.CharField(max_length=255, verbose_name="Titre")
    client = models.ForeignKey(
        Client, related_name="contracts", on_delete=models.CASCADE
    )
    advance = models.DecimalField(
        max_digits=7, decimal_places=2, blank=True, verbose_name="Acompte", default=0
    )
    reference = models.CharField(
        max_length=255, verbose_name="Référence", blank=True, null=True, unique=True
    )
    is_finished = models.BooleanField(default=True, blank=True, verbose_name="Finie")
    is_paid = models.BooleanField(blank=True, default=False, verbose_name="Payée")
    date = models.DateField(auto_now_add=True)
    description = models.TextField(verbose_name="Description", blank=True, null=True)

    def __str__(self):
        return "%s" % self.title

    def __generate_reference(self):
        """ Génère automatiquement la référence du contract """
        if self.reference is None:
            if self.id is None:
                object_id = "XX"
            elif self.id < 10:
                object_id = "0" + str(self.id)
            else:
                object_id = self.id
            self.reference = str(self.date.year) + "-" + object_id

    def save(self, *args, **kwargs):
        """ Enregistre l'objet en DB après avoir calculé le montant total. """
        super().save(*args, **kwargs)
        self.__generate_reference()
        super().save(*args, **kwargs)


class Prestation(models.Model):
    class Meta:
        verbose_name = "Prestations"
        verbose_name_plural = "Prestations"
        ordering = ["date"]

    contract = models.ForeignKey(
        Contract,
        related_name="get_prestation",
        on_delete=models.CASCADE,
    )
    date = models.DateField()
    label = models.CharField(max_length=255, verbose_name="Libellé")
    unit = models.DecimalField(
        max_digits=7, decimal_places=2, verbose_name="Unité", default=1
    )
    unit_price = models.DecimalField(
        max_digits=7, decimal_places=2, verbose_name="Prix unitaire", default="12,5"
    )
    total_amount = models.DecimalField(
        max_digits=8, decimal_places=2, blank=True, verbose_name="Prix", default=0
    )

    def __compute_total_amount(self):
        """ Calcule le montant total de la prestation. """
        self.total_amount = self.unit * self.unit_price

    def save(self, *args, **kwargs):
        """ Enregistre l'objet en DB après avoir calculé le montant total. """
        self.__compute_total_amount()
        super().save(*args, **kwargs)