import uuid

from django.contrib.auth.models import AbstractUser
from django.db import models


class User(AbstractUser):
    color = models.CharField(
        max_length=7,
        default='#0000ff',
    )


class PermissionDefaults(models.Model):
    id = models.PositiveSmallIntegerField(primary_key=True, default=1, editable=False)
    request_leave = models.BooleanField(default=True)
    create_personal_event = models.BooleanField(default=True)
    create_publication = models.BooleanField(default=True)
    revision = models.PositiveIntegerField(default=0)

    class Meta:
        constraints = [models.CheckConstraint(condition=models.Q(id=1), name='single_permission_defaults')]


class UserPermissions(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='feature_permissions')
    # None : appliquer la règle de l'équipe. False : refuser. True : autoriser.
    request_leave = models.BooleanField(null=True, blank=True, default=None)
    create_personal_event = models.BooleanField(null=True, blank=True, default=None)
    create_publication = models.BooleanField(null=True, blank=True, default=None)


class DelegatedPermission(models.Model):
    """Responsabilité de gestion accordée à un utilisateur sur un périmètre précis."""

    class Code(models.TextChoices):
        APPROVE_REQUESTS = 'approve_requests', 'Approuver des demandes'
        MANAGE_SCHEDULES = 'manage_schedules', 'Gérer des emplois du temps'
        VIEW_STATISTICS = 'view_statistics', 'Consulter des statistiques'

    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='delegated_permissions',
    )
    code = models.CharField(max_length=32, choices=Code.choices)
    all_users = models.BooleanField(default=False)
    targets = models.ManyToManyField(
        User,
        blank=True,
        related_name='delegated_permission_targets',
    )

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=['user', 'code'],
                name='unique_delegated_permission',
            ),
        ]


class Invitation(models.Model):
    token = models.UUIDField(
        default=uuid.uuid4,
        unique=True,
        editable=False,
    )

    created_by = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='created_invitations',
    )

    created_at = models.DateTimeField(auto_now_add=True)

    expires_at = models.DateTimeField()

    used_at = models.DateTimeField(
        null=True,
        blank=True,
    )

    @property
    def is_valid(self):
        from django.utils import timezone

        return (
            self.used_at is None
            and self.expires_at > timezone.now()
        )