from django.conf import settings
from django.contrib.auth.models import (
    AbstractBaseUser, BaseUserManager, PermissionsMixin,
)
from django.db import models
from django.utils.translation import ugettext_lazy as _

from .base import LoggingMixin


class UserManager(BaseUserManager):
    """
    This is the user manager for our custom user model. See the User
    model documentation to see what's so special about our user model.
    """

    def create_user(self, email: str, password: str=None, **kwargs):
        user = self.model(email=email, **kwargs)
        user.set_password(password)
        user.save()
        return user

    def create_superuser(self, email: str, password: str=None):  # NOQA
        # Not used in the software but required by Django
        if password is None:
            raise Exception("You must provide a password")
        user = self.model(email=email)
        user.is_staff = True
        user.is_superuser = True
        user.set_password(password)
        user.save()
        return user


class User(AbstractBaseUser, PermissionsMixin, LoggingMixin):
    """
    This is the user model used by pretix for authentication.

    :param email: The user's email address, used for identification.
    :type email: str
    :param givenname: The user's given name. May be empty or null.
    :type givenname: str
    :param familyname: The user's given name. May be empty or null.
    :type familyname: str
    :param is_active: Whether this user account is activated.
    :type is_active: bool
    :param is_staff: ``True`` for system operators.
    :type is_staff: bool
    :param date_joined: The datetime of the user's registration.
    :type date_joined: datetime
    :param locale: The user's preferred locale code.
    :type locale: str
    :param timezone: The user's preferred timezone.
    :type timezone: str
    """

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = []

    email = models.EmailField(unique=True, db_index=True, null=True, blank=True,
                              verbose_name=_('E-mail'))
    givenname = models.CharField(max_length=255, blank=True, null=True,
                                 verbose_name=_('Given name'))
    familyname = models.CharField(max_length=255, blank=True, null=True,
                                  verbose_name=_('Family name'))
    is_active = models.BooleanField(default=True,
                                    verbose_name=_('Is active'))
    is_staff = models.BooleanField(default=False,
                                   verbose_name=_('Is site admin'))
    date_joined = models.DateTimeField(auto_now_add=True,
                                       verbose_name=_('Date joined'))
    locale = models.CharField(max_length=50,
                              choices=settings.LANGUAGES,
                              default=settings.LANGUAGE_CODE,
                              verbose_name=_('Language'))
    timezone = models.CharField(max_length=100,
                                default=settings.TIME_ZONE,
                                verbose_name=_('Timezone'))

    objects = UserManager()

    class Meta:
        verbose_name = _("User")
        verbose_name_plural = _("Users")

    def save(self, *args, **kwargs):
        self.email = self.email.lower()
        super().save(*args, **kwargs)

    def __str__(self):
        return self.email

    def get_short_name(self) -> str:
        """
        Returns the first of the following user properties that is found to exist:

        * Given name
        * Family name
        * Email address
        """
        if self.givenname:
            return self.givenname
        elif self.familyname:
            return self.familyname
        else:
            return self.email

    def get_full_name(self) -> str:
        """
        Returns the first of the following user properties that is found to exist:

        * A combination of given name and family name, depending on the locale
        * Given name
        * Family name
        * User name
        """
        if self.givenname and not self.familyname:
            return self.givenname
        elif not self.givenname and self.familyname:
            return self.familyname
        elif self.familyname and self.givenname:
            return _('%(family)s, %(given)s') % {
                'family': self.familyname,
                'given': self.givenname
            }
        else:
            return self.email