from django.core.exceptions import ValidationError
from django.db import models
from coresite.mixin import AbstractTimeStampModel
from apps.core.constants import UserType
from django.contrib.auth.models import (
    BaseUserManager,
    AbstractBaseUser,
)


class UserManager(BaseUserManager):
    def create_user(
            self,
            email,
            username,
            password=None,
            user_type=UserType.USER
    ):
        """
        Creates and saves a User with the given email, date of
        birth and password.
        """
        if not email:
            raise ValueError('Users must have an email address')

        if not UserType.is_valid(user_type):
            raise ValueError("Invalid user type")

        user = self.model(
            email=self.normalize_email(email),
            username=username,
            user_type=user_type,
        )

        user.set_password(password)
        user.is_staff = user_type in {UserType.ADMIN, UserType.SUPER_ADMIN}
        user.save()
        return user

    def create_superuser(
            self,
            email,
            username=None,
            password=None,
    ):
        """
        Creates and saves a superuser with the given email, date of
        birth and password.
        """
        user = self.create_user(
            email=email,
            password=password,
            username=username,
            user_type=UserType.SUPER_ADMIN,
        )
        user.is_superuser = True
        user.is_admin = True
        user.is_staff = True
        user.is_active = True
        user.save()
        return user

class User(AbstractBaseUser, AbstractTimeStampModel):
    """
    Our custom user model that extends Django's AbstractBaseUser."""
    email = models.EmailField(
        verbose_name='email address',
        max_length=255,
        unique=True,
    )
    user_type = models.CharField(
        max_length=50,
        default=UserType.USER,
        db_index=True,
    )
    username = models.CharField(max_length=255, unique=True)
    is_active = models.BooleanField(default=False)
    is_superuser = models.BooleanField(default=False)
    is_admin = models.BooleanField(default=False)
    is_staff = models.BooleanField(default=False)

    objects = UserManager()

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['password', 'username']

    def save(self, *args, **kwargs):
        self.full_clean()
        super().save(*args, **kwargs)

    def clean(self):
        if not UserType.is_valid(self.user_type):
            raise ValidationError({"user_type": "Invalid user type"})

    def __str__(self):
        return self.email

    def has_perm(self, perm, obj=None):
        """Does the user have a specific permission?"""
        # Simplest possible answer: Yes, always
        return True

    def has_module_perms(self, app_label):
        """Does the user have permissions to view the app `app_label`?"""
        # Simplest possible answer: Yes, always
        return True

    @property
    def is_super_admin(self):
        return self.user_type == UserType.SUPER_ADMIN

    @property
    def is_admin_user(self):
        return self.user_type in {UserType.ADMIN, UserType.SUPER_ADMIN}