from hashlib import md5

from django.contrib.auth.models import AnonymousUser as DjangoAnonymousUser
from django.contrib.auth.models import UserManager as BaseUserManager
from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin
from django.contrib.auth.password_validation import validate_password
from django.contrib.postgres.fields import HStoreField, JSONField
from django.core.mail import send_mail
from django.db import IntegrityError, models, transaction
from django.urls import reverse
from django.utils import timezone
from django.utils.translation import ugettext_lazy as _

from misago.acl import get_user_acl
from misago.acl.models import Role
from misago.conf import settings
from misago.core.pgutils import PgPartialIndex
from misago.core.utils import slugify
from misago.users import avatars
from misago.users.signatures import is_user_signature_valid
from misago.users.utils import hash_email

from .rank import Rank


class UserManager(BaseUserManager):
    @transaction.atomic
    def create_user(
            self, username, email, password=<PASSWORD>, set_default_avatar=False, **extra_fields
    ):
        from misago.users.validators import validate_email, validate_username

        email = self.normalize_email(email)
        username = self.model.normalize_username(username)

        if not email:
            raise ValueError(_("User must have an email address."))
        if not password:
            raise ValueError(_("User must have a password."))

        if not 'joined_from_ip' in extra_fields:
            extra_fields['joined_from_ip'] = '127.0.0.1'

        WATCH_DICT = {
            'no': self.model.SUBSCRIBE_NONE,
            'watch': self.model.SUBSCRIBE_NOTIFY,
            'watch_email': self.model.SUBSCRIBE_ALL,
        }

        if not 'subscribe_to_started_threads' in extra_fields:
            new_value = WATCH_DICT[settings.subscribe_start]
            extra_fields['subscribe_to_started_threads'] = new_value

        if not 'subscribe_to_replied_threads' in extra_fields:
            new_value = WATCH_DICT[settings.subscribe_reply]
            extra_fields['subscribe_to_replied_threads'] = new_value

        extra_fields.update({'is_staff': False, 'is_superuser': False})

        now = timezone.now()
        user = self.model(last_login=now, joined_on=now, **extra_fields)

        user.set_username(username)
        user.set_email(email)
        user.set_password(password)

        validate_username(username)
        validate_email(email)
        validate_password(password, user=user)

        if not 'rank' in extra_fields:
            user.rank = Rank.objects.get_default()

        user.save(using=self._db)

        if set_default_avatar:
            avatars.set_default_avatar(
                user, settings.default_avatar, settings.default_gravatar_fallback
            )
        else:
            # just for test purposes
            user.avatars = [{'size': 400, 'url': '/placekitten.com/400/400'}]

        authenticated_role = Role.objects.get(special_role='authenticated')
        if authenticated_role not in user.roles.all():
            user.roles.add(authenticated_role)
        user.update_acl_key()

        user.save(update_fields=['avatars', 'acl_key'])

        # populate online tracker with default value
        Online.objects.create(
            user=user,
            current_ip=extra_fields['joined_from_ip'],
            last_click=now,
        )

        return user

    @transaction.atomic
    def create_superuser(self, username, email, password, set_default_avatar=False):
        user = self.create_user(
            username,
            email,
            password=password,
            set_default_avatar=set_default_avatar,
        )

        try:
            user.rank = Rank.objects.get(name=_("Forum team"))
            user.update_acl_key()
        except Rank.DoesNotExist:
            pass

        user.is_staff = True
        user.is_superuser = True

        updated_fields = ('rank', 'acl_key', 'is_staff', 'is_superuser')
        user.save(update_fields=updated_fields, using=self._db)
        return user

    def get_by_username(self, username):
        return self.get(slug=slugify(username))

    def get_by_email(self, email):
        return self.get(email_hash=hash_email(email))

    def get_by_username_or_email(self, login):
        queryset = models.Q(slug=slugify(login))
        queryset = queryset | models.Q(email_hash=hash_email(login))
        return self.get(queryset)


class User(AbstractBaseUser, PermissionsMixin):
    ACTIVATION_NONE = 0
    ACTIVATION_USER = 1
    ACTIVATION_ADMIN = 2

    SUBSCRIBE_NONE = 0
    SUBSCRIBE_NOTIFY = 1
    SUBSCRIBE_ALL = 2

    SUBSCRIBE_CHOICES = [
        (SUBSCRIBE_NONE, _("No")),
        (SUBSCRIBE_NOTIFY, _("Notify")),
        (SUBSCRIBE_ALL, _("Notify with e-mail")),
    ]

    LIMIT_INVITES_TO_NONE = 0
    LIMIT_INVITES_TO_FOLLOWED = 1
    LIMIT_INVITES_TO_NOBODY = 2

    LIMIT_INVITES_TO_CHOICES = [
        (LIMIT_INVITES_TO_NONE, _("Everybody")),
        (LIMIT_INVITES_TO_FOLLOWED, _("Users I follow")),
        (LIMIT_INVITES_TO_NOBODY, _("Nobody")),
    ]
    # Note that "username" field is purely for shows.
    # When searching users by their names, always use lowercased string
    # and slug field instead that is normalized around DB engines
    # differences in case handling.
    username = models.CharField(max_length=30)
    slug = models.CharField(max_length=30, unique=True)

    # Misago stores user email in two fields:
    # "email" holds normalized email address
    # "email_hash" is lowercase hash of email address used to identify account
    # as well as enforcing on database level that no more than one user can be
    # using one email address
    email = models.EmailField(max_length=255, db_index=True)
    email_hash = models.CharField(max_length=32, unique=True)

    joined_on = models.DateTimeField(_('joined on'), default=timezone.now)
    joined_from_ip = models.GenericIPAddressField()
    last_ip = models.GenericIPAddressField(null=True, blank=True)
    is_hiding_presence = models.BooleanField(default=False)

    rank = models.ForeignKey(
        'Rank',
        null=True,
        blank=True,
        on_delete=models.deletion.PROTECT,
    )
    title = models.CharField(max_length=255, null=True, blank=True)
    requires_activation = models.PositiveIntegerField(default=ACTIVATION_NONE)

    is_staff = models.BooleanField(
        _('staff status'),
        default=False,
        help_text=_('Designates whether the user can log into admin sites.'),
    )

    roles = models.ManyToManyField('misago_acl.Role')
    acl_key = models.CharField(max_length=12, null=True, blank=True)

    is_active = models.BooleanField(
        _('active'),
        db_index=True,
        default=True,
        help_text=_(
            "Designates whether this user should be treated as active. "
            "Unselect this instead of deleting accounts."
        ),
    )
    is_active_staff_message = models.TextField(null=True, blank=True)

    avatar_tmp = models.ImageField(
        max_length=255,
        upload_to=avatars.store.upload_to,
        null=True,
        blank=True,
    )
    avatar_src = models.ImageField(
        max_length=255,
        upload_to=avatars.store.upload_to,
        null=True,
        blank=True,
    )
    avatar_crop = models.CharField(max_length=255, null=True, blank=True)
    avatars = JSONField(null=True, blank=True)
    is_avatar_locked = models.BooleanField(default=False)
    avatar_lock_user_message = models.TextField(null=True, blank=True)
    avatar_lock_staff_message = models.TextField(null=True, blank=True)

    signature = models.TextField(null=True, blank=True)
    signature_parsed = models.TextField(null=True, blank=True)
    signature_checksum = models.CharField(max_length=64, null=True, blank=True)
    is_signature_locked = models.BooleanField(default=False)
    signature_lock_user_message = models.TextField(null=True, blank=True)
    signature_lock_staff_message = models.TextField(null=True, blank=True)

    followers = models.PositiveIntegerField(default=0)
    following = models.PositiveIntegerField(default=0)

    follows = models.ManyToManyField(
        'self',
        related_name='followed_by',
        symmetrical=False,
    )
    blocks = models.ManyToManyField(
        'self',
        related_name='blocked_by',
        symmetrical=False,
    )

    limits_private_thread_invites_to = models.PositiveIntegerField(
        default=LIMIT_INVITES_TO_NONE,
        choices=LIMIT_INVITES_TO_CHOICES,
    )
    unread_private_threads = models.PositiveIntegerField(default=0)
    sync_unread_private_threads = models.BooleanField(default=False)

    subscribe_to_started_threads = models.PositiveIntegerField(
        default=SUBSCRIBE_NONE,
        choices=SUBSCRIBE_CHOICES,
    )
    subscribe_to_replied_threads = models.PositiveIntegerField(
        default=SUBSCRIBE_NONE,
        choices=SUBSCRIBE_CHOICES,
    )

    threads = models.PositiveIntegerField(default=0)
    posts = models.PositiveIntegerField(default=0, db_index=True)

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

    profile_fields = HStoreField(default=dict)

    USERNAME_FIELD = 'slug'
    REQUIRED_FIELDS = ['email']

    objects = UserManager()

    class Meta:
        indexes = [
            PgPartialIndex(
                fields=['is_staff'],
                where={'is_staff': True},
            ),
            PgPartialIndex(
                fields=['requires_activation'],
                where={'requires_activation__gt': 0},
            ),
        ]

    def clean(self):
        self.username = self.normalize_username(self.username)
        self.email = UserManager.normalize_email(self.email)

    def lock(self):
        """locks user in DB, shortcut for locking user model in views"""
        return User.objects.select_for_update().get(pk=self.pk)

    def delete(self, *args, **kwargs):
        if kwargs.pop('delete_content', False):
            self.delete_content()

        avatars.delete_avatar(self)

        return super(User, self).delete(*args, **kwargs)

    def delete_content(self):
        from misago.users.signals import delete_user_content
        delete_user_content.send(sender=self)

    @property
    def acl_cache(self):
        try:
            return self._acl_cache
        except AttributeError:
            self._acl_cache = get_user_acl(self)
            return self._acl_cache

    @acl_cache.setter
    def acl_cache(self, value):
        raise TypeError("acl_cache can't be assigned")

    @property
    def acl_(self):
        raise NotImplementedError('user.acl_ property was renamed to user.acl')

    @property
    def requires_activation_by_admin(self):
        return self.requires_activation == self.ACTIVATION_ADMIN

    @property
    def requires_activation_by_user(self):
        return self.requires_activation == self.ACTIVATION_USER

    @property
    def can_be_messaged_by_everyone(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_NONE

    @property
    def can_be_messaged_by_followed(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_FOLLOWED

    @property
    def can_be_messaged_by_nobody(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_NOBODY

    @property
    def has_valid_signature(self):
        return is_user_signature_valid(self)

    def get_absolute_url(self):
        return reverse(
            'misago:user', kwargs={
                'slug': self.slug,
                'pk': self.pk,
            }
        )

    def get_username(self):
        """dirty hack: return real username instead of normalized slug"""
        return self.username

    def get_full_name(self):
        return self.username

    def get_short_name(self):
        return self.username

    def set_username(self, new_username, changed_by=None):
        new_username = self.normalize_username(new_username)
        if new_username != self.username:
            old_username = self.username
            self.username = new_username
            self.slug = slugify(new_username)

            if self.pk:
                changed_by = changed_by or self
                self.record_name_change(changed_by, new_username, old_username)

                from misago.users.signals import username_changed
                username_changed.send(sender=self)

    def record_name_change(self, changed_by, new_username, old_username):
        self.namechanges.create(
            new_username=new_username,
            old_username=old_username,
            changed_by=changed_by,
            changed_by_username=changed_by.username,
        )

    def set_email(self, new_email):
        self.email = UserManager.normalize_email(new_email)
        self.email_hash = hash_email(new_email)

    def get_any_title(self):
        return self.title or self.rank.title or self.rank.name

    def get_roles(self):
        roles_pks = []
        roles_dict = {}

        for role in self.roles.all():
            roles_pks.append(role.pk)
            role.origin = self
            roles_dict[role.pk] = role

        if self.rank:
            for role in self.rank.roles.all():
                if role.pk not in roles_pks:
                    role.origin = self.rank
                    roles_pks.append(role.pk)
                    roles_dict[role.pk] = role

        return [roles_dict[r] for r in sorted(roles_pks)]

    def update_acl_key(self):
        roles_pks = []
        for role in self.get_roles():
            if role.origin == 'self':
                roles_pks.append('u%s' % role.pk)
            else:
                roles_pks.append('%s:%s' % (self.rank.pk, role.pk))

        self.acl_key = md5(','.join(roles_pks).encode()).hexdigest()[:12]

    def email_user(self, subject, message, from_email=None, **kwargs):
        """sends an email to this user (for compat with Django)"""
        send_mail(subject, message, from_email, [self.email], **kwargs)

    def is_following(self, user):
        try:
            self.follows.get(pk=user.pk)
            return True
        except User.DoesNotExist:
            return False

    def is_blocking(self, user):
        try:
            self.blocks.get(pk=user.pk)
            return True
        except User.DoesNotExist:
            return False


class Online(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        primary_key=True,
        related_name='online_tracker',
        on_delete=models.CASCADE,
    )
    current_ip = models.GenericIPAddressField()
    last_click = models.DateTimeField(default=timezone.now)

    def save(self, *args, **kwargs):
        try:
            super(Online, self).save(*args, **kwargs)
        except IntegrityError:
            pass  # first come is first serve in online tracker


class UsernameChange(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        related_name='namechanges',
        on_delete=models.CASCADE,
    )
    changed_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        related_name='user_renames',
        on_delete=models.SET_NULL,
    )
    changed_by_username = models.CharField(max_length=30)
    changed_on = models.DateTimeField(default=timezone.now)
    new_username = models.CharField(max_length=255)
    old_username = models.CharField(max_length=255)

    class Meta:
        get_latest_by = "changed_on"

    def set_change_author(self, user):
        self.changed_by = user
        self.changed_by_username = user.username


class AnonymousUser(DjangoAnonymousUser):
    acl_key = 'anonymous'

    @property
    def acl_cache(self):
        try:
            return self._acl_cache
        except AttributeError:
            self._acl_cache = get_user_acl(self)
            return self._acl_cache

    @acl_cache.setter
    def acl_cache(self, value):
        raise TypeError("AnonymousUser instances can't be made ACL aware")

    def get_roles(self):
        try:
            return [Role.objects.get(special_role="anonymous")]
        except Role.DoesNotExist:
            raise RuntimeError("Anonymous user role not found.")

    def update_acl_key(self):
        raise TypeError("Can't update ACL key on anonymous users")

from hashlib import md5

from django.contrib.auth.models import AnonymousUser as DjangoAnonymousUser
from django.contrib.auth.models import UserManager as BaseUserManager
from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin
from django.contrib.auth.password_validation import validate_password
from django.contrib.postgres.fields import HStoreField, JSONField
from django.core.mail import send_mail
from django.db import IntegrityError, models, transaction
from django.urls import reverse
from django.utils import timezone
from django.utils.translation import ugettext_lazy as _

from misago.acl import get_user_acl
from misago.acl.models import Role
from misago.conf import settings
from misago.core.pgutils import PgPartialIndex
from misago.core.utils import slugify
from misago.users import avatars
from misago.users.signatures import is_user_signature_valid
from misago.users.utils import hash_email

from .rank import Rank


class UserManager(BaseUserManager):
    @transaction.atomic
    def create_user(
            self, username, email, password=<PASSWORD>, set_default_avatar=False, **extra_fields
    ):
        from misago.users.validators import validate_email, validate_username

        email = self.normalize_email(email)
        username = self.model.normalize_username(username)

        if not email:
            raise ValueError(_("User must have an email address."))
        if not password:
            raise ValueError(_("User must have a password."))

        if not 'joined_from_ip' in extra_fields:
            extra_fields['joined_from_ip'] = '127.0.0.1'

        WATCH_DICT = {
            'no': self.model.SUBSCRIBE_NONE,
            'watch': self.model.SUBSCRIBE_NOTIFY,
            'watch_email': self.model.SUBSCRIBE_ALL,
        }

        if not 'subscribe_to_started_threads' in extra_fields:
            new_value = WATCH_DICT[settings.subscribe_start]
            extra_fields['subscribe_to_started_threads'] = new_value

        if not 'subscribe_to_replied_threads' in extra_fields:
            new_value = WATCH_DICT[settings.subscribe_reply]
            extra_fields['subscribe_to_replied_threads'] = new_value

        extra_fields.update({'is_staff': False, 'is_superuser': False})

        now = timezone.now()
        user = self.model(last_login=now, joined_on=now, **extra_fields)

        user.set_username(username)
        user.set_email(email)
        user.set_password(password)

        validate_username(username)
        validate_email(email)
        validate_password(password, user=user)

        if not 'rank' in extra_fields:
            user.rank = Rank.objects.get_default()

        user.save(using=self._db)

        if set_default_avatar:
            avatars.set_default_avatar(
                user, settings.default_avatar, settings.default_gravatar_fallback
            )
        else:
            # just for test purposes
            user.avatars = [{'size': 400, 'url': '/placekitten.com/400/400'}]

        authenticated_role = Role.objects.get(special_role='authenticated')
        if authenticated_role not in user.roles.all():
            user.roles.add(authenticated_role)
        user.update_acl_key()

        user.save(update_fields=['avatars', 'acl_key'])

        # populate online tracker with default value
        Online.objects.create(
            user=user,
            current_ip=extra_fields['joined_from_ip'],
            last_click=now,
        )

        return user

    @transaction.atomic
    def create_superuser(self, username, email, password, set_default_avatar=False):
        user = self.create_user(
            username,
            email,
            password=password,
            set_default_avatar=set_default_avatar,
        )

        try:
            user.rank = Rank.objects.get(name=_("Forum team"))
            user.update_acl_key()
        except Rank.DoesNotExist:
            pass

        user.is_staff = True
        user.is_superuser = True

        updated_fields = ('rank', 'acl_key', 'is_staff', 'is_superuser')
        user.save(update_fields=updated_fields, using=self._db)
        return user

    def get_by_username(self, username):
        return self.get(slug=slugify(username))

    def get_by_email(self, email):
        return self.get(email_hash=hash_email(email))

    def get_by_username_or_email(self, login):
        queryset = models.Q(slug=slugify(login))
        queryset = queryset | models.Q(email_hash=hash_email(login))
        return self.get(queryset)


class User(AbstractBaseUser, PermissionsMixin):
    ACTIVATION_NONE = 0
    ACTIVATION_USER = 1
    ACTIVATION_ADMIN = 2

    SUBSCRIBE_NONE = 0
    SUBSCRIBE_NOTIFY = 1
    SUBSCRIBE_ALL = 2

    SUBSCRIBE_CHOICES = [
        (SUBSCRIBE_NONE, _("No")),
        (SUBSCRIBE_NOTIFY, _("Notify")),
        (SUBSCRIBE_ALL, _("Notify with e-mail")),
    ]

    LIMIT_INVITES_TO_NONE = 0
    LIMIT_INVITES_TO_FOLLOWED = 1
    LIMIT_INVITES_TO_NOBODY = 2

    LIMIT_INVITES_TO_CHOICES = [
        (LIMIT_INVITES_TO_NONE, _("Everybody")),
        (LIMIT_INVITES_TO_FOLLOWED, _("Users I follow")),
        (LIMIT_INVITES_TO_NOBODY, _("Nobody")),
    ]
    # Note that "username" field is purely for shows.
    # When searching users by their names, always use lowercased string
    # and slug field instead that is normalized around DB engines
    # differences in case handling.
    username = models.CharField(max_length=30)
    slug = models.CharField(max_length=30, unique=True)

    # Misago stores user email in two fields:
    # "email" holds normalized email address
    # "email_hash" is lowercase hash of email address used to identify account
    # as well as enforcing on database level that no more than one user can be
    # using one email address
    email = models.EmailField(max_length=255, db_index=True)
    email_hash = models.CharField(max_length=32, unique=True)

    joined_on = models.DateTimeField(_('joined on'), default=timezone.now)
    joined_from_ip = models.GenericIPAddressField()
    last_ip = models.GenericIPAddressField(null=True, blank=True)
    is_hiding_presence = models.BooleanField(default=False)

    rank = models.ForeignKey(
        'Rank',
        null=True,
        blank=True,
        on_delete=models.deletion.PROTECT,
    )
    title = models.CharField(max_length=255, null=True, blank=True)
    requires_activation = models.PositiveIntegerField(default=ACTIVATION_NONE)

    is_staff = models.BooleanField(
        _('staff status'),
        default=False,
        help_text=_('Designates whether the user can log into admin sites.'),
    )

    roles = models.ManyToManyField('misago_acl.Role')
    acl_key = models.CharField(max_length=12, null=True, blank=True)

    is_active = models.BooleanField(
        _('active'),
        db_index=True,
        default=True,
        help_text=_(
            "Designates whether this user should be treated as active. "
            "Unselect this instead of deleting accounts."
        ),
    )
    is_active_staff_message = models.TextField(null=True, blank=True)

    avatar_tmp = models.ImageField(
        max_length=255,
        upload_to=avatars.store.upload_to,
        null=True,
        blank=True,
    )
    avatar_src = models.ImageField(
        max_length=255,
        upload_to=avatars.store.upload_to,
        null=True,
        blank=True,
    )
    avatar_crop = models.CharField(max_length=255, null=True, blank=True)
    avatars = JSONField(null=True, blank=True)
    is_avatar_locked = models.BooleanField(default=False)
    avatar_lock_user_message = models.TextField(null=True, blank=True)
    avatar_lock_staff_message = models.TextField(null=True, blank=True)

    signature = models.TextField(null=True, blank=True)
    signature_parsed = models.TextField(null=True, blank=True)
    signature_checksum = models.CharField(max_length=64, null=True, blank=True)
    is_signature_locked = models.BooleanField(default=False)
    signature_lock_user_message = models.TextField(null=True, blank=True)
    signature_lock_staff_message = models.TextField(null=True, blank=True)

    followers = models.PositiveIntegerField(default=0)
    following = models.PositiveIntegerField(default=0)

    follows = models.ManyToManyField(
        'self',
        related_name='followed_by',
        symmetrical=False,
    )
    blocks = models.ManyToManyField(
        'self',
        related_name='blocked_by',
        symmetrical=False,
    )

    limits_private_thread_invites_to = models.PositiveIntegerField(
        default=LIMIT_INVITES_TO_NONE,
        choices=LIMIT_INVITES_TO_CHOICES,
    )
    unread_private_threads = models.PositiveIntegerField(default=0)
    sync_unread_private_threads = models.BooleanField(default=False)

    subscribe_to_started_threads = models.PositiveIntegerField(
        default=SUBSCRIBE_NONE,
        choices=SUBSCRIBE_CHOICES,
    )
    subscribe_to_replied_threads = models.PositiveIntegerField(
        default=SUBSCRIBE_NONE,
        choices=SUBSCRIBE_CHOICES,
    )

    threads = models.PositiveIntegerField(default=0)
    posts = models.PositiveIntegerField(default=0, db_index=True)

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

    profile_fields = HStoreField(default=dict)

    USERNAME_FIELD = 'slug'
    REQUIRED_FIELDS = ['email']

    objects = UserManager()

    class Meta:
        indexes = [
            PgPartialIndex(
                fields=['is_staff'],
                where={'is_staff': True},
            ),
            PgPartialIndex(
                fields=['requires_activation'],
                where={'requires_activation__gt': 0},
            ),
        ]

    def clean(self):
        self.username = self.normalize_username(self.username)
        self.email = UserManager.normalize_email(self.email)

    def lock(self):
        """locks user in DB, shortcut for locking user model in views"""
        return User.objects.select_for_update().get(pk=self.pk)

    def delete(self, *args, **kwargs):
        if kwargs.pop('delete_content', False):
            self.delete_content()

        avatars.delete_avatar(self)

        return super(User, self).delete(*args, **kwargs)

    def delete_content(self):
        from misago.users.signals import delete_user_content
        delete_user_content.send(sender=self)

    @property
    def acl_cache(self):
        try:
            return self._acl_cache
        except AttributeError:
            self._acl_cache = get_user_acl(self)
            return self._acl_cache

    @acl_cache.setter
    def acl_cache(self, value):
        raise TypeError("acl_cache can't be assigned")

    @property
    def acl_(self):
        raise NotImplementedError('user.acl_ property was renamed to user.acl')

    @property
    def requires_activation_by_admin(self):
        return self.requires_activation == self.ACTIVATION_ADMIN

    @property
    def requires_activation_by_user(self):
        return self.requires_activation == self.ACTIVATION_USER

    @property
    def can_be_messaged_by_everyone(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_NONE

    @property
    def can_be_messaged_by_followed(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_FOLLOWED

    @property
    def can_be_messaged_by_nobody(self):
        preference = self.limits_private_thread_invites_to
        return preference == self.LIMIT_INVITES_TO_NOBODY

    @property
    def has_valid_signature(self):
        return is_user_signature_valid(self)

    def get_absolute_url(self):
        return reverse(
            'misago:user', kwargs={
                'slug': self.slug,
                'pk': self.pk,
            }
        )

    def get_username(self):
        """dirty hack: return real username instead of normalized slug"""
        return self.username

    def get_full_name(self):
        return self.username

    def get_short_name(self):
        return self.username

    def set_username(self, new_username, changed_by=None):
        new_username = self.normalize_username(new_username)
        if new_username != self.username:
            old_username = self.username
            self.username = new_username
            self.slug = slugify(new_username)

            if self.pk:
                changed_by = changed_by or self
                self.record_name_change(changed_by, new_username, old_username)

                from misago.users.signals import username_changed
                username_changed.send(sender=self)

    def record_name_change(self, changed_by, new_username, old_username):
        self.namechanges.create(
            new_username=new_username,
            old_username=old_username,
            changed_by=changed_by,
            changed_by_username=changed_by.username,
        )

    def set_email(self, new_email):
        self.email = UserManager.normalize_email(new_email)
        self.email_hash = hash_email(new_email)

    def get_any_title(self):
        return self.title or self.rank.title or self.rank.name

    def get_roles(self):
        roles_pks = []
        roles_dict = {}

        for role in self.roles.all():
            roles_pks.append(role.pk)
            role.origin = self
            roles_dict[role.pk] = role

        if self.rank:
            for role in self.rank.roles.all():
                if role.pk not in roles_pks:
                    role.origin = self.rank
                    roles_pks.append(role.pk)
                    roles_dict[role.pk] = role

        return [roles_dict[r] for r in sorted(roles_pks)]

    def update_acl_key(self):
        roles_pks = []
        for role in self.get_roles():
            if role.origin == 'self':
                roles_pks.append('u%s' % role.pk)
            else:
                roles_pks.append('%s:%s' % (self.rank.pk, role.pk))

        self.acl_key = md5(','.join(roles_pks).encode()).hexdigest()[:12]

    def email_user(self, subject, message, from_email=None, **kwargs):
        """sends an email to this user (for compat with Django)"""
        send_mail(subject, message, from_email, [self.email], **kwargs)

    def is_following(self, user):
        try:
            self.follows.get(pk=user.pk)
            return True
        except User.DoesNotExist:
            return False

    def is_blocking(self, user):
        try:
            self.blocks.get(pk=user.pk)
            return True
        except User.DoesNotExist:
            return False


class Online(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        primary_key=True,
        related_name='online_tracker',
        on_delete=models.CASCADE,
    )
    current_ip = models.GenericIPAddressField()
    last_click = models.DateTimeField(default=timezone.now)

    def save(self, *args, **kwargs):
        try:
            super(Online, self).save(*args, **kwargs)
        except IntegrityError:
            pass  # first come is first serve in online tracker


class UsernameChange(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        related_name='namechanges',
        on_delete=models.CASCADE,
    )
    changed_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        related_name='user_renames',
        on_delete=models.SET_NULL,
    )
    changed_by_username = models.CharField(max_length=30)
    changed_on = models.DateTimeField(default=timezone.now)
    new_username = models.CharField(max_length=255)
    old_username = models.CharField(max_length=255)

    class Meta:
        get_latest_by = "changed_on"

    def set_change_author(self, user):
        self.changed_by = user
        self.changed_by_username = user.username


class AnonymousUser(DjangoAnonymousUser):
    acl_key = 'anonymous'

    @property
    def acl_cache(self):
        try:
            return self._acl_cache
        except AttributeError:
            self._acl_cache = get_user_acl(self)
            return self._acl_cache

    @acl_cache.setter
    def acl_cache(self, value):
        raise TypeError("AnonymousUser instances can't be made ACL aware")

    def get_roles(self):
        try:
            return [Role.objects.get(special_role="anonymous")]
        except Role.DoesNotExist:
            raise RuntimeError("Anonymous user role not found.")

    def update_acl_key(self):
        raise TypeError("Can't update ACL key on anonymous users")

# just for test purposes # populate online tracker with default value # Note that "username" field is purely for shows. # When searching users by their names, always use lowercased string # and slug field instead that is normalized around DB engines # differences in case handling. # Misago stores user email in two fields: # "email" holds normalized email address # "email_hash" is lowercase hash of email address used to identify account # as well as enforcing on database level that no more than one user can be # using one email address locks user in DB, shortcut for locking user model in views dirty hack: return real username instead of normalized slug sends an email to this user (for compat with Django) # first come is first serve in online tracker