Add Move activity for user migration

FEDERATION.md

@@ -13,14 +13,15 @@ User relationship interactions follow the standard ActivityPub spec.
 - `Block`: prevent users from seeing one another's statuses, and prevents the blocked user from viewing the actor's profile
 - `Update`: updates a user's profile and settings
 - `Delete`: deactivates a user
-- `Undo`: reverses a `Follow` or `Block`
+- `Undo`: reverses a `Block` or `Follow`
 
 ### Activities
 - `Create/Status`: saves a new status in the database.
 - `Delete/Status`: Removes a status
 - `Like/Status`: Creates a favorite on the status
 - `Announce/Status`: Boosts the status into the actor's timeline
-- `Undo/*`,: Reverses a `Like` or `Announce`
+- `Undo/*`,: Reverses an `Announce`, `Like`, or `Move`
+- `Move/User`: Moves a user from one ActivityPub id to another.
 
 ### Collections
 User's books and lists are represented by [`OrderedCollection`](https://www.w3.org/TR/activitystreams-vocabulary/#dfn-orderedcollection)

bookwyrm/activitypub/__init__.py

@@ -19,6 +19,7 @@
 from .verbs import Follow, Accept, Reject, Block
 from .verbs import Add, Remove
 from .verbs import Announce, Like
+from .verbs import Move
 
 # this creates a list of all the Activity types that we can serialize,
 # so when an Activity comes in from outside, we can check if it's known

bookwyrm/activitypub/person.py

@@ -40,4 +40,6 @@ class Person(ActivityObject):
     manuallyApprovesFollowers: str = False
     discoverable: str = False
     hideFollows: str = False
+    movedTo: str = None
+    alsoKnownAs: dict[str] = None
     type: str = "Person"

bookwyrm/activitypub/verbs.py

@@ -231,3 +231,30 @@ class Announce(Verb):
     def action(self, allow_external_connections=True):
         """boost"""
         self.to_model(allow_external_connections=allow_external_connections)
+
+
+@dataclass(init=False)
+class Move(Verb):
+    """a user moving an object"""
+
+    object: str
+    type: str = "Move"
+    origin: str = None
+    target: str = None
+
+    def action(self, allow_external_connections=True):
+        """move"""
+
+        object_is_user = resolve_remote_id(remote_id=self.object, model="User")
+
+        if object_is_user:
+            model = apps.get_model("bookwyrm.MoveUser")
+
+            self.to_model(
+                model=model,
+                save=True,
+                allow_external_connections=allow_external_connections,
+            )
+        else:
+            # we might do something with this to move other objects at some point
+            pass

bookwyrm/forms/edit_user.py

@@ -70,6 +70,22 @@ class Meta:
         fields = ["password"]
 
 
+class MoveUserForm(CustomForm):
+    target = forms.CharField(widget=forms.TextInput)
+
+    class Meta:
+        model = models.User
+        fields = ["password"]
+
+
+class AliasUserForm(CustomForm):
+    username = forms.CharField(widget=forms.TextInput)
+
+    class Meta:
+        model = models.User
+        fields = ["password"]
+
+
 class ChangePasswordForm(CustomForm):
     current_password = forms.CharField(widget=forms.PasswordInput)
     confirm_password = forms.CharField(widget=forms.PasswordInput)

bookwyrm/migrations/0182_auto_20230924_0821.py

@@ -0,0 +1,161 @@
+# Generated by Django 3.2.20 on 2023-09-24 08:21
+
+import bookwyrm.models.activitypub_mixin
+import bookwyrm.models.fields
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bookwyrm", "0181_merge_20230806_2302"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="user",
+            name="also_known_as",
+            field=bookwyrm.models.fields.ManyToManyField(to=settings.AUTH_USER_MODEL),
+        ),
+        migrations.AddField(
+            model_name="user",
+            name="moved_to",
+            field=bookwyrm.models.fields.RemoteIdField(
+                max_length=255,
+                null=True,
+                validators=[bookwyrm.models.fields.validate_remote_id],
+            ),
+        ),
+        migrations.AlterField(
+            model_name="notification",
+            name="notification_type",
+            field=models.CharField(
+                choices=[
+                    ("FAVORITE", "Favorite"),
+                    ("REPLY", "Reply"),
+                    ("MENTION", "Mention"),
+                    ("TAG", "Tag"),
+                    ("FOLLOW", "Follow"),
+                    ("FOLLOW_REQUEST", "Follow Request"),
+                    ("BOOST", "Boost"),
+                    ("IMPORT", "Import"),
+                    ("ADD", "Add"),
+                    ("REPORT", "Report"),
+                    ("LINK_DOMAIN", "Link Domain"),
+                    ("INVITE", "Invite"),
+                    ("ACCEPT", "Accept"),
+                    ("JOIN", "Join"),
+                    ("LEAVE", "Leave"),
+                    ("REMOVE", "Remove"),
+                    ("GROUP_PRIVACY", "Group Privacy"),
+                    ("GROUP_NAME", "Group Name"),
+                    ("GROUP_DESCRIPTION", "Group Description"),
+                    ("MOVE", "Move"),
+                ],
+                max_length=255,
+            ),
+        ),
+        migrations.CreateModel(
+            name="MoveUserNotification",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("created_date", models.DateTimeField(auto_now_add=True)),
+                (
+                    "target",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="moved_user_notification_target",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+                (
+                    "user",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="moved_user_notifications",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+        ),
+        migrations.CreateModel(
+            name="Move",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("created_date", models.DateTimeField(auto_now_add=True)),
+                ("updated_date", models.DateTimeField(auto_now=True)),
+                (
+                    "remote_id",
+                    bookwyrm.models.fields.RemoteIdField(
+                        max_length=255,
+                        null=True,
+                        validators=[bookwyrm.models.fields.validate_remote_id],
+                    ),
+                ),
+                ("object", bookwyrm.models.fields.CharField(max_length=255)),
+                (
+                    "origin",
+                    bookwyrm.models.fields.CharField(
+                        blank=True, default="", max_length=255, null=True
+                    ),
+                ),
+                (
+                    "user",
+                    bookwyrm.models.fields.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+            bases=(bookwyrm.models.activitypub_mixin.ActivityMixin, models.Model),
+        ),
+        migrations.CreateModel(
+            name="MoveUser",
+            fields=[
+                (
+                    "move_ptr",
+                    models.OneToOneField(
+                        auto_created=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to="bookwyrm.move",
+                    ),
+                ),
+                (
+                    "target",
+                    bookwyrm.models.fields.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="move_target",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+            bases=("bookwyrm.move",),
+        ),
+    ]

bookwyrm/models/__init__.py

@@ -27,6 +27,8 @@
 
 from .import_job import ImportJob, ImportItem
 
+from .move import MoveUser, MoveUserNotification
+
 from .site import SiteSettings, Theme, SiteInvite
 from .site import PasswordReset, InviteRequest
 from .announcement import Announcement

bookwyrm/models/move.py

@@ -0,0 +1,87 @@
+""" move an object including migrating a user account """
+from django.core.exceptions import PermissionDenied
+from django.db import models
+
+from bookwyrm import activitypub
+from .activitypub_mixin import ActivityMixin
+from .base_model import BookWyrmModel
+from . import fields
+
+
+class Move(ActivityMixin, BookWyrmModel):
+    """migrating an activitypub user account"""
+
+    user = fields.ForeignKey(
+        "User", on_delete=models.PROTECT, activitypub_field="actor"
+    )
+
+    object = fields.CharField(
+        max_length=255,
+        blank=False,
+        null=False,
+        activitypub_field="object",
+    )
+
+    origin = fields.CharField(
+        max_length=255,
+        blank=True,
+        null=True,
+        default="",
+        activitypub_field="origin",
+    )
+
+    activity_serializer = activitypub.Move
+
+
+class MoveUser(Move):
+    """migrating an activitypub user account"""
+
+    target = fields.ForeignKey(
+        "User",
+        on_delete=models.PROTECT,
+        related_name="move_target",
+        activitypub_field="target",
+    )
+
+    def save(self, *args, **kwargs):
+        """update user info and broadcast it"""
+
+        # only allow if the source is listed in the target's alsoKnownAs
+        if self.user in self.target.also_known_as.all():
+
+            self.user.also_known_as.add(self.target.id)
+            self.user.update_active_date()
+            self.user.moved_to = self.target.remote_id
+            self.user.save(update_fields=["moved_to"])
+
+            if self.user.local:
+                kwargs[
+                    "broadcast"
+                ] = True  # Only broadcast if we are initiating the Move
+
+            super().save(*args, **kwargs)
+
+            for follower in self.user.followers.all():
+                if follower.local:
+                    MoveUserNotification.objects.create(user=follower, target=self.user)
+
+        else:
+            raise PermissionDenied()
+
+
+class MoveUserNotification(models.Model):
+    """notify followers that the user has moved"""
+
+    created_date = models.DateTimeField(auto_now_add=True)
+
+    user = models.ForeignKey(
+        "User", on_delete=models.PROTECT, related_name="moved_user_notifications"
+    )  # user we are notifying
+
+    target = models.ForeignKey(
+        "User", on_delete=models.PROTECT, related_name="moved_user_notification_target"
+    )  # new account of user who moved
+
+    def save(self, *args, **kwargs):
+        """send notification"""
+        super().save(*args, **kwargs)

bookwyrm/models/notification.py

@@ -2,7 +2,14 @@
 from django.db import models, transaction
 from django.dispatch import receiver
 from .base_model import BookWyrmModel
-from . import Boost, Favorite, GroupMemberInvitation, ImportJob, LinkDomain
+from . import (
+    Boost,
+    Favorite,
+    GroupMemberInvitation,
+    ImportJob,
+    LinkDomain,
+    MoveUserNotification,
+)
 from . import ListItem, Report, Status, User, UserFollowRequest
 
 
@@ -40,11 +47,14 @@ class Notification(BookWyrmModel):
     GROUP_NAME = "GROUP_NAME"
     GROUP_DESCRIPTION = "GROUP_DESCRIPTION"
 
+    # Migrations
+    MOVE = "MOVE"
+
     # pylint: disable=line-too-long
     NotificationType = models.TextChoices(
         # there has got be a better way to do this
         "NotificationType",
-        f"{FAVORITE} {REPLY} {MENTION} {TAG} {FOLLOW} {FOLLOW_REQUEST} {BOOST} {IMPORT} {ADD} {REPORT} {LINK_DOMAIN} {INVITE} {ACCEPT} {JOIN} {LEAVE} {REMOVE} {GROUP_PRIVACY} {GROUP_NAME} {GROUP_DESCRIPTION}",
+        f"{FAVORITE} {REPLY} {MENTION} {TAG} {FOLLOW} {FOLLOW_REQUEST} {BOOST} {IMPORT} {ADD} {REPORT} {LINK_DOMAIN} {INVITE} {ACCEPT} {JOIN} {LEAVE} {REMOVE} {GROUP_PRIVACY} {GROUP_NAME} {GROUP_DESCRIPTION} {MOVE}",
     )
 
     user = models.ForeignKey("User", on_delete=models.CASCADE)
@@ -326,3 +336,12 @@ def notify_user_on_follow(sender, instance, created, *args, **kwargs):
             notification_type=Notification.FOLLOW,
             read=False,
         )
+
+
+@receiver(models.signals.post_save, sender=MoveUserNotification)
+# pylint: disable=unused-argument
+def notify_on_move(sender, instance, *args, **kwargs):
+    """someone migrated their account"""
+    Notification.notify(
+        instance.user, instance.target, notification_type=Notification.MOVE
+    )