✨(backend) add command to clean pending and deleted files

Since we have added custom backgrounds, they could be
soft deleted but were never really deleted.
This commits introduces a command to actually delete
this files.
In introduces also a command to purge pending upload
.

src/backend/core/tests/commands/test_clean_pending_files.py

@@ -0,0 +1,90 @@
+"""Tests for the clean_pending_files management command."""
+
+from datetime import timedelta
+
+from django.core.files.storage import default_storage
+from django.core.management import call_command
+from django.utils import timezone
+
+import pytest
+
+from core import factories, models
+
+pytestmark = pytest.mark.django_db
+
+
+def test_clean_pending_files_no_stale_files():
+    """Nothing happens when there are no stale pending files."""
+    call_command("clean_pending_files")
+
+
+def test_clean_pending_files_recent_pending_not_deleted():
+    """Recent pending files (within threshold) should not be deleted."""
+    file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        update_upload_state=models.FileUploadStateChoices.PENDING,
+        upload_bytes=b"hello",
+    )
+
+    call_command("clean_pending_files")
+
+    file.refresh_from_db()
+    assert file.deleted_at is None
+    assert default_storage.exists(file.file_key)
+
+
+def test_clean_pending_files_old_pending_deleted():
+    """Pending files older than the threshold should be deleted."""
+    old_date = timezone.now() - timedelta(hours=49)
+    file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        update_upload_state=models.FileUploadStateChoices.PENDING,
+        upload_bytes=b"hello",
+    )
+    assert default_storage.exists(file.file_key)
+    models.File.objects.filter(pk=file.pk).update(created_at=old_date)
+
+    call_command("clean_pending_files")
+
+    assert not models.File.objects.filter(pk=file.pk).exists()
+    assert not default_storage.exists(file.file_key)
+
+
+def test_clean_pending_files_old_non_pending_not_deleted():
+    """Old files that are not pending should not be deleted."""
+    old_date = timezone.now() - timedelta(hours=49)
+    file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        update_upload_state=models.FileUploadStateChoices.READY,
+    )
+    models.File.objects.filter(pk=file.pk).update(created_at=old_date)
+
+    call_command("clean_pending_files")
+
+    file.refresh_from_db()
+    assert file.deleted_at is None
+    assert file.hard_deleted_at is None
+
+
+def test_clean_pending_files_custom_hours():
+    """The --hours argument controls the age threshold."""
+    old_date = timezone.now() - timedelta(hours=10)
+    file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        update_upload_state=models.FileUploadStateChoices.PENDING,
+        upload_bytes=b"hello",
+    )
+    models.File.objects.filter(pk=file.pk).update(created_at=old_date)
+
+    # Default 24h threshold -> file not deleted
+    call_command("clean_pending_files")
+
+    file.refresh_from_db()
+    assert file.deleted_at is None
+    assert default_storage.exists(file.file_key)
+
+    # 8h threshold -> file deleted
+    call_command("clean_pending_files", "--hours=8")
+
+    assert not models.File.objects.filter(pk=file.pk).exists()
+    assert not default_storage.exists(file.file_key)

src/backend/core/tests/commands/test_purge_deleted_files.py

@@ -0,0 +1,85 @@
+"""Tests for the purge_deleted_files management command."""
+
+from datetime import timedelta
+from io import StringIO
+from random import randint
+from unittest.mock import patch
+
+from django.core.files.storage import default_storage
+from django.core.management import call_command
+from django.utils import timezone
+
+import pytest
+
+from core import factories, models
+from core.tasks.file import process_file_deletion
+
+pytestmark = pytest.mark.django_db
+
+
+def test_purge_deleted_files_no_deleted_files(django_assert_num_queries):
+    """Nothing happens when there are no purgeable files."""
+    with django_assert_num_queries(1):
+        call_command("purge_deleted_files")
+
+
+@pytest.mark.django_db(transaction=True)
+def test_purge_deleted_files_success(settings):
+    """
+    Queue deletion for:
+    - hard-deleted files
+    - soft-deleted files past retention period + grace period.
+    """
+    out = StringIO()
+
+    settings.FILE_PURGE_GRACE_DAYS = grace = randint(1, 20)
+
+    now = timezone.now()
+    purge_now = now - timedelta(days=grace)
+
+    not_deleted_file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        upload_bytes=b"hello",
+    )
+
+    with patch("django.utils.timezone.now", return_value=now):
+        not_purgeable_file = factories.FileFactory(
+            type=models.FileTypeChoices.BACKGROUND_IMAGE,
+            upload_bytes=b"hello",
+        )
+        not_purgeable_file.soft_delete()
+
+    with patch("django.utils.timezone.now", return_value=purge_now):
+        purgeable_file = factories.FileFactory(
+            type=models.FileTypeChoices.BACKGROUND_IMAGE,
+            upload_bytes=b"hello",
+        )
+        purgeable_file.soft_delete()
+
+    hard_deleted_file = factories.FileFactory(
+        type=models.FileTypeChoices.BACKGROUND_IMAGE,
+        upload_bytes=b"hello",
+    )
+    hard_deleted_file.soft_delete()
+    hard_deleted_file.hard_delete()
+
+    with patch(
+        "core.management.commands.purge_deleted_files.process_file_deletion.delay",
+        side_effect=process_file_deletion,
+    ) as mock_delay:
+        call_command("purge_deleted_files", stdout=out)
+
+    assert "Purged 2 deleted file(s)." in out.getvalue()
+    assert mock_delay.call_count == 2
+    called_ids = {call.args[0] for call in mock_delay.call_args_list}
+    assert called_ids == {purgeable_file.id, hard_deleted_file.id}
+
+    assert models.File.objects.filter(id=not_deleted_file.id).exists()
+    assert models.File.objects.filter(id=not_purgeable_file.id).exists()
+    assert not models.File.objects.filter(id=purgeable_file.id).exists()
+    assert not models.File.objects.filter(id=hard_deleted_file.id).exists()
+
+    assert default_storage.exists(not_deleted_file.file_key)
+    assert default_storage.exists(not_purgeable_file.file_key)
+    assert not default_storage.exists(purgeable_file.file_key)
+    assert not default_storage.exists(hard_deleted_file.file_key)