Switch database migration engine (#546)

* switch to django's migration engine

* remove aerich

* update documentation

* generate default models

* skip path migration when there is no table found

* run migrations before running the bot

* missing line break

* handle missing config file

* test making a new migration

* models: add credits column

* Revert "models: add credits column"

This reverts commit 3221a5f.

* Properly add credits column this time

.pre-commit-config.yaml

@@ -38,7 +38,6 @@ repos:
           - Pillow
           - prometheus_client
           - tortoise-orm
-          - aerich==0.6.3
           - redis
           - django
           - dj_database_url

CONTRIBUTING.md

@@ -87,10 +87,16 @@ Their configurations are already written in `pyproject.toml`, so it should work
 
 ## Migrations
 
-> [!CAUTION]
-> The migration engine we've been using in the past is severely broken, and will be removed soon
-> in favor of Django's migration engine. In the meantime, all PRs that require database migrations
-> are put on hold.
+If you are modifying models definition, you need migrations to update the database schema.
+
+First, synchronize your changes between `ballsdex/core/models.py` and
+`admin_panel/bd_models/models.py`, they must be identical!
+
+Then you can run `python3 manage.py makemigrations` to generate a migration file. Re-read its
+contents to ensure there is only what you modified, and commit it.
+
+You can read more about migrations
+[here](https://docs.djangoproject.com/en/5.1/topics/migrations/), the engine is very extensive!
 
 ## Coding style
 

admin_panel/admin_panel/settings/base.py

@@ -9,7 +9,15 @@
 
 from ballsdex.settings import read_settings, settings
 
-read_settings(Path("../config.yml"))
+try:
+    read_settings(Path("../config.yml"))
+except FileNotFoundError:
+    from rich import print
+
+    print(
+        "[yellow][bold]Could not find ../config.yml file.[/bold] "
+        "Please run the bot once to generate this file.[/yellow]"
+    )
 
 BASE_DIR = Path(__file__).resolve().parent.parent
 

admin_panel/bd_models/migrations/0002_move_upload_files.py

@@ -4,7 +4,7 @@
 from typing import TYPE_CHECKING
 
 from bd_models.models import Ball, Economy, Regime, Special
-from django.db import migrations
+from django.db import connection, migrations
 from django.db.models import Case, ImageField, When
 from django.db.models.expressions import F, Value
 from django.db.models.functions import Concat, Replace
@@ -60,6 +60,10 @@ def _check_reserved_names():
 
 
 def move_forwards(apps: "Apps", schema_editor: "BaseDatabaseSchemaEditor"):
+    # only run this migration if there are existing tables (migrating from aerich)
+    if "ball" not in connection.introspection.table_names():
+        return
+
     # Run this first, as outdated objects are created by aerich's initial migrations
     Regime.objects.update(**_replace_text("background"))
     Special.objects.update(**_replace_text("background"))
@@ -80,6 +84,10 @@ def move_forwards(apps: "Apps", schema_editor: "BaseDatabaseSchemaEditor"):
 
 
 def move_backwards(apps: "Apps", schema_editor: "BaseDatabaseSchemaEditor"):
+    # only run this migration if the tables weren't deleted
+    if "ball" not in connection.introspection.table_names():
+        return
+
     Ball.objects.update(
         **_replace_text("wild_card", reverse=True),
         **_replace_text("collection_card", reverse=True),

admin_panel/bd_models/migrations/0003_delete_ball_delete_ballinstance_and_more.py

@@ -0,0 +1,55 @@
+# Generated by Django 5.1.4 on 2025-01-28 14:44
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bd_models", "0002_move_upload_files"),
+    ]
+
+    operations = [
+        migrations.DeleteModel(
+            name="Ball",
+        ),
+        migrations.DeleteModel(
+            name="BallInstance",
+        ),
+        migrations.DeleteModel(
+            name="BlacklistedGuild",
+        ),
+        migrations.DeleteModel(
+            name="BlacklistedID",
+        ),
+        migrations.DeleteModel(
+            name="BlacklistHistory",
+        ),
+        migrations.DeleteModel(
+            name="Block",
+        ),
+        migrations.DeleteModel(
+            name="Economy",
+        ),
+        migrations.DeleteModel(
+            name="Friendship",
+        ),
+        migrations.DeleteModel(
+            name="Guildconfig",
+        ),
+        migrations.DeleteModel(
+            name="Player",
+        ),
+        migrations.DeleteModel(
+            name="Regime",
+        ),
+        migrations.DeleteModel(
+            name="Special",
+        ),
+        migrations.DeleteModel(
+            name="Trade",
+        ),
+        migrations.DeleteModel(
+            name="Tradeobject",
+        ),
+    ]