dev: background migration for user custom themes (#1590)

apiserver/plane/db/migrations/0038_auto_20230720_1505.py

@@ -0,0 +1,35 @@
+# Generated by Django 4.2.3 on 2023-07-20 09:35
+
+from django.db import migrations, models
+
+
+def restructure_theming(apps, schema_editor):
+    Model = apps.get_model("db", "User")
+    updated_user = []
+    for obj in Model.objects.exclude(theme={}).all():
+        current_theme = obj.theme
+        updated_theme = {
+            "primary": current_theme.get("accent", ""),
+            "background": current_theme.get("bgBase", ""),
+            "sidebarBackground": current_theme.get("sidebar", ""),
+            "text": current_theme.get("textBase", ""),
+            "sidebarText": current_theme.get("textBase", ""),
+            "palette": f"""{current_theme.get("bgBase","")},{current_theme.get("textBase", "")},{current_theme.get("accent", "")},{current_theme.get("sidebar","")},{current_theme.get("textBase", "")}""",
+            "darkPalette": current_theme.get("darkPalette", "")
+        }
+        obj.theme = updated_theme
+        updated_user.append(obj)
+
+    Model.objects.bulk_update(
+        updated_user, ["theme"], batch_size=100
+    )
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("db", "0037_issue_archived_at_project_archive_in_and_more"),
+    ]
+
+    operations = [
+        migrations.RunPython(restructure_theming)
+    ]