feat: replace php migration with django migration

- keep latest legacy version in initial migration file
- move propel schema to api legacy app
- remove legacy upgrade tool

api/libretime_api/legacy/migrations/_migrations.py

@@ -0,0 +1,77 @@
+from typing import Callable, Optional
+
+from django.db import connection
+
+from ._version import parse_version
+
+
+def get_schema_version():
+    """
+    Get the schema version from a legacy database.
+
+    Don't use django models as they might break in the future. Our concern is to upgrade
+    the legacy database schema to the point where django is in charge of the migrations.
+    """
+
+    if "cc_pref" not in connection.introspection.table_names():
+        return None
+
+    with connection.cursor() as cursor:
+        cursor.execute("SELECT valstr FROM cc_pref WHERE keystr = 'schema_version'")
+        row = cursor.fetchone()
+        return row[0] if row else None
+
+
+def set_schema_version(cursor, version: str):
+    cursor.execute(
+        """
+        UPDATE cc_pref
+        SET valstr = %s
+        WHERE keystr = 'schema_version';
+        """,
+        [version],
+    )
+    if not cursor.rowcount:
+        cursor.execute(
+            """
+            INSERT INTO cc_pref (keystr, valstr)
+            VALUES ('schema_version', %s);
+            """,
+            [version],
+        )
+
+
+def legacy_migration_factory(
+    target: str,
+    before: Optional[Callable] = None,
+    sql: Optional[str] = None,
+    after: Optional[Callable] = None,
+    reverse: bool = False,
+):
+    target_version = parse_version(target)
+
+    def inner(_apps, _schema_editor):
+        current = get_schema_version()
+        if current is None:
+            raise Exception("current schema version was not found!")
+
+        current_version = parse_version(current)
+        if current_version >= target_version and not reverse:
+            return
+
+        if current_version < target_version and reverse:
+            return
+
+        with connection.cursor() as cursor:
+            if before is not None:
+                before(cursor)
+
+            if sql is not None:
+                cursor.execute(sql)
+
+            if after is not None:
+                after(cursor)
+
+            set_schema_version(cursor, version=target)
+
+    return inner