wip: database object

core/database/__init__.py

@@ -1,3 +1,4 @@
+from .conn import Database
 from .init_checker import DatabaseInitCheckResult, check_db_init
 from .utils import create_engine, db_path_to_sqlite_url, sqlite_url_to_db_path
 
@@ -5,6 +6,7 @@ __all__ = [
     "check_db_init",
     "create_engine",
     "db_path_to_sqlite_url",
+    "Database",
     "DatabaseInitCheckResult",
     "sqlite_url_to_db_path",
 ]

core/database/conn.py

@@ -0,0 +1,29 @@
+from pathlib import Path
+
+from sqlalchemy import text
+from sqlalchemy.orm import sessionmaker
+
+from core.settings import SettingsKeys, settings
+
+from .utils import create_engine, db_path_to_sqlite_url
+
+
+class Database:
+    def __init__(self):
+        if settings.stringValue(SettingsKeys.General.DatabaseType) != "file":
+            raise ValueError("DatabaseType is not file")
+
+        db_path = settings.stringValue(SettingsKeys.General.DatabaseConn)
+        if not db_path:
+            raise ValueError("DatabaseConn is empty")
+
+        self.engine = create_engine(db_path_to_sqlite_url(Path(db_path)))
+        self.sessionmaker = sessionmaker(bind=self.engine)
+
+    @property
+    def b30(self) -> float | None:
+        with self.sessionmaker() as session:
+            result = session.execute(
+                text("SELECT b30 FROM calculated_potential")
+            ).fetchone()
+            return result[0] if result else None