Update

utils/db.py

@@ -1,22 +1,62 @@
 # utils/db.py (top of file)
+# utils/db.py (top of file)
 import os
 import json
 import certifi
-import mysql.connector
-from mysql.connector import Error
 from contextlib import contextmanager
-from datetime import date, timedelta    
+from datetime import date, timedelta
 
+# password hashing
+import bcrypt
 
+# --- Feature flag: DB off by default in frontend Space ---
 DISABLE_DB = os.getenv("DISABLE_DB", "1") == "1"
 
-try:
-    if DISABLE_DB:
-        raise ImportError("DB disabled in frontend Space")
-    import mysql.connector  # provided by mysql-connector-python
-except Exception:
-    # fall back; only error if a DB function is actually called
-    mysql = None
+# Import mysql connector only when DB is enabled
+MYSQL_AVAILABLE = False
+if not DISABLE_DB:
+    try:
+        import mysql.connector  # provided by mysql-connector-python
+        from mysql.connector import Error  # noqa: F401
+        MYSQL_AVAILABLE = True
+    except Exception:
+        MYSQL_AVAILABLE = False  # will raise a friendly error if used
+
+def _db_disabled_error():
+    raise RuntimeError(
+        "Database access is disabled in this frontend (DISABLE_DB=1). "
+        "Route calls through your backend Space instead."
+    )
+
+def get_db_connection():
+    if DISABLE_DB or not MYSQL_AVAILABLE:
+        _db_disabled_error()
+    ssl_enabled = os.getenv("TIDB_ENABLE_SSL", "false").lower() == "true"
+    ssl_ca = certifi.where() if ssl_enabled else None
+    return mysql.connector.connect(
+        host=os.getenv("TIDB_HOST"),
+        port=int(os.getenv("TIDB_PORT", 4000)),
+        user=os.getenv("TIDB_USER"),
+        password=os.getenv("TIDB_PASSWORD"),
+        database=os.getenv("TIDB_DATABASE", "agenticfinance"),
+        ssl_ca=ssl_ca,
+        ssl_verify_cert=ssl_enabled,
+        autocommit=True,
+    )
+
+@contextmanager
+def cursor(dict_rows=True):
+    if DISABLE_DB or not MYSQL_AVAILABLE:
+        _db_disabled_error()
+    conn = get_db_connection()
+    try:
+        cur = conn.cursor(dictionary=dict_rows)
+        yield cur
+        conn.commit()
+    finally:
+        cur.close()
+        conn.close()
+
 
 
 # password hashing
@@ -172,10 +212,7 @@ def create_class(teacher_id:int, name:str):
                 return {"class_id": cid, "code": code}
     raise RuntimeError("Could not generate unique class code")
 
-def list_classes_by_teacher(teacher_id:int):
-    with cursor() as cur:
-        cur.execute("SELECT * FROM v_class_stats WHERE teacher_id=%s", (teacher_id,))
-        return cur.fetchall()
+
 
 def join_class_by_code(student_id:int, code:str):
     with cursor() as cur: