temporarily add, will change code to have better error handling

app_utils.py

@@ -4,20 +4,31 @@ import datetime
 from pathlib import Path
 from dotenv import load_dotenv
 from tinydb import TinyDB, Query
-from tinydb.storages import JSONStorage
-from tinydb.middlewares import CachingMiddleware
+from tinydb_serialization import SerializationMiddleware
+from tinydb_sqlite import SQLiteStorage
 import tempfile
 
 load_dotenv()
-SESSION_ID = os.getenv('SESSION_ID')
+SESSION_ID = os.getenv('SESSION_ID', 'default_session')
 print(f"Session ID: {SESSION_ID}")
-DB_PATH = 'submissions.json'
 ADMIN_PASSWD = os.getenv('ADMIN_PASSWD', 'default_password')
 SUBMISSIONS_DIR = 'submissions'
 
-# TinyDB connection setup
-db = TinyDB(DB_PATH, storage=CachingMiddleware(JSONStorage))
-submissions_table = db.table('submissions')
+print("Using TinyDB with SQLiteStorage for data storage")
+
+def get_db():
+    """Initialize and return a TinyDB instance with SQLiteStorage."""
+    serialization = SerializationMiddleware()
+    storage = SQLiteStorage(
+        'submissions.db',
+        serialization=serialization,
+        connection_kwargs={'check_same_thread': False}
+    )
+    db = TinyDB(storage=storage)
+    submissions_table = db.table('submissions')
+    return db, submissions_table
+
+
 print("Using TinyDB for data storage")
 
 def load_problems():
@@ -31,7 +42,9 @@ def load_problems():
         print(f"Loaded problem: {json_file.stem}")
     return problems
 
+
 def save_submission(session, name, email, problem_id, code, hint_requested):
+    db, submissions_table = get_db()
     timestamp = datetime.datetime.now().isoformat()
     submission = {
         'session': session,
@@ -44,29 +57,40 @@ def save_submission(session, name, email, problem_id, code, hint_requested):
     }
     query = Query()
     submissions_table.upsert(submission, (query.session == session) & (query.name == name) & (query.email == email) & (query.problem_id == problem_id))
+    db.close()
+
 
 def save_all_submissions(name, email, codes_dict, hints_dict):
+    db, submissions_table = get_db()
     try:
         for problem_id, code in codes_dict.items():
             hint_requested = hints_dict.get(problem_id, False)
             save_submission(SESSION_ID, name, email, problem_id, code, hint_requested)
+        db.close()
         return "✅ All submissions saved successfully!"
     except Exception as e:
+        db.close()
         return f"❌ Error saving submissions: {str(e)}"
 
 def check_password(password):
     return password == ADMIN_PASSWD
 
 def get_all_students():
-    return list(set([submission['name'] for submission in submissions_table.all()]))
+    db, submissions_table = get_db()
+    result = list(set([submission['name'] for submission in submissions_table.all()]))
+    db.close()
+    return result
 
 def get_student_submissions(name):
+    db, submissions_table = get_db()
     query = Query()
     submissions = submissions_table.search(query.name == name)
     submissions.sort(key=lambda x: datetime.datetime.fromisoformat(x['timestamp']), reverse=True)
+    db.close()
     return submissions
 
 def export_submissions():
+    db, submissions_table = get_db()
     try:
         submissions = submissions_table.all()
         submissions.sort(key=lambda x: datetime.datetime.fromisoformat(x['timestamp']), reverse=True)
@@ -76,12 +100,16 @@ def export_submissions():
         temp_file = tempfile.NamedTemporaryFile(delete=False, mode='w', suffix='.json')
         temp_file.write(data)
         temp_file.close()
+        db.close()
         return temp_file.name
     except Exception as e:
         print(f"Error in export_submissions: {str(e)}")
+        db.close()
         return None
 
 def refresh_submissions():
-    submissions = submissions_table.all()
-    submissions.sort(key=lambda x: datetime.datetime.fromisoformat(x['timestamp']), reverse=True)
-    return submissions
+    db, submissions_table = get_db()
+    all_submissions = submissions_table.all()
+    all_submissions.sort(key=lambda x: datetime.datetime.fromisoformat(x['timestamp']), reverse=True)
+    db.close()
+    return all_submissions