added leaderboard points collection

README.md

@@ -149,7 +149,7 @@ An example of how a user and its details is stored in the database:
     }
   }
 }
-```  
+```
 
 # Questions Database
 
@@ -179,3 +179,36 @@ An example of how a question and its details is stored in the database:
 
 As shown in the above example, one question can be answered by many users and each user is represented by his ID
 
+
+## leaderboard points collection:  
+
+```json  
+{
+  "topic": topic,
+  "hard": {
+    user_1_id: points,
+    user_2_id: points
+  },
+  "easy": {
+    user_1_id: points,
+    user_2_id: points
+  } 
+}
+```  
+### example:
+```json  
+{
+  "topic": "python",
+  "hard": {
+    "1": 0,
+    "2": 15
+  },
+  "easy": {
+    "3": 77
+  },
+  "medium": {
+    "3": 20
+  }
+}
+```
+

data_access_layer/leaderboard.py

@@ -0,0 +1,71 @@
+from data_access_layer.setup_mongodb import setup_mongodb
+from pymongo.errors import PyMongoError
+
+
+def add_user_points(user_id: str, points: int, topic: str, difficulty: str, client=None):
+    try:
+        collection = setup_mongodb(client, 'points')
+        db_topic = collection.find_one({'topic': topic})
+
+        if db_topic:
+            if difficulty not in db_topic:
+                db_topic[difficulty] = {user_id: points}
+            else:
+                if user_id in db_topic[difficulty]:
+                    db_topic[difficulty][user_id] += points
+                else:
+                    db_topic[difficulty][user_id] = points
+            collection.replace_one({'topic': topic}, db_topic)
+        else:
+            db_topic = {"topic": topic, difficulty: {user_id: points}}
+            collection.insert_one(db_topic)
+
+        if '_id' in db_topic:
+            del db_topic['_id']
+
+        return db_topic
+
+    except PyMongoError as e:
+        print(f"Database error: {str(e)}")
+        raise PyMongoError(f"Database error: {str(e)}")
+
+    except Exception as e:
+        print(f"Unexpected error: {str(e)}")
+        raise Exception(f"Unexpected error: {str(e)}")
+
+
+def check_user_points_existence(data, client=None):
+    collection = setup_mongodb(client, 'points')
+    db_topic = collection.find_one({'topic': data['topic']})
+
+    if not db_topic or data['difficulty'] not in db_topic or data['user_id'] not in db_topic[data['difficulty']]:
+        return False
+    previous_points = db_topic[data['difficulty']][data['user_id']] - data['points']
+    if previous_points < 0:
+        return False
+    return True
+
+
+def restore_db(data, client=None):
+    collection = setup_mongodb(client, 'points')
+    db_topic = collection.find_one({'topic': data['topic']})
+    previous_points = db_topic[data['difficulty']][data['user_id']] - data['points']
+    if previous_points == 0:
+        del db_topic[data['difficulty']][data['user_id']]
+
+        if not db_topic[data['difficulty']]:
+            del db_topic[data['difficulty']]
+        if len(db_topic) == 1:
+            collection.delete_one({'topic': data['topic']})
+            return True
+    else:
+        db_topic[data['difficulty']][data['user_id']] = previous_points
+
+    collection.replace_one({'topic': data['topic']}, db_topic)
+    return True
+
+
+def get_user_points(data, client=None):
+    collection = setup_mongodb(client, 'points')
+    db_topic = collection.find_one({'topic': data['topic']})
+    return db_topic[data['difficulty']][data['user_id']]

tests/test_leaderboard.py

@@ -0,0 +1,29 @@
+from data_access_layer.leaderboard import add_user_points, check_user_points_existence, get_user_points, restore_db
+import pytest
+
+
+def test_add_user_points_success():
+    data = {
+        'user_id': '123',
+        'topic': 'python',
+        'difficulty': 'hard',
+        'points': 8,
+    }
+    user_exist = check_user_points_existence(data)
+    previous_points = 0
+    if user_exist:
+        previous_points = get_user_points(data)
+    add_user_points(user_id=data['user_id'], topic=data['topic'], difficulty=data['difficulty'],
+                    points=data['points'])
+    assert check_user_points_existence(data)
+    assert get_user_points(data) == 8 + previous_points
+    data['points'] = 3
+    add_user_points(user_id=data['user_id'], topic=data['topic'], difficulty=data['difficulty'],
+                    points=data['points'])
+    assert check_user_points_existence(data)
+    assert get_user_points(data) == 11 + previous_points
+    data['points'] = 11
+    assert restore_db(data=data)
+    if previous_points != 0:
+        assert get_user_points(data) == previous_points
+    assert check_user_points_existence(data) == user_exist