Add match termination endpoint, fix issue when joining a match you had created

main.py

@@ -12,6 +12,7 @@ app.add_middleware(
     allow_methods=["*"],
     allow_headers=["*"],
 )
+
 class RegisterRequest(BaseModel):
     email: str
     display_name: str
@@ -175,8 +176,13 @@ def join_match(request: JoinMatchRequest):
         match = cursor.fetchone()
         if not match:
             raise HTTPException(status_code=404, detail="Match not found")
+
+        if match["player1_uid"] == player2_uid:
+            raise HTTPException(status_code=503, detail="You cannot join a match you created")
+
         if match["player2_uid"] is not None:
             raise HTTPException(status_code=400, detail="Match is already full")
+
         cursor.execute(
             """
             UPDATE matches
@@ -194,6 +200,81 @@ def join_match(request: JoinMatchRequest):
         cursor.close()
         conn.close()
 
+def calculate_elo(player1_elo, player2_elo, player1_score, player2_score):
+    k_factor = 32
+    expected1 = 1 / (1 + 10 ** ((player2_elo - player1_elo) / 400))
+    expected2 = 1 / (1 + 10 ** ((player1_elo - player2_elo) / 400))
+    actual1 = 1 if player1_score > player2_score else 0 if player1_score < player2_score else 0.5
+    actual2 = 1 - actual1
+    elo_change1 = round(k_factor * (actual1 - expected1))
+    elo_change2 = round(k_factor * (actual2 - expected2))
+    return elo_change1, elo_change2
+
+@app.post("/endmatch")
+def end_match(request: EndMatchRequest):
+    conn = get_db_connection()
+    cursor = conn.cursor()
+    try:
+        cursor.execute(
+            """
+            SELECT player1_uid, player2_uid
+            FROM matches
+            WHERE match_id = %s;
+            """,
+            (request.match_id,)
+        )
+        match = cursor.fetchone()
+        if not match:
+            raise HTTPException(status_code=404, detail="Match not found")
+        
+        player1_uid, player2_uid = match["player1_uid"], match["player2_uid"]
+
+        cursor.execute(
+            """
+            SELECT uid, current_elo
+            FROM users
+            WHERE uid IN (%s, %s);
+            """,
+            (player1_uid, player2_uid)
+        )
+        players = cursor.fetchall()
+        player1_elo = next(p["current_elo"] for p in players if p["uid"] == player1_uid)
+        player2_elo = next(p["current_elo"] for p in players if p["uid"] == player2_uid)
+
+        elo_change1, elo_change2 = calculate_elo(
+            player1_elo, player2_elo, request.player1_score, request.player2_score
+        )
+
+        cursor.execute(
+            """
+            UPDATE matches
+            SET player1_score = %s, player2_score = %s,
+                player1_elo_change = %s, player2_elo_change = %s
+            WHERE match_id = %s;
+            """,
+            (request.player1_score, request.player2_score, elo_change1, elo_change2, request.match_id)
+        )
+        new_player1_elo = player1_elo + elo_change1
+        new_player2_elo = player2_elo + elo_change2
+        cursor.execute(
+            """
+            UPDATE users
+            SET current_elo = CASE WHEN uid = %s THEN %s WHEN uid = %s THEN %s END
+            WHERE uid IN (%s, %s);
+            """,
+            (player1_uid, new_player1_elo, player2_uid, new_player2_elo, player1_uid, player2_uid)
+        )
+        
+        conn.commit()
+        return {"message": "Match ended successfully"}
+    except Exception as e:
+        conn.rollback()
+        raise HTTPException(status_code=400, detail=str(e))
+    finally:
+        cursor.close()
+        conn.close()
+
+
 @app.post("/getprofile")
 def get_profile(request: ProfileRequest):
     conn = get_db_connection()