Initial work on cart management

app/services/cart_service.py

@@ -0,0 +1,30 @@
+from mysql.connector import Error
+from typing import Tuple, Union
+
+from app.extensions import db_cursor, db_connection
+
+class CartService:
+
+	@staticmethod
+	def add_to_cart(user_id: str, product_id: int, count: int) -> Tuple[Union[dict, str], int]:
+		try:
+			with db_connection.cursor() as cursor:
+				db_connection.begin()
+
+				db_cursor.execute("select * from cart_item where cart_id = %s and product_id = %s", (user_id, product_id))
+
+				if db_cursor.rowcount != 0:
+					db_cursor.execute("update cart_item set count = count + %s where cart_id = %s and product_id = %s", (count, user_id, product_id))
+				else:
+					db_cursor.execute("insert into cart_item(cart_id, product_id, count) values (%s, %s, %s)", (user_id, product_id, count))
+
+				db_connection.commit()
+
+				return {"Success": "Successfully added to cart"}, 200
+		
+		except Error as e:
+			return {"Failed": f"Failed to add item to cart. {e}"}
+	
+	@staticmethod
+	def show_cart(user_id: str):
+		return None