class ReservedItem{
    uid,
    orderID;
    prodID;
    qtty
    expiryTime
};

class Product{
    uint id;
    string name;
}

class Inventory{
    unordered_map<uint,uint> ItemQtty;
    unordered_map<uint, unordered_map<uint,ReservedItem>> reservedItems; //orderID vs prodID vs qtty
    bool checkAvailability(uint productID, size_t qtty){
        return ItemQtty[productID] >= qtty;
    }
    bool reserve(orderID, prodID, qtty){
            {
            lock(mtx);
            if(checkAvailability(prodID, qtty) == false) return false;
            reservedItems[orderID][prodID]+= qtty;
            ItemQtty[prodID]-= qtty;
            }
    }
    void handleExpiredreservedItems(){
        for(all reservedItem  : reservedItems)
            if(reservedItem.expired())
                deleteItem;
                ItemQtty[reserveditem.prodID]+= reserveditem.qtty;
    }
    void confirm(orderID){
        reservedItems.erase(orderID);
    }
    void release(orderID){
        for(all prodID : reservedItems[orderID]
            ItemQtty[prodID]+= qtty;
        reservedItems.erase(orderID);        
    }
};

class Order{
    uint id;
    uint usrID;
    vector<uint> productID;
}

class Orders{
    hasmap<uint, Order> orders;
}

class Blinkit{
    Inventory inv;
    bool checkAvailability(productID, qtty){
        return inv.checkAvailiabilty(productID, qtty);    
    }
};