A Deep Dive into Parking Spot LLD Design

#lld #systemdesign #java #oop

Greetings, dear reader! 🌟

In this blog, we're crafting functional and super-efficient parking spots. And guess what? We're diving into design patterns to make them even smarter and more effective. So reading.start()🚗💡

Responsibility

🚗 Vehicle Entry and Exit: Finding the appropriate parking spot for the vehicle and creating the ticket.

🅿️ Parking Spot Allocation: Efficiently allocate available parking spots to incoming vehicles based on factors like size, type, and user preferences.

💰 Cost Computation and Payment: Calculate parking costs based on duration and vehicle type, offering flexible payment options for users.

🏆 Parking Strategy Options: Different parking strategies (e.g., park near entrance, park near elevator) should be available to users and prioritize spot allocation based on user preferences and vehicle type.

Our Parking Model Lineup 🌟

ParkingSpot 🅿️
Vehicle 🚗
ParkingSpotManager (EntranceManager and ExitManager) 🅿️
Ticket 🎫
ParkingSpotType and VehicleType (enum) 🚗
ParkingStrategy 🚦
CostConfiguration 💸
CostComputationStrategy💰

ParkingSpot Interface 🚗🏍️

🚙 The ParkingSpotManager holds a collection of ParkingSpot catering to various Vehicle types (2-wheelers and 4-wheelers).

🛠️ To achieve this, we'll create an interface that Concrete Classes (like twoWheelerParkingSpot and FourWheelerParkingSpot) can implement.

🏁 Additionally, it employs a ParkingSpotType enumeration to categorize the types of parking spots available.

🚀 The benefit of employing this interface is that if we decide to introduce a new type of parking spot later on, we can simply create a class that adheres to the interface.

🅿️ParkingManager: Central hub for parking spot management, handling addition/removal, spot allocation, ticket creation, and price computation.

🚗EntranceManager: This manager is responsilbe for efficiently allocating parking spots to incoming vehicles based on vehicle types and parking strategies and Generating the ticket.

🚦 ExitManager: Calculate parking fees using a Cost computation strategy considering duration and spot type.

Finding the Right Spot for you Vehicle 🚗

🚀Imagine the EntranceManager as a matchmaker for vehicles.

🎯 It take two parameter: a vehicle to know vehicle type, and a ParkingStrategy to understand the user preference.

💡Using this, it finds the right parking spot and makes a ticket for that vehicle and strategy.

🚫After the successfull allocation of the spot, the spot in marked as the occupied and hence not available for the other Vehicle.

🎉 Unraveling the Magic:
You might notice our usage of

Optional<Ticket>

In essence, an Optional acts as a container that may or may not hold a ticket. Optional are used to avoid null check if object not found

🎩 Exit Manager: Calculate your Parking Fare!

🚗 When your trusty vehicle bids adieu and rolls out from the parking haven, the Exit Manager springs into action.

💰By summoning the mighty Cost Computation Strategy (including the HourlyCostComputation and DailyCostComputation) and your ride Duration ,it crafts a fair and fancy price tag🤑.