Requirements

Functional Requirements:

1. Assign spot by vehicle size (motorcycles, cars, trucks). Flexible with sizes
2. Issue ticket on entry - record vehicle info, assigned spot, and entry time
3. Compute fee on exit - calculate based on duration with a configurable pricing formula
4. Handle lot-full - reject entry and display if no suitable spot is available
5. Support multiple floors - each floor has a mix of spot sizes

Non-Functional Requirements:

1. Thread safety - multiple entry gates run simultaneously, so spot assignment must prevent double-booking (locks, synchronized, etc.)
2. Extensibility - new pricing strategies or vehicle types should be addable without changing existing code
3. Correctness - no invalid state through the public API

Core Objects & Relationships

Class: ParkingLot

Fields: floors[], entryGates[], exitGates[], pricingStrategy

Relationships: Has many ParkingFloors, depends on PricingStrategy (interface)

Interface: PricingStrategy

Methods: calculateFee(ticket, exitTime)

Relationships: Implemented by HourlyRateStrategy, WeekendRateStrategy

Class: ParkingFloor

Fields: spots, floorNumber

Relationships: Has many ParkingSpots

Class: ParkingSpot

Fields: spotId, spotType (SMALL/MEDIUM/LARGE), isAvailable

Relationships: Assigned to a Vehicle via Ticket

Class: Vehicle

Fields: vehicleType (MOTORCYCLE/CAR/TRUCK)

Relationships: Belongs to a ParkingSpot via Ticket

Class: Ticket

Fields: issuedAt, status (PAID/UNPAID), finalCost

Relationships: Belongs to ??

abstract class Gate { gateId: string; }

class EntryGate extends Gate { /* entry-specific */ }

class ExitGate extends Gate { /* exit-specific */ }

APIs & Class Members

For each class, define the attributes (data) it will hold and the methods (functions) that operate on the attributes. Ensure they align with the object's responsibilities and adhere to the principle of encapsulation. Write your code in the code editor below.

Deep Dive

Explain design tradeoffs you considered. Check and explain whether your design adheres to SOLID principles. Explain how your design can handle changes in scale and whether it would be easy to extend with new functionalities. Identify areas for future improvement...