Parking Lot

Functional requirements

1. Support multiple floors with each floor having mulitple parking spots of different sizes
2. Support three vehicle types with fixed size: SMALL, MEDIUM , LARGE
3. Each parking spot has a size , and can accommodate vehicle of equal or small size
4. On entry, find a parking spot for the vehicle based on nearest-to-entry-point assignment , assign to the vehicle and create a ticket
5. If there is no parking spot left return some message
6. On exit, validate the ticket , calculate the parking duration and fee and release the spot and return fee amount

Non-Functional Requriements

1. Handle concurrent request from multiple gate safely without assigning the same spot
2. Extensible logic for payment calculation and spot assignment
3. System should support addition of more spots and floors

Entities and classes

1.Parking floor - which will store the floor and list of parking spots. Initialize with empty parking spot

• int floor

• list <ParkingSpot>

+addSpot()

2. ParkingSpot -

-int spotid - unique number generate

-isOccupied - initialize false

-VehicleSize size

+canFitVehicle()

+parkVehicle()
+unparkVehicle()
+isAvailable()

3.Vehicle -

-string licenseNumber

-VehicleSize size

4. VehicleSize - (enum) SMALL , MEDIUM , LARGE

5.ParkingTicket

-ticketId

-vehicleID

-parkingspot

-entryTime

-existTime

+updateExistTime()

6.Find the spot for assigning the vehicle
ParkingSpotAssignmentStrategy - interface

nearestToEntryPointStrategy - implement ParkingSpotAssignmentStrategy
+ findSpot(size)

7.FeeStrategy - interface
FlatRateFeeStrategy - implement FeeStrategy

-double RatePerHour;
+ calaculateRate();

8.ParkingLotSystem - (orchestrator class)
-parkingStrategy

-feeStrategy

-activeTickets

+addFloors()

+addSpot(floor)
+vehicleEntry() - assign spot , assign ticket

+vehicleExist() - feeamount, release parking spot

5.ParkingTicket

-ticketId

-vehicleID

-parkingspot

-entryTime

-existTime

+updateExistTime()

vehicleExist(vehicle v) {
Fetch the ticket -
If not valid ticket return some message like " in valid ticket found"
Update the end time to now - updateExistTime()
Release the spot - unparkVehicle() - parkingspot
Calculate the free using the feestategy - like for this we have add FlatRateFeeStrategy - in this it calculate the hour from entry time and current time
}
synchronized tryPark(vehicle v) {
if(canFit(v) ) -> parkvehicle(V)
}
Boolean canFit(vehicle v) {
 Return v.size() <= spot.size()
}
parkVehicle(vehicle v){
parkedVehicle = v;
Occupied = true;
}