ParkingLot.txt

Requirement Gathering / Clarification:

How many Entrances?
    - 1 Entrance
    - 1 Exit
    - Different type of parking spots:
        - 2 Wheeler
        - 4 Wheeler
    - Payment: Hourly / Minute based charge => Mix
    - Floors? => No

Objects:

- Vehicle
    1 Vehicle No.
    2 Vehicle Type (Enum)
- Ticket
    1. Entry Time
    2. Parking Spot
- Entrance Gate
    1. Find Parking Space (Nearest Parking to the entrance)
    2. Update Parking space
    3. Generate Ticket
- Parking Spot
    1. id
    2. isEmpty
    3. Vehicle
    4. Price
    5. Type
- Exit Gate
    1. Cost Calculation
    2. Payment
    3. Update Parking Spot



2 Approaches possible -
    1 Top Down
    2 Bottom Up <-

Design Patterns Used: Strategy, Factory, Dependency Inversion

Vehicle
_________
vehicleNo: Int
vehicleType: VehicleType

______________________________________________________________________

<< General Class >>
Parking Spot (has-a vehicle)
__________________
id: Int
isEmpty: Boolean
vehicle: Vehicle
price: Int
___________________
parkVehicle(vehicle)
removeVehicle(vehicle)
____________________

(is-a parking spot)     (is-a parking spot)
TwoWheelerSpot          FourWheelerSpot
Price() { 10 }          Price() {20}


ParkingSpotManager (has-a parking spot)
_____________________________________
list: List<ParkingSpot>
_____________________________________
PSManager(list: List<ParkingSpot>) {
    this.list = list
}
findParkingSpace() => (has-a parking strategy)
addParkingSpace()
removeParkingSpace()
parkVehicle(vehicle)
removeVehicle(vehicle)

(is-a parking spot manager)         (is-a parking spot manager)
TwoWheelerManager                   FourWheelerManager
_________________________         __________________________
list: List<ParkingSpot>             list: List<ParkingSpot>
_________________________         __________________________
TwoWheelerManager() {               FourWheelerManager() {
    super(list)                         super(list)
}                                   }

Parking Strategy

NearToEntrance                                  NearToEntranceAndElevator       default
____________                                  _______________________       ____________
find()                                          find()
// Can use a min-heap for each Entrance
E1 - minHeap
E2 - minHeap
.
.
En - minHeap

ParkingSpotManagerFactory (has-a ParkingSpotManager)
____________________________________________
getParkingSpotManager(vehicle): ParkingSpotManager {
    vehicleType Basis
        return PSM Object
}
______________________________________________________________________

Ticket (has-a vehicle, parking spot)
_____________
entryTime: Long
vehicle: Vehicle
parkingSpot: ParkingSpot
// Getters & Setters
________________________________________________________________________

EntranceGate (has-a ParkingSpotManagerFactory, Ticket)
____________________________________________________
factory: ParkingSpotManagerFactory
parkingSpaceManager: ParkingSpaceManager
ticket: Ticket
findParkingSpace() {
    factory(vehicleType).findParkingSpace()
}
bookSpot(vehicle): ParkingSpot
generateTicket(vehicle, parkingSpot)

________________________________________________________________________

ExitGate
_________________________________
paymentMethod: String
parkingSpotManagerFactory: ParkingSpotManager
ticket: Ticket
costComputationFactory: CostComputationFactory
paymentFactory: PaymentFactory
_________________________________
priceCalculation() {
    amount = costComputationFactory.getCostComputation(ticket).price()
}
makePayment() {
    paymentFactory.getPaymentMethod(paymentMethod).makePayment(amount)
}
removeVehicle() {
    parkingSpotManagerFactory.getParkingSpotManager(ticket.vehicle).removeVehicle(ticket.vehicle)
}

CostComputationFactory
____________________
getCostComputation(ticket) {
    ticket.vehicle.vehicleType basis
        return CostComputation Obj // (Two/Four Wheeler)
}

CostComputation (has-a Pricing Strategy)
_____________________________
pricingStrategy: PricingStrategy
price(ticket) {
    pricingStrategy.price(ticket)
}

TwoWheelerCostComputation                       FourWheelerCostComputation
________________________                      _________________________
TwoWheelerCostComputation() {                   FourWheelerCostComputation() {
    super(Hourly())                                 super(Minute())
}                                               }

PricingStrategy

Default                                 Hourly                                      MinuteBasis
_____________                         ________                                  ____________
price(ticket) {                         price(ticket) {                             price(ticket) {
    return parkingSpot.price                hours = currTimeH - ticket.etH              minutes = currTimeM - ticket.etM
}                                           hours*parkingSpot.price                     minutes*parkingSpot.price
                                        }                                           }

PaymentFactory
____________________
getPayment(paymentMethod) {
    paymentMethod basis
        return Payment Obj // (Cash/Card/UPI)
}

Payment
_______________________________
paymentStrategy: PaymentStrategy
_______________________________
makePayment(amount) {
    paymentStrategy.makePayment(amount)
}

CardPayment                             CashPayment
_________________                     _______________
CardPayment() {                         CashPayment() {
    super(Card())                          super(Cash())
}                                       }

PaymentStrategy

Default                                 Cash                                        Card
_____________                         ________                                  ____________
makePayment(amount) {                   makePayment(amount) {                       makePayment(amount) {
    // save in cash table                   // save in cash table                       // save in card table
}                                       }