using System;

using System.Collections.Concurrent;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading;

using System.Threading.Tasks;

​

namespace ParkingLot

{

    /// <summary>

    /// Represents a parking lot terminal at a parking lot. The parking lot may contain 1 or more

    /// terminals operating simultaneously

    /// </summary>

    public abstract class ParkingLotBase

    {

        private static readonly ReaderWriterLockSlim slimLock = new ReaderWriterLockSlim();

        private static Dictionary<int, ParkingSpot> parkingSpots = new Dictionary<int, ParkingSpot>();

​

        // TODO: Implement support methods and constructor.

        public ParkingLotBase()

        {

            Init(new Config());

        }

​

        public ParkingLotBase(Config assignmentMap)

        {

            if (assignmentMap == null)

                throw new ArgumentNullException();

​

            Init(assignmentMap);

        }

​

        private void Init(Config parkingLotConfiguration)

        {

            try

            {

                var spots = parkingLotConfiguration.GetParkingAssignment();

​

                slimLock.EnterWriteLock();

                foreach (var spot in spots)

                {

                    if (!parkingSpots.Keys.Contains(spot.ParkingSpotNumber))

                        parkingSpots.Add(spot.ParkingSpotNumber, spot);

                }

            }

            // Of course don't use this in production

            catch (Exception ex)

            {

​

            }

            finally

            {

                slimLock.ExitWriteLock();

            }

        }

​

        /// <summary>

        /// Locates a free parking spot for the given vehicle type. A parking spot may fit one

        /// or more types of vehicles defined by a known mapping.

        /// TODO: Define error criteria.

        /// </summary>

        public ParkingSpot FindParkingSpot(VehicleBase vehicle)

        {

            if (vehicle == null)

                throw new ArgumentNullException();

​

            slimLock.EnterReadLock();

            try

            {

                return parkingSpots.Values.Where(spot => spot.Size >= vehicle.Size && spot.isAvailable == true).FirstOrDefault();

            }

            finally

            {

                slimLock.ExitReadLock();

            }

        }

​

        /// <summary>

        /// Find parking spot by parking spot number

        /// </summary>

        public ParkingSpot FindParkingSpot(int parkingSpotNumber)

        {

            if (parkingSpotNumber == 0)

                throw new ArgumentException();

​

            slimLock.EnterReadLock();

            try

            {

                return parkingSpots.Values.Where(spot => spot.ParkingSpotNumber == parkingSpotNumber).FirstOrDefault();

            }

            finally

            {

                slimLock.ExitReadLock();

            }

        }

​

        /// <summary>

        /// Simulate vehicle parking

        /// </summary>

        public ParkingSpot ParkVehicle(VehicleBase vehicle)

        {

            if (vehicle == null)

                throw new ArgumentNullException();

​

            slimLock.EnterWriteLock();

            try

            {

                var parkingSpot = parkingSpots.Values.Where(spot => spot.Size >= vehicle.Size && spot.isAvailable == true).FirstOrDefault();

                if (parkingSpot != null)

                {

                    parkingSpot.isAvailable = false;

                    parkingSpot.ParkedVehicle = vehicle;

                    parkingSpots[parkingSpot.ParkingSpotNumber] = parkingSpot;

                }

                return parkingSpot;

            }

            finally

            {

                slimLock.ExitWriteLock();

            }

        }

​

        public int CountAllParkingSpots()

        {

            return parkingSpots.Count;

        }

        public int CountAvailableParkingSpots()

        {

            slimLock.EnterReadLock();

            try

            {

                return parkingSpots.Values.Where(spot => spot.isAvailable == true).Count();

            }

            finally

            {

                slimLock.ExitReadLock();

            }

        }

    }

​

}

​