using System;

using System.Collections.Generic;

//Create a new interface, named IAlertDAO, that contains the same methods as AlertDAO.

//AlertDAO should implement the IAlertDAO interface.

//AlertService should have a public constructor that accepts IAlertDAO.

//The RaiseAlert and GetAlertTime methods should use the object passed through the constructor.

//Validate whether object passed through constructor is type of AlertDAO and if not then throw an generic exception with message "Wrong object type"

​

public class AlertService   

{

    private readonly IAlertDAO _alertDaoService;

    public AlertService(IAlertDAO alertDaoService){

        if(!(alertDaoService is AlertDAO))

        {

            throw new Exception("Wrong object type");

        }

        _alertDaoService = alertDaoService;

    }

    public Guid RaiseAlert()

    {

        return _alertDaoService.AddAlert(DateTime.Now);

    }

    public DateTime GetAlertTime(Guid id)

    {

        return _alertDaoService.GetAlert(id);

    }   

}

public class AlertDAO : IAlertDAO

{

    private readonly Dictionary<Guid, DateTime> alerts = new Dictionary<Guid, DateTime>();

    public Guid AddAlert(DateTime time)

    {

        Guid id = Guid.NewGuid();

        this.alerts.Add(id, time);

        return id;

    }

    public DateTime GetAlert(Guid id)

    {

        return this.alerts[id];

    }   

}

​

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public interface IAlertDAO{

    Guid AddAlert(DateTime time);

    DateTime GetAlert(Guid id);

}

​

​

​