EXP3

using System;

namespace MultimediaDevice
{
    public interface IPowerControl
    {
        void TurnOn();
        void TurnOff();
    }

    public interface IVolumeControl
    {
        void IncreaseVolume();
        void DecreaseVolume();
    }

    public interface IChannelControl
    {
        void NextChannel();
        void PreviousChannel();
    }

    public class Television : IPowerControl, IVolumeControl, IChannelControl
    {
        private bool _isOn = false;
        private int _volume = 0;
        private int _currentChannel = 1;

        public void TurnOn()
        {
            _isOn = true;
            Console.WriteLine("The Television is ON");
        }

        public void TurnOff()
        {
            _isOn = false;
            Console.WriteLine("The Television is OFF");
        }

        public void IncreaseVolume()
        {
            if (_isOn)
            {
                _volume++;
                Console.WriteLine("Volume increased to {0}", _volume);
            }
            else
            {
                Console.WriteLine("Please turn on the television first.");
            }
        }

        public void DecreaseVolume()
        {
            if (_isOn)
            {
                if (_volume > 0)
                {
                    _volume--;
                    Console.WriteLine("Volume increased to {0}", _volume);
                }
                else
                {
                    Console.WriteLine("Volume is already at minimum.");
                }
            }
            else
            {
                Console.WriteLine("Please turn on the television first.");
            }
        }

        public void NextChannel()
        {
            if (_isOn)
            {
                _currentChannel++;
                Console.WriteLine("Switched to channel {0}", _currentChannel);
            }
            else
            {
                Console.WriteLine("Please turn on the television first.");
            }
        }

        public void PreviousChannel()
        {
            if (_isOn)
            {
                if (_currentChannel > 1)
                {
                    _currentChannel--;
                    Console.WriteLine("Switched to channel {0}", _currentChannel);
                }
                else
                {
                    Console.WriteLine("You are already on the first channel.");
                }
            }
            else
            {
                Console.WriteLine("Please turn on the television first.");
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Television tv = new Television();

            Console.WriteLine("TV is OFF \n");

            int choice;
            do
            {
                Console.WriteLine("\nChoose the function to use: ");
                Console.WriteLine("1. Power Control");
                Console.WriteLine("2. Volume Control");
                Console.WriteLine("3. Channel Control");
                Console.WriteLine("4. Exit\n");

                choice = int.Parse(Console.ReadLine());

                switch (choice)
                {
                    case 1:
                        Console.WriteLine("1. Turn On\n2. Turn Off\n");
                        int powerChoice = int.Parse(Console.ReadLine());
                        if (powerChoice == 1)
                        {
                            tv.TurnOn();
                        }
                        else if (powerChoice == 2)
                        {
                            tv.TurnOff();
                        }
                        break;

                    case 2:
                        Console.WriteLine("1. Increase Volume\n2. Decrease Volume\n");
                        int volumeChoice = int.Parse(Console.ReadLine());
                        if (volumeChoice == 1)
                        {
                            tv.IncreaseVolume();
                        }
                        else if (volumeChoice == 2)
                        {
                            tv.DecreaseVolume();
                        }
                        break;

                    case 3:
                        Console.WriteLine("1. Next Channel\n2. Previous Channel\n");
                        int channelChoice = int.Parse(Console.ReadLine());
                        if (channelChoice == 1)
                        {
                            tv.NextChannel();
                        }
                        else if (channelChoice == 2)
                        {
                            tv.PreviousChannel();
                        }
                        break;

                    case 4:
                        Console.WriteLine("Exiting...");
                        break;

                    default:
                        Console.WriteLine("Invalid choice! Please choose again.");
                        break;
                }

            } while (choice != 4);
        }
    }
}