OOP.1.1 MobilePhoneConstructors

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class MyGSM
{
    static void Main()
    {
        // some test what happens
        GSM mygsm = new GSM("k850", "sony ericsson");
        Console.Write("Phone manufacturer: {0}\nPhone model: {1}\nPhopne price: {2}\nPhone owner: {3}",mygsm.Manufacturer, mygsm.Model,mygsm.Price, mygsm.Owner);

        Console.WriteLine();
        //some other test
        //add gsm properties directly
        mygsm.Owner = "me";
        mygsm.Price = 0; //no negative value check implemented int this property!
        mygsm.Display.Size = 1000;
        mygsm.Display.Colors = 2;
        mygsm.Battery.HoursIdle = 1;
        mygsm.Battery.HoursTalk = 1;
        mygsm.Battery.Model = "who cares";

        //....
        //add new batery and than add it to the gsm
        Battery mybaterry = new Battery();
        mybaterry.Model = "blabla";
        mybaterry.HoursIdle = 1;
        mybaterry.HoursTalk = 0;

        mygsm.Battery = mybaterry;

        //and no more tests...I`m lazy
    }
}

public class GSM
{
    Display gsmDisplay = new Display();
    Battery gsmBattery = new Battery();

    private string model;
    private string manufacturer;
    private int? price = null;
    private string owner = null;
    private Display display = new Display();
    private Battery battery = new Battery();

    public Display Display
    {
        get { return this.display; }
        set { this.display = value; }
    }
    public Battery Battery
    {
        get { return this.battery; }
        set { this.battery = value; }
    }

    public string Model
    {
        get { return this.model; }
        set { this.model = value; }
    }
    public string Manufacturer
    {
        get { return this.manufacturer; }
        set { this.manufacturer = value; }
    }
    public int? Price
    {
        get { return this.price; }
        set { this.price = value; }
    }
    public string Owner
    {
        get { return this.owner; }
        set { this.owner = value; }
    }
    public GSM(string model, string manufacturer)
    {
        this.Model = model;
        this.Manufacturer = manufacturer;
    }
    public GSM(string model, string manufacturer, int price) : this(model, manufacturer)
    {
        this.Price = price;
    }
    public GSM(string model, string manufacturer, int price, Display gsmDisplay, Battery gsmBattery)
        : this(model, manufacturer, price)
    {
        this.gsmDisplay = gsmDisplay;
        this.gsmBattery = gsmBattery;
    }
    public GSM(string model, string manufacturer, int price, Display gsmDisplay, Battery gsmBattery, string owner)
        : this(model, manufacturer, price, gsmDisplay, gsmBattery)
    {
        this.Owner = owner;
    }
}

public class Display
{
    private int? size = null;
    private int? colors = null;

    public int? Size
    {
        get { return this.size; }
        set { this.size = value; }
    }
    public int? Colors
    {
        get { return this.colors; }
        set { this.colors = value; }
    }
    public Display()
    {
    }
    public Display(int size)
    {
        this.Size = size;
    }
    public Display(int size, int colors)
        : this(size)
    {
        this.Colors = colors;
    }
}

public class Battery
{
    private string model = null;
    private int? hoursIdle = null;
    private int? hoursTalk = null;

    public string Model
    {
        get { return this.model; }
        set { this.model = value; }
    }
    public int? HoursIdle
    {
        get { return this.hoursIdle; }
        set { this.hoursIdle = value; }
    }
    public int? HoursTalk
    {
        get { return this.hoursTalk; }
        set { this.hoursTalk = value; }
    }

    public Battery()
    {
    }
    public Battery(string model)
    {
        this.Model = model;
    }
    public Battery(string model, int hoursIdle) : this(model)
    {
        this.HoursIdle = hoursIdle;
    }
    public Battery(string model, int hoursIdle, int hoursTalk) : this(model, hoursIdle)
    {
        this.HoursTalk = hoursTalk;
    }
}