using System;

namespace DelegateExample
{
    public class Heater
    {
        private int temperature;
        public string type = "RealFire 001"; // 新增型號作為演示
        public string area = "China Xi'an"; // 新增產地作為演示
                                            //宣告委託
        public delegate void BoiledEventHandler(Object sender, BoiledEventArgs e);
        public event BoiledEventHandler Boiled; //宣告事件
                                                // 定義BoiledEventArgs類，傳遞給Observer所感興趣的資訊
                                                //繼承EventArgs
        public class BoiledEventArgs : EventArgs
        {
            public readonly int temperature;//
            public BoiledEventArgs(int temperature)
            {
                this.temperature = temperature;
            }
        }
        // 可以供繼承自 Heater 的類重寫，以便繼承類拒絕其他物件對它的監視
        protected virtual void OnBoiled(BoiledEventArgs e)
        {
            if (Boiled != null)
            { // 如果有物件註冊
                Boiled(this, e); // 呼叫所有註冊物件的方法
            }
        }
        public void BoilWater()
        {
            for (int i = 100; i <= 100; i++)
            {
                temperature = i;
                if (temperature > 95)
                {
                    //建立BoiledEventArgs 物件。
                    BoiledEventArgs e = new BoiledEventArgs(temperature);
                    OnBoiled(e); // 呼叫 OnBoiled方法
                }
            }
        }
    }
    public class Alarm
    {
        public void MakeAlert(Object sender, Heater.BoiledEventArgs e)
        {
            Heater heater = (Heater)sender; //這裡是不是很熟悉呢？
                                            //訪問 sender 中的公共欄位
            Console.WriteLine("Alarm：{0} - {1}: ", heater.area, heater.type);
            Console.WriteLine("Alarm: 嘀嘀嘀，水已經 {0} 度了：", e.temperature);
            Console.WriteLine();
        }
    }
    public class Display
    {
        public static void ShowMsg(Object sender, Heater.BoiledEventArgs e)
        { //靜態方法
            Heater heater = (Heater)sender;
            Console.WriteLine("Display：{0} - {1}: ", heater.area, heater.type);
            Console.WriteLine("Display：水快燒開了，當前溫度：{0}度。", e.temperature);
            Console.WriteLine();
        }
    }
    class Program
    {
        static void Main()
        {
            Heater heater = new Heater();
            Alarm alarm = new Alarm();
            heater.Boiled += alarm.MakeAlert; //註冊方法
            heater.Boiled += (new Alarm()).MakeAlert; //給匿名物件註冊方法
            heater.Boiled += new Heater.BoiledEventHandler(alarm.MakeAlert); //也可以這麼註冊
            heater.Boiled += Display.ShowMsg; //註冊靜態方法
            heater.BoilWater(); //燒水，會自動呼叫註冊過物件的方法
        }
    }
}