namespace DesignPattern
{
    public class CashContext
    {
        public CashSuper cs = null;
        private string Type;
        public CashContext(string Type, object[] parameters)  
        {  
            //应用反射将原来的switch语句去掉  
            this.Type = Type;
            cs = (CashSuper)Assembly.Load("DesignPattern").CreateInstance("DesignPattern." + this.Type,
                true,System.Reflection.BindingFlags.Default,null,parameters,null,null);  
        }
        public CashContext(CashSuper cs)
        {
            this.cs = cs;
        }
        public double GetResult(double money)
        {
            return cs.acceptCash(money);
        }
    }
}

namespace DesignPattern
{
    /* 策略模式
    应用场景：
    1、 多个类只区别在表现行为不同，可以使用Strategy模式，在运行时动态选择具体要执行的行为。
    2、 需要在不同情况下使用不同的策略(算法)，或者策略还可能在未来用其它方式来实现。
    3、 对客户隐藏具体策略(算法)的实现细节，彼此完全独立。
     */
    class Strategy
    {
    }
    /// <summary>  
    /// 现金收取父类,算法的抽象类  
    /// </summary>  
    public abstract class CashSuper
    {
        /// <summary>  
        /// 抽象方法：收取现金  
        /// </summary>  
        /// <param name="money">原价</param>  
        /// <returns>当前价</returns>  
        public abstract double acceptCash(double money);
    }
    /// <summary>  
    /// 正常收费  
    /// </summary>  
    public class CashNormal : CashSuper
    {
        public override double acceptCash(double money)
        {
            return money;
        }
    }  
    /// <summary>  
    /// 打折收费  
    /// </summary>  
    public class CashRebate : CashSuper
    {
        private double moneyRebate = 1d;

        public CashRebate(string money)
        {
            this.moneyRebate = double.Parse(money);
        }

        //初始化时必需输入折扣率，如八折就是0.8  
        public override double acceptCash(double money)
        {
            return money * moneyRebate;
        }
    }
    /// <summary>  
    /// 返利收费  
    /// </summary>  
    public class CashReturn : CashSuper
    {
        private double moneyCondition = 0.0d;
        private double moneyReturn = 0.0d;

        /// <summary>  
        /// 初始化时必须要输入返利条件和返利值，比如满300返100，则moneyCondition为300，moneyReturn为100  
        /// </summary>  
        /// <param name="moneyCondition"></param>  
        /// <param name="moneyReturn"></param>  
        public CashReturn(string moneyCondition, string moneyReturn)
        {
            this.moneyCondition = double.Parse(moneyCondition);
            this.moneyReturn = double.Parse(moneyReturn);
        }

        public override double acceptCash(double money)
        {
            double result = money;
            //若大于返利条件，则需要减去返利值  
            if (money >= moneyCondition)
            {
                result = money - Math.Floor(money / moneyCondition) * moneyReturn;
            }
            return result;
        }
    }  
}