using System;
using IwbZero.Expr;
using IwbZero.ToolCommon.StringModel;

namespace IwbZero.ExprFunctions.Functions
{
    /// <summary>
    /// 随机概率选择(给出一个（或两个）权重（0-100），产生一个随机数判断是否在 权重范围内)
    /// </summary>
    public class FunRandomSelection : IIwbFunction
    {
        public string Invoke(ExprObject exprObj)
        {
            string result = "TRUE";
            var child = exprObj.GetChild(0);
            var child2 = exprObj.GetChild(2);
            int num1 = child?.Expr.ValI()??0, num2= child2?.Expr.ValI()??0;
            if (num2 == 0)
            {
                num2 =  num1 > 100 ? 100 : num1 < 0 ? 0 : num1;
                num1 = 0;
            }
            else 
            {
                num1 = num1 > 100 ? 100 : num1 < 0 ? 0 : num1;
                num2 = num2 > 100 ? 100 : num2 < 0 ? 0 : num2;
            }

            if (num2 < num1)
            {
                var num3 = num2;
                num2 = num1;
                num1 = num3;
            }
            var random = new Random().Next(0, 100);
            if (random<num1 || random>num2)
            {
                result = "FALSE";
            }
            return result;
        }
    }
}