using Microsoft.CSharp;
using System;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace SmartCoalApplication.Base.CommTool
{
    /// <summary>
    /// 公式相关工具类
    /// </summary>
    public class FormulaHelper
    {
        /// <summary>
        /// 计算公式
        /// </summary>
        /// <param name="formula">公式</param>
        /// <returns></returns>
        public static string outPutResult(string formula)
        {
            try
            {
                MSScriptControl.ScriptControl sc = new MSScriptControl.ScriptControlClass();
                sc.Language = "JavaScript";
                var str = sc.Eval(formula).ToString();
                return str;
            }
            catch (Exception ex)
            {
                return "0";
            }
        }

        ///   <summary>  
        ///  接受一个string类型的表达式并计算结果,返回一个object对象,静态方法 
        ///   </summary>  
        ///   <param name="expression"></param>  
        ///   <returns></returns>  
        public static object Calculate(string expression)
        {
            try
            {
                string className = "Calc";
                string methodName = "Run";
                expression = expression.Replace(" / ", " *1.0/ ");

                // 设置编译参数
                CompilerParameters paras = new CompilerParameters();
                paras.GenerateExecutable = false;
                paras.GenerateInMemory = true;

                // 创建动态代码
                StringBuilder classSource = new StringBuilder();
                classSource.Append(" public class  " + className + " \n ");
                classSource.Append(" {\n ");
                classSource.Append("  public object  " + methodName + " ()\n ");
                classSource.Append("  {\n ");
                classSource.Append("  return  " + expression + " ;\n ");
                classSource.Append("  }\n ");
                classSource.Append(" } ");

                // 编译代码
                CompilerResults result = new CSharpCodeProvider().CompileAssemblyFromSource(paras, classSource.ToString());

                // 获取编译后的程序集。 
                Assembly assembly = result.CompiledAssembly;

                // 动态调用方法。 
                object eval = assembly.CreateInstance(className);
                MethodInfo method = eval.GetType().GetMethod(methodName);
                object reobj = method.Invoke(eval, null);
                GC.Collect();
                return reobj;
            }
            catch (Exception)
            {
                return "0";
            }
        }

        /// <summary>
        /// 计算 字符串表达式
        /// </summary>
        /// <param name="Formule">字符串计算表达式</param>
        /// <returns></returns>
        public static string CaleByFormule(string Formule)
        {
            try
            {
                Microsoft.JScript.Vsa.VsaEngine ve = Microsoft.JScript.Vsa.VsaEngine.CreateEngine();
                return Microsoft.JScript.Eval.JScriptEvaluate(Formule, ve).ToString();
            }
            catch (Exception)
            {
                return "0";
            }
        }
    }
}