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

namespace HMI.Core.Util
{
    /// <summary>
    /// DLL文件操作类
    /// </summary>
    public class DllHelper
    {
        /// <summary>
        /// 获取当前DLL所处的路径
        /// </summary>
        /// <returns>Dll路径</returns>
        public static string GetAssemblyPath()
        {
            string CodeBase = System.Reflection.Assembly.GetExecutingAssembly().CodeBase;
            CodeBase = CodeBase.Substring(8, CodeBase.Length - 8);    // 8是 file:// 的长度
            string[] arrSection = CodeBase.Split(new char[] { '/' });
            string FolderPath = string.Empty;
            for (int i = 0; i < arrSection.Length - 1; i++)
            {
                FolderPath += arrSection[i] + "\\";
            }

            return FolderPath;
        }

        /// <summary>
        /// 导入DLL(要导入的DLL要放在程序的根目录中）
        /// </summary>
        /// <param name="DLLName">要导入的DLL名称</param>
        public static void ImportDLL(string DllPath)
        {
            try
            {
                //string DllPath = GetAssemblyPath() + DLLName;
                Assembly[] assemblyArray = AppDomain.CurrentDomain.GetAssemblies();
                foreach (Assembly dll in assemblyArray)
                {
                    if (dll.Location == DllPath)
                    {
                        return;
                    }
                }

                Assembly.LoadFrom(DllPath);
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 导入DLL
        /// </summary>
        /// <param name="DllPath">要导入的DLL文件路径</param>
        public static void ImportDLL2(string DllPath)
        {
            try
            {
                Assembly[] assemblyArray = AppDomain.CurrentDomain.GetAssemblies();
                foreach (Assembly dll in assemblyArray)
                {
                    if (!dll.FullName.Contains("Microsoft.GeneratedCode"))
                    {
                        if (dll.Location == DllPath)
                        {
                            return;
                        }
                    }
                }

                Assembly.LoadFile(DllPath);
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 生成无参数的构造函数的实例
        /// </summary>
        /// <param name="NameSpaceStr">命名空间</param>
        /// <param name="ClassStr">包含命名控件的类名</param>
        /// <returns>生成的对应类的实例</returns>
        public static object CreateInstance(string NameSpaceStr, string ClassStr)
        {
            try
            {
                Type DllType = Assembly.Load(NameSpaceStr).GetType(ClassStr); // 生成类型
                object Instance = Activator.CreateInstance(DllType); // 生成实例
                return Instance;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 动态编译和执行语句
        /// </summary>
        /// <param name="Expression">要编译执行的语句</param>
        /// <returns>执行的结果</returns>
        public static object GetValue(string Expression)
        {
            object Rtn = null;
            // 1.CSharpCodePrivoder
            CSharpCodeProvider objCSharpCodePrivoder = new CSharpCodeProvider();
            // 2.ICodeComplier
            ICodeCompiler objICodeCompiler = objCSharpCodePrivoder.CreateCompiler();
            // 3.CompilerParameters
            CompilerParameters objCompilerParameters = new CompilerParameters();
            objCompilerParameters.ReferencedAssemblies.Add("System.dll");
            objCompilerParameters.GenerateExecutable = false;
            objCompilerParameters.GenerateInMemory = true;
            // 4.CompilerResults
            CompilerResults cr = objICodeCompiler.CompileAssemblyFromSource(objCompilerParameters, GenerateCode(Expression));
            if (cr.Errors.HasErrors)
            {
                throw new Exception("编译错误:" + cr.Errors[0].ErrorText);
            }
            else
            {
                // 通过反射，调用HelloWorld的实例
                Assembly objAssembly = cr.CompiledAssembly;
                object Obj = objAssembly.CreateInstance("CommonLibs.Eval");
                MethodInfo objMI = Obj.GetType().GetMethod("GetValue");
                Rtn = objMI.Invoke(Obj, null);
            }
            return Rtn;
        }

        /// <summary>
        /// 生成编译语句
        /// </summary>
        /// <param name="Expression">需要编译的语句</param>
        /// <returns>编译执行后的结果</returns>
        private static string GenerateCode(string Expression)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("using System;");
            sb.Append(Environment.NewLine);
            sb.Append("namespace CommonLibs");
            sb.Append(Environment.NewLine);
            sb.Append("{");
            sb.Append(Environment.NewLine);
            sb.Append("    public class Eval");
            sb.Append(Environment.NewLine);
            sb.Append("    {");
            sb.Append(Environment.NewLine);
            sb.Append("        public object GetValue()");
            sb.Append(Environment.NewLine);
            sb.Append("        {");
            sb.Append(Environment.NewLine);
            sb.Append("             return " + Expression + " ;");
            sb.Append(Environment.NewLine);
            sb.Append("        }");
            sb.Append(Environment.NewLine);
            sb.Append("    }");
            sb.Append(Environment.NewLine);
            sb.Append("}");
            string code = sb.ToString();
            return code;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <returns></returns>
        public static T DeepCopy<T>(T obj)
        {
            //如果是字符串或值类型则直接返回
            if (obj is string || obj.GetType().IsValueType) return obj;

            object retval = Activator.CreateInstance(obj.GetType());
            FieldInfo[] fields = obj.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static);
            foreach (FieldInfo field in fields)
            {
                try { field.SetValue(retval, DeepCopy(field.GetValue(obj))); }
                catch { }
            }
            return (T)retval;
        }
    }
}