using System;
using System.Linq;
using System.Reflection;
using System.Reflection.Emit;

namespace NewLife.Reflection
{
    /// <summary>全局方法程序集</summary>
    internal class DynamicAssembly
    {
        /// <summary>名称</summary>
        public String Name { get; set; }

        public DynamicAssembly(String name) { Name = name; }

        private AssemblyBuilder _AsmBuilder;
        /// <summary>程序集创建器</summary>
        public AssemblyBuilder AsmBuilder
        {
            get
            {
                if (_AsmBuilder == null)
                {
                    AssemblyName aname = new AssemblyName(Name);
                    _AsmBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(aname, AssemblyBuilderAccess.RunAndSave);
                }
                return _AsmBuilder;
            }
            //set { _AsmBuilder = value; }
        }

        private ModuleBuilder _ModBuilder;
        /// <summary>模块创建器</summary>
        public ModuleBuilder ModBuilder
        {
            get
            {
                if (_ModBuilder == null) _ModBuilder = AsmBuilder.DefineDynamicModule(Name + ".dll");
                return _ModBuilder;
            }
            //set { _ModBuilder = value; }
        }

        /// <summary>类型创建器</summary>
        public TypeBuilder TypeBuilder { get; private set; }

        /// <summary>添加全局方法</summary>
        /// <param name="method"></param>
        /// <param name="fun"></param>
        public void AddGlobalMethod(MethodInfo method, Action<ILGenerator> fun)
        {
            ParameterInfo[] ps = method.GetParameters();
            //ListX<Type> paramTypes = ListX<Type>.From<ParameterInfo>(ps, delegate(ParameterInfo item) { return item.ParameterType; });
            Type[] paramTypes = ps.Select<ParameterInfo, Type>(item => item.ParameterType).ToArray<Type>();

            //TypeBuilder tbuilder = mbuilder.DefineType(method.DeclaringType.Name, TypeAttributes.Public);
            //MethodBuilder mb = tbuilder.DefineMethod(method.Name.Replace(".", "_"), method.Attributes, method.ReturnType, paramTypes);
            if (TypeBuilder == null) TypeBuilder = ModBuilder.DefineType(Name, TypeAttributes.Public);

            String name = method.Name.Replace(".", "_");
            if (String.IsNullOrEmpty(name)) name = "Test" + DateTime.Now.Ticks;
            //MethodBuilder mb = ModBuilder.DefineGlobalMethod(name, method.Attributes, method.ReturnType, paramTypes.ToArray());
            MethodBuilder mb = TypeBuilder.DefineMethod(name, method.Attributes, method.ReturnType, paramTypes);

            ILGenerator il = mb.GetILGenerator();
            fun(il);
        }

        /// <summary>保存</summary>
        /// <param name="fileName"></param>
        public void Save(String fileName)
        {
            //ModBuilder.CreateGlobalFunctions();
            TypeBuilder.CreateType();

            if (String.IsNullOrEmpty(fileName)) fileName = Name + ".dll";

            AsmBuilder.Save(fileName);
        }
    }
}