using Serein.Library;
using Serein.NodeFlow.Tool;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;

namespace Serein.NodeFlow
{

    /// <summary>
    /// 
    /// </summary>
    public class FlowLibrary
    {
        private readonly Assembly assembly;
        private readonly Action actionOfUnloadAssmbly;
        private string _assemblyFilePath;

        public FlowLibrary(string assemblyFilePath,
                           Assembly assembly,
                           Action actionOfUnloadAssmbly)
        {
            this._assemblyFilePath = assemblyFilePath;
            this.assembly = assembly;
            this.actionOfUnloadAssmbly = actionOfUnloadAssmbly;
            LoadAssembly(assembly);
        }


        public string FullName => assembly.GetName().FullName;

        public string Version => assembly.GetName().Version.ToString();

        /// <summary>
        /// 加载程序集时创建的方法描述
        /// </summary>
        public ConcurrentDictionary<string, MethodDetails> MethodDetailss { get; } = new ConcurrentDictionary<string, MethodDetails>();

        /// <summary>
        /// 管理通过Emit动态构建的委托
        /// </summary>
        public ConcurrentDictionary<string, DelegateDetails> DelegateDetailss { get; } = new ConcurrentDictionary<string, DelegateDetails>();

        /// <summary>
        /// 记录不同的注册时机需要自动创建全局唯一实例的类型信息
        /// </summary>
        public ConcurrentDictionary<RegisterSequence, List<Type>> RegisterTypes { get; } = new ConcurrentDictionary<RegisterSequence, List<Type>>();


        /// <summary>
        /// 卸载当前程序集以及附带的所有信息
        /// </summary>
        public void Upload()
        {
            actionOfUnloadAssmbly?.Invoke();
        }

        public NodeLibraryInfo ToInfo()
        {
            return new NodeLibraryInfo
            {
                AssemblyName = FullName,
                FileName = Path.GetFileName(_assemblyFilePath),
                FilePath = _assemblyFilePath,
            };
        }


        //public void LoadAssmely(Assembly assembly)
        //{
        //    (var registerTypes, var mdlist) = LoadAssembly2(assembly);
        //    if (mdlist.Count > 0)
        //    {
        //        var nodeLibraryInfo = new NodeLibraryInfo
        //        {
        //            //Assembly = assembly,
        //            AssemblyName = assembly.FullName,
        //            FileName = Path.GetFileName(_assemblyFilePath),
        //            FilePath = _assemblyFilePath,
        //        };

        //        //LibraryInfos.TryAdd(nodeLibraryInfo.AssemblyName, nodeLibraryInfo);

        //        MethodDetailss.TryAdd(nodeLibraryInfo.AssemblyName, mdlist);

        //        foreach (var md in mdlist)
        //        {
        //            MethodDetailss.TryAdd(md.MethodName, md);
        //        }

        //        foreach (var kv in registerTypes)
        //        {
        //            if (!RegisterTypes.TryGetValue(kv.Key, out var types))
        //            {
        //                types = new List<Type>();
        //                RegisterTypes.TryAdd(kv.Key, types);
        //            }
        //            types.AddRange(kv.Value);
        //        }
        //        var mdInfos = mdlist.Select(md => md.ToInfo()).ToList(); // 转换成方法信息
        //    }
        //}


        /// <summary>
        /// 动态加载程序集
        /// </summary>
        /// <param name="assembly">程序集本身</param>
        /// <returns></returns>
        private bool LoadAssembly(Assembly assembly)
        {
            #region 检查入参

            // 加载DLL，创建 MethodDetails、实例作用对象、委托方法
            var assemblyName = assembly.GetName().Name;
            if (string.IsNullOrEmpty(assemblyName)) // 防止动态程序集没有定义程序集名称 
            {
                return false;
            }

            List<Type> types = assembly.GetTypes().ToList(); // 获取程序集中的所有类型
            if (types.Count < 0) // 防止动态程序集中没有类型信息？
            {
                return false;
            }

            #endregion

           
            try
            {


                #region 获取 DynamicFlow 特性的流程控制器，如果没有退出
                // Type   ： 具有 DynamicFlowAttribute 标记的类型
                // string ： 类型元数据 DynamicFlowAttribute 特性中的 Name 属性 （用于生成方法描述时，添加在方法别名中提高可读性）
                List<(Type Type, string Name)> scanTypes = new List<(Type Type, string Name)>();

                // (Type, string)
                // Type   ： 具有 DynamicFlowAttribute 标记的类型
                // string ： 类型元数据 DynamicFlowAttribute 特性中的 Name 属性
                foreach (var  type in types)
                {
                    if (type.GetCustomAttribute<DynamicFlowAttribute>() is DynamicFlowAttribute dynamicFlowAttribute && dynamicFlowAttribute.Scan == true)
                    {
                        scanTypes.Add((type, dynamicFlowAttribute.Name));
                    }
                }
                if (scanTypes.Count == 0)
                {
                    // 类型没有流程控制器
                    return false;
                }
                #endregion


                #region 创建对应的方法元数据
                // 从 scanTypes.Type 创建的方法信息
                // Md : 方法描述
                // Dd ：方法对应的Emit委托
                List<(MethodDetails Md, DelegateDetails Dd)> detailss = new List<(MethodDetails Md, DelegateDetails Dd)>();

                // 遍历扫描的类型
                foreach ((var type, var flowName) in scanTypes)
                {
                    var methodInfos = NodeMethodDetailsHelper.GetMethodsToProcess(type);
                    foreach (var methodInfo in methodInfos) // 遍历流程控制器类型中的方法信息
                    {
                        // 尝试创建
                        if (!NodeMethodDetailsHelper.TryCreateDetails(type, methodInfo, assemblyName,
                                                                       out var md, out var dd)) // 返回的描述
                        {
                            Console.WriteLine($"无法加载方法信息：{assemblyName}-{type}-{methodInfo}");
                            continue;
                        }
                        md.MethodAnotherName = flowName + md.MethodAnotherName; // 方法别名
                        detailss.Add((md, dd));
                    }
                }

                #endregion

                #region 检查是否成功加载，如果成功，则真正写入到缓存的集合中
                if(detailss.Count == 0)
                {
                    return false;
                }
                #region 加载成功，缓存所有方法、委托的信息
                foreach((var md,var dd) in detailss)
                {
                    MethodDetailss.TryAdd(md.MethodName, md);
                    DelegateDetailss.TryAdd(md.MethodName, dd);
                }

                #endregion
                #region 加载成功，开始获取并记录所有需要自动实例化的类型（在流程启动时）
                foreach (Type type in types)
                {
                    if (type.GetCustomAttribute<AutoRegisterAttribute>() is AutoRegisterAttribute attribute)
                    {
                        if (!RegisterTypes.TryGetValue(attribute.Class, out var valus))
                        {
                            valus = new List<Type>();
                            RegisterTypes.TryAdd(attribute.Class, valus);
                        }
                        valus.Add(type);
                    }
                }
                #endregion

                #endregion

                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return false;
            }
        }


    }

}