//------------------------------------------------------------------------------
//  此代码版权（除特别声明或在XREF结尾的命名空间的代码）归作者本人若汝棋茗所有
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//  CSDN博客：https://blog.csdn.net/qq_40374647
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//  Github源代码仓库：https://github.com/RRQM
//  API首页：https://www.yuque.com/rrqm/touchsocket/index
//  交流QQ群：234762506
//  感谢您的下载和使用
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace TouchSocket.Core
{
    /// <summary>
    /// 表示插件管理器。
    /// </summary>
    public class PluginsManager : IPluginsManager
    {
        private readonly Dictionary<Type, Dictionary<string, PluginMethod>> m_pluginInfoes = new Dictionary<Type, Dictionary<string, PluginMethod>>();
        private readonly List<PluginModel> m_plugins = new List<PluginModel>();

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="container"></param>
        public PluginsManager(IContainer container)
        {
            Container = container;
        }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public IContainer Container { get; }

        /// <summary>
        /// <inheritdoc/>
        /// </summary>
        public bool Enable { get; set; } = true;

        /// <summary>
        /// 添加插件
        /// </summary>
        /// <param name="plugin">插件</param>
        /// <exception cref="ArgumentNullException"></exception>
        void IPluginsManager.Add(IPlugin plugin)
        {
            lock (this)
            {
                if (plugin == null)
                {
                    throw new ArgumentNullException();
                }
                if (plugin.GetType().GetCustomAttribute<SingletonPluginAttribute>() is SingletonPluginAttribute singletonPlugin)
                {
                    foreach (var item in m_plugins)
                    {
                        if (item.PluginType == plugin.GetType())
                        {
                            throw new InvalidOperationException($"插件{plugin.GetType()}不能重复使用。");
                        }
                    }
                }
                m_plugins.Add(new PluginModel(plugin, plugin.GetType()));
                var types = plugin.GetType().GetInterfaces().Where(a => typeof(IPlugin).IsAssignableFrom(a)).ToArray();
                foreach (var type in types)
                {
                    if (!m_pluginInfoes.ContainsKey(type))
                    {
                        Dictionary<string, PluginMethod> pairs = new Dictionary<string, PluginMethod>();
                        var ms = type.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
                        foreach (var item in ms)
                        {
                            if (item.GetParameters().Length == 2 && typeof(TouchSocketEventArgs).IsAssignableFrom(item.GetParameters()[1].ParameterType))
                            {
                                if (pairs.ContainsKey(item.Name))
                                {
                                    throw new Exception("插件的接口方法不允许重载");
                                }
                                PluginMethod pluginMethod = new PluginMethod(type);
                                if (item.GetCustomAttribute<AsyncRaiserAttribute>() != null)
                                {
                                    var asyncMethod = type.GetMethod($"{item.Name}Async", BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
                                    if (asyncMethod == null)
                                    {
                                        throw new Exception("当接口标识为异步时，还应当定义其异步方法，以“Async”结尾");
                                    }

                                    if (asyncMethod.GetParameters().Length != 2 && typeof(TouchSocketEventArgs).IsAssignableFrom(asyncMethod.GetParameters()[1].ParameterType))
                                    {
                                        throw new Exception("异步接口方法不符合设定");
                                    }
                                    if (asyncMethod.ReturnType != typeof(Task))
                                    {
                                        throw new Exception("异步接口方法返回值必须为Task。");
                                    }
                                    pluginMethod.MethodAsync=new Method(asyncMethod);
                                }
                                pluginMethod.Method = new Method(item);
                                pairs.Add(item.Name, pluginMethod);
                            }
                        }
                        m_pluginInfoes.Add(type, pairs);
                    }
                }

                m_plugins.Sort(delegate (PluginModel x, PluginModel y)
                {
                    if (x.Plugin.Order == y.Plugin.Order) return 0;
                    else if (x.Plugin.Order < y.Plugin.Order) return 1;
                    else return -1;
                });

                Container.RegisterSingleton(plugin);
            }
        }

        /// <summary>
        /// 清除所有插件
        /// </summary>
        void IPluginsManager.Clear()
        {
            lock (this)
            {
                foreach (var item in m_plugins)
                {
                    item.Plugin.SafeDispose();
                }
                m_plugins.Clear();
            }
        }

        IEnumerator<IPlugin> IEnumerable<IPlugin>.GetEnumerator()
        {
            lock (this)
            {
                return m_plugins.Select(a => a.Plugin).GetEnumerator();
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            lock (this)
            {
                return m_plugins.Select(a => a.Plugin).GetEnumerator();
            }
        }

        /// <summary>
        /// 触发对应方法
        /// </summary>
        /// <typeparam name="TPlugin">接口类型，此处也必须是接口类型</typeparam>
        /// <param name="name">触发名称</param>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        bool IPluginsManager.Raise<TPlugin>(string name, object sender, TouchSocketEventArgs e)
        {
            if (!Enable)
            {
                return false;
            }
            if (m_pluginInfoes.TryGetValue(typeof(TPlugin), out var value))
            {
                if (value.TryGetValue(name, out PluginMethod pluginMethod))
                {
                    for (int i = 0; i < m_plugins.Count; i++)
                    {
                        if (e.Handled)
                        {
                            return true;
                        }
                        if (pluginMethod.Type.IsAssignableFrom(m_plugins[i].PluginType))
                        {
                            try
                            {
                                pluginMethod.Method.Invoke(m_plugins[i].Plugin, sender, e);
                            }
                            catch (Exception ex)
                            {
                                Container.Resolve<ILog>()?.Exception(ex);
                            }

                            try
                            {
                                pluginMethod.MethodAsync?.InvokeAsync(m_plugins[i].Plugin, sender, e);
                            }
                            catch (Exception ex)
                            {
                                Container.Resolve<ILog>()?.Exception(ex);
                            }
                        }
                    }
                }
            }
            return false;
        }

        /// <summary>
        /// 移除插件
        /// </summary>
        /// <param name="plugin"></param>
        void IPluginsManager.Remove(IPlugin plugin)
        {
            lock (this)
            {
                if (plugin == null)
                {
                    throw new ArgumentNullException();
                }
                foreach (var item in m_plugins)
                {
                    if (plugin == item.Plugin)
                    {
                        if (m_plugins.Remove(item))
                        {
                            plugin.SafeDispose();
                            return;
                        }
                    }
                }
            }
        }

        /// <summary>
        /// 移除插件
        /// </summary>
        /// <param name="type"></param>
        void IPluginsManager.Remove(Type type)
        {
            lock (this)
            {
                for (int i = m_plugins.Count - 1; i >= 0; i--)
                {
                    IPlugin plugin = m_plugins[i].Plugin;
                    if (plugin.GetType() == type)
                    {
                        m_plugins.RemoveAt(i);
                        plugin.SafeDispose();
                    }
                }
            }
        }
    }

    internal class PluginMethod
    {
        public PluginMethod(Type type)
        {
            this.Type = type;
        }
        public Method Method;
        public Method MethodAsync;
        public readonly Type Type;
    }

    internal class PluginModel
    {
        public PluginModel(IPlugin plugin, Type pluginType)
        {
            Plugin = plugin;
            PluginType = pluginType;
        }

        public IPlugin Plugin;
        public Type PluginType;
    }
}