using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using TeamAAS.Communication.Attributes;
using TeamAAS.Communication.Base;
using TeamAAS.Communication.Interfaces;
using TeamAAS.Communication.Models;
using TeamAAS.Communication.PLCs;

namespace TeamAAS.Communication
{
    /// <summary>
    /// 通讯设备统一管理器。
    /// 整合设备管理、类型注册（反射）、连接操作、PLC读写和配置持久化。
    /// 同时作为懒汉单例使用：<c>CommunicationManager.Instance</c>。
    /// </summary>
    public class CommunicationManager : IDisposable
    {
        #region 单例

        private static readonly Lazy<CommunicationManager> _instance =
            new Lazy<CommunicationManager>(() => new CommunicationManager(), isThreadSafe: true);

        /// <summary>
        /// 懒汉单例入口。首次访问时初始化，线程安全。
        /// </summary>
        public static CommunicationManager Instance => _instance.Value;

        #endregion

        private readonly object _sync = new object();
        private readonly Dictionary<Guid, ICommunication> _devices = new Dictionary<Guid, ICommunication>();

        #region 类型注册（反射扫描）

        private static readonly Lazy<List<CommunicationTypeInfo>> _types =
            new Lazy<List<CommunicationTypeInfo>>(Scan);

        public IReadOnlyList<CommunicationTypeInfo> GetAvailableTypes() => _types.Value;

        public CommunicationTypeInfo GetTypeInfo(string typeKey) =>
            string.IsNullOrWhiteSpace(typeKey) ? null : _types.Value.FirstOrDefault(t => t.TypeKey == typeKey);

        public IReadOnlyList<CommunicationTypeInfo> GetPlcTypes() =>
            _types.Value.Where(t => typeof(PlcCommunicationBase).IsAssignableFrom(t.Type)).ToList();

        public IReadOnlyList<CommunicationTypeInfo> GetBasicTypes() =>
            _types.Value.Where(t => string.Equals(t.Category, "基础通讯", StringComparison.Ordinal)).ToList();

        private static List<CommunicationTypeInfo> Scan()
        {
            var result = new List<CommunicationTypeInfo>();

            // 通用模块扫描:收集全部 ICommunication 实现(含 Runtime\Plugins 里的插件 DLL),
            // 插件项目新增的通讯设备类型无需修改主程序即可被发现。
            foreach (var type in TeamAAS.Modularity.AssemblyScanner.FindImplementations<ICommunication>())
            {
                var attr = type.GetCustomAttribute<CommunicationAttribute>();
                if (attr == null) continue;

                result.Add(new CommunicationTypeInfo
                {
                    TypeKey = type.FullName,
                    DisplayName = attr.DisplayName,
                    Category = attr.Category,
                    Description = attr.Description,
                    Type = type,
                });
            }

            return result
                .GroupBy(t => t.TypeKey)
                .Select(g => g.First())
                .OrderBy(t => t.Category)
                .ThenBy(t => t.DisplayName)
                .ToList();
        }

        #endregion

        #region 设备列表

        public IReadOnlyList<ICommunication> Devices
        {
            get { lock (_sync) return _devices.Values.OrderBy(d => d.Index).ToList(); }
        }

        public int Count
        {
            get { lock (_sync) return _devices.Count; }
        }

        #endregion

        #region 创建与注册

        public ICommunication Create(string typeKey, Guid id, string name, int index)
        {
            if (string.IsNullOrWhiteSpace(typeKey))
                throw new ArgumentException("TypeKey 不能为空。", nameof(typeKey));

            var typeInfo = GetTypeInfo(typeKey);
            if (typeInfo == null)
                throw new InvalidOperationException($"未找到通讯设备类型: {typeKey}");

            var device = (ICommunication)Activator.CreateInstance(typeInfo.Type);
            device.Id = id;
            device.Index = index;
            device.Name = name;
            Register(device);
            return device;
        }

        public void Register(ICommunication device)
        {
            if (device == null) throw new ArgumentNullException(nameof(device));

            ICommunication replaced = null;
            lock (_sync)
            {
                if (_devices.TryGetValue(device.Id, out replaced)
                    && ReferenceEquals(replaced, device))
                {
                    return;
                }

                _devices[device.Id] = device;
            }

            // 替换同一 ID 的设备时，先从注册表移除旧实例，再在锁外释放底层连接资源，
            // 避免 Dispose/Disconnect 回调反向访问管理器造成锁重入。
            if (replaced != null)
            {
                try { replaced.Disconnect(); } catch { }
                try { replaced.Dispose(); } catch { }
            }
        }

        #endregion

        #region 设备获取

        public ICommunication Get(Guid id)
        {
            lock (_sync) { _devices.TryGetValue(id, out var device); return device; }
        }

        public bool TryGet(Guid id, out ICommunication device)
        {
            lock (_sync) { return _devices.TryGetValue(id, out device); }
        }

        public ICommunication GetByName(string name) => Devices.FirstOrDefault(d => d.Name == name);

        public bool Remove(Guid id)
        {
            ICommunication device;
            lock (_sync)
            {
                if (!_devices.TryGetValue(id, out device)) return false;
                _devices.Remove(id);
            }
            try { device.Disconnect(); } catch { }
            device.Dispose();
            return true;
        }

        #endregion

        #region 便捷查询

        public IReadOnlyList<ICommunication> GetAll() => Devices;
        public IReadOnlyList<ICommunication> GetConnected() => Devices.Where(d => d.IsConnected).ToList();
        public IReadOnlyList<ICommunication> GetDisconnected() => Devices.Where(d => !d.IsConnected).ToList();
        public IReadOnlyList<ICommunication> GetTcpClients() => Devices.Where(d => d is Devices.TcpClientCommunication).ToList();
        public IReadOnlyList<ICommunication> GetTcpServers() => Devices.Where(d => d is Devices.TcpServerCommunication).ToList();
        public IReadOnlyList<ICommunication> GetSerials() => Devices.Where(d => d is Devices.SerialCommunication).ToList();
        public IReadOnlyList<ICommunication> GetUdps() => Devices.Where(d => d is Devices.UdpCommunication).ToList();
        public IReadOnlyList<ICommunication> GetWebs() => Devices.Where(d => d is Devices.WebCommunication).ToList();

        #endregion

        #region PLC 查询

        public IReadOnlyList<ICommunication> GetAllPlcModules() => Devices.Where(d => d is PlcCommunicationBase).ToList();
        public IReadOnlyList<ICommunication> GetConnectedPlcModules() => GetAllPlcModules().Where(p => p.IsConnected).ToList();
        public IReadOnlyList<ICommunication> GetPlcByProtocol(string typeKey) => Devices.Where(d => d is PlcCommunicationBase && d.TypeKey == typeKey).ToList();

        #endregion

        #region 连接操作

        public void Connect(Guid id)
        {
            var device = Get(id);
            if (device != null) device.Connect();
        }

        public void Disconnect(Guid id)
        {
            var device = Get(id);
            if (device != null) device.Disconnect();
        }

        public void ConnectAll()
        {
            foreach (var device in Devices) try { device.Connect(); } catch { }
        }

        public void DisconnectAll()
        {
            foreach (var device in Devices) try { device.Disconnect(); } catch { }
        }

        public void ConnectAllPlc()
        {
            foreach (var plc in GetAllPlcModules()) try { plc.Connect(); } catch { }
        }

        public void DisconnectAllPlc()
        {
            foreach (var plc in GetAllPlcModules()) try { plc.Disconnect(); } catch { }
        }

        #endregion

        #region PLC 读写便捷方法

        public object ReadPlcValue(Guid plcId, string address)
        {
            var plc = Get(plcId);
            if (plc == null) throw new InvalidOperationException($"PLC 设备未找到: {plcId}");
            return plc.ReadValue(address);
        }

        public void WritePlcValue(Guid plcId, string address, object value)
        {
            var plc = Get(plcId);
            if (plc == null) throw new InvalidOperationException($"PLC 设备未找到: {plcId}");
            plc.WriteValue(address, value);
        }

        public async System.Threading.Tasks.Task<object> ReadPlcValueAsync(Guid plcId, string address)
        {
            var plc = Get(plcId);
            if (plc == null) throw new InvalidOperationException($"PLC 设备未找到: {plcId}");
            return await plc.ReadValueAsync(address);
        }

        public async System.Threading.Tasks.Task WritePlcValueAsync(Guid plcId, string address, object value)
        {
            var plc = Get(plcId);
            if (plc == null) throw new InvalidOperationException($"PLC 设备未找到: {plcId}");
            await plc.WriteValueAsync(address, value);
        }

        #endregion

        #region 清理

        public void Clear()
        {
            List<ICommunication> all;
            lock (_sync) { all = _devices.Values.ToList(); _devices.Clear(); }
            foreach (var device in all) { try { device.Disconnect(); } catch { } device.Dispose(); }
        }

        public void Dispose() { Clear(); }

        #endregion

        #region 配置持久化（Newtonsoft.Json）

        public static string DefaultConfigPath
        {
            get
            {
                return Path.Combine(TeamAAS.PathHelper.ConfigDirectory, "Communications.json");
            }
        }

        private static readonly JsonSerializerSettings JsonSettings = new JsonSerializerSettings
        {
            TypeNameHandling = TypeNameHandling.All,
            Formatting = Formatting.Indented,
            ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
            ContractResolver = new CamelCasePropertyNamesContractResolver(),
            DefaultValueHandling = DefaultValueHandling.Populate,
        };

        public bool SaveConfig(string path = null)
        {
            path = path ?? DefaultConfigPath;
            var all = new List<ICommunication>();
            lock (_sync) { all.AddRange(_devices.Values.OrderBy(d => d.Index)); }
            return TeamAAS.JsonFileStore.Save(path, all, JsonSettings);
        }

        public void LoadConfig(string path = null)
        {
            path = path ?? DefaultConfigPath;
            if (!File.Exists(path)) return;

            var devices = TeamAAS.JsonFileStore.Load<List<ICommunication>>(path, JsonSettings);
            Clear();
            if (devices != null)
            {
                foreach (var d in devices.Where(x => x != null))
                {
                    Register(d);
                }
            }
        }

        #endregion
    }
}