using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using Newtonsoft.Json;
using TeamAAS.Feeder.Attributes;
using TeamAAS.Feeder.Devices;
using TeamAAS.Feeder.Interfaces;
using TeamAAS.Feeder.Models;
using TeamAAS.Feeder.Enums;
using TeamAAS.Feeder.Models;

namespace TeamAAS.Feeder
{
    /// <summary>
    /// 供料器管理器。懒汉单例：<c>FeederManager.Instance</c>。
    /// 整合：设备 CRUD + 配方管理 + 反射发现设备类型 + 配置持久化。
    /// 管理类按架构规则保留在根命名空间 TeamAAS.Feeder。
    /// </summary>
    public class FeederManager : IFeederManager
    {
        #region 单例

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

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

        #endregion

        private readonly object _sync = new object();
        private readonly Dictionary<Guid, FeederInfo> _feeders = new Dictionary<Guid, FeederInfo>();
        private readonly Dictionary<Guid, IFeeder> _devices = new Dictionary<Guid, IFeeder>();
        private List<FeederRecipe> _recipes = new List<FeederRecipe>();
        private List<FeederTypeInfo> _scannedTypes;
        private readonly object _scanLock = new object();

        public static string DefaultConfigPath => TeamAAS.PathHelper.FeedersConfigFile;

        private static string DefaultRecipeFilePath => TeamAAS.PathHelper.FeederRecipesFile;

        public event EventHandler FeederListChanged;

        public FeederManager()
        {
            _recipes = LoadAllRecipesInternal();
        }

        #region 设备配置 CRUD

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

            try
            {
                var list = TeamAAS.JsonFileStore.Load<List<FeederInfo>>(path);
                if (list == null) return;

                lock (_sync)
                {
                    _feeders.Clear();
                    foreach (var info in list)
                    {
                        if (!_feeders.ContainsKey(info.Id))
                            _feeders.Add(info.Id, info);
                    }
                }
                FeederListChanged?.Invoke(this, EventArgs.Empty);
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.LoadConfig 失败: {ex.Message}");
            }
        }

        public bool SaveConfig(string path = null)
        {
            path = path ?? DefaultConfigPath;
            try
            {
                List<FeederInfo> list;
                lock (_sync) { list = _feeders.Values.ToList(); }
                return TeamAAS.JsonFileStore.Save(path, list);
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.SaveConfig 失败: {ex.Message}");
                return false;
            }
        }

        public FeederInfo Add(FeederInfo info)
        {
            if (info == null) throw new ArgumentNullException(nameof(info));
            lock (_sync)
            {
                if (_feeders.ContainsKey(info.Id))
                    _feeders[info.Id] = info;
                else
                    _feeders.Add(info.Id, info);
            }
            FeederListChanged?.Invoke(this, EventArgs.Empty);
            return info;
        }

        public bool Remove(Guid id)
        {
            bool removed;
            lock (_sync)
            {
                removed = _feeders.Remove(id);
                if (_devices.TryGetValue(id, out var dev))
                {
                    dev.Dispose();
                    _devices.Remove(id);
                }
            }
            if (removed) FeederListChanged?.Invoke(this, EventArgs.Empty);
            return removed;
        }

        public FeederInfo Get(Guid id)
        {
            lock (_sync) { return _feeders.TryGetValue(id, out var f) ? f : null; }
        }

        public IReadOnlyList<FeederInfo> GetAll()
        {
            lock (_sync) { return _feeders.Values.ToList().AsReadOnly(); }
        }

        #endregion

        #region 设备实例管理

        public IFeeder GetDevice(Guid id)
        {
            lock (_sync) { return _devices.TryGetValue(id, out var d) ? d : null; }
        }

        public IFeeder GetOrCreateDevice(FeederInfo info)
        {
            if (info == null) return null;
            lock (_sync)
            {
                if (_devices.TryGetValue(info.Id, out var existing))
                {
                    try { existing.Dispose(); } catch { }
                    _devices.Remove(info.Id);
                }
                var device = CreateDeviceInstance(info);
                _devices[info.Id] = device;
                return device;
            }
        }

        #endregion

        #region 配方管理

        public IReadOnlyList<FeederRecipe> GetRecipes()
        {
            lock (_sync) { return _recipes.ToList().AsReadOnly(); }
        }

        public FeederRecipe GetRecipe(string name)
        {
            lock (_sync) { return _recipes.FirstOrDefault(r => r.RecipeName == name); }
        }

        public bool SaveRecipe(FeederRecipe recipe)
        {
            if (recipe == null || string.IsNullOrWhiteSpace(recipe.RecipeName)) return false;

            var ok = SaveRecipeInternal(recipe);
            if (ok)
            {
                lock (_sync)
                {
                    var existing = _recipes.FirstOrDefault(r => r.RecipeName == recipe.RecipeName);
                    if (existing != null)
                        _recipes[_recipes.IndexOf(existing)] = recipe;
                    else
                        _recipes.Add(recipe);
                }
            }
            return ok;
        }

        public bool DeleteRecipe(string name)
        {
            var ok = DeleteRecipeInternal(name);
            if (ok)
            {
                lock (_sync)
                {
                    var r = _recipes.FirstOrDefault(x => x.RecipeName == name);
                    if (r != null) _recipes.Remove(r);
                }
            }
            return ok;
        }

        public FeederRecipe LoadRecipe(string path)
        {
            var recipe = LoadRecipeInternal(path);
            if (recipe != null)
            {
                lock (_sync)
                {
                    var existing = _recipes.FirstOrDefault(r => r.RecipeName == recipe.RecipeName);
                    if (existing != null)
                        _recipes[_recipes.IndexOf(existing)] = recipe;
                    else
                        _recipes.Add(recipe);
                }
            }
            return recipe;
        }

        private static List<FeederRecipe> LoadAllRecipesInternal()
        {
            try
            {
                if (!File.Exists(DefaultRecipeFilePath)) return new List<FeederRecipe>();
                var json = File.ReadAllText(DefaultRecipeFilePath);
                var list = JsonConvert.DeserializeObject<List<FeederRecipe>>(json);
                return list ?? new List<FeederRecipe>();
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.LoadAllRecipes 失败: {ex.Message}");
                return new List<FeederRecipe>();
            }
        }

        private static bool SaveAllRecipesInternal(List<FeederRecipe> recipes)
        {
            try
            {
                var json = JsonConvert.SerializeObject(recipes, Formatting.Indented);
                File.WriteAllText(DefaultRecipeFilePath, json);
                return true;
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.SaveAllRecipes 失败: {ex.Message}");
                return false;
            }
        }

        private static bool SaveRecipeInternal(FeederRecipe recipe)
        {
            try
            {
                recipe.UpdatedAt = DateTime.Now;
                var list = LoadAllRecipesInternal();
                var idx = list.FindIndex(r => r.RecipeName == recipe.RecipeName);
                if (idx >= 0) list[idx] = recipe;
                else list.Add(recipe);
                return SaveAllRecipesInternal(list);
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.SaveRecipe 失败: {ex.Message}");
                return false;
            }
        }

        private static bool DeleteRecipeInternal(string recipeName)
        {
            try
            {
                var list = LoadAllRecipesInternal();
                var removed = list.RemoveAll(r => r.RecipeName == recipeName);
                if (removed > 0) return SaveAllRecipesInternal(list);
                return false;
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.DeleteRecipe 失败: {ex.Message}");
                return false;
            }
        }

        private static FeederRecipe LoadRecipeInternal(string path)
        {
            try
            {
                if (!File.Exists(path)) return null;
                var json = File.ReadAllText(path);
                return JsonConvert.DeserializeObject<FeederRecipe>(json);
            }
            catch (Exception ex)
            {
                Trace.WriteLine($"FeederManager.LoadRecipe 失败: {ex.Message}");
                return null;
            }
        }

        #endregion

        #region 反射扫描 + 工厂

        public IReadOnlyList<FeederTypeInfo> GetAvailableTypes()
        {
            if (_scannedTypes != null) return _scannedTypes.AsReadOnly();
            lock (_scanLock)
            {
                if (_scannedTypes != null) return _scannedTypes.AsReadOnly();
                _scannedTypes = ScanTypes();
                return _scannedTypes.AsReadOnly();
            }
        }

        private List<FeederTypeInfo> ScanTypes()
        {
            var result = new List<FeederTypeInfo>();

            // 通用模块扫描:收集全部 IFeeder 实现(含 Runtime\Plugins 里的插件 DLL)
            foreach (var type in TeamAAS.Modularity.AssemblyScanner.FindImplementations<IFeeder>())
            {
                var attrs = type.GetCustomAttributes<FeederAttribute>();
                foreach (var attr in attrs)
                {
                    result.Add(new FeederTypeInfo
                    {
                        TypeKey = type.FullName,
                        DisplayName = attr.DisplayName,
                        Brand = attr.Brand,
                        Description = attr.Description,
                        Type = type
                    });
                }
            }

            // fallback：如果反射没扫到品牌特性，注册内置 TeamFeeder（兼容旧代码）
            if (!result.Any(t => t.Brand == FeederBrand.Team))
            {
                result.Add(new FeederTypeInfo
                {
                    TypeKey = typeof(TeamFeeder).FullName,
                    DisplayName = "Team 供料器",
                    Brand = FeederBrand.Team,
                    Description = "内置 Team 品牌供料器实现",
                    Type = typeof(TeamFeeder)
                });
            }

            return result
                .GroupBy(t => t.TypeKey + "|" + t.Brand)
                .Select(g => g.First())
                .OrderBy(t => t.DisplayName)
                .ToList();
        }

        private IFeeder CreateDeviceInstance(FeederInfo info)
        {
            if (info == null) throw new ArgumentNullException(nameof(info));

            var types = GetAvailableTypes();
            var match = types.FirstOrDefault(t => t.Brand == info.FeederBrand);
            if (match == null)
                throw new NotSupportedException($"暂不支持的供料器品牌: {info.FeederBrand}");

            return (IFeeder)Activator.CreateInstance(
                match.Type,
                info.Id, info.FeederNo, info.FeederName, info.IP, info.Port);
        }

        #endregion
    }

    public class FeederTypeInfo
    {
        public string TypeKey { get; set; }
        public string DisplayName { get; set; }
        public FeederBrand Brand { get; set; }
        public string Description { get; set; }
        public Type Type { get; set; }

        public override string ToString() => DisplayName;
    }
}