using OxyPlot;
using OxyPlot.Axes;
using OxyPlot.Legends;
using OxyPlot.Series;
using System.Collections.ObjectModel;
using System.Reflection;
using System.Windows.Input;
using System.Windows.Threading;
using UIShare.GlobalVariable;
using UIShare.PubEvent;
using UIShare.ViewModelBase;
using Prism.Mvvm;
using Common.Attributes;

namespace MonitorModule.ViewModels
{
    public class MonitorViewModel : NavigateViewModelBase, IRegionMemberLifetime, IDisposable
    {
        #region 属性
        public bool KeepAlive => true;
        public ScopedContext _scopedContext { get; set; }
        public GlobalInfo _globalInfo { get; set; }

        public string TestStatus
        {
            get => _testStatus;
            set => SetProperty(ref _testStatus, value);
        }

        public PlotModel Plot { get; }

        /// <summary>已添加的监测通道列表</summary>
        public ObservableCollection<MonitorChannel> Channels { get; } = new();

        /// <summary>可添加的设备方法列表（供用户选择）</summary>
        public ObservableCollection<AvailableMethodItem> AvailableMethods { get; } = new();

        private MonitorChannel? _selectedChannel;
        public MonitorChannel? SelectedChannel
        {
            get => _selectedChannel;
            set => SetProperty(ref _selectedChannel, value);
        }

        private AvailableMethodItem? _selectedAvailableMethod;
        public AvailableMethodItem? SelectedAvailableMethod
        {
            get => _selectedAvailableMethod;
            set => SetProperty(ref _selectedAvailableMethod, value);
        }

        public string StatusMessage
        {
            get => _statusMessage;
            set => SetProperty(ref _statusMessage, value);
        }
        #endregion

        #region 命令
        public ICommand AddChannelCommand { get; }
        public ICommand DeleteChannelCommand { get; }
        public ICommand ResetViewCommand { get; }
        public ICommand RefreshDataCommand { get; }
        public ICommand RefreshCommand { get; }
        #endregion

        #region 私有字段
        private bool IsInitiated = false;
        private IScopedProvider _scope;
        private DeviceManager? _deviceManager;

        private static readonly OxyColor[] _palette =
        {
            OxyColors.SteelBlue, OxyColors.IndianRed, OxyColors.SeaGreen,
            OxyColors.DarkOrange, OxyColors.MediumPurple, OxyColors.Goldenrod,
            OxyColors.Teal, OxyColors.Crimson, OxyColors.OliveDrab
        };
        private int _colorIndex;

        private readonly DispatcherTimer _sampleTimer;
        private double _sampleTime;
        private const double _sampleInterval = 0.1; // 100ms
        private string _testStatus = string.Empty;
        private string _statusMessage = "图表已就绪，暂无监测项";

        /// <summary>反射方法缓存：Channel → (MethodInfo, DeviceInstance)</summary>
        private readonly Dictionary<MonitorChannel, (MethodInfo Method, object Device)> _methodCache = new();

        /// <summary>方法名前缀：匹配这些开头的公共方法被视为可监测项</summary>
        private static readonly string[] _methodPrefixes = { "查询", "读取", "获取", "测量" };
        #endregion

        public MonitorViewModel(IContainerExtension container) : base(container)
        {
            _globalInfo = container.Resolve<GlobalInfo>();
            Plot = BuildEmptyPlot();
            AddChannelCommand = new DelegateCommand(OnAddChannel);
            DeleteChannelCommand = new DelegateCommand(OnDeleteChannel);
            ResetViewCommand = new DelegateCommand(OnResetView);
            RefreshDataCommand = new DelegateCommand(OnRefreshData);
            RefreshCommand = new DelegateCommand(OnExpand);

            _sampleTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(_sampleInterval) };
            _sampleTimer.Tick += OnSampleTick;
        }

        public void Dispose()
        {
            _sampleTimer?.Stop();
            _scope?.Dispose();
        }

        #region PlotModel 构建
        private static PlotModel BuildEmptyPlot()
        {
            var pm = new PlotModel
            {
                Title = string.Empty,
                PlotAreaBorderColor = OxyColors.LightGray,
                Background = OxyColors.White
            };
            pm.Axes.Add(new LinearAxis
            {
                Position = AxisPosition.Bottom,
                Title = "时间 (s)",
                MajorGridlineStyle = LineStyle.Dot,
                MinorGridlineStyle = LineStyle.None
            });
            pm.Axes.Add(new LinearAxis
            {
                Position = AxisPosition.Left,
                Title = "值",
                MajorGridlineStyle = LineStyle.Dot,
                MinorGridlineStyle = LineStyle.None
            });
            pm.Legends.Add(new Legend
            {
                LegendPosition = LegendPosition.RightTop,
                LegendBackground = OxyColor.FromAColor(200, OxyColors.White),
                LegendBorder = OxyColors.LightGray
            });
            return pm;
        }
        #endregion

        #region 设备方法发现
        /// <summary>
        /// 扫描 DeviceManager.DeviceMap 中所有设备，反射找出可监测的方法。
        /// </summary>
        private void DiscoverAvailableMethods()
        {
            AvailableMethods.Clear();
            if (_deviceManager?.DeviceMap == null || _deviceManager.DeviceMap.Count == 0)
            {
                StatusMessage = "当前工位无可用设备";
                return;
            }

            foreach (var kvp in _deviceManager.DeviceMap)
            {
                string deviceName = kvp.Key;
                var device = kvp.Value;
                var deviceType = device.GetType();

                // 核心优化：直接通过特性和参数过滤方法
                var methods = deviceType.GetMethods(BindingFlags.Public | BindingFlags.Instance)
                    .Where(m =>
                    {
                        // 1. 核心过滤：必须包含 [Monitorable] 特性
                        var attribute = m.GetCustomAttribute<MonitorableAttribute>();
                        if (attribute == null) return false;

                        // 2. 返回类型校验（如果强制要求是 Task<string>）
                        if (m.ReturnType != typeof(Task<string>)) return false;

                        // 3. 参数校验：只取无参或仅有 CancellationToken 参数的方法
                        var parms = m.GetParameters();
                        bool validParams = parms.Length == 0 ||
                            (parms.Length == 1 && parms[0].ParameterType == typeof(CancellationToken));

                        return validParams;
                    });

                foreach (var method in methods)
                {
                    // 如果你在特性里写了 Description，这里可以拿出来赋给 DisplayName
                    var attr = method.GetCustomAttribute<MonitorableAttribute>();
                    string displayName = !string.IsNullOrEmpty(attr?.Description)
                        ? $"{deviceName}.{attr.Description}"
                        : $"{deviceName}.{method.Name}";

                    var item = new AvailableMethodItem
                    {
                        DeviceName = deviceName,
                        MethodName = method.Name,
                        DisplayName = displayName, // 优先使用特性的中文描述
                        MethodInfo = method,
                        Device = device
                    };
                    AvailableMethods.Add(item);
                }
            }

            StatusMessage = AvailableMethods.Count > 0
                ? $"发现 {AvailableMethods.Count} 个可监测项"
                : "未发现可监测的设备方法";
        }
        #endregion

        #region 命令处理
        private void OnAddChannel()
        {
            var method = SelectedAvailableMethod;
            if (method == null)
            {
                StatusMessage = "请先在列表中选择一个监测项";
                return;
            }

            // 防止重复添加同一设备方法
            if (Channels.Any(c => c.DeviceName == method.DeviceName && c.MethodName == method.MethodName))
            {
                StatusMessage = $"监测项 [{method.DisplayName}] 已存在";
                return;
            }

            var color = _palette[_colorIndex % _palette.Length];
            _colorIndex++;

            var channel = new MonitorChannel
            {
                DeviceName = method.DeviceName,
                MethodName = method.MethodName,
                DisplayName = method.DisplayName,
                Color = color,
                IsMonitored = true,
                IsDisplayed = true
            };

            // 创建 Series 并加入 Plot
            channel.Series = new LineSeries
            {
                Title = channel.DisplayName,
                Color = color,
                StrokeThickness = 1.5
            };
            Plot.Series.Add(channel.Series);

            // 缓存反射信息
            _methodCache[channel] = (method.MethodInfo, method.Device);

            // 订阅属性变化：IsDisplayed 控制显示/隐藏，MathExpression 控制数学变换
            channel.PropertyChanged += (s, e) =>
            {
                if (e.PropertyName == nameof(MonitorChannel.IsDisplayed))
                    OnChannelDisplayChanged(channel);
                else if (e.PropertyName == nameof(MonitorChannel.MathExpression))
                    OnChannelMathChanged(channel);
            };

            Channels.Add(channel);
            SelectedChannel = channel;

            Plot.InvalidatePlot(true);
            StatusMessage = $"已添加监测项 [{channel.DisplayName}]，当前共 {Channels.Count} 项";
        }

        private void OnDeleteChannel()
        {
            var target = SelectedChannel ?? Channels.LastOrDefault();
            if (target == null)
            {
                StatusMessage = "无可删除的监测项";
                return;
            }

            if (target.Series != null)
            {
                Plot.Series.Remove(target.Series);
            }
            _methodCache.Remove(target);
            Channels.Remove(target);
            SelectedChannel = Channels.LastOrDefault();

            Plot.InvalidatePlot(true);
            StatusMessage = $"已删除监测项 [{target.DisplayName}]，剩余 {Channels.Count} 项";
        }

        private void OnResetView()
        {
            Plot.ResetAllAxes();
            Plot.InvalidatePlot(false);
            StatusMessage = "视图已按数据范围复原";
        }

        private void OnRefreshData()
        {
            Plot.InvalidatePlot(true);
            StatusMessage = $"已刷新（{DateTime.Now:HH:mm:ss}）";
        }

        private void OnExpand()
        {
            if (string.IsNullOrEmpty(TestStatus)) return;
            _globalInfo.CurrentScope = TestStatus;
            _eventAggregator.GetEvent<ExpandViewEvent>().Publish(TestStatus);
        }
        #endregion

        #region 显示/隐藏切换
        /// <summary>
        /// 当 Channel.IsDisplayed 变化时调用：控制 Series 的创建/移除
        /// </summary>
        public void OnChannelDisplayChanged(MonitorChannel channel)
        {
            if (channel.IsDisplayed)
            {
                // 从 false → true：创建 Series，回填最近数据
                if (channel.Series == null)
                {
                    channel.Series = new LineSeries
                    {
                        Title = channel.DisplayName,
                        Color = channel.Color,
                        StrokeThickness = 1.5
                    };

                    // 回填最近 200 个数据点
                    var recent = channel.DataPoints.ToArray();
                    var startIdx = Math.Max(0, recent.Length - 200);
                    for (int i = startIdx; i < recent.Length; i++)
                    {
                        channel.Series.Points.Add(new DataPoint(recent[i].Time, recent[i].DisplayValue));
                    }

                    Plot.Series.Add(channel.Series);
                    Plot.InvalidatePlot(true);
                }
            }
            else
            {
                // 从 true → false：移除 Series，数据继续记录
                if (channel.Series != null)
                {
                    Plot.Series.Remove(channel.Series);
                    channel.Series = null;
                    Plot.InvalidatePlot(true);
                }
            }
        }

        /// <summary>
        /// 当 Channel.MathExpression 变化时调用：重新计算所有已记录数据点的 DisplayValue
        /// </summary>
        public void OnChannelMathChanged(MonitorChannel channel)
        {
            if (channel.Series == null) return;

            // 用新表达式重算 Series 中的点
            var points = channel.DataPoints.ToArray();
            channel.Series.Points.Clear();
            var startIdx = Math.Max(0, points.Length - 200);
            for (int i = startIdx; i < points.Length; i++)
            {
                channel.Series.Points.Add(new DataPoint(points[i].Time, points[i].DisplayValue));
            }
            Plot.InvalidatePlot(true);
        }
        #endregion

        #region 采样定时器
        private async void OnSampleTick(object? sender, EventArgs e)
        {
            _sampleTime += _sampleInterval;

            if (Channels.Count == 0 || _methodCache.Count == 0) return;

            foreach (var channel in Channels)
            {
                if (!channel.IsMonitored) continue;
                if (!_methodCache.TryGetValue(channel, out var entry)) continue;

                try
                {
                    var (method, device) = entry;
                    // 调用设备方法获取返回值
                    var task = (Task<string>)method.Invoke(device, null)!;
                    var raw = await task.ConfigureAwait(true);

                    // 尝试解析为 double
                    if (double.TryParse(raw, out double value))
                    {
                        channel.Record(_sampleTime, value);
                    }
                }
                catch
                {
                    // 设备读取失败时跳过该通道本次采样
                }
            }

            // 让 X 轴跟随最新数据滚动
            var xAxis = Plot.Axes.FirstOrDefault(a => a.Position == AxisPosition.Bottom);
            if (xAxis != null)
            {
                double window = 200 * _sampleInterval;
                xAxis.Minimum = Math.Max(0, _sampleTime - window);
                xAxis.Maximum = _sampleTime + 0.5;
            }

            Plot.InvalidatePlot(true);
        }
        #endregion

        #region 重写
        public override void OnNavigatedTo(NavigationContext navigationContext)
        {
            base.OnNavigatedTo(navigationContext);
            if (!IsInitiated && navigationContext.Parameters.ContainsKey("Name"))
            {
                TestStatus = navigationContext.Parameters.GetValue<string>("Name");
                Plot.Title = $"监控 - {TestStatus}";
                Plot.InvalidatePlot(false);
                _scope = _globalInfo.ScopeDic[TestStatus];
                _scopedContext = _scope.Resolve<ScopedContext>();
                _deviceManager = _scope.Resolve<DeviceManager>();
                IsInitiated = true;

                // 扫描可用监测项
                DiscoverAvailableMethods();

                // 启动采样定时器
                _sampleTimer.Start();
            }
        }
        #endregion
    }

    /// <summary>
    /// 可用设备方法项（供用户选择添加为监测通道）
    /// </summary>
    public class AvailableMethodItem
    {
        public string DeviceName { get; set; } = string.Empty;
        public string MethodName { get; set; } = string.Empty;
        public string DisplayName { get; set; } = string.Empty;
        public MethodInfo MethodInfo { get; set; } = null!;
        public object Device { get; set; } = null!;
    }
}