using OxyPlot;
using OxyPlot.Axes;
using OxyPlot.Legends;
using OxyPlot.Series;
using System.Collections.ObjectModel;
using System.Windows.Input;
using System.Windows.Threading;
using UIShare.GlobalVariable;
using UIShare.PubEvent;
using UIShare.ViewModelBase;

namespace MonitorModule.ViewModels
{
    /// <summary>
    /// 监控界面 VM —— 基于 OxyPlot 的曲线监控壳。
    /// 当前阶段不接入真实数据源，仅搭好框架：
    ///   - 添加信号 / 删除信号
    ///   - 重置视图（按数据范围复原）
    ///   - 刷新（重绘 PlotView）
    /// 仍延续 ScopedContext 隔离 + 双击展开 的范式，每个工位独立一份图表与信号列表。
    /// </summary>
    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);
        }

        /// <summary>PlotView 直接绑这个 PlotModel</summary>
        public PlotModel Plot { get; }

        /// <summary>当前已添加的信号集合（左侧列表展示）</summary>
        public ObservableCollection<SignalItem> Signals { get; } = new();

        public SignalItem? SelectedSignal
        {
            get => _selectedSignal;
            set => SetProperty(ref _selectedSignal, value);
        }

        public string StatusMessage
        {
            get => _statusMessage;
            set => SetProperty(ref _statusMessage, value);
        }
        #endregion
        #region 命令
        public ICommand AddSignalCommand { get; }
        public ICommand DeleteSignalCommand { get; }
        public ICommand ResetViewCommand { get; }
        public ICommand RefreshDataCommand { get; }
        // 双击展开/折叠：与 RecordView/AutomatedTestingView 共用同一套 ExpandViewEvent
        public ICommand RefreshCommand { get; }
        #endregion
        #region 私有字段
        private bool IsInitiated = false;
        private IScopedProvider _scope;
        // 颜色轮转池，给新加的信号自动分配区分色
        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 _signalCounter;

        // ===== 模拟数据相关 =====
        // 模拟定时器：周期性给每条信号追加新点，形成滚动效果
        private readonly DispatcherTimer _simTimer;
        // 全局采样时间（秒），每 tick 自增 _simInterval
        private double _simT;
        // 采样间隔（秒），与 DispatcherTimer.Interval 保持一致
        private const double _simInterval = 0.1;
        // 滚动窗口大小：每条曲线最多保留 200 个点（约 20 秒）
        private const int _maxPoints = 200;
        // 用于 random walk 的随机源
        private static readonly Random _rng = new();
        private string _testStatus = string.Empty;
        private SignalItem? _selectedSignal;
        private string _statusMessage = "图表已就绪，暂无信号";
        #endregion

        public MonitorViewModel(IContainerExtension container) : base(container)
        {
            _globalInfo = container.Resolve<GlobalInfo>();
            Plot = BuildEmptyPlot();
            AddSignalCommand = new DelegateCommand(OnAddSignal);
            DeleteSignalCommand = new DelegateCommand(OnDeleteSignal);
            ResetViewCommand = new DelegateCommand(OnResetView);
            RefreshDataCommand = new DelegateCommand(OnRefreshData);
            RefreshCommand = new DelegateCommand(OnExpand);

            // 启动模拟数据定时器：100ms 一帧，给每条信号喂一个新点
            _simTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(_simInterval) };
            _simTimer.Tick += OnSimTick;
            _simTimer.Start();

            // 默认预置 3 条模拟信号，便于直接看到滚动效果
            OnAddSignal(); // sin
            OnAddSignal(); // cos
            OnAddSignal(); // random walk
        }

        public void Dispose()
        {
            _simTimer?.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 = "X",
                MajorGridlineStyle = LineStyle.Dot,
                MinorGridlineStyle = LineStyle.None
            });
            pm.Axes.Add(new LinearAxis
            {
                Position = AxisPosition.Left,
                Title = "Y",
                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 命令处理
        /// <summary>
        /// 添加一条信号：按 _signalCounter 轮转选择不同波形 generator，
        /// 后续 _simTimer 每帧会调用 generator(t) 给曲线追加新点形成滚动效果。
        /// </summary>
        private void OnAddSignal()
        {
            _signalCounter++;
            var color = _palette[(_signalCounter - 1) % _palette.Length];

            // 6 种波形轮转：sin / cos / 锯齿 / 方波 / 衰减正弦 / random walk
            var (waveName, generator) = BuildGenerator(_signalCounter);
            var name = $"{waveName}_{_signalCounter}";

            var series = new LineSeries
            {
                Title = name,
                Color = color,
                StrokeThickness = 1.5
            };

            var item = new SignalItem(name, series, generator);
            Signals.Add(item);
            SelectedSignal = item;

            Plot.Series.Add(series);
            Plot.InvalidatePlot(true);

            StatusMessage = $"已添加信号 [{name}]，当前共 {Signals.Count} 条";
        }

        /// <summary>
        /// 按索引返回一种模拟波形发生器。
        /// 振幅 / 频率 / 相位都做了区分，让多条曲线视觉上分开。
        /// </summary>
        private static (string waveName, Func<double, double> generator) BuildGenerator(int index)
        {
            // 给同种波形不同实例一些随机偏移，避免完全重叠
            double phase = (index * 0.7) % (2 * Math.PI);
            double amp = 1.0 + (index % 3) * 0.3;
            double freq = 0.5 + (index % 4) * 0.2;

            return (index % 6) switch
            {
                0 => ("Sin", t => amp * Math.Sin(2 * Math.PI * freq * t + phase)),
                1 => ("Cos", t => amp * Math.Cos(2 * Math.PI * freq * t + phase)),
                2 => ("Saw", t => amp * (2 * ((t * freq) - Math.Floor(t * freq + 0.5)))),
                3 => ("Square", t => amp * Math.Sign(Math.Sin(2 * Math.PI * freq * t + phase))),
                4 => ("Decay", t => amp * Math.Exp(-0.05 * t) * Math.Sin(2 * Math.PI * freq * t + phase)),
                _ => RandomWalkGenerator(amp),
            };
        }

        /// <summary>构造一个随机游走 generator：在前一次值基础上叠加高斯噪声。</summary>
        private static (string, Func<double, double>) RandomWalkGenerator(double amp)
        {
            double last = 0;
            return ("Walk", _ =>
            {
                last += (_rng.NextDouble() - 0.5) * 0.2 * amp;
                // 软约束在 [-amp*3, amp*3]，避免一直跑偏
                if (last > amp * 3) last = amp * 3;
                if (last < -amp * 3) last = -amp * 3;
                return last;
            });
        }

        /// <summary>删除当前选中信号；若未选中则删除最后一条。</summary>
        private void OnDeleteSignal()
        {
            var target = SelectedSignal ?? Signals.LastOrDefault();
            if (target == null)
            {
                StatusMessage = "无可删除的信号";
                return;
            }

            Plot.Series.Remove(target.Series);
            Signals.Remove(target);
            SelectedSignal = Signals.LastOrDefault();

            Plot.InvalidatePlot(true);
            StatusMessage = $"已删除信号 [{target.Name}]，剩余 {Signals.Count} 条";
        }

        /// <summary>按数据范围复原视图（重置所有坐标轴的缩放/平移）。</summary>
        private void OnResetView()
        {
            Plot.ResetAllAxes();
            Plot.InvalidatePlot(false);
            StatusMessage = "视图已按数据范围复原";
        }

        /// <summary>刷新：触发 PlotView 重绘；后续接数据源时可在此重拉数据。</summary>
        private void OnRefreshData()
        {
            Plot.InvalidatePlot(true);
            StatusMessage = $"已刷新（{DateTime.Now:HH:mm:ss}）";
        }

        /// <summary>双击展开 / 折叠九宫格。</summary>
        private void OnExpand()
        {
            if (string.IsNullOrEmpty(TestStatus)) return;
            _globalInfo.CurrentScope = TestStatus;
            _eventAggregator.GetEvent<ExpandViewEvent>().Publish(TestStatus);
          
        }

        /// <summary>
        /// 模拟数据 tick：每条信号按当前 _simT 算出新点并追加。
        /// 超过 _maxPoints 时丢弃最旧的点形成滚动窗口。
        /// </summary>
        private void OnSimTick(object? sender, EventArgs e)
        {
            _simT += _simInterval;

            if (Signals.Count == 0)
            {
                return;
            }

            foreach (var item in Signals)
            {
                double y = item.Generator(_simT);
                item.Series.Points.Add(new DataPoint(_simT, y));
                if (item.Series.Points.Count > _maxPoints)
                {
                    item.Series.Points.RemoveAt(0);
                }
            }

            // 让 X 轴跟着最新数据滚动
            var xAxis = Plot.Axes.FirstOrDefault(a => a.Position == AxisPosition.Bottom);
            if (xAxis != null)
            {
                double window = _maxPoints * _simInterval;
                xAxis.Minimum = Math.Max(0, _simT - window);
                xAxis.Maximum = _simT + 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 = _globalInfo.ContextDic[TestStatus];
                IsInitiated = true;
            }
        }
        #endregion
    }

    /// <summary>
    /// 信号列表项：UI 显示名 + 对应的 OxyPlot LineSeries 引用 + 模拟数据 generator。
    /// generator(t) 接收当前模拟时间，返回该时刻 y 值。
    /// </summary>
    public class SignalItem
    {
        public string Name { get; }
        public LineSeries Series { get; }
        public Func<double, double> Generator { get; }
        public SignalItem(string name, LineSeries series, Func<double, double> generator)
        {
            Name = name;
            Series = series;
            Generator = generator;
        }
    }
}