using System.Collections.ObjectModel;
using System.Windows;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using SSPCTester.Devices.Interfaces;
using SSPCTester.Logic.Models;
using SSPCTester.Logic.Testing;
using SSPCTester.UI.Services;

namespace SSPCTester.UI.ViewModels;

/// <summary>基础测试页 VM：24 通道 + 行内开/关按钮 + 统计条 + 一键测试全部。</summary>
public partial class BasicTestViewModel : ObservableObject
{
    private const int SwitchSettleDelayMs = BasicTestCriteria.SwitchSettleDelayMs;
    private readonly ISspc _sspc;
    private readonly UiLogSink _log;
    private readonly object _pollLock = new();
    private readonly HashSet<int> _pollingChannels = new();
    private CancellationTokenSource? _pollCts;
    private Task? _pollTask;
    private CancellationTokenSource? _runAllCts;

    [ObservableProperty] private bool _busy;
    [ObservableProperty] private bool _isBatchRunning;
    [ObservableProperty] private Project? _project;
    [ObservableProperty] private int _selectedRefreshRateHz = 5;

    public ObservableCollection<ChannelResult> Rows { get; } = new();
    public IReadOnlyList<int> RefreshRatesHz { get; } = new[] { 2, 5 };

    public BasicTestViewModel(ISspc sspc, UiLogSink log)
    {
        _sspc = sspc; _log = log;
    }

    public int Total => Rows.Count;
    public int PassCount => Rows.Count(r => r.Status == TestStatus.Pass);
    public int FailCount => Rows.Count(r => r.Status == TestStatus.Fail);
    public int UntestedCount => Rows.Count(r => r.Status == TestStatus.Untested);
    public bool CanRunAll => !Busy && !IsBatchRunning;

    partial void OnBusyChanged(bool value) => OnPropertyChanged(nameof(CanRunAll));

    partial void OnIsBatchRunningChanged(bool value) => OnPropertyChanged(nameof(CanRunAll));

    public void SetProject(Project p)
    {
        StopAllPolling();
        Project = p;
        Rows.Clear();
        if (p.BasicResults.Count == 0)
        {
            for (int i = 1; i <= _sspc.ChannelCount; i++)
                p.BasicResults.Add(new ChannelResult { Channel = i });
        }
        foreach (var r in p.BasicResults)
        {
            r.PropertyChanged += (_, _) => RaiseStats();
            Rows.Add(r);
        }
        RaiseStats();
    }

    private void RaiseStats()
    {
        Application.Current?.Dispatcher.Invoke(() =>
        {
            OnPropertyChanged(nameof(PassCount));
            OnPropertyChanged(nameof(FailCount));
            OnPropertyChanged(nameof(UntestedCount));
            OnPropertyChanged(nameof(Total));
        });
    }

    [RelayCommand]
    private async Task TurnOn(ChannelResult? row)
    {
        if (row == null) return;
        Busy = true;
        try
        {
            if (!_sspc.IsConnected) await _sspc.ConnectAsync();
            row.Status = TestStatus.Running;
            await _sspc.TurnOnAsync(row.Channel);
            await Task.Delay(SwitchSettleDelayMs);
            var measurement = await ReadDisplayedMeasurementAsync(row.Channel, CancellationToken.None);
            ApplyOnMeasurement(row, measurement);
            bool onOk = BasicTestCriteria.IsOnState(row.VoltageOn, row.CurrentOn);
            row.Status = onOk ? TestStatus.Running : TestStatus.Fail;
            StartPolling(row.Channel);
            _log.Add(onOk ? UiLogLevel.Info : UiLogLevel.Error,
                $"CH{row.Channel} 开 -> V={row.VoltageOn:F2}V I={row.CurrentOn:F3}A  {(onOk ? "开状态合格" : "开状态不合格")}");
        }
        catch (Exception ex)
        {
            await StopPollingAsync(row.Channel);
            row.Status = TestStatus.Fail;
            _log.Add(UiLogLevel.Error, $"CH{row.Channel} 开启或读取失败：{ex.Message}");
            try { await _sspc.TurnOffAsync(row.Channel); } catch { }
        }
        finally { Busy = false; }
    }

    [RelayCommand]
    private async Task TurnOff(ChannelResult? row)
    {
        if (row == null) return;
        Busy = true;
        try
        {
            if (!_sspc.IsConnected) await _sspc.ConnectAsync();
            await StopPollingAsync(row.Channel);
            await _sspc.TurnOffAsync(row.Channel);
            await Task.Delay(SwitchSettleDelayMs);
            var offResult = await BasicTestCriteria.WaitForStableOffAsync(
                _sspc,
                row.Channel,
                onSample: measurement => ApplyOffMeasurement(row, measurement),
                readSampleAsync: ReadDisplayedMeasurementAsync);
            ApplyOffMeasurement(row, offResult.Measurement);
            bool onOk = BasicTestCriteria.IsOnState(row.VoltageOn, row.CurrentOn);
            bool offOk = offResult.IsStableOff;
            row.Status = (onOk && offOk) ? TestStatus.Pass : TestStatus.Fail;
            string verdict = row.Status == TestStatus.Pass ? "合格" : "不合格";
            string offState = offOk ? "已稳定关断" : "关断超时";
            _log.Add(row.Status == TestStatus.Pass ? UiLogLevel.Success : UiLogLevel.Error,
                $"CH{row.Channel} 关 -> V={row.VoltageOff:F2}V I={row.CurrentOff:F3}A  {offState}  {verdict}");
        }
        catch (Exception ex)
        {
            await StopPollingAsync(row.Channel);
            row.Status = TestStatus.Fail;
            _log.Add(UiLogLevel.Error, $"CH{row.Channel} 关断或读取失败：{ex.Message}");
            try { await _sspc.TurnOffAsync(row.Channel); } catch { }
        }
        finally { Busy = false; }
    }

    [RelayCommand]
    private async Task RunAll()
    {
        if (IsBatchRunning) return;

        _runAllCts?.Dispose();
        _runAllCts = new CancellationTokenSource();
        var ct = _runAllCts.Token;

        Busy = true;
        IsBatchRunning = true;
        try
        {
            foreach (var row in Rows)
            {
                ct.ThrowIfCancellationRequested();
                await RunChannelAsync(row, ct);
            }
            _log.Add(UiLogLevel.Success, "基础测试全部完成。");
        }
        catch (OperationCanceledException)
        {
            foreach (var row in Rows)
            {
                if (row.Status == TestStatus.Running)
                    row.Status = TestStatus.Untested;
            }
            _log.Add(UiLogLevel.Warning, "基础测试批量测试已中断。");
        }
        finally
        {
            _runAllCts?.Dispose();
            _runAllCts = null;
            IsBatchRunning = false;
            Busy = false;
        }
    }

    [RelayCommand]
    private async Task CancelRunAll()
    {
        if (!IsBatchRunning) return;

        _runAllCts?.Cancel();
        foreach (var row in Rows)
        {
            if (row.Status != TestStatus.Running) continue;

            try
            {
                await StopPollingAsync(row.Channel);
                await _sspc.TurnOffAsync(row.Channel);
            }
            catch { }
        }
    }

    private async Task RunChannelAsync(ChannelResult row, CancellationToken ct)
    {
        if (!_sspc.IsConnected) await _sspc.ConnectAsync(ct);

        row.Status = TestStatus.Running;
        _log.Add(UiLogLevel.Info, $"CH{row.Channel} 基础测试开始：执行开状态测试。");
        await _sspc.TurnOnAsync(row.Channel, ct);
        await Task.Delay(SwitchSettleDelayMs, ct);

        var measurement = await ReadDisplayedMeasurementAsync(row.Channel, ct);
        ApplyOnMeasurement(row, measurement);
        bool onOk = BasicTestCriteria.IsOnState(row.VoltageOn, row.CurrentOn);
        _log.Add(onOk ? UiLogLevel.Info : UiLogLevel.Error,
            $"CH{row.Channel} 开 -> V={row.VoltageOn:F2}V I={row.CurrentOn:F3}A  {(onOk ? "开状态合格" : "开状态不合格")}");
        StartPolling(row.Channel);

        ct.ThrowIfCancellationRequested();

        await StopPollingAsync(row.Channel);
        _log.Add(UiLogLevel.Info, $"CH{row.Channel} 执行关状态测试。");
        await _sspc.TurnOffAsync(row.Channel, ct);
        await Task.Delay(SwitchSettleDelayMs, ct);

        var offResult = await BasicTestCriteria.WaitForStableOffAsync(
            _sspc,
            row.Channel,
            ct,
            measurement => ApplyOffMeasurement(row, measurement),
            ReadDisplayedMeasurementAsync);
        ApplyOffMeasurement(row, offResult.Measurement);
        bool offOk = offResult.IsStableOff;
        row.Status = (onOk && offOk) ? TestStatus.Pass : TestStatus.Fail;
        string verdict = row.Status == TestStatus.Pass ? "合格" : "不合格";
        string offState = offOk ? "已稳定关断" : "关断超时";
        _log.Add(row.Status == TestStatus.Pass ? UiLogLevel.Success : UiLogLevel.Error,
            $"CH{row.Channel} 关 -> V={row.VoltageOff:F2}V I={row.CurrentOff:F3}A  {offState}  {verdict}");
    }

    [RelayCommand]
    private void Clear()
    {
        foreach (var r in Rows)
        {
            r.VoltageOn = 0; r.CurrentOn = 0; r.VoltageOff = 0; r.CurrentOff = 0;
            r.DisplayVoltage = 0; r.DisplayCurrent = 0;
            r.Status = TestStatus.Untested;
        }
    }

    private void StartPolling(int channel)
    {
        lock (_pollLock)
        {
            _pollingChannels.Add(channel);
            if (_pollTask is { IsCompleted: false }) return;

            _pollCts = new CancellationTokenSource();
            _pollTask = PollMeasurementsAsync(_pollCts.Token);
        }
    }

    private async Task StopPollingAsync(int channel)
    {
        Task? taskToWait = null;
        CancellationTokenSource? ctsToDispose = null;
        lock (_pollLock)
        {
            _pollingChannels.Remove(channel);
            if (_pollingChannels.Count != 0 || _pollCts == null) return;

            _pollCts.Cancel();
            taskToWait = _pollTask;
            ctsToDispose = _pollCts;
            _pollTask = null;
            _pollCts = null;
        }

        if (taskToWait != null)
        {
            try { await taskToWait; }
            catch (OperationCanceledException) { }
        }
        ctsToDispose?.Dispose();
    }

    private void StopAllPolling()
    {
        lock (_pollLock)
        {
            _pollingChannels.Clear();
            _pollCts?.Cancel();
            _pollCts = null;
            _pollTask = null;
        }
    }

    private async Task<ChannelMeasurement> ReadDisplayedMeasurementAsync(int channel, CancellationToken ct)
    {
        var measurements = await _sspc.ReadMeasurementsAsync(ct);
        var measurement = measurements.FirstOrDefault(x => x.PhysicalSlot == channel);
        if (measurement != null)
            return measurement;

        return await _sspc.ReadMeasurementAsync(channel, ct);
    }

    private static void ApplyOnMeasurement(ChannelResult row, ChannelMeasurement measurement)
    {
        ApplyMeasurement(row, measurement, isOnMeasurement: true);
    }

    private static void ApplyOffMeasurement(ChannelResult row, ChannelMeasurement measurement)
    {
        ApplyMeasurement(row, measurement, isOnMeasurement: false);
    }

    private static void ApplyMeasurement(ChannelResult row, ChannelMeasurement measurement, bool isOnMeasurement)
    {
        void Apply()
        {
            double voltage = measurement.Voltage;
            double current = Math.Abs(measurement.Current);
            if (isOnMeasurement)
            {
                row.VoltageOn = voltage;
                row.CurrentOn = current;
            }
            else
            {
                row.VoltageOff = voltage;
                row.CurrentOff = current;
            }

            row.DisplayVoltage = voltage;
            row.DisplayCurrent = current;
        }

        var dispatcher = Application.Current?.Dispatcher;
        if (dispatcher == null || dispatcher.CheckAccess())
            Apply();
        else
            dispatcher.Invoke(Apply);
    }

    private async Task PollMeasurementsAsync(CancellationToken ct)
    {
        while (!ct.IsCancellationRequested)
        {
            int refreshRate = Math.Max(1, SelectedRefreshRateHz);
            await Task.Delay(TimeSpan.FromSeconds(1.0 / refreshRate), ct);

            IReadOnlyList<ChannelMeasurement> measurements;
            try
            {
                measurements = await _sspc.ReadMeasurementsAsync(ct);
            }
            catch (OperationCanceledException) when (ct.IsCancellationRequested)
            {
                break;
            }
            catch (Exception ex)
            {
                _log.Add(UiLogLevel.Error, $"基础测试刷新失败：{ex.Message}");
                continue;
            }

            HashSet<int> activeChannels;
            lock (_pollLock)
                activeChannels = _pollingChannels.ToHashSet();

            foreach (var measurement in measurements)
            {
                if (!activeChannels.Contains(measurement.PhysicalSlot)) continue;
                var row = Rows.FirstOrDefault(x => x.Channel == measurement.PhysicalSlot);
                if (row == null) continue;

                ApplyOnMeasurement(row, measurement);
            }
        }
    }
}