FieldWorkClient/ViewModel/Send/DownViewModel.cs

using System.Collections.Concurrent;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Windows.Data;
using System.Windows.Input;
using HeBianGu.Base.WpfBase;
using HeBianGu.Service.Mvc;
using Hopetry.Models;
using Hopetry.Provider;
using Hopetry.Services;
using Newtonsoft.Json;
using SqlSugar;

namespace Hopetry.ViewModel.Send;

[ViewModel("Down")]
public class DownViewModel : MvcViewModelBase
{
    private readonly MinioService _minioService;

    public RelayCommand<MinioDownloadTask> OpenDownItemFolder { get; set; }
    private readonly ConcurrentQueue<MinioDownloadTask> _taskQueue = new();
    private SemaphoreSlim _concurrencySemaphore;

    private CancellationTokenSource _processingCts = new();
    public int count { get; set; }

    private SemaphoreSlim _semaphore;
    private readonly ReaderWriterLockSlim _lock = new();

    /// <summary>
    /// 全部任务动态标题
    /// </summary>
    private string _allTaskHeader;

    public string AllTaskHeader
    {
        get => _allTaskHeader;
        set
        {
            _allTaskHeader = value;
            RaisePropertyChanged();
        }
    }

    private string _runningTaskHeader;

    public string RunningTaskHeader
    {
        get => _runningTaskHeader;
        set
        {
            _runningTaskHeader = value;
            RaisePropertyChanged();
        }
    }

    private string _finishedTaskHeader;

    public string FinishedTaskHeader
    {
        get => _finishedTaskHeader;
        set
        {
            _finishedTaskHeader = value;
            RaisePropertyChanged();
        }
    }

    // 绑定属性
    public ObservableCollection<MinioDownloadTask> AllTasks { get; set; } = new();


    public ICollectionView RunningTasksView { get; set; }
    public ICollectionView FinishedTasksView { get; set; }
    private int _maxConcurrent = 3;

    public int MaxConcurrent
    {
        get => _maxConcurrent;
        set
        {
            if (value < 1) value = 1;
            if (_maxConcurrent == value) return;

            _maxConcurrent = value;
            //AdjustConcurrency();
            RaisePropertyChanged();
        }
    }

    private int _runningTasks;

    public int RunningTasks
    {
        get => _runningTasks;
        private set
        {
            _runningTasks = value;
            RaisePropertyChanged();
        }
    }

    // 命令
    public ICommand AddTaskCommand { get; set; }
    public ICommand ClearFinishedCommand { get; }


    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="minioService"></param>
    public DownViewModel(MinioService minioService, SemaphoreSlim semaphore)
    {
        _minioService = minioService;
        _semaphore = semaphore;
        Console.WriteLine("初始化DownViewModel");
        using var client = SqlSugarConfig.GetSqlSugarScope();
        var data = client.Ado.SqlQuery<MinioDownloadTask>($"select * from download_task");
        //DownItems = new ObservableCollection<DownItem>(data);
        AllTasks = new ObservableCollection<MinioDownloadTask>(data);
        AllTaskHeader = $"全部（{AllTasks.Count}）";
        //Console.WriteLine(JsonConvert.SerializeObject(data));
        OpenDownItemFolder = new RelayCommand<MinioDownloadTask>(DoOpenDownItemFolder);
        // 命令初始化
        // AddTaskCommand = new RelayCommand(AddTask, CanAddTask);
        // 修正：使用 CollectionViewSource 确保通知
        var cvsRunning = new CollectionViewSource { Source = AllTasks };
        cvsRunning.Filter += (s, e) =>
        {
            var b = ((MinioDownloadTask)e.Item).Status is "下载中" or "等待中" or "已暂停";
            e.Accepted = b;
        };
        RunningTasksView = cvsRunning.View;

        var cvsFinished = new CollectionViewSource { Source = AllTasks };
        cvsFinished.Filter += (s, e) =>
        {
            var b = ((MinioDownloadTask)e.Item).Status == "已完成";
            e.Accepted = b;
        };
        FinishedTasksView = cvsFinished.View;
        if (FinishedTasksView is ListCollectionView finishListView)
        {
            FinishedTaskHeader = $"已完成（{finishListView.Count}）";
        }

        if (RunningTasksView is ListCollectionView runningListView)
        {
            RunningTaskHeader = $"下载中（{runningListView.Count}）";
        }

        // 关键：订阅数据源变更事件，强制视图刷新
        AllTasks.CollectionChanged += (s, e) =>
        {
            RunningTasksView.Refresh();
            FinishedTasksView.Refresh();
        };

        ClearFinishedCommand = new CustomCommand(() =>
        {
            // todo 删除已完成的下载记录
        });

        // 启动任务处理线程
        _semaphore = new SemaphoreSlim(_maxConcurrent);
        // 启动任务处理线程
        _concurrencySemaphore = new SemaphoreSlim(_maxConcurrent);
        new Thread(ProcessTasksLoop) { IsBackground = true }.Start();


        AddTaskCommand = new ActionCommand(AddTask);
    }

    private void ProcessTasksLoop()
    {
        while (!_processingCts.IsCancellationRequested)
        {
            _semaphore.WaitAsync();
            // 按当前并发数启动任务
            for (int i = 0; i < _maxConcurrent; i++)
            {
                if (_taskQueue.TryDequeue(out var task))
                {
                    // 启动新线程执行下载任务
                    _ = Task.Run(() => ExecuteTaskAsync(task));
                }
            }

            Thread.Sleep(100);
        }
    }

    private void AddTask()
    {
        string[] objectKeys = { "demo/06.mp4", "demo/07.mp4", "demo/08.mp4", "demo/10.mp4" };
        var task = new MinioDownloadTask(_minioService, "demo", objectKeys[count++]);
        using var client = SqlSugarConfig.GetSqlSugarScope();
        client.Insertable(task).ExecuteCommandIdentityIntoEntity();
        AllTasks.Add(task);
        _taskQueue.Enqueue(task);
    }


    private async Task ExecuteTaskAsync(MinioDownloadTask task)
    {
        try
        {
            await task.StartDownload();
            // todo 任务完成下载
        }
        finally
        {
            _semaphore.Release();
        }
    }

    private void AdjustConcurrency()
    {
        lock (_concurrencySemaphore)
        {
            // 调整信号量容量
            var delta = _maxConcurrent - _concurrencySemaphore.CurrentCount;
            if (delta > 0)
            {
                for (int i = 0; i < delta; i++)
                {
                    _concurrencySemaphore.Release();
                }
            }
        }
    }

    public void DoOpenDownItemFolder(MinioDownloadTask para)
    {
        Console.WriteLine($"点击item值：{JsonConvert.SerializeObject(para)}");
        Process.Start("explorer.exe", para.FilePath);
    }

    public void DoCancelDownItem(MinioDownloadTask item)
    {
        Console.WriteLine("取消下载");
        // todo 实现取消下载
    }

    public void DoPauseDownItem(MinioDownloadTask item)
    {
        Console.WriteLine("暂停下载");
        // todo 实现暂停下载
    }

    protected override void Init()
    {
    }

    protected override void Loaded(string args)
    {
    }
}