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;
using System.Windows.Data;

namespace Hopetry.ViewModel.Send;

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

    // todo 完成取消下载及暂停下载逻辑
    public RelayCommand<DownItem> OpenDownItemFolder { get; set; }
    public RelayCommand<string> LoadData { get; set; }
    private readonly ConcurrentQueue<MinioDownloadTask> _taskQueue = new();
    private SemaphoreSlim _concurrencySemaphore;

    private CancellationTokenSource _processingCts = new();

    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> Tasks { get; } = new();

    // 所有任务
    public ObservableCollection<MinioDownloadTask> AllTasks { get; set; }

    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; }
    public ICommand ClearFinishedCommand { get; }


    private ObservableCollection<DownItem> _downItems;


    public ObservableCollection<DownItem> DownItems
    {
        get => _downItems;
        set
        {
            _downItems = value;
            RaisePropertyChanged();
        }
    }

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="minioService"></param>
    public DownViewModel(MinioService minioService)
    {
        _minioService = minioService;
        Console.WriteLine("初始化DownViewModel");
        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<DownItem>(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 == "下载中";
            e.Accepted = b;
        };
        RunningTasksView = cvsRunning.View;

        var cvsPaused = new CollectionViewSource { Source = AllTasks };
        cvsPaused.Filter += (s, e) =>
        {
            var b = ((MinioDownloadTask)e.Item).Status == "已完成";
            e.Accepted = b;
        };
        FinishedTasksView = cvsPaused.View;
        if (FinishedTasksView is ListCollectionView finishListView)
        {
            FinishedTaskHeader = $"下载中（{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
        _concurrencySemaphore = new SemaphoreSlim(_maxConcurrent);
        new Thread(ProcessTasksLoop) { IsBackground = true }.Start();
    }

    private void ProcessTasksLoop()
    {
        while (!_processingCts.IsCancellationRequested)
        {
            // 按当前并发数启动任务
            for (int i = 0; i < _maxConcurrent; i++)
            {
                if (_taskQueue.TryDequeue(out var task))
                {
                    _ = ExecuteTaskAsync(task);
                }
            }

            Thread.Sleep(100);
        }
    }

    private void AddTask()
    {
        var task = new MinioDownloadTask(_minioService, NewBucket, NewObjectName);
        Tasks.Add(task);
        _taskQueue.Enqueue(task);
        RaisePropertyChanged(nameof(NewBucket));
        RaisePropertyChanged(nameof(NewObjectName));
    }

    private bool CanAddTask() => !string.IsNullOrEmpty(NewBucket) && !string.IsNullOrEmpty(NewObjectName);

    private async Task ExecuteTaskAsync(MinioDownloadTask task)
    {
        RunningTasks++;
        try
        {
            // todo 配置下载路径
            var savePath = Path.Combine(task.FileName);
            await task.StartDownload(savePath);
        }
        finally
        {
            RunningTasks--;
            // 任务完成后自动处理下一个
            if (!_processingCts.IsCancellationRequested)
                ProcessTasksLoop();
        }
    }

    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();
                }
            }
        }
    }

    // 绑定属性
    private string _newBucket;

    public string NewBucket
    {
        get => _newBucket;
        set
        {
            _newBucket = value;
            RaisePropertyChanged();
        }
    }

    private string _newObjectName;

    public string NewObjectName
    {
        get => _newObjectName;
        set
        {
            _newObjectName = value;
            RaisePropertyChanged();
        }
    }

    public void DoOpenDownItemFolder(DownItem para)
    {
        Console.WriteLine($"点击了什么值：{JsonConvert.SerializeObject(para)}");
        Process.Start("explorer.exe", para.FilePath);
    }

    protected override void Init()
    {
    }

    protected override void Loaded(string args)
    {
    }

    [SugarTable("f_down_item")]
    public class DownItem
    {
        public DownItem()
        {
        }

        [SugarColumn(IsPrimaryKey = true, IsIdentity = true, ColumnName = "id")]
        public long Id { get; set; }

        // 进度  已下载  多久下载完成 下载速度  
        [SugarColumn(IsIgnore = true)] public int ProgressInt { get; set; }

        /// <summary>
        /// object key 
        /// </summary>
        [SugarColumn(ColumnName = "object_key")]
        public string ObjectKey { get; set; }

        /// <summary>
        /// 文件名称
        /// </summary>
        [SugarColumn(ColumnName = "file_name")]
        public string FileName { get; set; }

        /// <summary>
        /// 文件类型
        /// </summary>
        [SugarColumn(ColumnName = "file_type")]
        public string FileType { get; set; }

        /// <summary>
        /// 文件大小
        /// </summary>
        [SugarColumn(ColumnName = "file_size")]
        public long FileSize { get; set; }

        /// <summary>
        /// 速度   100kb/s
        /// </summary>
        [SugarColumn(IsIgnore = true)]
        public long Speed { get; set; }

        /// <summary>
        /// 本地保存路径
        /// </summary>
        [SugarColumn(ColumnName = "file_path")]
        public string FilePath { get; set; }

        /// <summary>
        /// 文件的ETag
        /// </summary>
        [SugarColumn(ColumnName = "file_etag")]
        public string FileETag { get; set; }
    }
}