FieldWorkClient/Services/MinioDownloadTask.cs

using System.Windows;
using System.Windows.Input;
using HeBianGu.Base.WpfBase;
using Hopetry.Models;
using SqlSugar;

namespace Hopetry.Services;

using System;
using System.IO;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.ComponentModel;
using Minio;

[SugarTable(TableName = "download_task")]
public class MinioDownloadTask : INotifyPropertyChanged
{
    private readonly MinioService _minio;

    /// <summary>
    /// 
    /// </summary>
    private CancellationTokenSource _cts;

    /// <summary>
    /// 
    /// </summary>
    private ManualResetEventSlim _pauseEvent = new(true);

    // 任务属性（绑定到UI）
    [SugarColumn(ColumnName = "task_id")] public int TaskId { get; set; }

    [SugarColumn(ColumnName = "file_name")]
    public string FileName { get; set; }

    [SugarColumn(ColumnName = "bucket_name")]
    public string Bucket { get; set; }

    [SugarColumn(ColumnName = "object_key")]
    public string ObjectKey { get; set; }

    [SugarColumn(ColumnName = "total_size")]
    public long TotalSize { get; private set; }

    [SugarColumn(ColumnName = "downloaded")]
    public long Downloaded { get; private set; }

    [SugarColumn(ColumnName = "file_path")]
    public string FilePath { get; set; }

    [SugarColumn(ColumnName = "status")]
    public string Status { get; private set; } = "等待中";

    public string Progress
    {
        get { return TotalSize == 0 ? "0%" : $"{(Downloaded * 100 / TotalSize):0.0}%"; }
    }

    // 命令
    public ICommand PauseCommand { get; }
    public ICommand CancelCommand { get; }

    public MinioDownloadTask()
    {
        PauseCommand = new CustomCommand(OnPause);
        CancelCommand = new CustomCommand(OnCancel);
    }
    public MinioDownloadTask(MinioService minio, string bucket, string objectKey)
    {
        _minio = minio;
        Bucket = bucket;
        ObjectKey = objectKey;
        TaskId = Interlocked.Increment(ref _globalId);
        FileName = Path.GetFileName(objectKey);

        PauseCommand = new CustomCommand(OnPause);
        CancelCommand = new CustomCommand(OnCancel);
    }

    /// <summary>
    /// 下载
    /// </summary>
    /// <param name="savePath"></param>
    public async Task StartDownload(string savePath)
    {
        Status = "初始化";
        _cts = new CancellationTokenSource();
        var tmpPath = $"{savePath}.download";

        try
        {
            // 断点续传初始化
            if (File.Exists(tmpPath))
                Downloaded = new FileInfo(tmpPath).Length;

            // 获取文件信息
            var stat = await _minio.GetObjectMetadata(Bucket, ObjectKey);
            TotalSize = stat.Size;

            if (Downloaded >= TotalSize)
            {
                Status = "已完成";
                return;
            }

            // todo 下载逻辑
            Status = "已完成";
        }
        catch (OperationCanceledException)
        {
            Status = "已取消";
        }
        catch (Exception ex)
        {
            Status = $"错误：{ex.Message}";
        }
        finally
        {
            _pauseEvent.Dispose();
            OnPropertyChanged(nameof(Status));
        }
    }

    private void OnPause()
    {
        if (Status == "下载中")
        {
            _pauseEvent.Reset();
            Status = "已暂停";
        }
        else if (Status == "已暂停")
        {
            _pauseEvent.Set();
            Status = "下载中";
        }

        OnPropertyChanged(nameof(Status));
    }

    private void OnCancel()
    {
        _cts?.Cancel();
        Status = "已取消";
        OnPropertyChanged(nameof(Status));
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string propertyName)
        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

    private static int _globalId;
}