Refactor and enhance Download Manager application

- Added new services: IContentDialogService, ISnackbarService
- Replaced DashboardPage and DashboardViewModel with DownloadingPage, DownloadingPageViewModel, WaitingPage, and WaitingPageViewModel
- Introduced AddNewTaskPage and AddNewTaskViewModel
- Replaced DownloadServiceManger with DownloadManagerService
- Updated WPF-UI package to 3.0.4 and added HtmlAgilityPack 1.11.61
- Refactored DownloadWorker to use async methods and added retry logic
- Converted DownloadItemData to partial class with ObservableProperty attributes
- Changed initial navigation page to DownloadingPage
- Updated MainWindow navigation items and title
- Added new utility classes: DoubleUtilities, MD5Utilities, StringExtension
- Added new XAML pages and ViewModels for task management and display
- Removed obsolete DashboardPage and related files

DownloaderCore/DownloadWorker.cs

@@ -1,32 +1,41 @@
 using Downloader;
 using DownloadManager.Models;
+using DownloadManager.Models.UrlGetter;
+using DownloadManager.Utilities;
 using System.ComponentModel;
+using System.Diagnostics;
+using System.IO;
 
 namespace DownloadManager.DownloaderCore;
 public class DownloadWorker(DownloadItemData itemData)
 {
-    IDownload? _worker;
-    DownloadItemData _downloadData = itemData;
+    private IDownload? _worker;
+    private DownloadItemData _downloadData = itemData;
+    public DownloadItemData DownloadData => _downloadData;
 
-    public Action<DownloadWorker> OnDownloadStarted;
-    public Action<DownloadWorker> OnDownloadFileCompleted;
-    public Action<DownloadWorker> OnDownloadStop;
+    public Action? OnDownloadStarted;
+    public Action? OnDownloadFileCompleted;
+    public Action? OnDownloadStop;
 
-    public bool BuildDownloadRequest()
+    private int retryCount = 0;
+
+    public async Task<bool> BuildDownloadRequestAsync()
     {
+        var urlGetter = UrlGetterFactory.CreateUrlGetter(_downloadData.UrlGetterType);
+        var fileUrl = await urlGetter.GetFileUrl(_downloadData.Url);
+
+        if (fileUrl.Url == null || fileUrl.Name == null)
+            return false;
+
+        _downloadData.Url = fileUrl.Url;
+        _downloadData.FileName = fileUrl.Name;
+        _downloadData.MD5 = fileUrl.MD5;
+
+        retryCount = _downloadData.DownloadConfiguration.MaxTryAgainOnFailover;
+
         try
         {
-            _worker = new DownloadBuilder()
-                .WithUrl(_downloadData.Url)
-                .WithDirectory(_downloadData.FilePath)
-                .WithFileName(_downloadData.FileName)
-                .WithConfiguration(_downloadData.downloadConfiguration)
-                .Build();
-
-            _worker.DownloadStarted += DownloadStarted;
-            _worker.DownloadProgressChanged += DownloadProgressChanged;
-            _worker.DownloadFileCompleted += DownloadFileCompleted;
-
+            BuildWorker();
             return true;
         }
         catch (Exception)
@@ -36,33 +45,82 @@ public class DownloadWorker(DownloadItemData itemData)
         }
     }
 
+    private void BuildWorker()
+    {
+        _worker = new DownloadBuilder()
+            .WithUrl(_downloadData.Url)
+            .WithDirectory(_downloadData.FilePath)
+            .WithFileName(_downloadData.FileName)
+            .WithConfiguration(_downloadData.DownloadConfiguration)
+            .Build();
+
+        _worker.DownloadStarted += DownloadStarted;
+        _worker.DownloadProgressChanged += DownloadProgressChanged;
+        _worker.DownloadFileCompleted += DownloadFileCompleted;
+    }
+
     private void DownloadStarted(object? sender, DownloadStartedEventArgs e)
     {
         _downloadData.Status = DownloadStatus.Running;
-        OnDownloadStarted?.Invoke(this);
+        _downloadData.FileSize = DoubleUtilities.BytesToMegaBytes(e.TotalBytesToReceive, 2);
+        OnDownloadStarted?.Invoke();
     }
 
     private void DownloadProgressChanged(object? sender, DownloadProgressChangedEventArgs e)
     {
         _downloadData.Progress = (int)e.ProgressPercentage;
-        _downloadData.Speed = e.BytesPerSecondSpeed;
+        _downloadData.Speed = DoubleUtilities.BytesToMegaBytes(e.BytesPerSecondSpeed, 2);
     }
 
-    private void DownloadFileCompleted(object? sender, AsyncCompletedEventArgs e)
+    private async void DownloadFileCompleted(object? sender, AsyncCompletedEventArgs e)
     {
         if (e.Error != null)
         {
             _downloadData.Status = DownloadStatus.Failed;
+            throw e.Error;
         }
         else
         {
             _downloadData.Status = DownloadStatus.Completed;
-        }
+            _worker!.Dispose();
 
-        OnDownloadFileCompleted?.Invoke(this);
+            // Check md5
+            if (_downloadData.MD5 != null)
+            {
+                var fileFullName = Path.Combine(_downloadData.FilePath, _downloadData.FileName!);
+                var md5 = MD5Utilities.GetMD5HashFromFile(fileFullName);
+                if (md5 != _downloadData.MD5)
+                {
+                    await RetryDownload();
+                    return;
+                }
+            }
+
+            OnDownloadFileCompleted?.Invoke();
+        }
     }
 
-    public void StartDownload()
+    private async Task<bool> RetryDownload()
+    {
+        if (retryCount > 0)
+        {
+            retryCount--;
+
+            await Task.Delay(1000);
+
+            await BuildDownloadRequestAsync();
+            StartDownloadAsync();
+
+            return true;
+        }
+        else
+        {
+            _downloadData.Status = DownloadStatus.Failed;
+            return false;
+        }
+    }
+
+    public void StartDownloadAsync()
     {
         if (_worker == null)
             return;
@@ -72,27 +130,18 @@ public class DownloadWorker(DownloadItemData itemData)
 
     public void PauseDownload()
     {
-        if (_worker == null)
-            return;
-
-        _worker.Pause();
-        OnDownloadStop?.Invoke(this);
+        _worker?.Pause();
+        OnDownloadStop?.Invoke();
     }
 
     public void ResumeDownload()
     {
-        if (_worker == null)
-            return;
-
-        _worker.Resume();
+        _worker?.Resume();
     }
 
     public void StopDownload()
     {
-        if (_worker == null)
-            return;
-
-        _worker.Stop();
-        OnDownloadStop?.Invoke(this);
+        _worker?.Stop();
+        OnDownloadStop?.Invoke();
     }
 }