Feature: Add & edit hosts file entry

Author: BornToBeRoot

Source/NETworkManager.Models/HostsFileEditor/HostsFileEditor.cs

@@ -287,6 +287,113 @@ private static HostsFileEntryModifyResult DisableEntry(HostsFileEntry entry)
         return HostsFileEntryModifyResult.Success;
     }
 
+    /// <summary>
+    /// Add a hosts file entry asynchronously.
+    /// </summary>
+    /// <param name="entry">Entry to add.</param>
+    /// <returns><see cref="HostsFileEntryModifyResult.Success"/> if the entry was added successfully, otherwise an error result.</returns>"/>
+    public static Task<HostsFileEntryModifyResult> AddEntryAsync(HostsFileEntry entry)
+    {
+        return Task.Run(() => AddEntry(entry));
+    }
+
+    /// <summary>
+    /// Add a hosts file entry.
+    /// </summary>
+    /// <param name="entry">Entry to add.</param>
+    /// <returns><see cref="HostsFileEntryModifyResult.Success"/> if the entry was added successfully, otherwise an error result.</returns>"/>
+    private static HostsFileEntryModifyResult AddEntry(HostsFileEntry entry)
+    {
+        // Create a backup of the hosts file before making changes
+        if (CreateBackup() == false)
+        {
+            Log.Error("AddEntry - Failed to create backup before adding entry.");
+            return HostsFileEntryModifyResult.BackupError;
+        }
+
+        // Add the entry to the hosts file
+        var hostsFileLines = File.ReadAllLines(HostsFilePath).ToList();
+
+        hostsFileLines.Add(CreateEntryLine(entry));
+
+        try
+        {
+            Log.Debug($"AddEntry - Writing changes to hosts file: {HostsFilePath}");
+            File.WriteAllLines(HostsFilePath, hostsFileLines);
+        }
+        catch (Exception ex)
+        {
+            Log.Error($"AddEntry - Failed to write changes to hosts file: {HostsFilePath}", ex);
+            return HostsFileEntryModifyResult.WriteError;
+        }
+
+        return HostsFileEntryModifyResult.Success;
+    }
+
+    /// <summary>
+    /// Edit a hosts file entry asynchronously.
+    /// </summary>
+    /// <param name="entry">Entry to edit.</param>
+    /// <param name="newEntry">New entry to replace the old one.</param>
+    /// <returns><see cref="HostsFileEntryModifyResult.Success"/> if the entry was edited successfully, otherwise an error result.</returns>"/>
+    public static Task<HostsFileEntryModifyResult> EditEntryAsync(HostsFileEntry entry, HostsFileEntry newEntry)
+    {
+        return Task.Run(() => EditEntry(entry, newEntry));
+    }
+
+    /// <summary>
+    /// Edit a hosts file entry.
+    /// </summary>
+    /// <param name="entry">Entry to edit.</param>
+    /// <param name="newEntry">New entry to replace the old one.</param>
+    /// <returns><see cref="HostsFileEntryModifyResult.Success"/> if the entry was edited successfully, otherwise an error result.</returns>"/>
+    public static HostsFileEntryModifyResult EditEntry(HostsFileEntry entry, HostsFileEntry newEntry)
+    {
+        // Create a backup of the hosts file before making changes
+        if (CreateBackup() == false)
+        {
+            Log.Error("EditEntry - Failed to create backup before editing entry.");
+            return HostsFileEntryModifyResult.BackupError;
+        }
+
+        // Replace the entry from the hosts file
+        var hostsFileLines = File.ReadAllLines(HostsFilePath).ToList();
+
+        bool entryFound = false;
+
+        for (var i = 0; i < hostsFileLines.Count; i++)
+        {
+            if (hostsFileLines[i] == entry.Line)
+            {
+                entryFound = true;
+
+                hostsFileLines.RemoveAt(i);
+                hostsFileLines.Insert(i, CreateEntryLine(newEntry));
+
+                break;
+            }
+        }
+
+        if (!entryFound)
+        {
+            Log.Warn($"EditEntry - Entry not found in hosts file: {entry.Line}");
+            return HostsFileEntryModifyResult.NotFound;
+        }
+
+        try
+        {
+            Log.Debug($"EditEntry - Writing changes to hosts file: {HostsFilePath}");
+            File.WriteAllLines(HostsFilePath, hostsFileLines);
+        }
+        catch (Exception ex)
+        {
+            Log.Error($"EditEntry - Failed to write changes to hosts file: {HostsFilePath}", ex);
+            return HostsFileEntryModifyResult.WriteError;
+        }
+
+        return HostsFileEntryModifyResult.Success;
+    }
+
     /// <summary>
     /// Delete a hosts file entry asynchronously.
     /// </summary>
@@ -344,10 +451,29 @@ private static HostsFileEntryModifyResult DeleteEntry(HostsFileEntry entry)
             Log.Error($"DeleteEntry - Failed to write changes to hosts file: {HostsFilePath}", ex);
             return HostsFileEntryModifyResult.WriteError;
         }
-        OnHostsFileChanged();
+
         return HostsFileEntryModifyResult.Success;
     }
 
+    /// <summary>
+    /// Create a line for the hosts file entry.
+    /// </summary>
+    /// <param name="entry">Entry to create the line for.</param>
+    /// <returns>Line for the hosts file entry.</returns>
+    private static string CreateEntryLine(HostsFileEntry entry)
+    {
+        var line = entry.IsEnabled ? "" : "# ";
+
+        line += $"{entry.IPAddress}    {entry.Hostname}";
+
+        if (!string.IsNullOrWhiteSpace(entry.Comment))
+        {
+            line += $"        # {entry.Comment}";
+        }
+
+        return line.Trim();
+    }
+
     /// <summary>
     /// Create a "daily" backup of the hosts file (before making a change).
     /// </summary>

Source/NETworkManager/ViewModels/HostsFileEditorViewModel.cs

@@ -295,11 +295,19 @@ private async Task AddEntryAction()
 
         var childWindow = new HostsFileEditorEntryChildWindow();
 
-        var childWindowViewModel = new HostsFileEditorEntryViewModel(async _ =>
+        var childWindowViewModel = new HostsFileEditorEntryViewModel(async instance =>
         {
             childWindow.IsOpen = false;
             ConfigurationManager.Current.IsChildWindowOpen = false;
 
+            await HostsFileEditor.AddEntryAsync(new HostsFileEntry
+            {
+                IsEnabled = instance.IsEnabled,
+                IPAddress = instance.IPAddress,
+                Hostname = instance.Hostname,
+                Comment = instance.Comment
+            });
+
             IsModifying = false;
         }, _ =>
         {
@@ -326,11 +334,19 @@ private async Task EditEntryAction()
 
         var childWindow = new HostsFileEditorEntryChildWindow();
 
-        var childWindowViewModel = new HostsFileEditorEntryViewModel(async _ =>
+        var childWindowViewModel = new HostsFileEditorEntryViewModel(async instance =>
         {
             childWindow.IsOpen = false;
             ConfigurationManager.Current.IsChildWindowOpen = false;
 
+            await HostsFileEditor.EditEntryAsync(instance.Entry, new HostsFileEntry
+            {
+                IsEnabled = instance.IsEnabled,
+                IPAddress = instance.IPAddress,
+                Hostname = instance.Hostname,
+                Comment = instance.Comment
+            });
+
             IsModifying = false;
         }, _ =>
         {