Add config save/load support

SqlcmdGuiApp/Configuration.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+
+namespace SqlcmdGuiApp
+{
+    public class Configuration
+    {
+        public string FilePath { get; set; } = string.Empty;
+        public string Server { get; set; } = string.Empty;
+        public string Database { get; set; } = string.Empty;
+        public bool UseSqlAuth { get; set; }
+        public string User { get; set; } = string.Empty;
+        public string Password { get; set; } = string.Empty;
+        public bool Encrypt { get; set; }
+        public bool TrustServerCertificate { get; set; }
+        public bool ReadOnlyIntent { get; set; }
+        public List<SqlParameter> Parameters { get; set; } = new();
+    }
+}

SqlcmdGuiApp/MainWindow.xaml

@@ -65,6 +65,8 @@
         </GroupBox>
 
         <StackPanel Grid.Row="3" Grid.ColumnSpan="2" Orientation="Horizontal" HorizontalAlignment="Center" Margin="0 5 0 0">
+            <Button Content="Load Config" Margin="5" Width="100" Click="LoadConfigButton_Click"/>
+            <Button Content="Save Config" Margin="5" Width="100" Click="SaveConfigButton_Click"/>
             <Button Content="Test Connection" Margin="5" Width="120" Click="TestConnectionButton_Click"/>
             <Button Content="View Command-Line" Margin="5" Width="120" Click="ViewCommandLineButton_Click"/>
             <Button Content="Execute" Margin="5" Width="80" Click="ExecuteButton_Click"/>

SqlcmdGuiApp/MainWindow.xaml.cs

@@ -9,6 +9,7 @@
 using System.Linq;
 using System.Text.RegularExpressions;
 using System.Security.Principal;
+using System.Text.Json;
 
 namespace SqlcmdGuiApp
 {
@@ -143,6 +144,71 @@ private string BuildCommandLine()
             return "sqlcmd " + string.Join(" ", args);
         }
 
+        private void SaveConfigButton_Click(object sender, RoutedEventArgs e)
+        {
+            var dlg = new SaveFileDialog { Filter = "JSON Files (*.json)|*.json|All Files (*.*)|*.*" };
+            if (dlg.ShowDialog() != true) return;
+
+            var config = new Configuration
+            {
+                FilePath = FilePathTextBox.Text,
+                Server = ServerTextBox.Text,
+                Database = DatabaseTextBox.Text,
+                UseSqlAuth = AuthComboBox.SelectedIndex == 1,
+                User = UserTextBox.Text,
+                Password = PasswordBox.Password,
+                Encrypt = EncryptCheckBox.IsChecked == true,
+                TrustServerCertificate = TrustServerCertificateCheckBox.IsChecked == true,
+                ReadOnlyIntent = ReadOnlyIntentCheckBox.IsChecked == true,
+                Parameters = Parameters.Select(p => new SqlParameter { Name = p.Name, Value = p.Value }).ToList()
+            };
+
+            try
+            {
+                var json = JsonSerializer.Serialize(config, new JsonSerializerOptions { WriteIndented = true });
+                File.WriteAllText(dlg.FileName, json);
+            }
+            catch (Exception ex)
+            {
+                App.LogError(ex.ToString());
+                MessageBox.Show("Failed to save configuration. See error.log for details.");
+            }
+        }
+
+        private void LoadConfigButton_Click(object sender, RoutedEventArgs e)
+        {
+            var dlg = new OpenFileDialog { Filter = "JSON Files (*.json)|*.json|All Files (*.*)|*.*" };
+            if (dlg.ShowDialog() != true) return;
+
+            try
+            {
+                var json = File.ReadAllText(dlg.FileName);
+                var config = JsonSerializer.Deserialize<Configuration>(json);
+                if (config == null) throw new InvalidOperationException("Invalid configuration file.");
+
+                FilePathTextBox.Text = config.FilePath;
+                ServerTextBox.Text = config.Server;
+                DatabaseTextBox.Text = config.Database;
+                AuthComboBox.SelectedIndex = config.UseSqlAuth ? 1 : 0;
+                UserTextBox.Text = config.User;
+                PasswordBox.Password = config.Password;
+                EncryptCheckBox.IsChecked = config.Encrypt;
+                TrustServerCertificateCheckBox.IsChecked = config.TrustServerCertificate;
+                ReadOnlyIntentCheckBox.IsChecked = config.ReadOnlyIntent;
+
+                Parameters.Clear();
+                foreach (var p in config.Parameters)
+                {
+                    Parameters.Add(new SqlParameter { Name = p.Name, Value = p.Value });
+                }
+            }
+            catch (Exception ex)
+            {
+                App.LogError(ex.ToString());
+                MessageBox.Show("Failed to load configuration. See error.log for details.");
+            }
+        }
+
         private async void ExecuteButton_Click(object sender, RoutedEventArgs e)
         {
             if (!File.Exists(FilePathTextBox.Text))