[fxcop] Settings UI library (part 4) - project/namespace renames (#7403)

* Rename Interface to Interfaces in namespaces

* Rename Lib to Library in namespaces

* Rename project and directory and enable fxcop

* Add CA2213 suppression

* Minor fixes

src/core/Microsoft.PowerToys.Settings.UI.Library/SettingsUtils.cs

@@ -0,0 +1,137 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Text.Json;
+using Microsoft.PowerToys.Settings.UI.Library.Interfaces;
+using Microsoft.PowerToys.Settings.UI.Library.Utilities;
+
+namespace Microsoft.PowerToys.Settings.UI.Library
+{
+    public class SettingsUtils : ISettingsUtils
+    {
+        private const string DefaultFileName = "settings.json";
+        private const string DefaultModuleName = "";
+        private IIOProvider _ioProvider;
+
+        public SettingsUtils(IIOProvider ioProvider)
+        {
+            _ioProvider = ioProvider ?? throw new ArgumentNullException(nameof(ioProvider));
+        }
+
+        private bool SettingsFolderExists(string powertoy)
+        {
+            return _ioProvider.DirectoryExists(System.IO.Path.Combine(LocalApplicationDataFolder(), $"Microsoft\\PowerToys\\{powertoy}"));
+        }
+
+        private void CreateSettingsFolder(string powertoy)
+        {
+            _ioProvider.CreateDirectory(System.IO.Path.Combine(LocalApplicationDataFolder(), $"Microsoft\\PowerToys\\{powertoy}"));
+        }
+
+        public void DeleteSettings(string powertoy = "")
+        {
+            _ioProvider.DeleteDirectory(System.IO.Path.Combine(LocalApplicationDataFolder(), $"Microsoft\\PowerToys\\{powertoy}"));
+        }
+
+        /// <summary>
+        /// Get path to the json settings file.
+        /// </summary>
+        /// <returns>string path.</returns>
+        public static string GetSettingsPath(string powertoy, string fileName = DefaultFileName)
+        {
+            if (string.IsNullOrWhiteSpace(powertoy))
+            {
+                return System.IO.Path.Combine(
+                    LocalApplicationDataFolder(),
+                    $"Microsoft\\PowerToys\\{fileName}");
+            }
+
+            return System.IO.Path.Combine(
+                LocalApplicationDataFolder(),
+                $"Microsoft\\PowerToys\\{powertoy}\\{fileName}");
+        }
+
+        public bool SettingsExists(string powertoy = DefaultModuleName, string fileName = DefaultFileName)
+        {
+            return _ioProvider.FileExists(GetSettingsPath(powertoy, fileName));
+        }
+
+        /// <summary>
+        /// Get a Deserialized object of the json settings string.
+        /// This function creates a file in the powertoy folder if it does not exist and returns an object with default properties.
+        /// </summary>
+        /// <returns>Deserialized json settings object.</returns>
+        public T GetSettings<T>(string powertoy = DefaultModuleName, string fileName = DefaultFileName)
+            where T : ISettingsConfig, new()
+        {
+            if (SettingsExists(powertoy, fileName))
+            {
+                // Given the file already exists, to deserialize the file and read it's content.
+                T deserializedSettings = GetFile<T>(powertoy, fileName);
+
+                // IF the file needs to be modified, to save the new configurations accordingly.
+                if (deserializedSettings.UpgradeSettingsConfiguration())
+                {
+                    SaveSettings(deserializedSettings.ToJsonString(), powertoy, fileName);
+                }
+
+                return deserializedSettings;
+            }
+            else
+            {
+                // If the settings file does not exist, to create a new object with default parameters and save it to a newly created settings file.
+                T newSettingsItem = new T();
+                SaveSettings(newSettingsItem.ToJsonString(), powertoy, fileName);
+                return newSettingsItem;
+            }
+        }
+
+        // Given the powerToy folder name and filename to be accessed, this function deserializes and returns the file.
+        private T GetFile<T>(string powertoyFolderName = DefaultModuleName, string fileName = DefaultFileName)
+        {
+            // Adding Trim('\0') to overcome possible NTFS file corruption.
+            // Look at issue https://github.com/microsoft/PowerToys/issues/6413 you'll see the file has a large sum of \0 to fill up a 4096 byte buffer for writing to disk
+            // This, while not totally ideal, does work around the problem by trimming the end.
+            // The file itself did write the content correctly but something is off with the actual end of the file, hence the 0x00 bug
+            var jsonSettingsString = _ioProvider.ReadAllText(GetSettingsPath(powertoyFolderName, fileName)).Trim('\0');
+            return JsonSerializer.Deserialize<T>(jsonSettingsString);
+        }
+
+        // Save settings to a json file.
+        [SuppressMessage("Design", "CA1031:Do not catch general exception types", Justification = "General exceptions will be logged until we can better understand runtime exception scenarios")]
+        public void SaveSettings(string jsonSettings, string powertoy = DefaultModuleName, string fileName = DefaultFileName)
+        {
+            try
+            {
+                if (jsonSettings != null)
+                {
+                    if (!SettingsFolderExists(powertoy))
+                    {
+                        CreateSettingsFolder(powertoy);
+                    }
+
+                    _ioProvider.WriteAllText(GetSettingsPath(powertoy, fileName), jsonSettings);
+                }
+            }
+            catch (Exception e)
+            {
+                Logger.LogError($"Exception encountered while saving {powertoy} settings.", e);
+#if DEBUG
+                if (e is ArgumentException || e is ArgumentNullException || e is PathTooLongException)
+                {
+                    throw;
+                }
+#endif
+            }
+        }
+
+        private static string LocalApplicationDataFolder()
+        {
+            return Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+        }
+    }
+}