refactor: extract interface for storage provider

src/StevanFreeborn.Extensions.Configuration.Secure/Storage/ISecureStorageProvider.cs

@@ -0,0 +1,39 @@
+namespace StevanFreeborn.Extensions.Configuration.Secure.Storage;
+
+/// <summary>
+/// Defines a contract for a provider that stores and retrieves secure configuration data.
+/// </summary>
+public interface ISecureStorageProvider
+{
+  /// <summary>
+  /// Reads the value associated with the specified key asynchronously.
+  /// </summary>
+  /// <param name="key">The key of the configuration value to read.</param>
+  /// <param name="ct">A cancellation token that can be used to cancel the read operation.</param>
+  /// <returns>A task that represents the asynchronous read operation. The task result contains the value associated with the specified key, or an empty string if the key is not found.</returns>
+  Task<string> ReadAsync(string key, CancellationToken ct = default);
+
+  /// <summary>
+  /// Reads all configuration values asynchronously.
+  /// </summary>
+  /// <param name="ct">A cancellation token that can be used to cancel the read operation.</param>
+  /// <returns>A task that represents the asynchronous read operation. The task result contains a dictionary of all configuration keys and their encrypted values.</returns>
+  Task<IDictionary<string, string>> ReadAllAsync(CancellationToken ct = default);
+
+  /// <summary>
+  /// Writes the specified key and encrypted data asynchronously.
+  /// </summary>
+  /// <param name="key">The key of the configuration value to write.</param>
+  /// <param name="encryptedData">The encrypted configuration data to write.</param>
+  /// <param name="ct">A cancellation token that can be used to cancel the write operation.</param>
+  /// <returns>A task that represents the asynchronous write operation.</returns>
+  Task WriteAsync(string key, string encryptedData, CancellationToken ct = default);
+
+  /// <summary>
+  /// Deletes the configuration value associated with the specified key asynchronously.
+  /// </summary>
+  /// <param name="key">The key of the configuration value to delete.</param>
+  /// <param name="ct">A cancellation token that can be used to cancel the delete operation.</param>
+  /// <returns>A task that represents the asynchronous delete operation. The task result contains <c>true</c> if the value was successfully deleted; otherwise, <c>false</c>.</returns>
+  Task<bool> DeleteAsync(string key, CancellationToken ct = default);
+}

src/StevanFreeborn.Extensions.Configuration.Secure/Storage/JsonFileStorageProvider.cs

@@ -6,7 +6,7 @@ namespace StevanFreeborn.Extensions.Configuration.Secure.Storage;
 /// Provides a mechanism to store and retrieve secure configuration data in a JSON file.
 /// </summary>
 /// <param name="options">The <see cref="JsonStorageOptions"/> configuring the storage provider, including file paths.</param>
-public sealed class JsonFileStorageProvider(JsonStorageOptions options)
+public sealed class JsonFileStorageProvider(JsonStorageOptions options) : ISecureStorageProvider
 {
   private static readonly SemaphoreSlim FileLock = new(1, 1);
   private static readonly JsonSerializerOptions JsonOptions = new()
@@ -39,7 +39,7 @@ public sealed class JsonFileStorageProvider(JsonStorageOptions options)
   /// </summary>
   /// <param name="ct">A cancellation token that can be used to cancel the read operation.</param>
   /// <returns>A task that represents the asynchronous read operation. The task result contains a dictionary of all configuration keys and their values.</returns>
-  public Task<Dictionary<string, string>> ReadAllAsync(CancellationToken ct = default)
+  public Task<IDictionary<string, string>> ReadAllAsync(CancellationToken ct = default)
   {
     return AcquireLockAndLoadAsync(ct);
   }
@@ -95,7 +95,7 @@ public sealed class JsonFileStorageProvider(JsonStorageOptions options)
   /// </summary>
   /// <param name="ct">A cancellation token to observe while waiting for the lock or during the load operation.</param>
   /// <returns>A dictionary containing the loaded configuration data.</returns>
-  private async Task<Dictionary<string, string>> AcquireLockAndLoadAsync(CancellationToken ct)
+  private async Task<IDictionary<string, string>> AcquireLockAndLoadAsync(CancellationToken ct)
   {
     await FileLock.WaitAsync(ct).ConfigureAwait(false);