Use typesafe options

USEntryCoach.Server/Settings/APISettings.cs

@@ -0,0 +1,42 @@
+using System.ComponentModel.DataAnnotations;
+using System.Diagnostics.CodeAnalysis;
+using System.Text;
+using Microsoft.Extensions.Options;
+
+namespace USEntryCoach.Server.Settings;
+
+public sealed class ApiSettings
+{
+    public const string SectionName = "API";
+
+    [Required(ErrorMessage = "OpenAI API token is required!", AllowEmptyStrings = false)]
+    public required string OpenAiToken { get; set; }
+}
+
+public sealed class AuthenticationSettings
+{
+    public const string SectionName = "Authentication";
+
+    private string _jwtGenerationSecret = null!;
+
+    [Required(ErrorMessage = "JWT generation secret token is required!", AllowEmptyStrings = false)]
+    public required string JwtGenerationSecret
+    {
+        get => _jwtGenerationSecret;
+        set
+        {
+            _jwtGenerationSecret = value;
+            JwtGenerationSecretBytes = Encoding.UTF8.GetBytes(value);
+        }
+    }
+
+    public byte[] JwtGenerationSecretBytes { get; private set; }
+
+    const string JwtExpiryTimeMin = "00:00:30";
+    const string JwtExpiryTimeMax = "24:00:00";
+
+    [Range(typeof(TimeSpan), JwtExpiryTimeMin, JwtExpiryTimeMax,
+        ErrorMessage = $"JWT expiry time must be in the range from {JwtExpiryTimeMin} to {JwtExpiryTimeMax}.")]
+    public TimeSpan JwtExpiryTime { get; set; } = TimeSpan.FromMinutes(5);
+}
+