Major 2.0 (#20)

* New 2.0 version + DependencyInjection library

* Updated docs and repo settings (devcontainers, vscode, github, etc.)

* Added tests

* Fixed bugs

* Minor test project refactoring

* Updated projects
- Added symbol packages
- Updated package versions to pre-release

* Updated SECURITY.md

* Added GitHub Actions workflows

libraries/SimpleOTP.DependencyInjection/OtpService.cs

@@ -0,0 +1,95 @@
+using System.Collections.Specialized;
+using SimpleOTP.Fluent;
+
+namespace SimpleOTP.DependencyInjection;
+
+/// <summary>
+/// Provides methods for generating and validating One-Time Passwords.
+/// </summary>
+/// <param name="configuration">The configuration for the One-Time Password service.</param>
+internal class OtpService(OtpOptions configuration) : IOtpService
+{
+	private readonly string _issuerName = configuration.Issuer;
+	private readonly string? _issuerDomain = configuration.IssuerDomain;
+	private readonly OtpAlgorithm _algorithm = configuration.Algorithm;
+	private readonly OtpType _type = configuration.Type;
+	private readonly OtpUriFormat _format = configuration.UriFormat |
+		(string.IsNullOrWhiteSpace(configuration.IssuerDomain) ? 0 : OtpUriFormat.Apple);
+	private readonly int _digits = configuration.Digits;
+	private readonly int _period = configuration.Period;
+	private readonly NameValueCollection _customProperties = configuration.CustomProperties;
+	private readonly ToleranceSpan _tolerance = configuration.ToleranceSpan;
+
+	/// <summary>
+	/// Creates an OTP URI for specified user and secret.
+	/// </summary>
+	/// <param name="username">The username of the user.</param>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	/// <returns>The generated URI.</returns>
+	public Uri CreateUri(string username, OtpSecret secret, long counter = 0)
+	{
+		OtpConfig config = new(username)
+		{
+			Algorithm = _algorithm,
+			Type = _type,
+			Issuer = _issuerName,
+			Digits = _digits,
+			Period = _period,
+
+			Secret = secret,
+			Counter = counter
+		};
+
+		if (!string.IsNullOrWhiteSpace(_issuerDomain))
+			config.WithAppleIssuer(_issuerName, _issuerDomain);
+
+		config.CustomProperties.Add(_customProperties);
+
+		return config.ToUri(_format);
+	}
+
+	/// <summary>
+	/// Creates an OTP code for specified user and secret.
+	/// </summary>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	/// <returns>The generated code.</returns>
+	/// <exception cref="NotSupportedException">The service was not configured properly. Check the "Authenticator:Type" configuration.</exception>
+	public OtpCode GenerateCode(OtpSecret secret, long counter = 0)
+	{
+		using OtpSecret secretClone = OtpSecret.CreateCopy(secret);
+
+		Otp generator = _type switch
+		{
+			OtpType.Hotp => new Hotp(secret, counter, _algorithm, _digits),
+			OtpType.Totp => new Totp(secret, _period, _algorithm, _digits),
+			_ => throw new NotSupportedException("The service was not configured properly. Check the \"Authenticator:Type\" configuration.")
+		};
+
+		return generator.Generate();
+	}
+
+	/// <summary>
+	/// Validates an OTP code for specified user and secret.
+	/// </summary>
+	/// <param name="code">The code to validate.</param>
+	/// <param name="secret">The secret to use.</param>
+	/// <param name="resyncValue">The resync value. Shows how much the code is ahead or behind the current counter value.</param>
+	/// <param name="counter">(only for HOTP) The counter to use.</param>
+	/// <returns><c>true</c> if the code is valid; otherwise, <c>false</c>.</returns>
+	/// <exception cref="NotSupportedException">The service was not configured properly. Check the "Authenticator:Type" configuration.</exception>
+	public bool ValidateCode(OtpCode code, OtpSecret secret, out int resyncValue, long counter = 0)
+	{
+		using OtpSecret secretClone = OtpSecret.CreateCopy(secret);
+
+		Otp generator = _type switch
+		{
+			OtpType.Hotp => new Hotp(secret, counter, _algorithm, _digits),
+			OtpType.Totp => new Totp(secret, _period, _algorithm, _digits),
+			_ => throw new NotSupportedException("The service was not configured properly. Check the \"Authenticator:Type\" configuration.")
+		};
+
+		return generator.Validate(code, _tolerance, out resyncValue);
+	}
+}