introduce AuthenticatorInterface::MODE identifier and remove unnecessary property in Authenticator

Author: codemasher

src/Authenticator.php

@@ -34,7 +34,6 @@ class Authenticator{
 
 	protected SettingsContainerInterface|AuthenticatorOptions $options;
 	protected AuthenticatorInterface                          $authenticator;
-	protected string                                          $mode = AuthenticatorInterface::TOTP;
 
 	/**
 	 * Authenticator constructor
@@ -62,8 +61,7 @@ public function setOptions(SettingsContainerInterface|AuthenticatorOptions $opti
 		$this->options = $options;
 
 		// invoke a new authenticator interface if necessary
-		if(!isset($this->authenticator) || $this->options->mode !== $this->mode){
-			$this->mode          = $this->options->mode;
+		if(!isset($this->authenticator) || $this->authenticator::MODE !== $this->options->mode){
 			$this->authenticator = new (AuthenticatorInterface::MODES[$this->options->mode])($this->options);
 		}
 
@@ -150,28 +148,31 @@ public function getUri(string $label, string $issuer, int|null $hotpCounter = nu
 			'issuer' => $issuer,
 		];
 
-		if(($omitSettings ?? $this->options->omitUriSettings) !== true){
-			$values['digits']    = $this->options->digits;
-			$values['algorithm'] = $this->options->algorithm;
+		if($this->authenticator::MODE === AuthenticatorInterface::HOTP){
 
-			if($this->mode === AuthenticatorInterface::TOTP){
-				$values['period'] = $this->options->period;
+			if($hotpCounter === null || $hotpCounter < 0){
+				throw new InvalidArgumentException('initial counter value must be set and greater or equal to 0');
 			}
 
+			$values['counter'] = $hotpCounter;
 		}
 
-		if($this->mode === AuthenticatorInterface::HOTP){
+		if(($omitSettings ?? $this->options->omitUriSettings) !== true){
+			$values['digits']    = $this->options->digits;
+			$values['algorithm'] = $this->options->algorithm;
 
-			if($hotpCounter === null || $hotpCounter < 0){
-				throw new InvalidArgumentException('initial counter value must be set and greater or equal to 0');
+			if($this->authenticator::MODE === AuthenticatorInterface::TOTP){
+				$values['period'] = $this->options->period;
 			}
 
-			$values['counter'] = $hotpCounter;
 		}
 
-		$values = http_build_query($values, '', '&', PHP_QUERY_RFC3986);
-
-		return sprintf('otpauth://%s/%s?%s', $this->mode, rawurlencode($label), $values);
+		return sprintf(
+			'otpauth://%s/%s?%s',
+			$this->authenticator::MODE,
+			rawurlencode($label),
+			http_build_query($values, '', '&', PHP_QUERY_RFC3986),
+		);
 	}
 
 }

src/Authenticators/AuthenticatorInterface.php

@@ -39,6 +39,13 @@ interface AuthenticatorInterface{
 		self::ALGO_SHA512,
 	];
 
+	/**
+	 * Mode identifier. Do not call this constant from the interface. but rather from an authenticator instance.
+	 *
+	 * @var string
+	 */
+	public const MODE = '';
+
 	/**
 	 * Sets the options
 	 */

src/Authenticators/HOTP.php

@@ -27,6 +27,8 @@
  */
 class HOTP extends AuthenticatorAbstract{
 
+	public const MODE = self::HOTP;
+
 	/**
 	 * @inheritDoc
 	 */

src/Authenticators/SteamGuard.php

@@ -40,6 +40,8 @@
  */
 final class SteamGuard extends TOTP{
 
+	public const MODE = self::STEAM_GUARD;
+
 	private const steamCodeChars = '23456789BCDFGHJKMNPQRTVWXY';
 	private const steamTimeURL   = 'https://api.steampowered.com/ITwoFactorService/QueryTime/v0001';
 

src/Authenticators/TOTP.php

@@ -21,6 +21,8 @@
  */
 class TOTP extends HOTP{
 
+	public const MODE = self::TOTP;
+
 	/**
 	 * @inheritDoc
 	 */

tests/AuthenticatorTest.php

@@ -67,14 +67,14 @@ public function testGetUri():void{
 			->setSecret(self::secret);
 
 		$this::assertSame(
-			sprintf('otpauth://hotp/%s?secret=%s&issuer=%s&digits=8&algorithm=SHA1&counter=42', $label, self::secret, $issuer),
+			sprintf('otpauth://hotp/%s?secret=%s&issuer=%s&counter=42&digits=8&algorithm=SHA1', $label, self::secret, $issuer),
 			$this->authenticator->getUri(self::label, self::issuer, 42)
 		);
 
 		$this->options->algorithm = AuthenticatorInterface::ALGO_SHA512;
 		$this::assertSame(
-			sprintf('otpauth://hotp/%s?secret=%s&issuer=%s&digits=8&algorithm=SHA512', $label, self::secret, $issuer),
-			$this->authenticator->getUri(self::label, self::issuer)
+			sprintf('otpauth://hotp/%s?secret=%s&issuer=%s&counter=0&digits=8&algorithm=SHA512', $label, self::secret, $issuer),
+			$this->authenticator->getUri(self::label, self::issuer, 0)
 		);
 
 		// test omit settings