feat: Features check lib imports

This prevents errors when features are enabled by configuration but the
dependencies are missing.

canaille/__init__.py

@@ -46,7 +46,7 @@ def setup_blueprints(app):
 
         app.register_blueprint(canaille.oidc.endpoints.bp)
 
-    if "CANAILLE_SCIM" in app.config and app.config["CANAILLE_SCIM"]["ENABLE_SERVER"]:
+    if app.features.has_scim_server:
         import canaille.scim.endpoints
 
         app.register_blueprint(canaille.scim.endpoints.bp)

canaille/app/features.py

@@ -4,18 +4,28 @@ class Features:
 
     @property
     def has_smtp(self):
+        """Indicate whether the mail sending feature is enabled.
+
+        This feature is required to :attr:`validate user email addresses <canaille.app.features.Features.has_email_confirmation>`, send email OTP passwords etc.
+        It is controlled by the :attr:`CANAILLE.SMTP <canaille.core.configuration.CoreSettings.SMTP>` configuration parameter.
+        """
         return bool(self.app.config["CANAILLE"]["SMTP"])
 
-    @property
-    def has_oidc(self):
-        return "CANAILLE_OIDC" in self.app.config
-
     @property
     def has_password_recovery(self):
+        """Indicate whether the password recovery feature is enabled.
+
+        It is controlled by the :attr:`CANAILLE.ENABLE_PASSWORD_RECOVERY <canaille.core.configuration.CoreSettings.ENABLE_PASSWORD_RECOVERY>` configuration parameter.
+        """
         return self.app.config["CANAILLE"]["ENABLE_PASSWORD_RECOVERY"]
 
     @property
     def has_intruder_lockout(self):
+        """Indicate whether the intruder lockout feature is enabled.
+
+        It is controlled by the :attr:`CANAILLE.ENABLE_INTRUDER_LOCKOUT <canaille.core.configuration.CoreSettings.ENABLE_INTRUDER_LOCKOUT>` configuration parameter.
+        """
+
         return self.app.config["CANAILLE"]["ENABLE_INTRUDER_LOCKOUT"]
 
     @property
@@ -24,30 +34,108 @@ class Features:
 
     @property
     def has_otp(self):
+        """Indicate whether the OTP authentication factor is enabled.
+
+        It is controlled by the :attr:`CANAILLE.OTP_METHOD <canaille.core.configuration.CoreSettings.OTP_METHOD>` configuration parameter,
+        and needs the ``otp`` extra package to be installed.
+        """
+
+        try:
+            import otpauth  # noqa: F401
+
             return bool(self.app.config["CANAILLE"]["OTP_METHOD"])
+        except ImportError:  # pragma: no cover
+            return False
 
     @property
     def has_email_otp(self):
+        """Indicate whether the email OTP authentication factor is enabled.
+
+        It is controlled by the :attr:`CANAILLE.EMAIL_OTP <canaille.core.configuration.CoreSettings.EMAIL_OTP>` configuration parameter.
+        """
+
         return bool(self.app.config["CANAILLE"]["EMAIL_OTP"])
 
     @property
     def has_sms_otp(self):
+        """Indicate whether the SMS OTP authentication factor is enabled.
+
+        It is controlled by the :attr:`CANAILLE.SMS_OTP <canaille.core.configuration.CoreSettings.SMS_OTP>` configuration parameter,
+        and needs the ``smpp`` extra package to be installed.
+        """
+
+        try:
+            import smpplib  # noqa: F401
+
             return self.app.config["CANAILLE"]["SMS_OTP"]
+        except ImportError:  # pragma: no cover
+            return False
 
     @property
     def has_registration(self):
+        """Indicate whether the user account registration is enabled.
+
+        It is controlled by the :attr:`CANAILLE.ENABLE_REGISTRATION <canaille.core.configuration.CoreSettings.ENABLE_REGISTRATION>` configuration parameter.
+        """
+
         return self.app.config["CANAILLE"]["ENABLE_REGISTRATION"]
 
     @property
     def has_account_lockability(self):
+        """Indicate whether the user accounts can be locked.
+
+        It depends on the backend used by Canaille.
+        This is only disabled for OpenLDAP versions under 2.6.
+        """
+
         return self.app.backend.instance.has_account_lockability()
 
     @property
     def has_email_confirmation(self):
+        """Indicate whether the user email confirmation is enabled.
+
+        It is controlled by the :attr:`CANAILLE.EMAIL_CONFIRMATION <canaille.core.configuration.CoreSettings.EMAIL_CONFIRMATION>` configuration parameter.
+        """
+
         return self.app.config["CANAILLE"]["EMAIL_CONFIRMATION"] is True or (
             self.app.config["CANAILLE"]["EMAIL_CONFIRMATION"] is None and self.has_smtp
         )
 
+    @property
+    def has_oidc(self):
+        """Indicate whether the OIDC feature is enabled.
+
+        This feature is required to make Canaille an authorization server for other applications and enable SSO.
+        It is controlled by the :class:`CANAILLE_OIDC <canaille.oidc.configuration.OIDCSettings>` configuration parameter,
+        and needs the ``oidc`` extra package to be installed.
+        """
+
+        try:
+            import authlib  # noqa: F401
+
+            return "CANAILLE_OIDC" in self.app.config
+        except ImportError:  # pragma: no cover
+            return False
+
+    @property
+    def has_scim_server(self):
+        """Indicate whether the SCIM server feature is enabled.
+
+        This feature is required to make Canaille a provisioning server.
+        It is controlled by the :attr:`CANAILLE_SCIM.ENABLE_SERVER <canaille.scim.configuration.SCIMSettings.ENABLE_SERVER>` configuration parameter,
+        and needs the ``scim`` extra package to be installed.
+        """
+
+        try:
+            import scim2_models  # noqa: F401
+
+            return (
+                "CANAILLE_SCIM" in self.app.config
+                and self.app.config["CANAILLE_SCIM"]["ENABLE_SERVER"]
+            )
+        except ImportError:  # pragma: no cover
+            return False
+
 
 def setup_features(app):
     app.features = Features(app)