extract presentation layer

src/argenta/app/presentation/viewers.py

@@ -0,0 +1,27 @@
+from typing import Iterable
+
+from argenta.app.presentation.renderers import Renderer
+from argenta.app.protocols import Printer, DescriptionMessageGenerator
+from argenta.app.registered_routers.entity import RegisteredRouters
+
+
+class Viewer:
+    def __init__(self, printer: Printer, renderer: Renderer):
+        self._printer = printer
+        self._renderer = renderer
+
+    def view_messages_on_startup(self, messages: Iterable[str]) -> None:
+        self._printer(self._renderer.render_messages_on_startup(messages))
+
+    def view_command_groups_description(
+        self,
+        description_message_generator: DescriptionMessageGenerator,
+        registered_routers: RegisteredRouters
+    ) -> None:
+        self._printer(
+            self._renderer.render_command_groups_description(
+                description_message_generator,
+                registered_routers
+            )
+        )
+