first step to creating dream lib

argenta/app/exceptions.py

@@ -0,0 +1,39 @@
+class InvalidRouterInstanceException(Exception):
+    def __str__(self):
+        return "Invalid Router Instance"
+
+
+class InvalidDescriptionMessagePatternException(Exception):
+    def __init__(self, pattern: str):
+        self.pattern = pattern
+    def __str__(self):
+        return ("Invalid Description Message Pattern\n"
+                "Correct pattern example: [{command}] *=*=* {description}\n"
+                "The pattern must contain two variables: `command` and `description` - description of the command\n"
+                f"Your pattern: {self.pattern}")
+
+
+class OnlyOneMainRouterIsAllowedException(Exception):
+    def __init__(self, existing_main_router):
+        self.existing_main_router = existing_main_router
+
+    def __str__(self):
+        return ("Only One Main Router Allowed\n"
+                f"Existing main router is: {self.existing_main_router}")
+
+
+class MissingMainRouterException(Exception):
+    def __str__(self):
+        return ("Missing Main Router\n"
+                "One of the registered routers must be the main one")
+
+
+class MissingHandlersForUnknownCommandsOnMainRouterException(Exception):
+    def __str__(self):
+        return ("Missing Handlers For Unknown Commands On The Main Router\n"
+                "The main router must have a declared handler for unknown commands")
+
+
+class HandlerForUnknownCommandsCanOnlyBeDeclaredForMainRouterException(Exception):
+    def __str__(self):
+        return '\nThe handler for unknown commands can only be declared for the main router'