Add bumble-console --device-config support for gatt services

This PR adds support for bumble-console to be preloaded with gatt services via `--device-config`.
This PR also adds some type annotations

bumble/core.py

@@ -58,6 +58,12 @@ def padded_bytes(buffer, size):
     return buffer + bytes(padding_size)
 
 
+def get_dict_key_by_value(dictionary, value):
+    for key, val in dictionary.items():
+        if val == value:
+            return key
+    return None
+
 # -----------------------------------------------------------------------------
 # Exceptions
 # -----------------------------------------------------------------------------
@@ -135,7 +141,7 @@ class UUID:
             else:
                 uuid_str = uuid_str_or_int
             if len(uuid_str) != 32 and len(uuid_str) != 8 and len(uuid_str) != 4:
-                raise ValueError('invalid UUID format')
+                raise ValueError(f"invalid UUID format: {uuid_str}")
             self.uuid_bytes = bytes(reversed(bytes.fromhex(uuid_str)))
         self.name = name
 

bumble/device.py

@@ -540,6 +540,7 @@ class DeviceConfiguration:
         )
         self.irk      = bytes(16)  # This really must be changed for any level of security
         self.keystore = None
+        self.gatt_services = []
 
     def load_from_dict(self, config):
         # Load simple properties
@@ -556,6 +557,7 @@ class DeviceConfiguration:
         self.classic_accept_any       = config.get('classic_accept_any', self.classic_accept_any)
         self.connectable              = config.get('connectable', self.connectable)
         self.discoverable             = config.get('discoverable', self.discoverable)
+        self.gatt_services            = config.get('gatt_services', self.gatt_services)
 
         # Load or synthesize an IRK
         irk = config.get('irk')
@@ -589,7 +591,7 @@ def with_connection_from_handle(function):
     @functools.wraps(function)
     def wrapper(self, connection_handle, *args, **kwargs):
         if (connection := self.lookup_connection(connection_handle)) is None:
-            raise ValueError('no connection for handle')
+            raise ValueError(f"no connection for handle: 0x{connection_handle:04x}")
         return function(self, connection, *args, **kwargs)
     return wrapper
 
@@ -726,6 +728,26 @@ class Device(CompositeEventEmitter):
         self.connectable              = config.connectable
         self.classic_accept_any       = config.classic_accept_any
 
+        for service in config.gatt_services:
+            characteristics = []
+            for characteristic in service.get("characteristics", []):
+                descriptors = []
+                for descriptor in characteristic.get("descriptors", []):
+                    new_descriptor = Descriptor(
+                        descriptor_type=descriptor["descriptor_type"],
+                        permissions=descriptor["permission"],
+                    )
+                    descriptors.append(new_descriptor)
+                new_characteristic = Characteristic(
+                    uuid=characteristic["uuid"],
+                    properties=characteristic["properties"],
+                    permissions=int(characteristic["permissions"], 0),
+                    descriptors=descriptors,
+                )
+                characteristics.append(new_characteristic)
+            new_service = Service(uuid=service["uuid"], characteristics=characteristics)
+            self.gatt_server.add_service(new_service)
+
         # If a name is passed, override the name from the config
         if name:
             self.name = name

bumble/gatt.py

@@ -22,6 +22,7 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+from __future__ import annotations
 import asyncio
 import enum
 import types
@@ -187,7 +188,7 @@ class Service(Attribute):
     See Vol 3, Part G - 3.1 SERVICE DEFINITION
     '''
 
-    def __init__(self, uuid, characteristics, primary=True):
+    def __init__(self, uuid, characteristics: list[Characteristic], primary=True):
         # Convert the uuid to a UUID object if it isn't already
         if type(uuid) is str:
             uuid = UUID(uuid)
@@ -256,10 +257,21 @@ class Characteristic(Attribute):
             if properties & p
         ])
 
-    def __init__(self, uuid, properties, permissions, value = b'', descriptors = []):
+    @staticmethod
+    def string_to_properties(properties_str: str):
+        return functools.reduce(
+            lambda x, y: x | get_dict_key_by_value(Characteristic.PROPERTY_NAMES, y),
+            properties_str.split(","),
+            0,
+        )
+
+    def __init__(self, uuid, properties, permissions, value = b'', descriptors: list[Descriptor] = []):
         super().__init__(uuid, permissions, value)
         self.uuid        = self.type
-        self.properties  = properties
+        if type(properties) is str:
+            self.properties = Characteristic.string_to_properties(properties)
+        else:
+            self.properties = properties
         self.descriptors = descriptors
 
     def get_descriptor(self, descriptor_type):

bumble/gatt_server.py

@@ -60,6 +60,9 @@ class Server(EventEmitter):
         self.indication_semaphores = defaultdict(lambda: asyncio.Semaphore(1))
         self.pending_confirmations = defaultdict(lambda: None)
 
+    def __str__(self):
+        return "\n".join(map(str, self.attributes))
+
     def send_gatt_pdu(self, connection_handle, pdu):
         self.device.send_l2cap_pdu(connection_handle, ATT_CID, pdu)
 
@@ -87,7 +90,7 @@ class Server(EventEmitter):
         # Add this attribute to the list
         self.attributes.append(attribute)
 
-    def add_service(self, service):
+    def add_service(self, service: Service):
         # Add the service attribute to the DB
         self.add_attribute(service)