[client] support message cancellation

android_sms_gateway/client.py

@@ -166,6 +166,18 @@ def send(
             )
         )
 
+    def cancel_message(self, _id: str) -> None:
+        """
+        Cancels a pending message by ID.
+
+        Args:
+            _id: The message ID.
+        """
+        if self.http is None:
+            raise ValueError("HTTP client not initialized")
+
+        self.http.delete(f"{self.base_url}/messages/{_id}", headers=self.headers)
+
     def get_state(self, _id: str) -> domain.MessageState:
         """
         Returns message state by ID.
@@ -583,6 +595,20 @@ async def send(
             )
         )
 
+    async def cancel_message(self, _id: str) -> None:
+        """
+        Cancels a pending message by ID.
+
+        Args:
+            _id: The message ID.
+        """
+        if self.http is None:
+            raise ValueError("HTTP client not initialized")
+
+        await self.http.delete(
+            f"{self.base_url}/messages/{_id}", headers=self.headers
+        )
+
     async def get_state(self, _id: str) -> domain.MessageState:
         """
         Returns message state by ID.

android_sms_gateway/enums.py

@@ -3,6 +3,8 @@
 
 class ProcessState(enum.Enum):
     Pending = "Pending"
+    Cancelling = "Cancelling"
+    Cancelled = "Cancelled"
     Processed = "Processed"
     Sent = "Sent"
     Delivered = "Delivered"
@@ -29,6 +31,9 @@ class WebhookEvent(enum.Enum):
     SMS_FAILED = "sms:failed"
     """Triggered when an SMS processing fails."""
 
+    SMS_CANCELLED = "sms:cancelled"
+    """Triggered when an SMS is cancelled."""
+
     SYSTEM_PING = "system:ping"
     """Triggered when the device pings the server."""