Fix nonce, add auto retry on auth exception, fix session id int, improve code quality (#336)

This pull request includes several changes to improve error handling,
enhance functionality, and update configurations. The most important
changes include adding new exception handling for invalid sessions,
updating the `postCreateCommand` in the devcontainer, and adding custom
funding options.

### Error Handling Improvements:
* Added `InvalidSessionException` to handle invalid session errors and
updated relevant methods to raise this exception when needed
(`sagemcom_api/client.py`, `sagemcom_api/const.py`,
`sagemcom_api/exceptions.py`).
[[1]](diffhunk://#diff-052218051094ff1cc2c8352cd555cfb9eb02bf261eb5e635cf73b798809306a5R32)
[[2]](diffhunk://#diff-052218051094ff1cc2c8352cd555cfb9eb02bf261eb5e635cf73b798809306a5R46)
[[3]](diffhunk://#diff-052218051094ff1cc2c8352cd555cfb9eb02bf261eb5e635cf73b798809306a5R220-R225)
[[4]](diffhunk://#diff-57cf505b5e01fc69f170c5a1b839fb40b45a97a9c0ebc1fe53f4bd524ae9ac04R10)
[[5]](diffhunk://#diff-63c847110513149341a9f7e94d412bfb7c67d79df07a321774a9a2f3329ca34fR4-L43)
* Introduced `retry_login` function to retry login on specific
exceptions using backoff (`sagemcom_api/client.py`).
[[1]](diffhunk://#diff-052218051094ff1cc2c8352cd555cfb9eb02bf261eb5e635cf73b798809306a5R58-R62)
[[2]](diffhunk://#diff-052218051094ff1cc2c8352cd555cfb9eb02bf261eb5e635cf73b798809306a5R260-R270)

### Functional Enhancements:
* Modified `get_hosts` method to include `capability-flags` in the
options for retrieving hosts (`sagemcom_api/client.py`).
* Corrected the nonce generation logic to use the correct range
(`sagemcom_api/client.py`).

### Configuration Updates:
* Updated `postCreateCommand` in `.devcontainer/devcontainer.json` to
include `pre-commit install-hooks` for better pre-commit setup.
* Added a custom funding option in `.github/FUNDING.yml` to include a
PayPal link.

Author: iMicknl

.devcontainer/devcontainer.json

@@ -12,7 +12,7 @@
 	// Use 'forwardPorts' to make a list of ports inside the container available locally.
 	// "forwardPorts": [],
 	// Use 'postCreateCommand' to run commands after the container is created.
-	"postCreateCommand": "poetry config virtualenvs.in-project true && poetry install --with dev --no-interaction && . .venv/bin/activate && pre-commit install",
+	"postCreateCommand": "poetry config virtualenvs.in-project true && poetry install --with dev --no-interaction && . .venv/bin/activate && pre-commit install && pre-commit install-hooks",
 	// Configure tool-specific properties.
 	"customizations": {
 		"vscode": {

.github/FUNDING.yml

@@ -0,0 +1 @@
+custom: ["https://paypal.me/imick"]

sagemcom_api/client.py

@@ -3,11 +3,13 @@
 from __future__ import annotations
 
 import asyncio
+from collections.abc import Mapping
 import hashlib
 import json
 import math
 import random
 from types import TracebackType
+from typing import Any
 import urllib.parse
 
 from aiohttp import (
@@ -27,6 +29,7 @@
     DEFAULT_USER_AGENT,
     XMO_ACCESS_RESTRICTION_ERR,
     XMO_AUTHENTICATION_ERR,
+    XMO_INVALID_SESSION_ERR,
     XMO_LOGIN_RETRY_ERR,
     XMO_MAX_SESSION_COUNT_ERR,
     XMO_NO_ERR,
@@ -40,6 +43,7 @@
     AccessRestrictionException,
     AuthenticationException,
     BadRequestException,
+    InvalidSessionException,
     LoginRetryErrorException,
     LoginTimeoutException,
     MaximumSessionCountException,
@@ -51,6 +55,11 @@
 from .models import Device, DeviceInfo, PortMapping
 
 
+async def retry_login(invocation: Mapping[str, Any]) -> None:
+    """Retry login via backoff if an exception occurs."""
+    await invocation["args"][0].login()
+
+
 # pylint: disable=too-many-instance-attributes
 class SagemcomClient:
     """Client to communicate with the Sagemcom API."""
@@ -118,7 +127,7 @@ async def close(self) -> None:
 
     def __generate_nonce(self):
         """Generate pseudo random number (nonce) to avoid replay attacks."""
-        self._current_nonce = math.floor(random.randrange(0, 1) * 500000)
+        self._current_nonce = math.floor(random.randrange(0, 500000))
 
     def __generate_request_id(self):
         """Generate sequential request ID."""
@@ -187,6 +196,7 @@ def __get_response_value(self, response, index=0):
         (ClientConnectorError, ClientOSError, ServerDisconnectedError),
         max_tries=5,
     )
+    # pylint: disable=too-many-branches
     async def __post(self, url, data):
         async with self.session.post(url, data=data) as response:
             if response.status == 400:
@@ -207,6 +217,12 @@ async def __post(self, url, data):
             ):
                 return result
 
+            if error["description"] == XMO_INVALID_SESSION_ERR:
+                self._session_id = 0
+                self._server_nonce = ""
+                self._request_id = -1
+                raise InvalidSessionException(error)
+
             # Error in one of the actions
             if error["description"] == XMO_REQUEST_ACTION_ERR:
                 # pylint:disable=fixme
@@ -241,6 +257,17 @@ async def __post(self, url, data):
 
             return result
 
+    @backoff.on_exception(
+        backoff.expo,
+        (
+            AuthenticationException,
+            LoginRetryErrorException,
+            LoginTimeoutException,
+            InvalidSessionException,
+        ),
+        max_tries=2,
+        on_backoff=retry_login,
+    )
     async def __api_request_async(self, actions, priority=False):
         """Build request to the internal JSON-req API."""
         self.__generate_request_id()
@@ -252,7 +279,7 @@ async def __api_request_async(self, actions, priority=False):
         payload = {
             "request": {
                 "id": self._request_id,
-                "session-id": str(self._session_id),
+                "session-id": int(self._session_id),
                 "priority": priority,
                 "actions": actions,
                 "cnonce": self._current_nonce,
@@ -435,7 +462,9 @@ async def get_device_info(self) -> DeviceInfo:
 
     async def get_hosts(self, only_active: bool | None = False) -> list[Device]:
         """Retrieve hosts connected to Sagemcom F@st device."""
-        data = await self.get_value_by_xpath("Device/Hosts/Hosts")
+        data = await self.get_value_by_xpath(
+            "Device/Hosts/Hosts", options={"capability-flags": {"interface": True}}
+        )
         devices = [Device(**d) for d in data]
 
         if only_active:

sagemcom_api/const.py

@@ -7,6 +7,7 @@
 
 XMO_ACCESS_RESTRICTION_ERR = "XMO_ACCESS_RESTRICTION_ERR"
 XMO_AUTHENTICATION_ERR = "XMO_AUTHENTICATION_ERR"
+XMO_INVALID_SESSION_ERR = "XMO_INVALID_SESSION_ERR"
 XMO_NON_WRITABLE_PARAMETER_ERR = "XMO_NON_WRITABLE_PARAMETER_ERR"
 XMO_NO_ERR = "XMO_NO_ERR"
 XMO_REQUEST_ACTION_ERR = "XMO_REQUEST_ACTION_ERR"

sagemcom_api/exceptions.py

@@ -1,43 +1,51 @@
 """Exceptions for the Sagemcom F@st client."""
 
 
+class BaseSagemcomException(Exception):
+    """Base exception for Sagemcom F@st client."""
+
+
+# Broad exceptions provided by this library
+class BadRequestException(BaseSagemcomException):
+    """Bad request."""
+
+
+class UnauthorizedException(BaseSagemcomException):
+    """Unauthorized."""
+
+
+class UnknownException(BaseSagemcomException):
+    """Unknown exception."""
+
+
 # Exceptions provided by SagemCom API
-class AccessRestrictionException(Exception):
+class AccessRestrictionException(BaseSagemcomException):
     """Raised when current user has access restrictions."""
 
 
-class AuthenticationException(Exception):
+class AuthenticationException(UnauthorizedException):
     """Raised when authentication is not correct."""
 
 
-class LoginRetryErrorException(Exception):
+class InvalidSessionException(UnauthorizedException):
+    """Raised when session is invalid."""
+
+
+class LoginRetryErrorException(BaseSagemcomException):
     """Raised when too many login retries are attempted."""
 
 
-class LoginTimeoutException(Exception):
+class LoginTimeoutException(BaseSagemcomException):
     """Raised when a timeout is encountered during login."""
 
 
-class NonWritableParameterException(Exception):
+class NonWritableParameterException(BaseSagemcomException):
     """Raised when provided parameter is not writable."""
 
 
-class UnknownPathException(Exception):
+class UnknownPathException(BaseSagemcomException):
     """Raised when provided path does not exist."""
 
 
-class MaximumSessionCountException(Exception):
+class MaximumSessionCountException(BaseSagemcomException):
     """Raised when the maximum session count is reached."""
-
-
-# Broad exceptions provided by this library
-class BadRequestException(Exception):
-    """TODO."""
-
-
-class UnauthorizedException(Exception):
-    """TODO."""
-
-
-class UnknownException(Exception):
-    """TODO."""