Refactor models and add activity retrieval to client

Refactored data models to use optional types and default values for better robustness and flexibility. Enhanced the client by adding a method to retrieve activity data for issues, supporting filtration by categories and fields.

youtrack/youtrack/client.py

@@ -6,6 +6,7 @@
 import structlog
 from httpx import Response
 
+from youtrack.youtrack.models.activity import YouTrackActivityItem
 from youtrack.youtrack.models.comment import YouTrackComment
 from youtrack.youtrack.models.issue import YouTrackIssue
 from youtrack.youtrack.models.user import YouTrackUser
@@ -58,6 +59,19 @@ def get_user(self, user_id: str) -> YouTrackUser:
         response.raise_for_status()
         return YouTrackUser(**response.json())
 
+    def get_activities(
+        self, issue_id: str, categories: Iterable[str], fields: Iterable[str]
+    ) -> tuple[YouTrackActivityItem, ...]:
+        """Get activities for an issue."""
+        url = f"issues/{issue_id}/activities"
+        params = {
+            "categories": ",".join(categories),
+            "fields": ",".join(fields),
+        }
+        response = self.get(url, params=params)
+        response.raise_for_status()
+        return tuple(YouTrackActivityItem(**activity) for activity in response.json())
+
     def get(self, endpoint: str, params: dict[str, str] | None = None) -> Response:
         """Send request to YouTrack API."""
         response = httpx.get(f"{self._api_url}/{endpoint}", headers=self._headers, params=params)

youtrack/youtrack/models/activity.py

@@ -9,5 +9,5 @@
 
 
 class YouTrackActivityItem(BaseModel):
-    timestamp: MillisecondsDatetime
-    fixed_state: int | None = None
+    id: str
+    timestamp: MillisecondsDatetime | None = None

youtrack/youtrack/models/issue.py

@@ -26,8 +26,9 @@ class YouTrackCustomField(BaseModel):
 
 
 class YouTrackIssue(BaseModel):
-    id_readable: str = Field(alias="idReadable")
-    summary: str
-    created: MillisecondsDatetime
-    updated: MillisecondsDatetime
-    custom_fields: list[YouTrackCustomField] = Field(alias="customFields")
+    id = str
+    id_readable: str | None = Field(alias="idReadable", default=None)
+    summary: str | None = None
+    created: MillisecondsDatetime | None = None
+    updated: MillisecondsDatetime | None = None
+    custom_fields: list[YouTrackCustomField] = Field(alias="customFields", default_factory=list)