clan-app: Add plug and play middleware interface

pkgs/clan-cli/clan_lib/api/tasks.py

@@ -1,8 +1,10 @@
 import logging
 import threading
+import time
 from dataclasses import dataclass
 
 from clan_lib.api import API
+from clan_lib.async_run import get_async_ctx, is_async_cancelled
 
 log = logging.getLogger(__name__)
 
@@ -16,11 +18,12 @@ class WebThread:
 BAKEND_THREADS: dict[str, WebThread] | None = None
 
 
-@API.register_abstract
-def delete_task(task_id: str) -> None:
+@API.register
+def cancel_task(task_id: str) -> None:
     """Cancel a task by its op_key."""
     assert BAKEND_THREADS is not None, "Backend threads not initialized"
     future = BAKEND_THREADS.get(task_id)
+    log.debug(f"Thread ID: {threading.get_ident()}")
     if future:
         future.stop_event.set()
         log.debug(f"Task with id {task_id} has been cancelled.")
@@ -29,6 +32,24 @@ def delete_task(task_id: str) -> None:
         raise ValueError(msg)
 
 
+@API.register
+def long_blocking_task(somearg: str) -> str:
+    """A long blocking task that simulates a long-running operation."""
+    time.sleep(1)
+    ctx = get_async_ctx()
+    log.debug(f"Thread ID: {threading.get_ident()}")
+
+    for i in range(30):
+        if is_async_cancelled():
+            log.debug("Task was cancelled")
+            return "Task was cancelled"
+        log.debug(
+            f"Processing {i} for {somearg}. ctx.should_cancel={ctx.should_cancel()}"
+        )
+        time.sleep(1)
+    return f"Task completed with argument: {somearg}"
+
+
 @API.register
 def list_tasks() -> list[str]:
     """List all tasks."""