feat: integrate ordering and hierarchy into event bus

lib/crewai/src/crewai/events/event_bus.py

@@ -16,8 +16,17 @@ from typing import Any, Final, ParamSpec, TypeVar
 
 from typing_extensions import Self
 
-from crewai.events.base_events import BaseEvent
+from crewai.events.base_events import BaseEvent, get_next_emission_sequence
 from crewai.events.depends import Depends
+from crewai.events.event_context import (
+    SCOPE_ENDING_EVENTS,
+    SCOPE_STARTING_EVENTS,
+    VALID_EVENT_PAIRS,
+    get_current_parent_id,
+    get_enclosing_parent_id,
+    pop_event_scope,
+    push_event_scope,
+)
 from crewai.events.handler_graph import build_execution_plan
 from crewai.events.types.event_bus_types import (
     AsyncHandler,
@@ -326,6 +335,32 @@ class CrewAIEventsBus:
             ...     await asyncio.wrap_future(future)  # In async test
             ...     # or future.result(timeout=5.0) in sync code
         """
+        event.emission_sequence = get_next_emission_sequence()
+        if event.parent_event_id is None:
+            event_type_name = event.type
+            if event_type_name in SCOPE_ENDING_EVENTS:
+                event.parent_event_id = get_enclosing_parent_id()
+                popped = pop_event_scope()
+                if popped is None:
+                    self._console.print(
+                        f"[CrewAIEventsBus] Warning: Ending event '{event_type_name}' "
+                        "emitted with empty scope stack. Missing starting event?"
+                    )
+                else:
+                    _, popped_type = popped
+                    expected_start = VALID_EVENT_PAIRS.get(event_type_name)
+                    if expected_start and popped_type and popped_type != expected_start:
+                        self._console.print(
+                            f"[CrewAIEventsBus] Warning: Event pairing mismatch. "
+                            f"'{event_type_name}' closed '{popped_type}' "
+                            f"(expected '{expected_start}')"
+                        )
+            elif event_type_name in SCOPE_STARTING_EVENTS:
+                event.parent_event_id = get_current_parent_id()
+                push_event_scope(event.event_id, event_type_name)
+            else:
+                event.parent_event_id = get_current_parent_id()
+
         event_type = type(event)
 
         with self._rwlock.r_locked():