fix: balance nested same-instance ImportProfiler enter/exit

Track per-instance entry depth so `with profiler: with profiler:` only
uninstalls the import hook after the final exit, matching the number of
enters. Previously the first inner exit unregistered the context and
restored builtins.__import__, silently stopping profiling for the still-open
outer scope.

Co-authored-by: Mervin Praison <[email protected]>

src/praisonai/praisonai/profiler.py

@@ -1073,6 +1073,7 @@ class ImportProfiler:
     def __init__(self):
         self._imports: List[ImportRecord] = []
         self._active = False
+        self._entry_depth = 0
     
     def __enter__(self):
         import builtins
@@ -1080,12 +1081,14 @@ class ImportProfiler:
 
         with _IMPORT_HOOK_LOCK:
             if self._active:
+                self._entry_depth += 1
                 return self
             if not _IMPORT_HOOK_CONTEXTS:
                 _IMPORT_HOOK_ORIGINAL = builtins.__import__
                 builtins.__import__ = _profiled_import
             _IMPORT_HOOK_CONTEXTS.append(self)
             self._active = True
+            self._entry_depth = 1
         return self
     
     def __exit__(self, exc_type, exc_val, exc_tb):
@@ -1093,6 +1096,11 @@ class ImportProfiler:
         global _IMPORT_HOOK_ORIGINAL
 
         with _IMPORT_HOOK_LOCK:
+            if not self._active:
+                return False
+            self._entry_depth -= 1
+            if self._entry_depth > 0:
+                return False
             if self in _IMPORT_HOOK_CONTEXTS:
                 _IMPORT_HOOK_CONTEXTS.remove(self)
             self._active = False

src/praisonai/tests/unit/test_wrapper_regressions_3867.py

@@ -343,10 +343,20 @@ def test_import_profiler_defensive_and_idempotent_paths(monkeypatch):
 
     profiler = ImportProfiler()
     try:
+        original_hook = builtins.__import__
         assert profiler.__enter__() is profiler
         installed_hook = builtins.__import__
         assert profiler.__enter__() is profiler
         assert builtins.__import__ is installed_hook
+        assert profiler in profiler_module._IMPORT_HOOK_CONTEXTS
+        profiler.__exit__(None, None, None)
+        assert profiler._active is True
+        assert builtins.__import__ is installed_hook
+        assert profiler in profiler_module._IMPORT_HOOK_CONTEXTS
+        profiler.__exit__(None, None, None)
+        assert profiler._active is False
+        assert profiler not in profiler_module._IMPORT_HOOK_CONTEXTS
+        assert builtins.__import__ is original_hook
     finally:
         profiler.__exit__(None, None, None)