add delete handling for saved prompts

Signed-off-by: Jordan Dubrick <jdubrick@redhat.com>

Author: Jdubrick

src/utils/saved_prompts.py

@@ -184,6 +184,7 @@ def list_saved_prompts_by_user(user_id: str) -> list[SavedPrompt]:
 
     Returns:
         List of ``SavedPrompt`` rows for the user. Empty list if none exist.
+        Tie order when ``created_at`` values are equal is database-defined.
     """
     with get_session() as session:
         return (
@@ -192,3 +193,42 @@ def list_saved_prompts_by_user(user_id: str) -> list[SavedPrompt]:
             .order_by(SavedPrompt.created_at.desc())
             .all()
         )
+
+
+def delete_saved_prompt_by_id_and_user(prompt_id: str, user_id: str) -> None:
+    """Delete a saved prompt only if it belongs to the given user.
+
+    Parameters:
+        prompt_id: Primary key of the saved prompt.
+        user_id: Authenticated user attempting the delete.
+
+    Raises:
+        SavedPromptNotFoundError: If no row exists for ``prompt_id``.
+        SavedPromptAccessDeniedError: If the row exists but ``user_id`` does not
+            match the owner.
+    """
+    with get_session() as session:
+        saved_prompt = session.query(SavedPrompt).filter_by(id=prompt_id).first()
+        if saved_prompt is None:
+            logger.debug(
+                "Saved prompt not found for delete prompt_id=%s user_id=%s",
+                prompt_id,
+                user_id,
+            )
+            raise SavedPromptNotFoundError("Saved prompt not found")
+
+        if saved_prompt.user_id != user_id:
+            logger.debug(
+                "Saved prompt access denied for delete prompt_id=%s user_id=%s",
+                prompt_id,
+                user_id,
+            )
+            raise SavedPromptAccessDeniedError("Saved prompt access denied")
+
+        session.delete(saved_prompt)
+        session.commit()
+        logger.debug(
+            "Deleted saved prompt id=%s for user_id=%s",
+            prompt_id,
+            user_id,
+        )

tests/unit/utils/test_saved_prompts.py

@@ -13,10 +13,13 @@
 from models.database.base import Base
 from models.database.saved_prompts import SavedPrompt
 from utils.saved_prompts import (
+    SavedPromptAccessDeniedError,
     SavedPromptConflictError,
     SavedPromptLimitExceededError,
+    SavedPromptNotFoundError,
     SavedPromptValidationError,
     create_saved_prompt,
+    delete_saved_prompt_by_id_and_user,
     list_saved_prompts_by_user,
     validate_saved_prompt_content,
     validate_saved_prompt_name,
@@ -334,3 +337,51 @@ def test_list_returns_only_that_users_prompts_ordered_by_created_at_desc(
 
         assert [p.id for p in results] == [newer.id, older.id]
         assert all(p.user_id == "user-1" for p in results)
+
+
+class TestDeleteSavedPromptByIdAndUser:
+    """Test cases for delete_saved_prompt_by_id_and_user."""
+
+    def test_delete_owned_prompt(
+        self, patch_saved_prompts_get_session: None, sqlite_engine: Engine
+    ) -> None:
+        """Test deleting an owned prompt removes the row."""
+        created = create_saved_prompt(
+            "user-1", "to-delete", "body", max_prompts_per_user=50
+        )
+
+        delete_saved_prompt_by_id_and_user(created.id, "user-1")
+
+        session_factory = sessionmaker(
+            autocommit=False, autoflush=False, bind=sqlite_engine
+        )
+        with session_factory() as session:
+            assert session.get(SavedPrompt, created.id) is None
+
+    def test_delete_missing_raises_not_found(
+        self, patch_saved_prompts_get_session: None
+    ) -> None:
+        """Test deleting an unknown id raises SavedPromptNotFoundError."""
+        with pytest.raises(SavedPromptNotFoundError) as exc_info:
+            delete_saved_prompt_by_id_and_user("missing-id", "user-1")
+
+        assert str(exc_info.value) == "Saved prompt not found"
+
+    def test_delete_other_users_prompt_raises_access_denied(
+        self, patch_saved_prompts_get_session: None, sqlite_engine: Engine
+    ) -> None:
+        """Test delete by non-owner raises access denied and leaves the row."""
+        created = create_saved_prompt(
+            "owner", "private", "body", max_prompts_per_user=50
+        )
+
+        with pytest.raises(SavedPromptAccessDeniedError) as exc_info:
+            delete_saved_prompt_by_id_and_user(created.id, "intruder")
+
+        assert str(exc_info.value) == "Saved prompt access denied"
+
+        session_factory = sessionmaker(
+            autocommit=False, autoflush=False, bind=sqlite_engine
+        )
+        with session_factory() as session:
+            assert session.get(SavedPrompt, created.id) is not None