Remove delete_existing option; Introduce archive (#409)

* Remove `delete_existing` option; Introduce archive

* Update gpt_engineer/db.py

* Update gpt_engineer/main.py

* Update gpt_engineer/main.py

* Update gpt_engineer/steps.py

* Update gpt_engineer/steps.py

---------

Co-authored-by: Anton Osika <anton.osika@gmail.com>

tests/steps/test_archive.py

@@ -0,0 +1,44 @@
+import datetime
+import os
+
+from unittest.mock import MagicMock
+
+from gpt_engineer.db import DB, DBs
+from gpt_engineer.steps import archive
+
+
+def freeze_at(monkeypatch, time):
+    datetime_mock = MagicMock(wraps=datetime.datetime)
+    datetime_mock.now.return_value = time
+    monkeypatch.setattr(datetime, "datetime", datetime_mock)
+
+
+def setup_dbs(tmp_path, dir_names):
+    directories = [tmp_path / name for name in dir_names]
+
+    # Create DB objects
+    dbs = [DB(dir) for dir in directories]
+
+    # Create DBs instance
+    return DBs(*dbs)
+
+
+def test_archive(tmp_path, monkeypatch):
+    dbs = setup_dbs(
+        tmp_path, ["memory", "logs", "preprompts", "input", "workspace", "archive"]
+    )
+    freeze_at(monkeypatch, datetime.datetime(2020, 12, 25, 17, 5, 55))
+    archive(None, dbs)
+    assert not os.path.exists(tmp_path / "memory")
+    assert not os.path.exists(tmp_path / "workspace")
+    assert os.path.isdir(tmp_path / "archive" / "20201225_170555")
+
+    dbs = setup_dbs(
+        tmp_path, ["memory", "logs", "preprompts", "input", "workspace", "archive"]
+    )
+    freeze_at(monkeypatch, datetime.datetime(2022, 8, 14, 8, 5, 12))
+    archive(None, dbs)
+    assert not os.path.exists(tmp_path / "memory")
+    assert not os.path.exists(tmp_path / "workspace")
+    assert os.path.isdir(tmp_path / "archive" / "20201225_170555")
+    assert os.path.isdir(tmp_path / "archive" / "20220814_080512")