Add file-based document store and vector store (#96)

* Modify docstore and vectorstore objects to be reconstructable
* Simplify the file docstore
* Use the simple file docstore and vector store in MVP

tests/test_docstores.py

@@ -1,10 +1,15 @@
+import os
 from unittest.mock import patch
 
 import pytest
 from elastic_transport import ApiResponseMeta
 
 from kotaemon.base import Document
-from kotaemon.storages import ElasticsearchDocumentStore, InMemoryDocumentStore
+from kotaemon.storages import (
+    ElasticsearchDocumentStore,
+    InMemoryDocumentStore,
+    SimpleFileDocumentStore,
+)
 
 meta_success = ApiResponseMeta(
     status=200,
@@ -207,7 +212,7 @@ _elastic_search_responses = [
 ]
 
 
-def test_simple_document_store_base_interfaces(tmp_path):
+def test_inmemory_document_store_base_interfaces(tmp_path):
     """Test all interfaces of a a document store"""
 
     store = InMemoryDocumentStore()
@@ -260,6 +265,64 @@ def test_simple_document_store_base_interfaces(tmp_path):
     store2.load(tmp_path / "store.json")
     assert len(store2.get_all()) == 17, "Laded document store should have 17 documents"
 
+    os.remove(tmp_path / "store.json")
+
+
+def test_simplefile_document_store_base_interfaces(tmp_path):
+    """Test all interfaces of a a document store"""
+
+    path = tmp_path / "store.json"
+
+    store = SimpleFileDocumentStore(path=path)
+    docs = [
+        Document(text=f"Sample text {idx}", meta={"meta_key": f"meta_value_{idx}"})
+        for idx in range(10)
+    ]
+
+    # Test add and get all
+    assert len(store.get_all()) == 0, "Document store should be empty"
+    store.add(docs)
+    assert len(store.get_all()) == 10, "Document store should have 10 documents"
+
+    # Test add with provided ids
+    store.add(docs=docs, ids=[f"doc_{idx}" for idx in range(10)])
+    assert len(store.get_all()) == 20, "Document store should have 20 documents"
+
+    # Test add without exist_ok
+    with pytest.raises(ValueError):
+        store.add(docs=docs, ids=[f"doc_{idx}" for idx in range(10)])
+
+    # Update ok with add exist_ok
+    store.add(docs=docs, ids=[f"doc_{idx}" for idx in range(10)], exist_ok=True)
+    assert len(store.get_all()) == 20, "Document store should have 20 documents"
+
+    # Test get with str id
+    matched = store.get(docs[0].doc_id)
+    assert len(matched) == 1, "Should return 1 document"
+    assert matched[0].text == docs[0].text, "Should return the correct document"
+
+    # Test get with list of ids
+    matched = store.get([docs[0].doc_id, docs[1].doc_id])
+    assert len(matched) == 2, "Should return 2 documents"
+    assert [doc.text for doc in matched] == [doc.text for doc in docs[:2]]
+
+    # Test delete with str id
+    store.delete(docs[0].doc_id)
+    assert len(store.get_all()) == 19, "Document store should have 19 documents"
+
+    # Test delete with list of ids
+    store.delete([docs[1].doc_id, docs[2].doc_id])
+    assert len(store.get_all()) == 17, "Document store should have 17 documents"
+
+    # Test save
+    assert path.exists(), "File should exist"
+
+    # Test load
+    store2 = SimpleFileDocumentStore(path=path)
+    assert len(store2.get_all()) == 17, "Laded document store should have 17 documents"
+
+    os.remove(path)
+
 
 @patch(
     "elastic_transport.Transport.perform_request",