from unittest.mock import patch, MagicMock
from rag.retriever import retrieve_all

class MockDocument:
    def __init__(self, page_content, metadata=None):
        self.page_content = page_content
        self.metadata = metadata or {}

def test_retrieve_all_no_filter():
    """Verify that retrieval without a filter (or filter='none') delegates to vector store with filter=None."""
    with patch('rag.retriever.db') as mock_db:
        mock_docs = [
            MockDocument("Document 1"),
            MockDocument("Document 2")
        ]
        mock_db.similarity_search.return_value = mock_docs
        
        results = retrieve_all("How to buy a toy?", doc_type=None)
        
        assert len(results) == 2
        assert results[0].page_content == "Document 1"
        mock_db.similarity_search.assert_called_once_with("How to buy a toy?", k=3, filter=None)

def test_retrieve_all_policy_filter():
    """Verify that metadata filter is applied when doc_type is 'policy'."""
    with patch('rag.retriever.db') as mock_db, \
         patch('rag.retriever.models') as mock_models:
        
        # Configure mock models builder behavior
        mock_filter = MagicMock()
        mock_models.Filter.return_value = mock_filter
        
        mock_db.similarity_search.return_value = [MockDocument("Policy Doc")]
        
        results = retrieve_all("Return timeline?", doc_type="policy")
        
        assert len(results) == 1
        assert results[0].page_content == "Policy Doc"
        
        # Verify models.Filter was called to create the filter
        mock_models.Filter.assert_called_once()
        mock_db.similarity_search.assert_called_once_with("Return timeline?", k=3, filter=mock_filter)

def test_retrieve_all_product_filter():
    """Verify that metadata filter is applied when doc_type is 'product'."""
    with patch('rag.retriever.db') as mock_db, \
         patch('rag.retriever.models') as mock_models:
        
        mock_filter = MagicMock()
        mock_models.Filter.return_value = mock_filter
        
        mock_db.similarity_search.return_value = [MockDocument("Product Doc")]
        
        results = retrieve_all("Knights castle", doc_type="product")
        
        assert len(results) == 1
        assert results[0].page_content == "Product Doc"
        
        mock_models.Filter.assert_called_once()
        mock_db.similarity_search.assert_called_once_with("Knights castle", k=3, filter=mock_filter)

def test_retrieve_all_exception_handling():
    """Verify that exceptions in vector store similarity search return an empty list gracefully."""
    with patch('rag.retriever.db') as mock_db:
        mock_db.similarity_search.side_effect = Exception("Qdrant unavailable")
        
        results = retrieve_all("broken query", doc_type=None)
        assert results == []