"""Unit testcases for app handler."""

from unittest.mock import MagicMock, Mock, patch

import pytest

import app


@patch('app.GenerateFlowthroughAdjustmentsProcessor')
@patch('app.SnowflakeSQLExecutor')
def test_handler(mock_snowflake, mock_processor, mock_event):
    """Test handler returns OK when records are generated."""
    context = Mock()
    mock_snowflake.return_value.__enter__.return_value = MagicMock()
    mock_processor.return_value.process.return_value = 250
    result = app.handler(mock_event, context)

    assert result == {'status': 'OK'}
    mock_processor.assert_called_once_with(mock_event, mock_snowflake().__enter__())
    mock_processor.return_value.process.assert_called_once()


@patch('app.GenerateFlowthroughAdjustmentsProcessor')
@patch('app.SnowflakeSQLExecutor')
def test_handler_no_records(mock_snowflake, mock_processor, mock_event):
    """Test handler returns NO_RECORDS when no records are generated."""
    context = Mock()
    mock_snowflake.return_value.__enter__.return_value = MagicMock()
    mock_processor.return_value.process.return_value = 0
    result = app.handler(mock_event, context)

    assert result == {'status': 'NO_RECORDS'}
    mock_processor.assert_called_once_with(mock_event, mock_snowflake().__enter__())
    mock_processor.return_value.process.assert_called_once()


@patch('app.SnowflakeSQLExecutor')
def test_handler_exception_propagation(mock_snowflake, mock_event):
    """Test that exceptions are logged and re-raised."""
    context = Mock()
    mock_snowflake.side_effect = Exception('Snowflake Connection Failed')

    with pytest.raises(Exception) as exc_info:
        app.handler(mock_event, context)

    assert 'Snowflake Connection Failed' in str(exc_info.value)