import pytest
from unittest.mock import MagicMock
from sqlalchemy import func
from datetime import datetime, timezone
from src.models.activity import Activity
from src.models.segment import Segment

@pytest.fixture
def mock_db_session():
    return MagicMock()

def test_optimization_logic(mock_db_session):
    # Setup test data object
    activity = MagicMock(spec=Activity)
    activity.id = 256
    activity.last_segment_scan_timestamp = None
    
    # 1. Reset
    # Logic in original script: manually reset timestamp.
    # Here we test the optimization logic steps.
    
    # Scene 1: last_scan is None. Logic should PROCEED.
    last_scan = activity.last_segment_scan_timestamp
    assert last_scan is None
    # If the logic in Job Manager checks `if last_scan >= max_seg_date`, it returns False (Don't skip).
    
    # Scene 2: last_scan exists and new Segments exist.
    max_seg_date_mock = datetime(2023, 1, 2, 12, 0, 0, tzinfo=timezone.utc)
    mock_db_session.query.return_value.scalar.return_value = max_seg_date_mock
    
    # Set activity last scan to OLDER
    activity.last_segment_scan_timestamp = datetime(2023, 1, 1, 12, 0, 0, tzinfo=timezone.utc)
    
    # Check Logic
    should_skip = (activity.last_segment_scan_timestamp >= max_seg_date_mock)
    assert should_skip is False
    
    # Scene 3: last_scan is NEWER
    activity.last_segment_scan_timestamp = datetime(2023, 1, 3, 12, 0, 0, tzinfo=timezone.utc)
    should_skip = (activity.last_segment_scan_timestamp >= max_seg_date_mock)
    assert should_skip is True