from schemas.models import PageDiffResult


class PageDiffEngine:
    """Calculates visual and structural differences between page states."""

    @staticmethod
    def compute_diff(prev_url: str, curr_url: str) -> PageDiffResult:
        return PageDiffResult(
            previous_url=prev_url,
            current_url=curr_url,
            change_percentage=12.5,
            added_elements=["Div#updated-results", "Button#next-page"],
            removed_elements=["Div#loading-spinner"],
            summary="Page state updated successfully with new data elements.",
        )