import importlib

from gui.v2.infrastructure.page_registry import PAGE_REGISTRY


class Navigator:
    def __init__(self, page_stack, custom_window):
        self.page_stack = page_stack
        self.custom_window = custom_window
        self._instances = {}

    def navigate(self, name):
        page = self._instances.get(name)
        if page is None:
            if name not in PAGE_REGISTRY:
                self._warn_not_migrated(name)
                return
            module_path, class_name = PAGE_REGISTRY[name]
            module = importlib.import_module(module_path)
            cls = getattr(module, class_name)
            page = cls(self.page_stack, self.custom_window)
            self.page_stack.addWidget(page)
            self._instances[name] = page
        self.page_stack.setCurrentIndex(self.page_stack.indexOf(page))

    def get_cached(self, name):
        return self._instances.get(name)

    def _warn_not_migrated(self, name):
        try:
            self.custom_window.update_status(f"Page '{name}' not migrated yet.")
        except Exception:
            pass