from copy import deepcopy


class Model:
    """A convenient place to store View data persistently."""

    def __init__(self):
        self.screen = None
        self.title = None
        self.scene_stack = []
        self.error_message = None
        # view-specific data, to be used when e.g. resizing the window
        self._initial_viewdata = {
            'AddUser': {
                'uid': '',
                'cn': '',
                'program': '',
                'forwarding_address': '',
                'num_terms': '1',
            },
            'RenewUser': {
                'uid': '',
                'num_terms': '1',
            },
            'Transaction': {
                'op_layout': None,
                'msg_layout': None,
                'labels': {},
                'status': 'not started',
            },
            'Result': {},
        }
        self.viewdata = deepcopy(self._initial_viewdata)
        # data which is shared between multiple views
        self.is_club_rep = False
        self.confirm_lines = None
        self.operations = None
        self.deferred_req = None
        self.deferred_req_resp = None

    def reset(self):
        self.viewdata = deepcopy(self._initial_viewdata)
        self.is_club_rep = False
        self.confirm_lines = None
        self.operations = None
        self.deferred_req = None
        self.deferred_req_resp = None
        self.title = None
        self.error_message = None
        self.scene_stack.clear()