import copy
from modules.nlu import Act
import json


class DialogStateMonitor:
    def __init__(self):
        self.__initial_state = dict(
            belief_state={
                'item': {},
                'address': {},
                'card_nr': {},
                'delivery_method': {},
                'payment_method': {},
                'email': {},
                'order-completed': False,
            },
            act='',
            slot_names=[])

        self.state = copy.deepcopy(self.__initial_state)

    def is_value_empty(self, d, key):
        value = d.get(key, None)
        if value in [None, '', [], {}]:
            return True
        return False

    def update_act(self, intent):
        self.state['act'] = intent

    def update_slot_names(self, slots_names):
        self.state['slot_names'] = slots_names

    def check_order_complete(self):
        all_filled = all(bool(self.state['belief_state'][key]) for key in
                         ['item', 'address', 'card_nr', 'delivery_method', 'payment_method', 'email'])
        self.state['belief_state']['order-complete'] = all_filled

    def find_first_empty_slot(self):
        for slot_name, slot_value in self.state['belief_state'].items():
            if slot_name != 'order-completed' and slot_value in [None, '', [], {}]:
                return slot_name

    def update(self, act: Act) -> None:
        if act.intent == 'inform':
            self.update_act(act.intent)
            slots_mapping = {
                'item': [],
                'address': [],
                'card_nr': [],
                'delivery_method': [],
                'payment_method': [],
                'email': []
            }
            for slot in act.slots:
                if slot.name in slots_mapping and self.is_value_empty(self.state['belief_state'], slot.name):
                    slots_mapping[slot.name].append(slot.value)  # To do: normalization

            for slot_name, values in slots_mapping.items():
                if values:
                    self.state['belief_state'][slot_name] = values
        elif act.intent == 'request':
            self.update_act(act.intent)
            slots_names = [slot.name for slot in act.slots]
            self.update_slot_names(slots_names)
        elif act.intent == 'bye':
            self.update_act(act.intent)
        elif act.intent == 'unknown':
            self.update_act(act.intent)

        self.check_order_complete()