1import re
  2from collections import defaultdict
  3from random import choice
  4
  5
  6class Singleton(type):
  7    class_instances = {}
  8
  9    def __call__(cls, *args, **kwargs):
 10        if cls not in cls.class_instances:
 11            cls.class_instances[cls] = super().__call__(*args, **kwargs)
 12        return cls.class_instances[cls]
 13
 14
 15class Santa(metaclass=Singleton):
 16    def __init__(self):
 17        self.gifts = {}
 18        self.count_of_xmases = defaultdict(int)
 19        self.gifts_count = defaultdict(int)
 20        self.naughty_kids = set()
 21
 22    def __call__(self, kid_instance, message):
 23        wish = self.__extract_wish(message)
 24        self.gifts[kid_instance] = wish
 25        self.gifts_count[wish] += 1
 26
 27    def __matmul__(self, letter):
 28        wish = self.__extract_wish(letter)
 29        kid_id = int(self.__extract_signature(letter))
 30        kid = Kid.created_kids.get(kid_id)
 31        self.gifts[kid] = wish
 32        self.gifts_count[wish] += 1
 33
 34    def __iter__(self):
 35        for gift in self.gifts.values():
 36            yield gift
 37
 38    def choose_random_default_gift(self):
 39        curr_gift_count = 0
 40        most_wished_gifts = []
 41        for gift, count in self.gifts_count.items():
 42            if count > curr_gift_count:
 43                curr_gift_count = count
 44                most_wished_gifts = [gift]
 45            elif count == curr_gift_count:
 46                most_wished_gifts.append(gift)
 47        return most_wished_gifts
 48    
 49    def reset_christmas(self):
 50         # Reset gifts values for the new Christmas + incrementing the xmas count by 1
 51            for kid in self.gifts.keys():
 52                self.gifts[kid] = ""
 53                self.count_of_xmases[kid] += 1
 54                
 55    def xmas(self):
 56        if all(count == 0 for count in self.gifts_count.values()):
 57            self.reset_christmas()
 58            return
 59        
 60        most_wished_gifts = self.choose_random_default_gift()
 61        default_gift = choice(most_wished_gifts) if most_wished_gifts else None
 62        
 63        for kid, gift in self.gifts.items():
 64            if self.count_of_xmases[kid] >= 5:
 65                continue
 66
 67            if kid in self.naughty_kids:
 68                kid("coal")
 69            else:
 70                if gift == "":
 71                    final_gift = default_gift
 72                else:
 73                    final_gift = gift
 74                    
 75                if final_gift:
 76                    kid(final_gift)
 77
 78        self.reset_christmas()
 79        self.naughty_kids.clear()
 80        self.gifts_count = defaultdict(int)
 81
 82    @staticmethod
 83    def __extract_wish(message):
 84        match = re.search(r'["\']([a-zA-Z0-9 ]+)["\']', message)
 85        return match.group(1)
 86
 87    @staticmethod
 88    def __extract_signature(message):
 89        match = re.search(r'^\s*(\d+)\s*$', message, re.MULTILINE)
 90        return match.group(1)
 91
 92
 93class Kid(type):
 94    created_kids = {}
 95    
 96    @classmethod
 97    def is_naughty(cls, method):
 98        def wrapper(self, *args, **kwargs):
 99            try:
100                return method(self, *args, **kwargs)
101            except Exception:
102                Santa().naughty_kids.add(self)
103                raise
104        return wrapper
105
106    def __new__(cls, name, bases, dct):
107        if '__call__' not in dct:
108            raise NotImplementedError(
109                f"Tova meta dete/klas {name} neshto ne moje da se vika!")
110
111        for attr_name, attr_value in dct.items():
112            if callable(attr_value) and not attr_name.startswith("_"):
113                dct[attr_name] = cls.is_naughty(attr_value)
114        return super().__new__(cls, name, bases, dct)
115
116    def __call__(cls, *args, **kwargs):
117        instance = super().__call__(*args, **kwargs)
118        # Saving the (id -> kid) pair of each created kid for an easier access later in __matmul__
119        Kid.created_kids[id(instance)] = instance
120
121        # Set default value to each created kid
122        santa = Santa()
123        if instance not in santa.gifts:
124            santa.gifts[instance] = ""
125        return instance