1import re
  2
  3class Santa:
  4    _instance = None
  5    _WISH_PATTERN = r"(\"|\')[A-Za-z0-9\s]+\1"
  6    _ID_PATTERN = r"^\s*\d+\s*$"
  7    _MAX_XMAS_COUNT = 5
  8    _kid_presents = {}
  9    _all_presents = {}
 10    _all_kids = []
 11    _presents = []
 12
 13    def __new__(cls, *args, **kwargs):
 14        if cls._instance is None:
 15            cls._instance = super().__new__(cls)
 16        return cls._instance
 17    
 18    def _present_checker(self, present):
 19        wish_match = re.search(self._WISH_PATTERN, present) 
 20        if not wish_match:
 21            raise TypeError('not a valid wish')
 22        
 23        return re.sub(r'(\'|\")', '', wish_match.group())
 24
 25    def _add_present(self, kid, present):
 26        current_present = self._kid_presents.get(kid, None)
 27
 28        if current_present:
 29            idx = self._presents.index(current_present)
 30            self._presents[idx] = present
 31        else:
 32            self._presents.append(present)
 33
 34        self._kid_presents[kid] = present
 35        self._all_presents[present] = self._all_presents.get(present, 0) + 1
 36
 37    def __call__(self, kid, message):
 38        present = self._present_checker(message)
 39        self._add_present(kid, present)
 40
 41    def __matmul__(self, letter):
 42        present = self._present_checker(letter)
 43        id_match = re.search(self._ID_PATTERN, letter, re.MULTILINE)
 44
 45        kid_id = int(re.sub(r'\s', '', id_match.group()))
 46        kid = Kid.get_instance(kid_id)
 47
 48        if kid is None:
 49            raise TypeError('not a valid kid')
 50
 51        self._add_present(kid, present)
 52
 53    def __iter__(self):
 54        for present in self._presents:
 55            yield present
 56    
 57    def _clear_list(self):
 58        self._kid_presents.clear()
 59        self._all_presents.clear()
 60        self._presents.clear()
 61
 62    def _xmas_checker(self):
 63        for kid in self._all_kids:
 64            if kid.xmas_count == self._MAX_XMAS_COUNT:
 65                Kid.remove_from_xmas(kid)
 66                continue
 67            kid.xmas_count += 1
 68
 69    def xmas(self):
 70        self._xmas_checker()
 71        
 72        if not self._kid_presents:
 73            return None
 74        
 75        best_present = max(self._all_presents, key=self._all_presents.get)
 76
 77        for kid in self._all_kids:
 78            if not kid._has_present:
 79                continue
 80            if kid._has_exception:
 81                kid('coal')
 82                Kid.reset_exception_status(kid)
 83            else:
 84                if kid not in self._kid_presents.keys():
 85                    kid(best_present)
 86                else:
 87                    kid(self._kid_presents[kid])
 88        
 89        self._clear_list()
 90
 91    @classmethod
 92    def add_kid(cls, kid):
 93        cls._all_kids.append(kid)
 94
 95
 96class Kid(type):
 97    _instances = {}
 98
 99    def __new__(cls, name, bases, attr_dict):
100        if '__call__' not in attr_dict.keys():
101            raise NotImplementedError
102        attr_dict['xmas_count'] = 0
103        attr_dict['_has_exception'] = False
104        attr_dict['_has_present'] = True
105
106        for name, value in attr_dict.items():
107            if callable(value) and not name.startswith('_'):
108                attr_dict[name] = cls.check_exceptions(value)
109        return super().__new__(cls, name, bases, attr_dict)
110    
111    @staticmethod
112    def check_exceptions(func):
113        def decorator(self, *args, **kwargs):
114            try:
115                return func(self, *args, **kwargs)
116            except Exception as e:
117                self._has_exception = True
118                raise
119        return decorator
120
121    @classmethod
122    def reset_exception_status(cls, instance):
123        instance._has_exception = False
124
125    @classmethod
126    def remove_from_xmas(cls, instance):
127        instance._has_present = False
128
129    def __call__(cls, *args, **kwargs):
130        instance = super().__call__(*args, **kwargs)
131        Santa.add_kid(instance)
132
133        if id(instance) not in Kid._instances.keys():
134            Kid._instances[id(instance)] = instance
135        
136        return instance
137
138    @classmethod
139    def get_instance(cls, instance_id):
140        return cls._instances.get(instance_id, None)