from typing import TypeVar, Collection
from tudelft.utilities.immutablelist.ImmutableList import ImmutableList
from tudelft.utilities.immutablelist.Tuple import Tuple
from tudelft.utilities.immutablelist.AbstractImmutableList import AbstractImmutableList


T1 = TypeVar('T1')
T2 = TypeVar('T2')

class Tuples(AbstractImmutableList[Tuple[T1,T2]]):
    '''
    Generate list of Tuple[T1, T2] with all combinations of 1 element from list1
    and one from list2. Sometimes called "cartesian product". You can use this
    recursively to generate bigger products; but you can also use {@link Outer}.
    @param <T1> type of the first element of the tuple
    @param <T2> type of the second element of the tuple    
    @param <T> type of the elements
    '''

    def __init__(self, list1:ImmutableList[T1],
            list2:ImmutableList[T2] ): 
        '''
        contains all possible tuples with first element from list1 and second
        from list2
        
        @param list1 first element list
        @param list2 second element list
         '''
   
        self._list1 = list1
        self._list2 = list2
        self._size = list1.size()* list2.size()

    def get(self,  index:int) -> Tuple[T1, T2] :
        indices = divmod(index,self._list1.size())
        return Tuple(self._list1.get(indices[1]), self._list2.get(indices[0]))

    def size(self) ->int:
        return self._size


    def __hash__(self):
        return hash((self._list1, self._list2))

    def __eq__(self, other):
        return isinstance(other, self.__class__) \
            and self._list1==other._list1\
            and self._list2==other._list2