from collections import Counter
from dataclasses import dataclass, field
from typing import Iterable, List

from graph_exploring_tool.query import Prefix


def get_duplicates(candidates: Iterable) -> List:
    for key, count in Counter(candidates).items():
        if count > 1:
            yield key


@dataclass(init=True, repr=True, order=False, frozen=True)
class Configuration:
    endpoint_sparql: str = ""
    example_prefix: str = ""
    example_query: str = ""
    prefixes: List[Prefix] = field(default_factory=list)

    def check_for_duplicate_prefixes(self):
        """"""
        yield from get_duplicates(prefix.name for prefix in self.prefixes)
        yield from get_duplicates(prefix.namespace for prefix in self.prefixes)