from typing import List, Iterable

from .source import SourceAttribute
from ..utils import string_processing


class Collection:
    """
    This an class for the iterables
    like tracklist or discography
    """
    _data: List[SourceAttribute]

    _by_url: dict
    _by_attribute: dict

    def __init__(self, data: list = None, map_attributes: list = None, element_type=None) -> None:
        """
        Attribute needs to point to
        """
        self._by_url = dict()

        self.map_attributes = map_attributes or []
        self.element_type = element_type
        self._by_attribute = {attr: dict() for attr in map_attributes}

        self._data = data or []

        for element in self._data:
            self.map_element(element=element)

    def sort(self, reverse: bool = False, **kwargs):
        self._data.sort(reverse=reverse, **kwargs)

    def map_element(self, element: SourceAttribute):
        for source_url in element.source_url_map:
            self._by_url[source_url] = element

        for attr in self.map_attributes:
            value = element.__getattribute__(attr)
            if type(value) != str:
                # this also throws out all none values
                continue

            self._by_attribute[attr][string_processing.unify(value)] = element

    def get_object_with_source(self, url: str) -> any:
        """
        Returns either None, or the object, that has a source
        matching the url.
        """
        if url in self._by_url:
            return self._by_url[url]

    def get_object_with_attribute(self, name: str, value: str):
        if name not in self.map_attributes:
            raise ValueError(f"didn't map the attribute {name}")

        unified = string_processing.unify(value)
        if unified in self._by_attribute[name]:
            return self._by_attribute[name][unified]

    def append(self, element, merge_on_conflict: bool = True):
        if type(element) is not self.element_type and self.element_type is not None:
            raise TypeError(f"{type(element)} is not the set type {self.element_type}")

        for source_url in element.source_url_map:
            if source_url in self._by_url:
                return

        for attr in self.map_attributes:
            value = element.__getattribute__(attr)
            if value in self._by_attribute[attr]:
                return

        self._data.append(element)
        self.map_element(element)

    def extend(self, element_list: Iterable, merge_on_conflict: bool = True):
        for element in element_list:
            self.append(element, merge_on_conflict=merge_on_conflict)

    def __iter__(self):
        for element in self._data:
            yield element

    def __str__(self) -> str:
        return "\n".join([f"{str(j).zfill(2)}: {i.__repr__()}" for j, i in enumerate(self._data)])

    def __len__(self) -> int:
        return len(self._data)

    def __getitem__(self, item):
        if type(item) != int:
            return ValueError("key needs to be an integer")

        return self._data[item]

    def copy(self) -> List:
        """
        returns a shallow copy of the data list
        """
        return self._data.copy()