import re
from pathlib import Path
from typing import Any, Callable, Dict, Generator, List, Optional

from ..utils.config import main_settings
from ..utils.exception import MKComposeException
from ..utils.string_processing import unify


class Option:
    """
    This could represent a data object, a string or a page.
    """

    def __init__(
        self, 
        value: Any, 
        text: Optional[str] = None, 
        keys: List[Any] = None, 
        hidden: bool = False, 
        parse_key: Callable[[Any], Any] = lambda x: x,
    ):
        self._parse_key: Callable[[Any], Any] = parse_key
        
        self.value = value
        self.text = text or str(value)
        self.hidden = hidden

        self._raw_keys = set(keys or [])
        self._raw_keys.add(self.text)
        self.keys = set(self.parse_key(key) for key in self._raw_keys)
    
    def register_key(self, key: Any):
        self._raw_keys.add(key)
        self.keys.add(self._parse_key(key))

    @property
    def parse_key(self) -> Callable[[Any], Any]:
        return self._parse_key

    @parse_key.setter
    def parse_key(self, value: Callable[[Any], Any]):
        self._parse_key = value
        self.keys = set(self._parse_key(key) for key in self._raw_keys)

    def __str__(self):
        return self.text


class Select:
    def __init__(
        self, 
        options: Generator[Option, None, None] = None, 
        option_factory: Callable[[Any], Option] = None,
        raw_options: List[Any] = None,
        parse_option_key: Callable[[Any], Any] = lambda x: x,
        ask_for_creating_option: Callable[[Option], bool] = lambda x: True,
        sort: bool = False,
        **kwargs
    ):
        self._parse_option_key: Callable[[Any], Any] = parse_option_key
        self._ask_for_creating_option: Callable[[Option], bool] = ask_for_creating_option

        self._key_to_option: Dict[Any, Option] = dict()
        self._options: List[Option] = []

        options = options or []
        self.option_factory: Optional[Callable[[Any], Option]] = option_factory
        if self.can_create_options:
            _raw_options = raw_options or []
            if sort:
                _raw_options = sorted(_raw_options)

            for raw_option in _raw_options:
                self.append(self.option_factory(raw_option))
        elif raw_options is not None:
            raise MKComposeException("Cannot create options without a factory.")

        self.extend(options)

    @property
    def can_create_options(self) -> bool:
        return self.option_factory is not None

    def append(self, option: Option):
        option.parse_key = self._parse_option_key
        self._options.append(option)
        for key in option.keys:
            self._key_to_option[key] = option

    def extend(self, options: List[Option]):
        for option in options:
            self.append(option)

    def __iter__(self) -> Generator[Option, None, None]:
        for option in self._options:
            if option.hidden:
                continue
            
            yield option

    def __contains__(self, key: Any) -> bool:
        return key in self._key_to_option

    def __getitem__(self, key: Any) -> Option:
        return self._key_to_option[key]

    def create_option(self, key: Any, **kwargs) -> Option:
        if not self.can_create_options:
            raise MKComposeException("Cannot create options without a factory.")

        option = self.option_factory(key, **kwargs)
        self.append(option)
        return option

    def choose(self, key: Any) -> Optional[Option]:
        if key not in self:
            if self.can_create_options and self._ask_for_creating_option(key):
                return self.create_option(key)
            return None

        return self[key]



class StringSelect(Select):
    def __init__(self, **kwargs):
        self._current_index = 0
        kwargs["option_factory"] = self.next_option
        kwargs["parse_option_key"] = lambda x: unify(str(x))

        super().__init__(**kwargs)

    def next_option(self, value: Any) -> Optional[Option]:
        o = Option(value=value, keys=[self._current_index], text=f"{self._current_index:0>2}: {value}")
        self._current_index += 1
        return o


class GenreSelect(StringSelect):
    @staticmethod
    def is_valid_genre(genre: Path) -> bool:
        """
        gets the name of all subdirectories of shared.MUSIC_DIR,
        but filters out all directories, where the name matches with any Patern
        from shared.NOT_A_GENRE_REGEX.
        """
        if not genre.is_dir():
            return False

        if any(re.match(regex_pattern, genre.name) for regex_pattern in main_settings["not_a_genre_regex"]):
            return False

        return True

    def __init__(self):
        super().__init__(sort=True, raw_options=(genre.name for genre in filter(self.is_valid_genre, main_settings["music_directory"].iterdir())))