import os
from typing import List, Tuple, Dict
from mutagen.easyid3 import EasyID3

from .id3_mapping import Mapping as ID3_MAPPING
from ...utils.shared import (
    MUSIC_DIR,
    DATABASE_LOGGER as logger
)
from .database_object import (
    DatabaseObject,
    Reference
)

"""
All Objects dependent 
"""


class SongAttribute:
    def __init__(self, song=None):
        # the reference to the song the lyrics belong to
        self.song = song

    def add_song(self, song):
        self.song = song

    def get_ref_song_id(self):
        if self.song is None:
            return None
        return self.song.reference.id

    def set_ref_song_id(self, song_id):
        self.song_ref = Reference(song_id)

    song_ref_id = property(fget=get_ref_song_id, fset=set_ref_song_id)


class Metadata:
    """
    Shall only be read or edited via the Song object.
    call it like a dict to read/write values
    """

    def __init__(self, data: dict = {}) -> None:
        # this is pretty self explanatory
        # the key is a 4 letter key from the id3 standarts like TITL
        self.id3_attributes: Dict[str, list] = {}
        
        # its a null byte for the later concatination of text frames
        self.null_byte = "\x00"

    def get_all_metadata(self):
        return list(self.id3_attributes.items())

    def __setitem__(self, key: str, value: list):
        if len(value) == 0:
            return
        if type(value) != list:
            raise ValueError(f"can only set attribute to list, not {type(value)}")
        self.id3_attributes[key] = value

    def __getitem__(self, key):
        if key not in self.id3_attributes:
            return None
        return self.id3_attributes[key]

    def delete_item(self, key: str):
        if key in self.id3_attributes:
            return self.id3_attributes.pop(key)

    def get_id3_value(self, key: str):
        if key not in self.id3_attributes:
            return None
        
        list_data = self.id3_attributes[key]

        """
        Version 2.4 of the specification prescribes that all text fields (the fields that start with a T, except for TXXX) can contain multiple values separated by a null character. 
        Thus if above conditions are met, I concetonate the list,
        else I take the first element
        """
        if key[0].upper() == "T" and key.upper() != "TXXX":
            return self.null_byte.join(list_data)

        return list_data[0]

    def __iter__(self):
        for key in self.id3_attributes:
            yield (key, self.get_id3_value(key))

    def __str__(self) -> str:
        rows = []
        for key, value in self.id3_attributes.items():
            rows.append(f"{key} - {str(value)}")
        return "\n".join(rows)


class Source(DatabaseObject, SongAttribute):
    """
    create somehow like that
    ```python
    # url won't be a valid one due to it being just an example
    Source(src="youtube", url="https://youtu.be/dfnsdajlhkjhsd")
    ```
    """

    def __init__(self, id_: str = None, src: str = None, url: str = None) -> None:
        DatabaseObject.__init__(self, id_=id_)
        SongAttribute.__init__(self)

        self.src = src
        self.url = url

    def __str__(self):
        return f"{self.src}: {self.url}"


class Target(DatabaseObject, SongAttribute):
    """
    create somehow like that
    ```python
    # I know path is pointless, and I will change that (don't worry about backwards compatibility there)
    Target(file="~/Music/genre/artist/album/song.mp3", path="~/Music/genre/artist/album")
    ```
    """

    def __init__(self, id_: str = None, file: str = None, path: str = None) -> None:
        DatabaseObject.__init__(self, id_=id_)
        SongAttribute.__init__(self)
        self._file = file
        self._path = path

    def set_file(self, _file: str):
        self._file = _file

    def get_file(self) -> str | None:
        if self._file is None:
            return None
        return os.path.join(MUSIC_DIR, self._file)

    def set_path(self, _path: str):
        self._path = _path

    def get_path(self) -> str | None:
        if self._path is None:
            return None
        return os.path.join(MUSIC_DIR, self._path)

    def get_exists_on_disc(self) -> bool:
        """
        returns True when file can be found on disc
        returns False when file can't be found on disc or no filepath is set
        """
        if not self.is_set():
            return False

        return os.path.exists(self.file)

    def is_set(self) -> bool:
        return not (self._file is None or self._path is None)

    file = property(fget=get_file, fset=set_file)
    path = property(fget=get_path, fset=set_path)

    exists_on_disc = property(fget=get_exists_on_disc)


class Lyrics(DatabaseObject, SongAttribute):
    def __init__(self, text: str, language: str, id_: str = None) -> None:
        DatabaseObject.__init__(self, id_=id_)
        SongAttribute.__init__(self)
        self.text = text
        self.language = language


class Song(DatabaseObject):
    def __init__(
            self,
            id_: str = None,
            mb_id: str = None,
            title: str = None,
            album_name: str = None,
            artist_names: List[str] = [],
            isrc: str = None,
            length: int = None,
            tracksort: int = None,
            sources: List[Source] = None,
            target: Target = None,
            lyrics: List[Lyrics] = None,
            album=None,
            main_artist_list: list = [],
            feature_artist_list: list = []
    ) -> None:
        """
        id: is not NECESARRILY the musicbrainz id, but is DISTINCT for every song
        mb_id: is the musicbrainz_id
        target: Each Song can have exactly one target which can be either full or empty
        lyrics: There can be multiple lyrics. Each Lyrics object can me added to multiple lyrics
        """
        super().__init__(id_=id_)
        # attributes
        # *private* attributes
        self._title = None
        self._isrc = None
        self._length = None
        self._sources: List[Source] = []

        self.metadata = Metadata()

        self.title = title
        self.isrc = isrc
        self.length = length

        self.mb_id: str | None = mb_id
        self.album_name: str | None = album_name
        self.artist_names = artist_names
        self.tracksort: int | None = tracksort

        if sources is not None:
            self.set_sources(source_list=sources)

        if target is None:
            target = Target()
        self.target: Target = target
        self.target.add_song(self)

        if lyrics is None:
            lyrics = []
        self.lyrics: List[Lyrics] = lyrics
        for lyrics_ in self.lyrics:
            lyrics_.add_song(self)

        self.album: Album = album

        self.main_artist_list = main_artist_list
        self.feature_artist_list = feature_artist_list

    def __eq__(self, other):
        if type(other) != type(self):
            return False
        return self.id == other.id

    def get_artist_credits(self) -> str:
        feature_str = ""
        if len(self.feature_artist_list) > 0:
            feature_str = " feat. " + ", ".join([artist.name for artist in self.feature_artist_list])
        return ", ".join([artist.name for artist in self.main_artist_list]) + feature_str

    def __str__(self) -> str:
        artist_credit_str = ""
        artist_credits = self.get_artist_credits()
        if artist_credits != "":
            artist_credit_str = f" by {artist_credits}"

        return f"\"{self.title}\"{artist_credit_str}"

    def __repr__(self) -> str:
        return self.__str__()

    def set_simple_metadata(self, name: str, value):
        """
        this method is for setting values of attributes,
        that directly map to an ID3 value.
        A good example is the title or the isrc.

        for more complex data I will use seperate functions

        the naming convention for the name I follow is, to name
        the attribute the same as the defined property, but with one underscore infront:
        title -> _title
        """
        if value is None:
            return

        attribute_map = {
            "_title": ID3_MAPPING.TITLE,
            "_isrc": ID3_MAPPING.ISRC,
            "_length": ID3_MAPPING.LENGTH
        }

        # if this crashes/raises an error the function is
        # called wrongly. I DO NOT CATCH ERRORS DUE TO PERFORMANCE AND DEBUGGING
        self.__setattr__(name, value)

        # convert value to id3 value if necessary
        id3_value = value
        if type(value) == int:
            id3_value = str(value)

        self.metadata[attribute_map[name].value] = [id3_value]

    def add_source(self, source_obj: Source):
        source_obj.add_song(self)

        print(source_obj)
        self._sources.append(source_obj)
        self.metadata[ID3_MAPPING.FILE_WEBPAGE_URL.value] = source_obj.url

    def set_sources(self, source_list):
        self._sources = source_list
        for source in self._sources:
            source.add_song(self)
            
        self.metadata[ID3_MAPPING.FILE_WEBPAGE_URL.value] = [s.url for s in self._sources]

    def get_metadata(self):
        return self.metadata.get_all_metadata()

    def has_isrc(self) -> bool:
        return self._isrc is not None

    def add_source(self, source: Source):
        pass

    def get_artist_names(self) -> List[str]:
        return self.artist_names

    def get_length(self):
        if self._length is None:
            return None
        return int(self._length)

    def get_album_id(self):
        if self.album is None:
            return None
        return self.album.id

    title: str = property(fget=lambda self: self._title,
                          fset=lambda self, value: self.set_simple_metadata("_title", value))
    isrc: str = property(fget=lambda self: self._isrc,
                         fset=lambda self, value: self.set_simple_metadata("_isrc", value))
    length: int = property(fget=get_length, fset=lambda self, value: self.set_simple_metadata("_length", value))
    album_id: str = property(fget=get_album_id)

    sources: List[Source] = property(fget=lambda self: self._sources, fset=set_sources)


"""
All objects dependent on Album
"""


class Album(DatabaseObject):
    """
    -------DB-FIELDS-------
    title           TEXT, 
    copyright       TEXT,
    album_status    TEXT,
    language        TEXT,
    year            TEXT,
    date            TEXT,
    country         TEXT,
    barcode         TEXT,
    song_id         BIGINT,
    is_split        BOOLEAN NOT NULL DEFAULT 0
    """

    def __init__(
            self,
            id_: str = None,
            title: str = None,
            copyright_: str = None,
            album_status: str = None,
            language: str = None,
            year: str = None,
            date: str = None,
            country: str = None,
            barcode: str = None,
            is_split: bool = False,
            albumsort: int = None,
            dynamic: bool = False
    ) -> None:
        DatabaseObject.__init__(self, id_=id_, dynamic=dynamic)
        self.title: str = title
        self.copyright: str = copyright_
        self.album_status: str = album_status
        self.language: str = language
        self.year: str = year
        self.date: str = date
        self.country: str = country
        self.barcode: str = barcode
        self.is_split: bool = is_split
        self.albumsort: int | None = albumsort

        self.tracklist: List[Song] = []
        self.artists: List[Artist] = []

    def __str__(self) -> str:
        return f"Album: \"{self.title}\""

    def __repr__(self):
        return self.__str__()

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

    def set_tracklist(self, tracklist: List[Song]):
        self.tracklist = tracklist

        for i, track in enumerate(self.tracklist):
            track.tracksort = i + 1

    def add_song(self, song: Song):
        for existing_song in self.tracklist:
            if existing_song == song:
                return

        song.tracksort = len(self.tracklist)
        self.tracklist.append(song)


"""
All objects dependent on Artist
"""


class Artist(DatabaseObject):
    """
    main_songs
    feature_song

    albums
    """

    def __init__(
            self,
            id_: str = None,
            name: str = None,
            main_songs: List[Song] = None,
            feature_songs: List[Song] = None,
            main_albums: List[Album] = None
    ):
        DatabaseObject.__init__(self, id_=id_)

        if main_albums is None:
            main_albums = []
        if feature_songs is None:
            feature_songs = []
        if main_songs is None:
            main_songs = []

        self.name: str | None = name

        self.main_songs = main_songs
        self.feature_songs = feature_songs

        self.main_albums = main_albums

    def __str__(self):
        return self.name or ""

    def __repr__(self):
        return self.__str__()

    def get_features(self) -> Album:
        feature_release = Album(
            title="features",
            copyright_=self.name,
            album_status="dynamic",
            is_split=True,
            albumsort=666,
            dynamic=True
        )
        for feature in self.feature_songs:
            feature_release.add_song(feature)

        return feature_release

    def get_songs(self) -> Album:
        song_release = Album(
            title="song collection",
            copyright_=self.name,
            album_status="dynamic",
            is_split=False,
            albumsort=666,
            dynamic=True
        )
        for song in self.main_songs:
            song_release.add_song(song)
        for song in self.feature_songs:
            song_release.add_song(song)
        return song_release

    def get_discography(self) -> List[Album]:
        flat_copy_discography = self.main_albums.copy()
        flat_copy_discography.append(self.get_features())

        return flat_copy_discography

    discography: List[Album] = property(fget=get_discography)
    features: Album = property(fget=get_features)
    songs: Album = property(fget=get_songs)