"""
This module creates and initiliazes a MongoDB instance. It also contains the
`convert_one()` and `conver_many()` methods for converting MongoDB cursors to Python dicts.
"""
import json

import pymongo
from app.db import AlbumMethods
from app.db import ArtistMethods
from app.db import PlaylistMethods
from app.db import TrackMethods
from bson import json_util


class Mongo:
    """
    The base class for all mongodb classes.
    """

    def __init__(self, database):
        mongo_uri = pymongo.MongoClient()
        self.db = mongo_uri[database]


class MongoAlbums(Mongo, AlbumMethods):

    def __init__(self):
        super(MongoAlbums, self).__init__("ALICE_ALBUMS")
        self.collection = self.db["ALL_ALBUMS"]


class MongoArtists(Mongo, ArtistMethods):

    def __init__(self):
        super(MongoArtists, self).__init__("ALICE_ARTISTS")
        self.collection = self.db["ALL_ARTISTS"]


class MongoPlaylists(Mongo, PlaylistMethods):

    def __init__(self):
        super(MongoPlaylists, self).__init__("ALICE_PLAYLISTS")
        self.collection = self.db["ALL_PLAYLISTS"]


class MongoTracks(Mongo, TrackMethods):

    def __init__(self):
        super(MongoTracks, self).__init__("ALICE_MUSIC_TRACKS")
        self.collection = self.db["ALL_TRACKS"]


# ====================================================================== #
# cursor convertion methods


def convert_one(song):
    """
    Converts a single mongodb cursor to a json object.
    """
    json_song = json.dumps(song, default=json_util.default)
    loaded_song = json.loads(json_song)

    return loaded_song


def convert_many(array):
    """
    Converts a list of mongodb cursors to a list of json objects.
    """

    songs = []

    for song in array:
        json_song = json.dumps(song, default=json_util.default)
        loaded_song = json.loads(json_song)

        songs.append(loaded_song)

    return songs