"""
This module contains a simple function to connect to the spotify API without having to load your credentials within your script or notebook.   

???+ warning "Pre-requisites" 
    To use this module, the following variables must be defined in your .env file:   
    `spotifyClientId`, `spotifyClientSecret`   
    + `spotifyUsername` if you want to use the endpoints that need authentication.   

    Or alternatively, you need to pass your ID and Secret as arguments to the `connect_spotify` function.   

    See the [.env file configuration][configure-your-env-file] section if needed

It uses the [spotipy](https://spotipy.readthedocs.io/en/latest/) package under the hood, so you can use all of this package features.  
You can use the `sp` object as your spotipy object and access the spotify API from there.      

???+ example
    === "To use the public endpoints"
        ```
        from djagitit.api.spotify import connect_spotify
        sp = connect_spotify()

        #Or if you want to specify your credentials manually:
        sp = connect_spotify(CLIENT_ID='YOUR_CLIENT_ID', CLIENT_SECRET='YOUR_CLIENT_SECRET')

        #To get data on a masterpiece in history of music:
        sp.album('1cCAb1vN8uUsdfEylVmTLs')
        ```
    === "To use endpoints with specific scopes that require authentication"
        By default, the function uses `https://play.spotify.com/` as the redirect URL.   
        You can either add it to your app redirect urls or use a different one by passing the `REDIRECT_URL` argument (see 2nd example).
        ```
        from djagitit.api.spotify import connect_spotify
        sp = connect_spotify(SCOPE='user-library-read')

        #Or if you want to specify your credentials manually:
        sp = connect_spotify(CLIENT_ID='YOUR_CLIENT_ID', 
                             CLIENT_SECRET='YOUR_CLIENT_SECRET', 
                             SCOPE='user-library-read', 
                             USERNAME='YOUR_USERNAME', 
                             REDIRECT_URL='YOUR_REDIRECT_URL'
                            )

        #To get the last 10 tracks played by the current user:
        sp.current_user_recently_played(limit=10)
        ```
"""

from dotenv import load_dotenv
import os
import pathlib

import spotipy
from spotipy.oauth2 import SpotifyClientCredentials
from spotipy.oauth2 import CacheFileHandler
from spotipy.oauth2 import SpotifyOAuth




load_dotenv()

def __safely_getenv(var):
    """Checks if environment variable is defined before returning it"""
    if not os.getenv(var):
        raise EnvironmentError(f'Environment variable {var} not defined!')
    return os.getenv(var)

def connect_spotify(CLIENT_ID=None, CLIENT_SECRET=None, USERNAME=None, SCOPE=None, REDIRECT_URL='https://play.spotify.com/'):
    if not CLIENT_ID:
        CLIENT_ID = __safely_getenv('spotifyClientId')
    if not CLIENT_SECRET:
        CLIENT_SECRET = __safely_getenv('spotifyClientSecret')


    if not SCOPE:
        client_credentials_manager = SpotifyClientCredentials(client_id=CLIENT_ID, client_secret=CLIENT_SECRET)
        sp = spotipy.Spotify(client_credentials_manager=client_credentials_manager)
    
    else:
        if not USERNAME:
            USERNAME = os.getenv('spotifyUsername')
            if not USERNAME:
                raise Exception("Error: USERNAME is required when SCOPE is specified OR fill the spotifyUsername variable in your .env file.")
        
        spotifyTokenPath = pathlib.Path(__safely_getenv('spotifyTokenDirPath'))
        cacheHandler = CacheFileHandler(cache_path=spotifyTokenPath.joinpath(f'.spotify_{USERNAME}_{SCOPE}.cache'))
        
        auth_manager = SpotifyOAuth(client_id=CLIENT_ID,
                                                client_secret=CLIENT_SECRET,
                                                redirect_uri=REDIRECT_URL,
                                                scope=SCOPE,
                                                cache_handler=cacheHandler)
        
        sp = spotipy.Spotify(auth_manager=auth_manager)


    sp.trace = False

    return sp