spotify-lib-vis/api/views.py

#  imports {{{ # 

import math
import random
import requests
import urllib
import secrets
import pprint
import string

from django.shortcuts import render, redirect
from django.http import JsonResponse
from django.db.models import Count, Q
from .utils import *
from .models import *
from login.models import User
from login.utils import get_user_context

#  }}} imports # 

USER_TRACKS_LIMIT = 50
ARTIST_LIMIT = 50
FEATURES_LIMIT = 100
#  ARTIST_LIMIT = 25
#  FEATURES_LIMIT = 25
TRACKS_TO_QUERY = 100

console_logging = True

#  parse_library {{{ # 

def parse_library(request, user_secret):
    """Scans user's library for num_tracks and store the information in a
    database.

    :user_secret: secret for User object who's library is being scanned.
    :returns: None
    """

    offset = 0
    payload = {'limit': str(USER_TRACKS_LIMIT)}
    artist_genre_queue = []
    features_queue = []
    user_obj = User.objects.get(secret=user_secret)
    user_headers = get_user_header(user_obj)

    # create this obj so loop runs at least once
    saved_tracks_response = [0]
    # scan until reach num_tracks or no tracks left if scanning entire library
    while (TRACKS_TO_QUERY == 0 or offset < TRACKS_TO_QUERY) and len(saved_tracks_response) > 0:
        payload['offset'] = str(offset)
        saved_tracks_response = requests.get('https://api.spotify.com/v1/me/tracks', 
                headers=user_headers,
                params=payload).json()['items']

        if console_logging:
            tracks_processed = 0

        for track_dict in saved_tracks_response:
            #  add artists {{{ # 
            
            # update artist info before track so that Track object can reference
            # Artist object
            track_artists = []
            for artist_dict in track_dict['track']['artists']:
                artist_obj, artist_created = Artist.objects.get_or_create(
                        id=artist_dict['id'],
                        name=artist_dict['name'],)
                # only add/tally up artist genres if new
                if artist_created:
                    artist_genre_queue.append(artist_obj)
                    if len(artist_genre_queue) == ARTIST_LIMIT:
                        add_artist_genres(user_headers, artist_genre_queue)
                        artist_genre_queue = []
                track_artists.append(artist_obj)
            
            #  }}} add artists # 
            
            track_obj, track_created = save_track_obj(track_dict['track'], 
                    track_artists, user_obj)

            #  add audio features {{{ # 
            
            # if a new track is not created, the associated audio feature does
            # not need to be created again
            if track_created:
                features_queue.append(track_obj)
                if len(features_queue) == FEATURES_LIMIT:
                    get_audio_features(user_headers, features_queue)
                    features_queue = []
            
            #  }}} add audio features # 

            if console_logging:
                tracks_processed += 1
                print("Added track #{}: {} - {}".format(
                    offset + tracks_processed,
                    track_obj.artists.first(), 
                    track_obj.name,
                    ))

        # calculates num_songs with offset + songs retrieved
        offset += USER_TRACKS_LIMIT

    #  clean-up {{{ # 
    
    # update remaining artists without genres and songs without features if
    # there are any
    if len(artist_genre_queue) > 0:
        add_artist_genres(user_headers, artist_genre_queue)
    if len(features_queue) > 0:
        get_audio_features(user_headers, features_queue)
    
    #  }}} clean-up # 

    update_track_genres(user_obj)

    return render(request, 'graphs/logged_in.html', get_user_context(user_obj))

#  }}} parse_library # 

#  get_artist_data {{{ # 

def get_artist_data(request, user_secret):
    """Returns artist data as a JSON serialized list of dictionaries
    The (key, value) pairs are (artist name, song count for said artist)

    :param request: the HTTP request
    :param user_secret: the user secret used for identification
    :return: a JsonResponse
    """
    user = User.objects.get(secret=user_secret)
    artist_counts = Artist.objects.annotate(num_songs=Count('track',
        filter=Q(track__users=user)))
    processed_artist_counts = [{'name': artist.name, 'num_songs': artist.num_songs} 
            for artist in artist_counts]
    pprint.pprint(processed_artist_counts)
    return JsonResponse(data=processed_artist_counts, safe=False) 

#  }}} get_artist_data # 

#  get_audio_feature_data {{{ # 

def get_audio_feature_data(request, audio_feature, user_secret):
    """Returns all data points for a given audio feature

    Args:
        request: the HTTP request
        audio_feature: The audio feature to be queried
        user_secret: client secret, used to identify the user
    """
    user = User.objects.get(secret=user_secret)
    user_tracks = Track.objects.filter(users=user)
    response_payload = {
        'data_points': [],
    }
    for track in user_tracks:
        try:
            audio_feature_obj = AudioFeatures.objects.get(track=track)
            response_payload['data_points'].append(getattr(audio_feature_obj, audio_feature))
        except AudioFeatures.DoesNotExist:
            continue
    return JsonResponse(response_payload)

#  }}} get_audio_feature_data # 

#  get_genre_data {{{ # 

def get_genre_data(request, user_secret):
    """Return genre data needed to create the graph user.
    TODO
    """
    user = User.objects.get(secret=user_secret)
    genre_counts = (Track.objects.filter(users__exact=user)
            .values('genre')
            .order_by('genre')
            .annotate(num_songs=Count('genre'))
            )
    for genre_dict in genre_counts:
        genre_dict['artists'] = get_artists_in_genre(user, genre_dict['genre'],
                genre_dict['num_songs'])
    print("*** Genre Breakdown ***")
    pprint.pprint(list(genre_counts))
    return JsonResponse(data=list(genre_counts), safe=False) 

#  }}} get_genre_data  #