added the ability to get all artist's songs as suggested by #366 (#389)

* added the ability to get all artist's songs as suggested by #366

* added log to featch_all_albums_from_artist function and removed the use of a uri

* updated the functionality to get all albums with the ability to get singles

* updated main function with new write_all_albums_from_artist function to get all albums from an artist

* fixed typos

* updated test case for getting all albums from artist

* fixed typos

spotdl/handle.py

@@ -110,6 +110,11 @@ def get_arguments(raw_args=None, to_group=True, to_merge=True):
         group.add_argument(
             "-b", "--album", help="load tracks from album URL into <album_name>.txt"
         )
+        group.add_argument(
+            "-ab",
+            "--all-albums",
+            help="load all tracks from artist URL into <artist_name>.txt"
+        )
         group.add_argument(
             "-u",
             "--username",

spotdl/spotdl.py

@@ -214,6 +214,7 @@ def main():
     log.debug("Platform: {}".format(platform.platform()))
     log.debug(pprint.pformat(const.args.__dict__))
 
+    
     try:
         if const.args.song:
             download_single(raw_song=const.args.song)
@@ -227,6 +228,8 @@ def main():
             spotify_tools.write_playlist(playlist_url=const.args.playlist)
         elif const.args.album:
             spotify_tools.write_album(album_url=const.args.album)
+        elif const.args.all_albums:
+            spotify_tools.write_all_albums_from_artist(artist_url=const.args.all_albums)
         elif const.args.username:
             spotify_tools.write_user_playlist(username=const.args.username)
 

spotdl/spotify_tools.py

@@ -10,7 +10,6 @@ from titlecase import titlecase
 import pprint
 import sys
 
-
 def generate_token():
     """ Generate the token. Please respect these credentials :) """
     credentials = oauth2.SpotifyClientCredentials(
@@ -150,6 +149,60 @@ def fetch_album(album):
     album = spotify.album(album_id)
     return album
 
+def fetch_album_from_artist(artist_url, album_type='album'):
+    """
+    This funcction returns all the albums from a give artist_url using the US
+    market
+    :param artist_url - spotify artist url
+    :param album_type - the type of album to fetch (ex: single) the default is
+                        a standard album
+    :param return - the album from the artist    
+    """
+
+    #fetching artist's albums limitting the results to the US to avoid duplicate
+    #albums from multiple markets
+    results = spotify.artist_albums(artist_url, album_type=album_type, country='US')
+
+    albums = results['items']
+
+    #indexing all pages of results
+    while results['next']:
+        results = spotify.next(results)
+        albums.extend(results['items'])
+
+    return albums
+        
+
+def write_all_albums_from_artist(artist_url, text_file=None):
+    """
+    This function gets all albums from an artist and writes it to a file in the
+    current working directory called [ARTIST].txt, where [ARTIST] is the artist
+    of the album
+    :param artist_url - spotify artist url
+    :param text_file - file to write albums to 
+    """
+
+    album_base_url = 'https://open.spotify.com/album/'
+
+    #fetching all default albums
+    albums = fetch_album_from_artist(artist_url)
+
+    #if no file if given, the default save file is in the current working
+    #directory with the name of the artist
+    if text_file is None:
+        text_file = albums[0]['artists'][0]['name']+'.txt'
+
+    for album in albums:
+       #logging album name 
+       log.info('Fetching album: ' + album['name'])
+       write_album(album_base_url + album['id'], text_file=text_file)
+
+    #fetching all single albums
+    singles = fetch_album_from_artist(artist_url, album_type='single') 
+
+    for single in singles:
+        log.info('Fetching single: ' + single['name'])
+        write_album(album_base_url + single['id'], text_file=text_file)
 
 def write_album(album_url, text_file=None):
     album = fetch_album(album_url)

test/test_list.py

@@ -7,6 +7,7 @@ from spotdl import spotdl
 
 PLAYLIST_URL = "https://open.spotify.com/user/alex/playlist/0iWOVoumWlkXIrrBTSJmN8"
 ALBUM_URL = "https://open.spotify.com/album/499J8bIsEnU7DSrosFDJJg"
+ARTIST_URL = "https://open.spotify.com/artist/4dpARuHxo51G3z768sgnrY"
 
 
 def test_user_playlists(tmpdir, monkeypatch):
@@ -37,6 +38,17 @@ def test_album(tmpdir):
         tracks = len(f.readlines())
     assert tracks == expect_tracks
 
+def test_all_albums(tmpdir):
+    #current number of tracks on spotify since as of 10/10/2018
+    #in US market only
+    expect_tracks = 49 
+    global text_file
+    text_file = os.path.join(str(tmpdir), 'test_ab.txt')
+    spotify_tools.write_all_albums_from_artist(ARTIST_URL, text_file)
+    with open(text_file, 'r') as f:
+        tracks = len(f.readlines())
+    assert tracks == expect_tracks
+
 
 def test_trim():
     with open(text_file, "r") as track_file: