# get_tracks is an api method to get recent tracks for a user, with paging and caching
# get_track is an api method to get a single track from mbid or artist+name, with caching

import itertools
from operator import itemgetter

def track_to_artist_and_duration(track):
    api_track = get_track(track)
    return (track.get('artist').get('name'), track.get('name'), api_track.get('duration'))

def ms_to_time(ms):
    seconds = ms / 1000
    m, s = divmod(seconds, 60)
    h, m = divmod(m, 60)
    return "{:d}:{:02d}:{:02d}".format(h, m, s)

track_artist_duration = itertools.imap(track_to_artist_and_duration, get_tracks())
with_duration = itertools.ifilter(lambda t: t[2] is not None and t[2] != "0", track_artist_duration)
grouped_by_artist = [[n, sum(itertools.imap(lambda d: long(d[2]), g))] for n,g in itertools.groupby(sorted(with_duration, key=itemgetter(0)), key=itemgetter(0))]
grouped_sorted = reversed(sorted(grouped_by_artist, key=itemgetter(1)))

for g in itertools.islice(grouped_sorted, 10):
    print(u'{}, {}'.format(g[0], ms_to_time(g[1])))

# Brian Eno, 34:05:03
# This American Life, 11:11:35
# Elder, 7:41:53
# These Arms Are Snakes, 7:32:11
# Brand New, 7:05:50
# King Gizzard & The Lizard Wizard, 6:44:53
# Aviator, 5:52:44
# The War on Drugs, 5:32:47
# Graves at Sea, 5:04:12
# Tigers Jaw, 4:44:36