from essentia.standard import Danceability
from essentia.standard import MonoLoader
from essentia.standard import RhythmDescriptors
import requests


def analyze_audio(audio_url):
    file_path = download_audio(audio_url)
    loader = get_audio_loader(file_path)
    audio_input = loader()
    result = {
        'bpm': get_bpm(audio_input),
        'danceability': get_danceability(audio_input)}
    return result


def download_audio(audio_url):
    # @todo: use Tempfile or whatever it is
    local_path = '/tmp/' + audio_url.split('/')[-1]
    response = requests.get(audio_url, stream=True)
    with open(local_path, 'wb') as local_file:
        for chunk in response.iter_content(chunk_size=1024):
            if chunk:
                local_file.write(chunk)
    return local_path


def get_audio_loader(file_path):
    """
    Creates an audio loader *function* that loads audio data from the given file.
    """

    return MonoLoader(filename=file_path)


def get_rhythm_descriptors(audio_input):
    rhythm = RhythmDescriptors()
    return rhythm(audio_input)


def get_bpm(audio_input):
    descriptors = get_rhythm_descriptors(audio_input)
    return descriptors[1]


def get_danceability(audio_input):
    dance_func = Danceability()
    raw_danceability = dance_func(audio_input)
    return raw_danceability / 3.0