import os
import fnmatch
import mimetypes


def scan_dir(dirname, extension=None):
    if extension is None:
        extension = "*"
    for root, dirnames, filenames in os.walk(dirname):
        for fname in fnmatch.filter(filenames, extension):
            yield os.path.join(root, fname)


def multi_fnmatch(fname, extensions):
    for ext in extensions:
        if fnmatch.fnmatch(fname, "*." + ext):
            return True
    return False


def is_audio(fname):
    mimetype = mimetypes.guess_type(fname)[0]
    if mimetype is None:
        return False
    return mimetype.split("/")[0] == "audio"


def scan_dir_audio(dirname, extensions=("mp3", "oga", "wav", "ogg")):
    for root, dirnames, filenames in os.walk(dirname):
        for fname in filenames:
            if is_audio(fname):
                yield os.path.join(root, fname)


def shortname(path):
    name = os.path.basename(path)  # filename
    name = name.rsplit(".", 1)[0]  # no extension
    name = "".join(c for c in name if c.isalnum())  # no strange chars
    return name