import os
import logging
from pysonic.scanner import PysonicFilesystemScanner
from pysonic.types import MUSIC_TYPES


LETTER_GROUPS = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t",
                 "u", "v", "w", "xyz", "0123456789"]


logging = logging.getLogger("library")


def memoize(function):
    memo = {}

    def wrapper(*args):
        if args in memo:
            return memo[args]
        else:
            rv = function(*args)
            memo[args] = rv
            return rv
    return wrapper


class NoDataException(Exception):
    pass


class PysonicLibrary(object):
    def __init__(self, database):
        self.db = database
        self.scanner = PysonicFilesystemScanner(self)
        logging.info("library ready")

    def update(self):
        """
        Start the library media scanner and
        """
        self.scanner.init_scan()

    def add_root_dir(self, path):
        """
        The music library consists of a number of root dirs. This adds a new root
        """
        path = os.path.abspath(os.path.normpath(path))
        self.db.add_root(path)