emmental/trackdb/__init__.py

# Copyright 2020 (c) Anna Schumaker.
from lib import bus
from lib import data
from lib import publisher
from . import library
from . import track
import pathlib
import threading

db_file = "trackdb.pickle"
save_bus = bus.Bus(500)
library_paths = [ ]
LibraryAdded = publisher.Publisher()
LibraryRemoved = publisher.Publisher()

def add_path(path):
    if get_library(path) == None:
        lib = library.LibraryPath(path)
        library_paths.append(lib)
        LibraryAdded.publish(lib)
        return lib

def get_library(path):
    for lib in library_paths:
        if lib.path == pathlib.Path(path):
            return lib
    return None

def get_track(trackid):
    for lib in library_paths:
        if (track := lib[trackid]) != None:
            return track
    return None

def remove_path(path):
    lib = get_library(path)
    library_paths.remove(lib)
    LibraryRemoved.publish(lib)

def _do_save():
    with data.DataFile(db_file, data.WRITE) as f:
            f.pickle([ library.Tracks, library_paths ])

def save(*args):
    save_bus.board(_do_save)

def load():
    global library_paths
    with data.DataFile(db_file, data.READ) as f:
        if f.exists():
            (library.Tracks, library_paths) = f.unpickle()

def __register_callbacks():
    LibraryAdded.register(save)
    LibraryRemoved.register(save)
    library.TrackAdded.register(save)
    library.TrackRemoved.register(save)
    track.TrackUpdated.register(save)
__register_callbacks()

def reset():
    library_paths.clear()
    LibraryAdded.reset()
    LibraryRemoved.reset()
    library.reset()
    track.reset()
    save_bus.clear()

    data.DataFile(db_file, data.READ).remove()
    __register_callbacks()