import pathlib
import threading
import weakref

import disk_paths
import disk_utils

DICTIONARY_LOCK = threading.Lock()
DISK_LOCKS = weakref.WeakValueDictionary()

def create_disk(request):
    paths = disk_paths.DiskPaths(request)
    workstation = request['workstation']

    with disk_lock(paths):
        if not paths.target_path.exists():
            disk_utils.create_os_disk(paths)

        if workstation['cpu'] == 'ARM' and not paths.nvram_target_path.exists():
            disk_utils.create_nvram_disk(paths)

def delete_disk(request):
    paths = disk_paths.DiskPaths(request)

    with disk_lock(paths):
        paths.target_path.unlink(missing_ok=True)
        paths.nvram_target_path.unlink(missing_ok=True)

def disk_lock(paths):
    with DICTIONARY_LOCK:
        return DISK_LOCKS.setdefault(paths.target_filename, threading.Lock())