"""Utilities for downloading models and ither resources."""

import logging

import urllib.request

import os

from os.path import expanduser

BASEURL = 'http://ufallab.ms.mff.cuni.cz/tectomt/share/data/'

def require_file(path):

"""Return absolute path to the file and download it if missing."""

if path.startswith('/') or path.startswith('.'):

if not os.path.isfile(path):

raise IOError(path + " does not exist")

return os.path.abspath(path)

udapi_data = os.environ.get('UDAPI_DATA', expanduser('~'))

if udapi_data is None:

raise IOError(f"Empty environment vars: UDAPI_DATA={os.environ.get('UDAPI_DATA')} HOME={expanduser('~')}")

full_path = os.path.join(udapi_data, path)

if not os.path.isfile(full_path):

logging.info('Downloading %s to %s', BASEURL + path, full_path)

os.makedirs(os.path.dirname(full_path), exist_ok=True)

urllib.request.urlretrieve(BASEURL + path, full_path)

return full_path