"""Default URL reading functions"""

__all__ = ['_defaultFetcher']

import functools

import urllib.error

import urllib.request

try:

from importlib import metadata

except ImportError:

import importlib_metadata as metadata

import encutils

from . import errorhandler

log = errorhandler.ErrorHandler()

@functools.lru_cache

def _get_version():

try:

return metadata.version('cssutils')

except metadata.PackageNotFoundError:

return 'unknown'

def _defaultFetcher(url):

"""Retrieve data from ``url``. cssutils default implementation of fetch

URL function.

Returns ``(encoding, string)`` or ``None``

"""

try:

request = urllib.request.Request(url)

agent = f'cssutils/{_get_version()} (https://pypi.org/project/cssutils)'

request.add_header('User-agent', agent)

res = urllib.request.urlopen(request)

except urllib.error.HTTPError as e:

# http error, e.g. 404, e can be raised

log.warn(f'HTTPError opening url={url}: {e.code} {e.msg}', error=e)

except urllib.error.URLError as e:

# URLError like mailto: or other IO errors, e can be raised

log.warn('URLError, %s' % e.reason, error=e)

except OSError as e:

# e.g if file URL and not found

log.warn(e, error=OSError)

except ValueError as e:

# invalid url, e.g. "1"

log.warn('ValueError, %s' % e.args[0], error=ValueError)

else:

if res:

mimeType, encoding = encutils.getHTTPInfo(res)

if mimeType != 'text/css':

log.error(

'Expected "text/css" mime type for url=%r but found: %r'

% (url, mimeType),

error=ValueError,

)

content = res.read()

if hasattr(res, 'close'):

res.close()

return encoding, content