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"""Wrapper module for fetching URLs."""

import urllib


class UrlFetcher(object):
    """Class with restricted interface to fetch URLs (makes testing easier)"""
    def __init__(self, filesystem):
        self._filesystem = filesystem

    def fetch(self, url):
        """Fetches the contents of the URL as a string."""
        file_object = urllib.urlopen(url)
        content = file_object.read()
        file_object.close()
        return content

    def fetch_into_file(self, url):
        """Fetches the contents of the URL into a temporary file and return the filename.

        This is the equivalent of urllib.retrieve() except that we don't return any headers.
        """
        file_object, filename = self._filesystem.open_binary_tempfile('-fetched')
        contents = self.fetch(url)
        file_object.write(contents)
        file_object.close()
        return filename