__author__ = 'stubbfel'

import feedparser
from utilities.textfile import TextFile
from utilities.serializer import Serializer

class FeedFile(TextFile):

    def __init__(self, filename):
        """
        init class
        :param filename: path to the file
        """
        super(FeedFile, self).__init__(filename)

    def read_feed_file(self):
        """
        method read and convert the content of the file to a FeedParserDict
        :return: dict - feed object
        """
        feed_str = self.read_text_file()
        return feedparser.parse(feed_str)

    def write_feed_file(self, feed, serializer=None):
        """
        method write a feedparpser object to a text file. It use a certain serializer or the default serializer
        if type of the serializer is none
        :param feed: expetc FeedparserDict
        :param serializer: None or a subclass of Serializer
        """
        assert isinstance(feed, feedparser.FeedParserDict)

        if serializer is None:
            serializer = Serializer()
            feed_string = serializer.serialize(feed)
        else:
            feed_string = serializer.toString(feed)
        self.write_text_file(feed_string)