#!/usr/bin/env python3

# TODO: rework by keeping the last successfully fetched list of feed
# items per feed and diffing against it

from time import mktime
from datetime import datetime
import sys
import feedparser

def eprint(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)

def entry_datetime(entry):
    time_struct = entry['updated_parsed'] or entry['published_parsed']
    return datetime.fromtimestamp(mktime(time_struct))

def is_entry_ok(entry):
    return (('updated_parsed' in entry or 'published_parsed' in entry) and
            'title' in entry and 'link' in entry)

def is_feed_ok(data):
    return all([is_entry_ok(entry) for entry in data.entries])

def process_url(url, timestamp):
    data = feedparser.parse(url)
    if not is_feed_ok(data):
        eprint('Invalid feed at {0}'.format(url))
        return

    entries = [entry for entry in data.entries
               if entry_datetime(entry) >= timestamp]
    for entry in entries:
        print(entry['title'])
        print(entry['link'])

def main():
    if len(sys.argv) != 3:
        print("usage: {0} <url_file> <timestamp>".format(sys.argv[0]))
        exit(1)

    url_file = sys.argv[1]
    timestamp = datetime.strptime(sys.argv[2], '%Y-%m-%d %H:%M:%S')

    with open(url_file) as f:
        for line in f:
            process_url(line.strip(), timestamp)

if __name__ == '__main__':
    main()