import datetime
import traceback

import lxml.html.soupparser
import requests
from dateutil.tz import tzlocal


class CantGetTitle(ValueError):
    pass


class PageTitle(object):

    def __init__(self, db):
        self.coll = db['pageTitle']

    def getPageTitleNow(self, uri):
        try:
            response = requests.get(uri,
                                    timeout=3,
                                    allow_redirects=True,
                                    headers={'user-agent': 'link title checker - drewp@bigasterisk.com'})
            if not str(response.status_code).startswith('2'):
                raise CantGetTitle("(got %s)" % response.status_code)
            root = lxml.html.soupparser.fromstring(response.text)

            for title in root.cssselect("title"):
                return title.text
        except Exception:
            traceback.print_exc()
            raise CantGetTitle("(error requesting title from site)")

    def pageTitle(self, uri):
        """page title from our db or by getting a new load from the page"""
        doc = self.coll.find_one({'_id': uri})
        if doc is None:
            try:
                title = self.getPageTitleNow(uri)
            except CantGetTitle as e:
                return str(e)
            doc = {'_id': uri, 'title': title, 'getTime': datetime.datetime.now(tzlocal())}
            self.coll.insert(doc)
        return doc['title']