#! /usr/bin/env python
# -*- coding: utf-8 -

# pyAggr3g470r - A Web based news aggregator.
# Copyright (C) 2010-2015  Cédric Bonhomme - https://www.cedricbonhomme.org
#
# For more information : https://bitbucket.org/cedricbonhomme/pyaggr3g470r/
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

__author__ = "Cedric Bonhomme"
__version__ = "$Revision: 3.0 $"
__date__ = "$Date: 2010/09/02 $"
__revision__ = "$Date: 2015/01/21 $"
__copyright__ = "Copyright (c) Cedric Bonhomme"
__license__ = "AGPLv3"

import asyncio
import logging
import requests
import feedparser
import dateutil.parser
from bs4 import BeautifulSoup

from pyaggr3g470r import utils
from pyaggr3g470r import conf
from pyaggr3g470r import db
from pyaggr3g470r.models import User, Article

logger = logging.getLogger(__name__)

#
# asyncio examples:
# -http://compiletoi.net/fast-scraping-in-python-with-asyncio.html
# - https://gist.github.com/kunev/f83146d407c81a2d64a6
#

@asyncio.coroutine
def fetch(user, feed):
    """
    Fetch a feed.
    """
    logger.info("Fetching the feed: " + feed.title)
    print("Fetching the feed: " + feed.title)
    a_feed = feedparser.parse(feed.link)
    if a_feed['bozo'] == 1:
        logger.error(a_feed['bozo_exception'])
    if a_feed['entries'] == []:
        return

    # Feed informations
    if feed.title == "":
        try:
            feed.title = a_feed.feed.title
        except:
            feed.title = "No title"
    if feed.link == "":
        try:
            feed.link = a_feed.feed.link
        except:
            feed.link = ""
    if feed.description == "":
        try:
            feed.description = a_feed.feed.subtitle
        except:
            feed.description = ""

    articles = []
    for article in a_feed['entries']:

        try:
            nice_url = article.link
        except:
            # if not able to get the link of the article, continue
            continue
        if conf.RESOLVE_ARTICLE_URL:
            try:
                # resolves URL behind proxies
                # (like feedproxy.google.com)
                r = requests.get(article.link, timeout=5.0)
                nice_url = r.url
            except Exception as error:
                logger.warning(
                        "Unable to get the real URL of %s. Error: %s",
                        article.link, error)
                continue
        # remove utm_* parameters
        nice_url = utils.clean_url(nice_url)

        description = ""
        article_title = article.get('title', '')
        try:
            # article content
            description = article.content[0].value
        except AttributeError:
            # article description
            description = article.get('description', '')

        try:
            description = BeautifulSoup(description, "lxml").decode()
        except:
            logger.error("Problem when sanitizing the content of the article %s (%s)",
                                article_title, nice_url)

        post_date = None
        for date_key in ('published_parsed', 'published',
                        'updated_parsed', 'updated'):
            if not date_key in article:
                continue

            try:
                post_date = dateutil.parser.parse(article[date_key],
                        dayfirst=True)
                break
            except:
                try:  # trying to clean date field from letters
                    post_date = dateutil.parser.parse(
                                re.sub('[A-z]', '', article[date_key]),
                                dayfirst=True)
                    break
                except:
                    pass

        # create the models.Article object and append it to the list of articles
        article = Article(link=nice_url, title=article_title,
                        content=description, readed=False, like=False,
                        date=post_date, user_id=user.id,
                        feed_id=feed.id)
        articles.append(article)
    return articles

@asyncio.coroutine
def insert_database(user, feed):

    articles = yield from asyncio.async(fetch(user, feed))

    print('inserting articles for {}'.format(feed.title))

    logger.info("Database insertion...")
    new_articles = []
    query1 = Article.query.filter(Article.user_id == user.id)
    query2 = query1.filter(Article.feed_id == feed.id)
    for article in articles:
        exist = query2.filter(Article.link == article.link).count() != 0
        if exist:
            #logger.debug("Article %r (%r) already in the database.", article.title, article.link)
            continue
        if article.date is None:
            article.date = datetime.now(dateutil.tz.tzlocal())
        new_articles.append(article)
        try:
            feed.articles.append(article)
            #db.session.merge(article)
            db.session.commit()
            #logger.info("New article % (%r) added.", article.title, article.link)
            print("New article added: " + article.title)
        except Exception as e:
            logger.error("Error when inserting article in database: " + str(e))
            continue
    #db.session.close()
    return new_articles

@asyncio.coroutine
def done(feed):
    print('done {}'.format(feed.title))

@asyncio.coroutine
def process_data(user, feed):
    data = yield from asyncio.async(insert_database(user, feed))
    print('inserted articles for {}'.format(feed.title))

def retrieve_feed(user, feed_id=None):
        """
        Launch the processus.
        """
        logger.info("Starting to retrieve feeds.")

        # 1 - Get the list of feeds to fetch
        user = User.query.filter(User.email == user.email).first()
        feeds = [feed for feed in user.feeds if feed.enabled]
        if feed_id is not None:
            feeds = [feed for feed in feeds if feed.id == feed_id]

        # 2 - Fetch the feeds.
        loop = asyncio.get_event_loop()
        f = asyncio.wait([process_data(user, feed) for feed in feeds])
        loop.run_until_complete(f)

        """
        # 4 - Indexation
        if not conf.ON_HEROKU:
            self.index(new_articles)

        # 5 - Mail notification
        if not conf.ON_HEROKU and conf.NOTIFICATION_ENABLED:
            self.mail_notification(new_articles)
        """

        logger.info("All articles retrieved. End of the processus.")