# -*- coding: utf-8 -*-
#
# Copyright Grégory Soutadé 2015

# This file is part of iwla

# iwla is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# iwla 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with iwla.  If not, see <http://www.gnu.org/licenses/>.
#

import re

from iwla import IWLA
from iplugin import IPlugin

"""
Post analysis hook

Find feeds parsers (first hit in feeds conf value and no viewed pages if it's a robot)
If there is ony one hit per day to a feed, merge feeds parsers with the same user agent
as it must be the same person with a different IP address.

Plugin requirements :
    None

Conf values needed :
    feeds
    feeds_referers*
    merge_one_hit_only_feeds_parsers*

Output files :
    None

Statistics creation :
   remote_addr =>
       feed_parser

Statistics update :
    None

Statistics deletion :
    None
"""

class IWLAPostAnalysisFeeds(IPlugin):
    NOT_A_FEED_PARSER = 0
    FEED_PARSER = 1
    MERGED_FEED_PARSER = 2
    BAD_FEED_PARSER = 3

    def __init__(self, iwla):
        super(IWLAPostAnalysisFeeds, self).__init__(iwla)
        self.API_VERSION = 1
        self.conf_requires = ['feeds']

    def load(self):
        feeds = self.iwla.getConfValue('feeds', [])
        feeds_referers = self.iwla.getConfValue('feeds_referers', [])
        self.merge_one_hit_only_feeds_parsers = self.iwla.getConfValue('merge_one_hit_only_feeds_parsers', True)

        if feeds is None: return False

        self.feeds_re = []
        for f in feeds:
            self.feeds_re.append(re.compile(f))

        self.bad_feeds_re = []
        self.bad_feeds_re.append(re.compile(r'.*crawl.*'))

        self.user_agents_re = []
        self.user_agents_re.append(re.compile(r'.*rss.*'))
        self.user_agents_re.append(re.compile(r'.*atom.*'))
        self.user_agents_re.append(re.compile(r'.*feed.*'))

        self.referers_uri = []
        for f in feeds_referers:
            self.referers_uri.append(f)

        return True
        
    def mergeOneHitOnlyFeedsParsers(self, isFeedParser, one_hit_only, hit):
        if isFeedParser and (hit['viewed_hits'][0] + hit['not_viewed_hits'][0]) == 1:
            user_agent = hit['requests'][0]['http_user_agent'].lower()
            if one_hit_only.get(user_agent, None) is None:
                # Merged
                isFeedParser = self.MERGED_FEED_PARSER
                one_hit_only[user_agent] = (hit)
            else:
                isFeedParser = self.NOT_A_FEED_PARSER
        hit['feed_parser'] = isFeedParser

    def hook(self):
        hits = self.iwla.getCurrentVisits()
        one_hit_only = {}
        for hit in hits.values():
            isFeedParser = hit.get('feed_parser', None)

            if isFeedParser == self.FEED_PARSER and\
                    self.merge_one_hit_only_feeds_parsers:
                self.mergeOneHitOnlyFeedsParsers(isFeedParser, one_hit_only, hit)

            if isFeedParser:
                if hit['feed_parser'] == self.BAD_FEED_PARSER: continue
                if not hit.get('feed_name_analysed', False) and\
                   hit.get('dns_name_replaced', False):
                    hit['feed_name_analysed'] = True
                    addr = hit.get('remote_addr', None)
                    for r in self.bad_feeds_re:
                        if r.match(addr):
                            hit['feed_parser'] = self.BAD_FEED_PARSER
                            return
                return

            request = hit['requests'][0]
            isFeedParser = self.NOT_A_FEED_PARSER
            uri = request['extract_request']['extract_uri'].lower()
            for regexp in self.feeds_re:
                if regexp.match(uri):
                    isFeedParser = self.FEED_PARSER
                    # Robot that views pages -> bot
                    if hit['robot']:
                        if hit['not_viewed_pages'][0]:
                            isFeedParser = self.NOT_A_FEED_PARSER
                    break

            if isFeedParser == self.NOT_A_FEED_PARSER:
                user_agent = request['http_user_agent'].lower()
                for regexp in self.user_agents_re:
                    if regexp.match(user_agent):
                        isFeedParser = self.FEED_PARSER
                        break
                
            if isFeedParser == self.NOT_A_FEED_PARSER and\
               request.get('extract_referer', False):
                referer = request['extract_referer']['extract_uri'].lower()
                for uri in self.referers_uri:
                    if referer == uri:
                        isFeedParser = self.FEED_PARSER
                        break

            if self.merge_one_hit_only_feeds_parsers:
                self.mergeOneHitOnlyFeedsParsers(isFeedParser, one_hit_only, hit)
            else:
                hit['feed_parser'] = isFeedParser