# -*- coding: utf-8 -*-
#
# Copyright Grégory Soutadé 2020

# 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
from display import *
from misc.geoiplookup import geoiplookup

"""
Post analysis hook

Filter users with given user conditions

Plugin requirements :
    None

Conf values needed :
    filtered_users : list of filters
    filtered_ip : list of ip (string)
    create_filtered_page*

Filter can be a function or a list of filter description combined by AND operator
Filter description can be a function or a list of 3 elements :

  * Field to match in visits
  * Operator '=', '==', '!=', '>', '>=', '<', '<=' for int value
  * Operator '=', '==', '!=', 'in', 'match' for str value
  * Target value

For easiest config, you can indicate both 'remote_addr' or 'ip' in field element

function prototype is func(iwla, hit) and must return True or False

Example :

def my_filter(iwla, hit):
    return True

filtered_users = [
    [['viewed_pages', '>=', '5'], ['viewed_hits', '>=', '5']],
    [['viewed_hits', '>=', '5'], my_filter],
    my_filter,
]

Output files :
    None

Statistics creation :
visits :
   remote_ip =>
       filtered
       geo_location

Statistics update :
visits :
   remote_ip =>
       keep_requests

Statistics deletion :
    None
"""

class IWLAPostAnalysisFilterUsers(IPlugin):
    def _check_filter(self, _filter):
        if len(_filter) != 3:
            raise Exception('Bad filter ' + ' '.join(_filter))
        (field, operator, value) = _filter
        try:
            if type(value) == str:
                value = int(value, 10)
                _filter[2] = value
            if operator not in ('=', '==', '!=', '>', '>=', '<', '<='):
                raise Exception('Bad filter ' + ' '.join(_filter))
        except Exception as e:
            if field == 'ip':
                _filter[0] = 'remote_ip'
            if operator not in ('=', '==', '!=', 'in', 'match'):
                raise Exception('Bad filter ' + ' '.join(_filter))
            if operator == 'match':
                _filter[2] = re.compile(value)
    
    def load(self):
        self.filters = self.iwla.getConfValue('filtered_users', [])
        self.ip_filters = self.iwla.getConfValue('filtered_ip', [])
        for _filter in self.filters:
            if type(_filter) == list:
                for sub_filter in _filter:
                    if not callable(sub_filter):
                        self._check_filter(sub_filter)
            elif callable(_filter):
                continue
            else:
                raise Exception(f'Invalid filter {_filter}')
        return True
    
    def __do_filter(self, hit, _filter):
        (field, operator, value) = _filter
        if not field in hit.keys(): return False
        hit_value = hit[field]
        # In dict, we have something like : {dayX : value} were day0 is total
        if type(value) == int and type(hit_value) == dict:
            hit_value = list(hit_value.values())[0]
        if operator == '=' or operator == '==':
            return hit_value == value
        elif operator == 'in':
            return hit_value in value
        elif operator == 'match':
            return re.match(value, hit_value)
        elif operator == '!=':
            return hit_value != value
        elif operator == '<':
            return hit_value < value
        elif operator == '<=':
            return hit_value <= value
        elif operator == '>':
            return hit_value > value
        elif operator == '>=':
            return hit_value >= value
    
    def _do_filter(self, ip, hits):
        if ip in self.ip_filters:
            return True
        
        for _filter in self.filters:
            if callable(_filter):
                if _filter(self.iwla, hits[ip]):
                    return True
                continue
            # Must match all sub filters
            filtered = True
            for sub_filter in _filter:
                if callable(sub_filter):
                    if not sub_filter(self.iwla, hits[ip]):
                        filtered = False
                        break
                elif not self.__do_filter(hits[ip], sub_filter):
                    filtered = False
                    break
            if filtered:
                return True
        return False
    
    def hook(self):
        if not len(self.filters) and not len(self.ip_filters):
            return

        hits = self.iwla.getValidVisitors()

        for (key,value) in hits.items():
            # Already filtered
            if value.get('filtered', False):
                continue

            if self._do_filter(key, hits):
                value['filtered'] = True
                value['keep_requests'] = True
                try:
                    if not value.get('geo_location', None):
                        value['geo_location'] = geoiplookup(value['remote_ip'])
                except Exception as e:
                    print(e)