#!/usr/bin/env python
# -*- 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 os
import shutil
import sys
import re
import time
import pickle
import gzip
import importlib 
import argparse
import logging
import gettext
from calendar import monthrange
from datetime import date

import default_conf as conf
import conf as _
conf.__dict__.update(_.__dict__)
del _

from iplugin import *
from display import *

"""
Main class IWLA
Parse Log, compute them, call plugins and produce output
For now, only HTTP log are valid

Plugin requirements :
    None

Conf values needed :
    analyzed_filename
    domain_name
    locales_path
    compress_output_files*

Output files :
    DB_ROOT/meta.db
    DB_ROOT/year/month/iwla.db
    OUTPUT_ROOT/index.html
    OUTPUT_ROOT/year/_stats.html
    OUTPUT_ROOT/year/month/index.html

Statistics creation :

meta :
    last_time
    start_analysis_time
    stats =>
        year =>
            month =>
                viewed_bandwidth
                not_viewed_bandwidth
                viewed_pages
                viewed_hits
                nb_visits
                nb_visitors

month_stats :
    viewed_bandwidth
    not_viewed_bandwidth
    viewed_pages
    viewed_hits
    nb_visits

days_stats :
    day =>
        viewed_bandwidth
        not_viewed_bandwidth
        viewed_pages
        viewed_hits
        nb_visits
        nb_visitors

visits :
   remote_addr =>
       remote_addr
       remote_ip
       viewed_pages
       viewed_hits
       not_viewed_pages
       not_viewed_hits
       bandwidth
       last_access
       requests =>
           [fields_from_format_log]
           extract_request =>
               extract_uri
               extract_parameters*
           extract_referer* =>
               extract_uri
               extract_parameters*
       robot
       hit_only
       is_page

valid_visitors:
    month_stats without robot and hit only visitors (if not conf.count_hit_only_visitors)

Statistics update :
    None

Statistics deletion :
    None
"""


class IWLA(object):

    ANALYSIS_CLASS = 'HTTP'
    API_VERSION = 1
    IWLA_VERSION = '0.1'

    def __init__(self, logLevel):
        self.meta_infos = {}
        self.analyse_started = False
        self.current_analysis = {}
        self.cache_plugins = {}
        self.display = DisplayHTMLBuild(self)
        self.valid_visitors = None

        self.log_format_extracted = re.sub(r'([^\$\w])', r'\\\g<1>', conf.log_format)
        self.log_format_extracted = re.sub(r'\$(\w+)', '(?P<\g<1>>.+)', self.log_format_extracted)
        self.http_request_extracted = re.compile(r'(?P<http_method>\S+) (?P<http_uri>\S+) (?P<http_version>\S+)')
        self.log_re = re.compile(self.log_format_extracted)
        self.uri_re = re.compile(r'(?P<extract_uri>[^\?#]+)(\?(?P<extract_parameters>[^#]+))?(#.*)?')
        self.domain_name_re = re.compile(r'.*%s' % conf.domain_name)
        self.plugins = [(conf.PRE_HOOK_DIRECTORY     , conf.pre_analysis_hooks),
                        (conf.POST_HOOK_DIRECTORY    , conf.post_analysis_hooks),
                        (conf.DISPLAY_HOOK_DIRECTORY , conf.display_hooks)]

        logging.basicConfig(format='%(name)s %(message)s', level=logLevel)
        self.logger = logging.getLogger(self.__class__.__name__)
        self.logger.info('==> Start')
        try:
            t = gettext.translation('iwla', localedir=conf.locales_path, languages=[conf.locale], codeset='utf8')
            self.logger.info('\tUsing locale %s' % (conf.locale))
        except IOError:
            t = gettext.NullTranslations()
            self.logger.info('\tUsing default locale en_EN')
        self._ = t.ugettext

    def getVersion(self):
        return IWLA.IWLA_VERSION

    def getConfValue(self, key, default=None):
        if not key in dir(conf):
            return default
        else:
            return conf.__dict__[key]

    def _clearVisits(self):
        self.current_analysis = {
            'days_stats' : {},
            'month_stats' : {},
            'visits' : {}
            }
        self.valid_visitors = None
        return self.current_analysis

    def getDaysStats(self):
        return self.current_analysis['days_stats']

    def getMonthStats(self):
        return self.current_analysis['month_stats']

    def getCurrentVisists(self):
        return self.current_analysis['visits']

    def getValidVisitors(self):
        return self.valid_visitors

    def getDisplay(self):
        return self.display

    def getCurTime(self):
        return self.meta_infos['last_time']

    def getStartAnalysisTime(self):
        return self.meta_infos['start_analysis_time']

    def isValidForCurrentAnalysis(self, request):
        cur_time = self.meta_infos['start_analysis_time']
        # Analyse not started
        if not cur_time: return False
        return (time.mktime(cur_time) < time.mktime(request['time_decoded']))

    def hasBeenViewed(self, request):
        return int(request['status']) in conf.viewed_http_codes

    def getCurDisplayPath(self, filename):
        cur_time = self.meta_infos['last_time']
        return os.path.join(str(cur_time.tm_year), '%02d' % (cur_time.tm_mon), filename)

    def getResourcesPath(self):
        return conf.resources_path

    def getCSSPath(self):
        return conf.css_path

    def _clearMeta(self):
        self.meta_infos = {
            'last_time' : None,
            'start_analysis_time' : None
            }
        return self.meta_infos

    def _clearDisplay(self):
        self.display = DisplayHTMLBuild(self)
	return self.display

    def getDBFilename(self, time):
        return os.path.join(conf.DB_ROOT, str(time.tm_year), '%02d' % (time.tm_mon), conf.DB_FILENAME)

    def _serialize(self, obj, filename):
        base = os.path.dirname(filename)
        if not os.path.exists(base):
            os.makedirs(base)

        # TODO : remove return
        #return

        with open(filename + '.tmp', 'wb+') as f, gzip.open(filename, 'w') as fzip:
            pickle.dump(obj, f)
            f.seek(0)
            fzip.write(f.read())
        os.remove(filename + '.tmp')

    def _deserialize(self, filename):
        if not os.path.exists(filename):
            return None

        with gzip.open(filename, 'r') as f:
            return pickle.load(f)
        return None

    def _callPlugins(self, target_root, *args):
        self.logger.info('==> Call plugins (%s)' % (target_root))
        for (root, plugins) in self.plugins:
            if root != target_root: continue
            for p in plugins:
                mod = self.cache_plugins.get(root + '.' + p, None)
                if mod:
                    self.logger.info('\t%s' % (p))
                    mod.hook(*args)

    def isPage(self, request):
        for e in conf.pages_extensions:
            if request.endswith(e):
                return True

        return False

    def _appendHit(self, hit):
        remote_addr = hit['remote_addr']
	
        if not remote_addr: return

        if not remote_addr in self.current_analysis['visits'].keys():
            self._createVisitor(hit)
	
        super_hit = self.current_analysis['visits'][remote_addr]
        super_hit['requests'].append(hit)
        super_hit['bandwidth'] += int(hit['body_bytes_sent'])
        super_hit['last_access'] = self.meta_infos['last_time']

        request = hit['extract_request']

        uri = request.get('extract_uri', request['http_uri'])

        hit['is_page'] = self.isPage(uri)

        if super_hit['robot'] or\
                not self.hasBeenViewed(hit):
            page_key = 'not_viewed_pages'
            hit_key  = 'not_viewed_hits'
        else:
            page_key = 'viewed_pages'
            hit_key  = 'viewed_hits'

        if hit['is_page']:
            super_hit[page_key] += 1
        else:
            super_hit[hit_key] += 1

    def _createVisitor(self, hit):
        super_hit = self.current_analysis['visits'][hit['remote_addr']] = {}
        super_hit['remote_addr'] = hit['remote_addr']
        super_hit['remote_ip'] = hit['remote_addr']
        super_hit['viewed_pages'] = 0
        super_hit['viewed_hits'] = 0
        super_hit['not_viewed_pages'] = 0
        super_hit['not_viewed_hits'] = 0
        super_hit['bandwidth'] = 0
        super_hit['last_access'] = self.meta_infos['last_time']
        super_hit['requests'] = []
        super_hit['robot'] = False
        super_hit['hit_only'] = 0

    def _decodeHTTPRequest(self, hit):
        if not 'request' in hit.keys(): return False

        groups = self.http_request_extracted.match(hit['request'])

        if groups:
            hit['extract_request'] = groups.groupdict()
            uri_groups = self.uri_re.match(hit['extract_request']['http_uri'])
            if uri_groups:
                d = uri_groups.groupdict()
                hit['extract_request']['extract_uri'] = d['extract_uri']
                if 'extract_parameters' in d.keys():
                    hit['extract_request']['extract_parameters'] = d['extract_parameters']
        else:
            self.logger.warning("Bad request extraction %s" % (hit['request']))
            return False

        if hit['http_referer']:
            referer_groups = self.uri_re.match(hit['http_referer'])
            if referer_groups:
                hit['extract_referer'] = referer_groups.groupdict()
        return True

    def _decodeTime(self, hit):
        try:
            hit['time_decoded'] = time.strptime(hit['time_local'], conf.time_format)
        except ValueError, e:
            if sys.version_info < (3, 2):
            # Try without UTC value at the end (%z not recognized)
                gmt_offset_str = hit['time_local'][-5:]
                gmt_offset_hours = int(gmt_offset_str[1:3])*60*60
                gmt_offset_minutes = int(gmt_offset_str[3:5])*60
                gmt_offset = gmt_offset_hours + gmt_offset_minutes
                hit['time_decoded'] = time.strptime(hit['time_local'][:-6], conf.time_format[:-3])
                if gmt_offset_str[0] == '+':
                    hit['time_decoded'] = time.localtime(time.mktime(hit['time_decoded'])+gmt_offset)
                else:
                    hit['time_decoded'] = time.localtime(time.mktime(hit['time_decoded'])-gmt_offset)
            else:
                raise e
        return hit['time_decoded']

    def getDisplayIndex(self):
        cur_time = self.meta_infos['last_time']
        filename = self.getCurDisplayPath('index.html')

        return self.display.getPage(filename)

    def _generateDisplayDaysStats(self):
        cur_time = self.meta_infos['last_time']
        title = createCurTitle(self, self._('Statistics'))
        filename = self.getCurDisplayPath('index.html')
        self.logger.info('==> Generate display (%s)' % (filename))
        page = self.display.createPage(title, filename, conf.css_path)
        link = DisplayHTMLRaw(self, '<iframe src="../_stats.html"></iframe>')
        page.appendBlock(link)

        _, nb_month_days = monthrange(cur_time.tm_year, cur_time.tm_mon)
        days = self.display.createBlock(DisplayHTMLBlockTableWithGraph, self._('By day'), [self._('Day'), self._('Visits'), self._('Pages'), self._('Hits'), self._('Bandwidth'), self._('Not viewed Bandwidth')], None, nb_month_days, range(1,6))
        days.setColsCSSClass(['', 'iwla_visit', 'iwla_page', 'iwla_hit', 'iwla_bandwidth', 'iwla_bandwidth'])
        nb_visits = 0
        nb_days = 0
        for i in range(1, nb_month_days+1):
            day = '%d<br/>%s' % (i, time.strftime('%b', cur_time))
            full_day = '%02d %s %d' % (i, time.strftime('%b', cur_time), cur_time.tm_year)
            if i in self.current_analysis['days_stats'].keys():
                stats = self.current_analysis['days_stats'][i]
                row = [full_day, stats['nb_visits'], stats['viewed_pages'], stats['viewed_hits'],
                       stats['viewed_bandwidth'], stats['not_viewed_bandwidth']]
                nb_visits += stats['nb_visits']
                nb_days += 1
            else:
                row = [full_day, 0, 0, 0, 0, 0]
            days.appendRow(row)
            days.setCellValue(i-1, 4, bytesToStr(row[4]))
            days.setCellValue(i-1, 5, bytesToStr(row[5]))
            days.appendShortTitle(day)
            adate = date(cur_time.tm_year, cur_time.tm_mon, i)
            week_day = adate.weekday()
            if week_day == 5 or week_day == 6:
                days.setRowCSSClass(i-1, 'iwla_weekend')
            if adate == date.today():
                css = days.getCellCSSClass(i-1, 0)
                if css: css = '%s %s' % (css, 'iwla_curday')
                else: css = 'iwla_curday'
                days.setCellCSSClass(i-1, 0, css)

        stats = self.current_analysis['month_stats']

        row = [0, nb_visits, stats['viewed_pages'], stats['viewed_hits'], stats['viewed_bandwidth'], stats['not_viewed_bandwidth']]
        if nb_days:
            average_row = map(lambda(v): int(v/nb_days), row)
        else:
            average_row = map(lambda(v): 0, row)

        average_row[0] = self._('Average')
        average_row[4] = bytesToStr(average_row[4])
        average_row[5] = bytesToStr(average_row[5])
        days.appendRow(average_row)

        row[0] = self._('Total')
        row[4] = bytesToStr(row[4])
        row[5] = bytesToStr(row[5])
        days.appendRow(row)
        page.appendBlock(days)
        self.display.addPage(page)

    def _generateDisplayMonthStats(self, page, year, month_stats):
        cur_time = time.localtime()
        months_name = ['', self._('Jan'), self._('Feb'), self._('Mar'), self._('Apr'), self._('May'), self._('June'), self._('Jul'), self._('Aug'), self._('Sep'), self._('Oct'), self._('Nov'), self._('Dec')]
        title = '%s %d' % (self._('Summary'), year)
        cols = [self._('Month'), self._('Visitors'), self._('Visits'), self._('Pages'), self._('Hits'), self._('Bandwidth'), self._('Not viewed Bandwidth'), self._('Details')]
        graph_cols=range(1,7)
        months = self.display.createBlock(DisplayHTMLBlockTableWithGraph, title, cols, None, 12, graph_cols)
        months.setColsCSSClass(['', 'iwla_visitor', 'iwla_visit', 'iwla_page', 'iwla_hit', 'iwla_bandwidth', 'iwla_bandwidth', ''])
        months_ = self.display.createBlock(DisplayHTMLBlockTableWithGraph, title, cols[:-1], None, 12, graph_cols[:-1])
        months_.setColsCSSClass(['', 'iwla_visitor', 'iwla_visit', 'iwla_page', 'iwla_hit', 'iwla_bandwidth', 'iwla_bandwidth'])
        total = [0] * len(cols)
        for i in range(1, 13):
            month = '%s<br/>%d' % (months_name[i], year)
            full_month = '%s %d' % (months_name[i], year)
            if i in month_stats.keys():
                stats = month_stats[i]
                link = '<a href="%d/%02d/index.html">%s</a>' % (year, i, self._('Details'))
                row = [full_month, stats['nb_visitors'], stats['nb_visits'], stats['viewed_pages'], stats['viewed_hits'],
                       stats['viewed_bandwidth'], stats['not_viewed_bandwidth'], link]
                for j in graph_cols:
                    total[j] += row[j]
            else:
                row = [full_month, 0, 0, 0, 0, 0, 0, '']
            months.appendRow(row)
            months.setCellValue(i-1, 5, bytesToStr(row[5]))
            months.setCellValue(i-1, 6, bytesToStr(row[6]))
            months.appendShortTitle(month)
            months_.appendRow(row[:-1])
            months_.setCellValue(i-1, 5, bytesToStr(row[5]))
            months_.setCellValue(i-1, 6, bytesToStr(row[6]))
            months_.appendShortTitle(month)
            if year == cur_time.tm_year and i == cur_time.tm_mon:
                css = months.getCellCSSClass(i-1, 0)
                if css: css = '%s %s' % (css, 'iwla_curday')
                else: css = 'iwla_curday'
                months.setCellCSSClass(i-1, 0, css)
                months_.setCellCSSClass(i-1, 0, css)

        total[0] = self._('Total')
        total[5] = bytesToStr(total[5])
        total[6] = bytesToStr(total[6])
        total[7] = u''
        months.appendRow(total)
        page.appendBlock(months)

        months_.appendRow(total[:-1])
        filename = '%d/_stats.html' % (year)
        page_ = self.display.createPage(u'', filename, conf.css_path)
        page_.appendBlock(months_)
        page_.build(conf.DISPLAY_ROOT, False)

    def _generateDisplayWholeMonthStats(self):
        title = '%s %s' % (self._('Statistics for'), conf.domain_name)
        filename = 'index.html'

        self.logger.info('==> Generate main page (%s)' % (filename))

        page = self.display.createPage(title, filename, conf.css_path)

        last_update = '<b>%s</b> %s<br />' % (self._('Last update'), time.strftime('%02d %b %Y %H:%M', time.localtime()))
        page.appendBlock(self.display.createBlock(DisplayHTMLRaw, last_update))

        for year in sorted(self.meta_infos['stats'].keys(), reverse=True):
            self._generateDisplayMonthStats(page, year, self.meta_infos['stats'][year])

        self.display.addPage(page)

    def _compressFile(self, build_time, root, filename):
        path = os.path.join(root, filename)
        gz_path = path + '.gz'

        self.logger.debug('Compress %s => %s' % (path, gz_path))

        if not os.path.exists(gz_path) or\
           os.stat(path).st_mtime > build_time:
            with open(path, 'rb') as f_in, gzip.open(gz_path, 'wb') as f_out:
                f_out.write(f_in.read())

    def _compressFiles(self, build_time, root):
        if not conf.compress_output_files: return
        for rootdir, subdirs, files in os.walk(root, followlinks=True):
            for f in files:
                for ext in conf.compress_output_files:
                    if f.endswith(ext):
                        self._compressFile(build_time, rootdir, f)
                        break
                        
    def _generateDisplay(self):
        self._generateDisplayDaysStats()
        self._callPlugins(conf.DISPLAY_HOOK_DIRECTORY)
        self._generateDisplayWholeMonthStats()
        build_time = time.localtime()
        self.display.build(conf.DISPLAY_ROOT)
        self._compressFiles(build_time, conf.DISPLAY_ROOT)

    def _createEmptyStats(self):
        stats = {}
        stats['viewed_bandwidth'] = 0
        stats['not_viewed_bandwidth'] = 0
        stats['viewed_pages'] = 0
        stats['viewed_hits'] = 0
        stats['nb_visits'] = 0

        return stats

    def _generateMonthStats(self):
        self._clearDisplay()

        visits = self.current_analysis['visits']

        stats = self._createEmptyStats()
        for (day, stat) in self.current_analysis['days_stats'].items():
            for k in stats.keys():
                stats[k] += stat[k]

        duplicated_stats = {k:v for (k,v) in stats.items()}

        cur_time = self.meta_infos['last_time']
        self.logger.info("== Stats for %d/%02d ==" % (cur_time.tm_year, cur_time.tm_mon))
        self.logger.info(stats)

        if not 'month_stats' in self.current_analysis.keys():
            self.current_analysis['month_stats'] = stats
        else:
            for (k,v) in stats.items():
                self.current_analysis['month_stats'][k] = v

        self.valid_visitors = {}
        for (k,v) in visits.items():
            if v['robot']: continue
            if not (conf.count_hit_only_visitors or\
                    v['viewed_pages']):
                continue
            self.valid_visitors[k] = v

        duplicated_stats['nb_visitors'] = stats['nb_visitors'] = len(self.valid_visitors.keys())

        self._callPlugins(conf.POST_HOOK_DIRECTORY)

        path = self.getDBFilename(cur_time)
        if os.path.exists(path):
            os.remove(path)

        self.logger.info("==> Serialize to %s" % (path))
        self._serialize(self.current_analysis, path)

        # Save month stats
        year = cur_time.tm_year
        month = cur_time.tm_mon
        if not 'stats' in self.meta_infos.keys():
            self.meta_infos['stats'] = {}
        if not year in self.meta_infos['stats'].keys():
            self.meta_infos['stats'][year] = {}
        self.meta_infos['stats'][year][month] = duplicated_stats
        
        self._generateDisplay()

    def _generateDayStats(self):
        visits = self.current_analysis['visits']
        cur_time = self.meta_infos['last_time']

        self._callPlugins(conf.PRE_HOOK_DIRECTORY)

        stats = self._createEmptyStats()

        for (k, super_hit) in visits.items():
            if super_hit['last_access'].tm_mday != cur_time.tm_mday:
                continue
            viewed_page = False
            for hit in super_hit['requests'][::-1]:
                if hit['time_decoded'].tm_mday != cur_time.tm_mday:
                    break
                if super_hit['robot'] or\
                        not self.hasBeenViewed(hit):
                    stats['not_viewed_bandwidth'] += int(hit['body_bytes_sent'])
                    continue
                stats['viewed_bandwidth'] += int(hit['body_bytes_sent'])
                if hit['is_page']:
                    stats['viewed_pages'] += 1
                    viewed_pages = True
                else:
                    stats['viewed_hits'] += 1
            if (conf.count_hit_only_visitors or\
                    viewed_pages) and\
                    not super_hit['robot']:
                stats['nb_visits'] += 1

        self.logger.info("== Stats for %d/%02d/%02d ==" % (cur_time.tm_year, cur_time.tm_mon, cur_time.tm_mday))
        self.logger.info(stats)

        self.current_analysis['days_stats'][cur_time.tm_mday] = stats

    def _newHit(self, hit):
        if not self.domain_name_re.match(hit['server_name']):
            return False

        t = self._decodeTime(hit)

        cur_time = self.meta_infos['last_time']

        if cur_time == None:
            self.current_analysis = self._deserialize(self.getDBFilename(t)) or self._clearVisits()
            self.analyse_started = True
        else:
            if time.mktime(t) <= time.mktime(cur_time):
                return False
            self.analyse_started = True
            if cur_time.tm_mon != t.tm_mon:
                self._generateMonthStats()
                self.current_analysis = self._deserialize(self.getDBFilename(t)) or self._clearVisits()
            elif cur_time.tm_mday != t.tm_mday:
                self._generateDayStats()

        self.meta_infos['last_time'] = t

        if not self.meta_infos['start_analysis_time']:
            self.meta_infos['start_analysis_time'] = t

        if not self._decodeHTTPRequest(hit): return False

        for k in hit.keys():
            if hit[k] == '-' or hit[k] == '*':
                hit[k] = ''
                
        self._appendHit(hit)

        return True

    def start(self, _file):
        self.logger.info('==> Load previous database')

        self.meta_infos = self._deserialize(conf.META_PATH) or self._clearMeta()
        if self.meta_infos['last_time']:
            self.logger.info('Last time')
            self.logger.info(self.meta_infos['last_time'])
            self.current_analysis = self._deserialize(self.getDBFilename(self.meta_infos['last_time'])) or self._clearVisits()
        else:
            self._clearVisits()

        self.meta_infos['start_analysis_time'] = None

        self.cache_plugins = preloadPlugins(self.plugins, self)

        self.logger.info('==> Analysing log')

        for l in _file:
            # print "line " + l

            groups = self.log_re.match(l)

            if groups:
                self._newHit(groups.groupdict())
            else:
                self.logger.warning("No match for %s" % (l))
                #break

        if self.analyse_started:
            self._generateDayStats()
            self._generateMonthStats()
            del self.meta_infos['start_analysis_time']
            self._serialize(self.meta_infos, conf.META_PATH)
        else:
            self.logger.info('==> Analyse not started : nothing new')

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Intelligent Web Log Analyzer')

    parser.add_argument('-c', '--clean-output', dest='clean_output', action='store_true',
                        default=False,
                        help='Clean output before starting')

    parser.add_argument('-i', '--stdin', dest='stdin', action='store_true',
                        default=False,
                        help='Read data from stdin instead of conf.analyzed_filename')

    parser.add_argument('-f', '--file', dest='file',
                        help='Analyse this log file')

    parser.add_argument('-d', '--log-level', dest='loglevel',
                        default='INFO', type=str,
                        help='Loglevel in %s, default : %s' % (['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'], 'INFO'))

    args = parser.parse_args()

    if args.clean_output:
        if os.path.exists(conf.DB_ROOT): shutil.rmtree(conf.DB_ROOT)
        if os.path.exists(conf.DISPLAY_ROOT): shutil.rmtree(conf.DISPLAY_ROOT)

    loglevel = getattr(logging, args.loglevel.upper(), None)
    if not isinstance(loglevel, int):
        raise ValueError('Invalid log level: %s' % (args.loglevel))
    
    iwla = IWLA(loglevel)
    
    required_conf = ['analyzed_filename', 'domain_name']
    if not validConfRequirements(required_conf, iwla, 'Main Conf'):
        sys.exit(0)

    if args.stdin:
        iwla.start(sys.stdin)
    else:
        filename = args.file or conf.analyzed_filename
        if not os.path.exists(filename):
            print 'No such file \'%s\'' % (filename)
            sys.exit(-1)
        with open(filename) as f:
            iwla.start(f)