'''
robotsReader.py

Copyright 2006 Andres Riancho

This file is part of w3af, w3af.sourceforge.net .

w3af 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 version 2 of the License.

w3af 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 w3af; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

'''

import core.controllers.outputManager as om

# options
from core.data.options.option import option
from core.data.options.optionList import optionList

from core.controllers.basePlugin.baseDiscoveryPlugin import baseDiscoveryPlugin
from core.controllers.w3afException import w3afRunOnce, w3afException
import core.data.parsers.urlParser as urlParser
from core.controllers.coreHelpers.fingerprint_404 import is_404

import core.data.kb.knowledgeBase as kb
import core.data.kb.info as info


class robotsReader(baseDiscoveryPlugin):
    '''
    Analyze the robots.txt file and find new URLs
    @author: Andres Riancho ( andres.riancho@gmail.com )
    '''

    def __init__(self):
        baseDiscoveryPlugin.__init__(self)
        
        # Internal variables
        self._exec = True

    def discover(self, fuzzableRequest ):
        '''
        Get the robots.txt file and parse it.
        
        @parameter fuzzableRequest: A fuzzableRequest instance that contains
                                                      (among other things) the URL to test.
        '''
        if not self._exec:
            # This will remove the plugin from the discovery plugins to be runned.
            raise w3afRunOnce()
        else:
            # Only run once
            self._exec = False
            
            dirs = []
            self._new_fuzzable_requests = []         
            
            base_url = urlParser.baseUrl( fuzzableRequest.getURL() )
            robots_url = urlParser.urlJoin(  base_url , 'robots.txt' )
            http_response = self._urlOpener.GET( robots_url, useCache=True )
            
            if not is_404( http_response ):
                # Save it to the kb!
                i = info.info()
                i.setName('robots.txt file')
                i.setURL( robots_url )
                i.setId( http_response.id )
                i.setDesc( 'A robots.txt file was found at: "'+ robots_url +'".' )
                kb.kb.append( self, 'robots.txt', i )
                om.out.information( i.getDesc() )


                # Work with it...
                dirs.append( robots_url )
                for line in http_response.getBody().split('\n'):
                    
                    line = line.strip()
                    
                    if len(line) > 0 and line[0] != '#' and (line.upper().find('ALLOW') == 0 or\
                    line.upper().find('DISALLOW') == 0 ):
                        
                        url = line[ line.find(':') + 1 : ]
                        url = url.strip()
                        url = urlParser.urlJoin(  base_url , url )
                        dirs.append( url )

            for url in dirs:
                #   Send the requests using threads:
                targs = ( url,  )
                self._tm.startFunction( target=self._get_and_parse, args=targs , ownerObj=self )
            
            # Wait for all threads to finish
            self._tm.join( self )
        
        return self._new_fuzzable_requests
    
    def _get_and_parse(self, url):
        '''
        GET and URL that was found in the robots.txt file, and parse it.
        
        @parameter url: The URL to GET.
        @return: None, everything is saved to self._new_fuzzable_requests.
        '''
    def _get_and_parse(self, url):
        '''
        GET and URL that was found in the robots.txt file, and parse it.
        
        @parameter url: The URL to GET.
        @return: None, everything is saved to self._new_fuzzable_requests.
        '''
        try:
            http_response = self._urlOpener.GET( url, useCache=True )
        except KeyboardInterrupt, k:
            raise k
        except w3afException, w3:
            msg = 'w3afException while fetching page in discovery.robotsReader, error: "'
            msg += str(w3) + '"'
            om.out.debug( msg )
        else:
            if not is_404( http_response ):
                fuzz_reqs = self._createFuzzableRequests( http_response )
                self._new_fuzzable_requests.extend( fuzz_reqs )
                
    def getOptions( self ):
        '''
        @return: A list of option objects for this plugin.
        '''    
        ol = optionList()
        return ol
        
    def setOptions( self, OptionList ):
        '''
        This method sets all the options that are configured using the user interface 
        generated by the framework using the result of getOptions().
        
        @parameter OptionList: A dictionary with the options for the plugin.
        @return: No value is returned.
        ''' 
        pass

    def getPluginDeps( self ):
        '''
        @return: A list with the names of the plugins that should be runned before the
        current one.
        '''
        return []

    def getLongDesc( self ):
        '''
        @return: A DETAILED description of the plugin functions and features.
        '''
        return '''
        This plugin searches for the robots.txt file, and parses it.
        
        This file is used to as an ACL that defines what URL's a search engine can access.
        By parsing this file, you can get more information about the site.
        '''