# 
# Copyright (C) 2007 Mobio Networks, Inc.
# 
# This program 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.
# 
# 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 General Public License for more
# details.
# 
# You should have received a copy of the GNU General Public License along with
# this program.  If not, see <http://www.gnu.org/licenses/>.
# 

# 
# This module contains custom wrapper logic on the rubycas client. Namely, we
# need to enhance parsing of the serviceResponse:
# 
# <cas:serviceResponse xmlns:cas='http://www.yale.edu/tp/cas'>
#  <cas:authenticationSuccess
#    <cas:uuid>someid</cas:uuid>
#    <cas:user>someuser</cas:user>
#  </cas:authenticationSuccess>
# </cas:serviceResponse>
# 
# In order to use this validation, we need to modify the rubycas client filter
# as well as the casclient itself.
# 

require 'rubycas-client'
require 'casclient/frameworks/rails/filter'
require 'casclient'
require 'rmobio/utils'

module Rmobio
  module Cas
    class MobioValidationResponse < CASClient::ValidationResponse
      attr_reader :uuid
      
      # Parse out our custom attributes
      def initialize(raw_text)
        parse(raw_text)
        parse_uuid(raw_text)
      end
        
      def parse_uuid(raw_text)
        raise BadResponseException, 
          "CAS response is empty/blank." if raw_text.blank?
      
        @xml = check_and_parse_xml(raw_text)
        
        if is_success?
          @uuid = @xml.elements["cas:uuid"].text.strip if @xml.elements["cas:uuid"]
          RAILS_DEFAULT_LOGGER.info 'CAS: Successfully authenticated user ' + @uuid.to_s + 
            '...' unless not defined? RAILS_DEFAULT_LOGGER
        else
          # this should never happen, since the response should already have
          # been recognized as invalid
          raise BadResponseException, "BAD CAS RESPONSE:\n#{raw_text.inspect}\n\nXML DOC:\n#{@xml.inspect}"
        end 
      end
    end
    
    class Client < CASClient::Client      
      attr_accessor :xml_response
      
      # Override service ticket validation so we use our XmlResponse
      def validate_service_ticket(st)
        RAILS_DEFAULT_LOGGER.debug 'CAS: Starting to validate service ticket...' unless not defined? RAILS_DEFAULT_LOGGER
        uri = URI.parse(validate_url)
        h = uri.query ? query_to_hash(uri.query) : {}
        h['service'] = st.service
        h['ticket'] = st.ticket
        h['renew'] = 1 if st.renew
        h['pgtUrl'] = proxy_callback_url if proxy_callback_url
          
        # Add our domain parameter
        h['domain'] = Rmobio::Utils.get_domain(st.service)
        uri.query = hash_to_query(h)

        # Override the validation response
        st.response = request_cas_response(uri, Rmobio::Cas::MobioValidationResponse)
        @xml_response = st.response
        return st
      end
      
      # We have to override this method because MobioValidationResponse is
      # uninitialized in the base class
      def request_cas_response(uri, type)
        log.debug "Requesting CAS response form URI #{uri.inspect}"
      
        uri = URI.parse(uri) unless uri.kind_of? URI
        https = Net::HTTP.new(uri.host, uri.port)
        https.use_ssl = (uri.scheme == 'https')
        raw_res = https.start do |conn|
          conn.get("#{uri.path}?#{uri.query}")
        end
      
        # TODO: check to make sure that response code is 200 and handle errors
        # otherwise
      
        RAILS_DEFAULT_LOGGER.debug "CAS Responded with " + 
          "#{raw_res.inspect}:\n#{raw_res.body}" unless not defined? RAILS_DEFAULT_LOGGER
      
        type.new(raw_res.body)
      end
      
      # Override to add the domain param
      def add_service_to_login_url(service_url)
        uri = super(service_url)
        domain = Rmobio::Utils.get_domain(service_url)
        
        if not domain.nil?
          RAILS_DEFAULT_LOGGER.debug 'CAS: Adding domain parameter ' +
            domain + '...' unless not defined? RAILS_DEFAULT_LOGGER
          param_token = uri.index("?").nil? ? '?' : '&'
          uri << param_token + 'domain=' + domain
        end
        uri.to_s
      end
    end   
    
    class MobioCasFilter < CASClient::Frameworks::Rails::Filter
      
      # Override configure so we use our cas client
      def self.configure(config)
        @@config = config
        @@config[:logger] = RAILS_DEFAULT_LOGGER unless @@config[:logger]
        @@client = Rmobio::Cas::Client.new(config)
        @@log = client.log
      end
      
      # Here's where we override the filter
      def self.filter(controller)
        RAILS_DEFAULT_LOGGER.debug 'CAS: Starting filter...' unless not defined? RAILS_DEFAULT_LOGGER
        
        @handset_id = controller.params[:handsetid]
        
        # handsetid gets appended to request uri, we need to remove it for 
        # service validation to work
        controller.params.delete('handsetid')
        
        # Call filter on the base class
        CASClient::Frameworks::Rails::Filter.filter(controller)  
        
        # Now let's put the handsetid back into the request in case we do a redirect
        controller.params[:handsetid] = @handset_id
        
        # Use the overloaded cas client to retrieve uuid. This should only
        # happen after service ticket validation.
        if not @@client.xml_response.nil?
          @uuid = @@client.xml_response.uuid
        end
        
        # Setup the uuid and handset_id session variables
        if not @uuid.nil? and not @uuid == '' and not @handset_id.nil? and not @handset_id == ''
          controller.session[:uuid] = @uuid
          controller.session[:handset_id] = @handset_id
          RAILS_DEFAULT_LOGGER.debug 'CAS: Stored cas uuid: ' + @uuid + ' and handset_id: ' + @handset_id +
            ' into the session.' unless not defined? RAILS_DEFAULT_LOGGER
          return true
        else
          # Should only happen on initial redirect
          RAILS_DEFAULT_LOGGER.debug 'CAS: MobioCasFilter cannot read the uuid/handset_id ' +
            'attributes for the user!' unless not defined? RAILS_DEFAULT_LOGGER
          return false
        end
      end
    end
    class BadResponseException < Exception
    end
  end
end
include Rmobio::Cas