=begin
    Copyright 2010-2013 Tasos Laskos <tasos.laskos@gmail.com>

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
=end

module Arachni

#
# Filter for Page elements used to keep track of what elements have already
# been seen and separate them from new ones.
#
# Mostly used by the {Trainer}.
#
# @author Tasos "Zapotek" Laskos <tasos.laskos@gmail.com>
#
module ElementFilter
    include Utilities

    @@forms    ||= Support::LookUp::HashSet.new
    @@links    ||= Support::LookUp::HashSet.new
    @@cookies  ||= Set.new

    def self.reset
        @@forms.clear
        @@links.clear
        @@cookies.clear
    end

    def init_db_from_page( page )
        init_links page.links
        init_forms page.forms
        init_cookies page.cookies
    end

    #
    # Initializes @@forms with the cookies found during the crawl/analysis
    #
    def init_forms( forms )
        forms.each { |form| @@forms << form.id }
    end

    #
    # Initializes @@links with the links found during the crawl/analysis
    #
    def init_links( links )
        links.each { |link| @@links << link.id }
    end

    #
    # Initializes @@cookies with the cookies found during the crawl/analysis
    #
    def init_cookies( cookies )
        @@cookies = cookies
    end

    #
    # Updates @@forms wth new forms that may have dynamically appeared<br/>
    # after analyzing the HTTP responses during the audit.
    #
    # @param    [Array<Element::Form>] forms
    #
    def update_forms( forms )
        return [], 0 if forms.size == 0

        form_cnt = 0
        new_forms ||= []

        forms.each do |form|
            next if @@forms.include?( form.id )
            @@forms   << form.id
            new_forms << form
            form_cnt += 1
        end

        [new_forms, form_cnt]
    end

    #
    # Updates @@links wth new links that may have dynamically appeared<br/>
    # after analyzing the HTTP responses during the audit.
    #
    # @param    [Array<Element::Link>]    links
    #
    def update_links( links )
      return [], 0 if links.size == 0

      link_cnt = 0
      new_links ||= []
      links.each do |link|
          next if @@links.include?( link.id )
          @@links   << link.id
          new_links << link
          link_cnt += 1
      end

      [new_links, link_cnt]
    end

    #
    # Updates @@cookies wth new cookies that may have dynamically appeared<br/>
    # after analyzing the HTTP responses during the audit.
    #
    # @param    [Array<Element::Cookie>]   cookies
    #
    def update_cookies( cookies )
        return [], 0 if cookies.size == 0

        cookie_cnt = 0
        @new_cookies ||= []

        cookies.reverse.each do |cookie|
            @@cookies.each_with_index do |page_cookie, i|
                if page_cookie.raw['name'] == cookie.raw['name']
                    @@cookies[i] = cookie
                elsif !cookie_in_jar?( cookie )
                    @new_cookies << cookie
                    cookie_cnt += 1
                end
            end
        end

        @@cookies.flatten!
        @@cookies |= @new_cookies

        [@@cookies, cookie_cnt]
    end

    def cookie_in_jar?( cookie )
        @@cookies.each { |c| return true if c.raw['name'] == cookie.raw['name'] }
        false
    end

end

end