#
# 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/>.
#

=begin
provides advertisement fetch for Google's Mobile Adsense 
(alpha level keyword version
and released "page scraping version"
=end
require 'digest/sha1'
require 'collections/sequenced_hash'
require 'open-uri'

module Rmobio
  module Ads
    module AdSense  
      
      @@adServer="http://pagead2.googlesyndication.com/pagead/ads"
      @@mobio_useragent="Mobio" # we should probably come up with a better string  
      @@default_ip="127.0.0.1"      
      
      def getAdParms
        getAd(params[:keywords],params[:adClient])
      end

      # this returns an ad from Google's mobile AdSense, given the current page
      # * ad_client - your Google adsense ID
      # * ip - optional, the IP you want to tell Google its coming from
      # * url - optional, the page you want to put an ad on. Defaults to what is detected  
      # * useragent - the useragent of the mobile browser. Defaults to what is detected.
      def getAdByPage(adClient,ip=request.remote_ip,url=request.request_uri,useragent=request.user_agent)
        @@userId=request.env['HTTP_USERID'] 
        adArgs= SequencedHash.new
        adArgs["ad_type"]="text"
        adArgs["channel"]="8618723264"
        adArgs["client"]=adClient
        adArgs["format"]="mobile_single"
        adArgs["host"]=request.host if request.host
        adArgs["ip"]=URI.escape(ip) if ip
        adArgs["markup"]="xhtml"
        adArgs["output"]="xhtml"
        adArgs["oe"]="utf8"
        #adArgs["ref"]=referer
        adArgs["url"]=url if url
        adArgs["useragent"]=URI.escape(useragent) if useragent 
        adArgs["eip"]=Digest::SHA1.hexdigest(@@userId)[0..20]  # oneway hashed userid  

        # now built the URL to call out to based upon the base URL and ad hash
        adURL=@@adServer + "?"
        first=1 # dont put ampersand on first one
        adArgs.each_key do |x|
          if adArgs[x]
            (adURL=adURL+"&") unless first
            first=nil # start putting in &s
            adURL = adURL + x + "=" + adArgs[x]   
          end
        end
        # ok, now call google's mobile adSense service and get back the full ad 
        @pagead=open(adURL,"User-Agent"=>useragent).read   
     
      end
      
      # this returns an ad from Google's mobile AdSense, given a supplied set of keywords
      # * keywords - keywords to use for search
      # * ad_client - your Google adsense ID
      # * ip - optional, the IP you want to say the request is coming from
      # * url - optional, the page you want to put an ad on
      # * useragent - the browser this is for. Defaults to the one detected
      def getAd(keywords,ad_client,ip=request.remote_ip,url=request.request_uri,useragent=request.user_agent)
        doTinyUrl=true
         
        @user_id=request.env['HTTP_USERID'] if request.env['HTTP_USERID']

        # build up the various arguments in the adArgs hash
        adArgs= SequencedHash.new
        adArgs["ad_type"]="text_image"
        adArgs["client"]=ad_client 
        adArgs["format"]="mobile_single" 
        adArgs["ip"]=URI.escape(ip) if ip
        adArgs["markup"]="xhtml"
        adArgs["output"]="xhtml"
        adArgs["oe"]="utf-8"
        adArgs["url"]=url if url
        adArgs["useragent"]=URI.escape(useragent) if useragent
        adArgs["eip"]=Digest::SHA1.hexdigest(@user_id)[0..20]  # oneway hashed userid
        if (keywords)
          adArgs["kw"]=CGI::escape(keywords) 
          adArgs["kw_type"]="broad"
        end
        # now built the URL to call out to based upon the base URL and ad hash
        adURL=@@adServer + "?"
        first=1 # dont put ampersand on first one
        adArgs.each_key do |x|
          if adArgs[x]
            (adURL=adURL+"&") unless first
            first=nil # start putting in &s
            adURL = adURL + x + "=" + adArgs[x]   
          end
        end
        
        # ok, now call google's mobile adSense service and get back the full ad 
        @ad=open(adURL,"User-Agent"=>CGI::escape(useragent)).read
        if @ad
          logger.info "Returned ad" + @ad 
          adDoc = REXML::Document.new @ad
          @text = adDoc.elements['//p']
          if @text  # do we have a <p> element
            # ok, now text has the full ad display content including links
            # grab @url, @urltext (link text for url), @phone, @phonetext (link text for call)      
            if defined? @text[1].attributes['href'] and @text[1].attributes['href']
              @adurl = doTinyUrl ? tinyUrl(@text[1].attributes['href']) : @text[1].attributes['href']
            else
              @adurl = "nolink.rwap" 
            end
            @urltext=@text[1].text
            @extratext=@text[2].to_s if @text[2] # this should have everything else that is not a child element
            if (@text.size>3 and @text[3]) # only process @text[3] for phone stuff if it exists
              @phone = (doTinyUrl ? tinyUrl(@text[3].attributes['href']) : @text[3].attributes['href']) if defined? @text[3].attributes['href'] and @text[3].attributes['href']
              @phonetext=@text[3].text if defined? @text[3].text and @text[3].text          
            end
          end
        end # if we get an ad back from adsense
        @ad # return the full ad text 

      end 
      
      private
      
      # need to use tinyURL since the URLs that come back from AdSense are just too long for our client
      def tinyUrl(url)
        shrinker="http://tinyurl.com/create.php?url="+url
        result=open(shrinker).read
        # ITS NOT WELLFORMED HTML SO WE CAN'T USE XML TO PARSE
        #result=result.gsub(/\<\/head\>/,"</link></base></head>")
        #resultDoc= Document.new result
        #tinyText=resultDoc.elements['//blockquote'][1]
        #tinyLink=tinyText.elements['./b'].text
        # find the second <blockquote> and extra out the contents of it
        pattern='<blockquote><b>'
        firstblock=result.index(pattern)
        if (firstblock)
          secondblock=result[firstblock+1...result.size].index('<blockquote><b>')+ firstblock+1 + pattern.size
          endsecondblock=result[secondblock...result.size].index('</b>') + secondblock    
          tinyLink=result[secondblock...endsecondblock]
        end
      end
      
    end
  end
end