# Video SEO Developer Kit Version 1.4
# Feb 10, 2010, Ooyala
#
# The Video SEO Develop Kit is a set of methods which enable publishers to increase the visibility of their content
# to search engines. The Develop Kit contains a primary class Ooyala::SEOFriendlyVideo, and two primary methods: 
# header() and body().
#
# See example.rb for an example of how to call these methods

require "rubygems"
require "base64"
require "cgi"
require "digest/sha2"
require "net/http"
require "rexml/document"

module Ooyala
  class BacklotAPIClient
    def initialize(partner_code, secret_code, cache_for_num_seconds=900)
      @partner_code = partner_code
      @secret_code = secret_code
      @cache_for_num_seconds = cache_for_num_seconds
    end

    def query(params)
      return send_request("query", params)
    end

    private
    
    def send_request(request_type, params)
      # Round expires to nearest @cache_for_num_seconds interval
      params['expires'] = ((Time.now.to_i + 15).to_f / @cache_for_num_seconds).ceil * @cache_for_num_seconds
	  
      string_to_sign = @secret_code
      url = "http://cdn.api.ooyala.com/partner/#{request_type}?pcode=#{@partner_code}"

      params.keys.sort.each do |key|
        string_to_sign += "#{key}=#{params[key]}"
        url += "&#{CGI.escape(key.to_s)}=#{CGI.escape(params[key].to_s)}"
      end

      digest = Digest::SHA256.digest(string_to_sign)
      signature = Base64::encode64(digest).chomp.gsub(/=+$/, '')

      url += "&signature=#{CGI.escape(signature)}"
      
      xml_data = Net::HTTP.get_response(URI.parse(url)).body
      
      return xml_data
    end
  end


  class SEOFriendlyVideo
    # Creates an SEOFriendlyVideo instance. Performs a calls to Ooyala's API to obtain relevant SEO data.
    # 
    # partner_code: the partner code found in your Backlot > Account > Developers tab
    # secret_code: the secret code found in your Backlot > Account > Developers tab
    # embed_code: the embed code of your video or channel, found in your Manage > Embed tab
    def initialize(partner_code, secret_code, embed_code)
      @api_client = BacklotAPIClient.new(partner_code, secret_code)
      @embed_code = embed_code
      
      fetch_data()
    end

    # Returns a string to be inserted into the header of your page.
    def header()
      # We assume keywords are stored in the metadata entry for "keywords".
      return %Q(
        <title>#{@title.to_s}</title>
        <meta name="description" content="#{@description.to_s}" />
        <meta name="keywords" content="#{@metadata.to_s}" />
      )
    end  

    # Returns a string to be inserted into the body of your page.
    #
    # width: the width of your video embed
    # height: the height of your video embed
    def body(width, height)
      player_id = "flashVideoPlayer";
      labels_html = '<ul>' + @labels.collect { |l| "<li>#{l.gsub(/^\//, '')}</li>" }.join('') + '</ul>'

      # use a fixed size div to embed the SEO text. We add overflow: hidden to make sure it doesn't get a larger than the size of the player
      return %Q(
        <div id="videoPlayer" style="width: #{width}px; height: #{height}px; overflow: hidden; text-overflow: hidden">
          <script src="http://player.ooyala.com/player.js?width=#{width}&height=#{height}&embedCode=#{@embed_code}"></script>
          <noscript>
            <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" id="#{player_id}" width="#{width}" height="#{height}"
                    codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">
              <param name="movie" value="http://player.ooyala.com/player.swf?embedCode=#{@embed_code}" />
              <param name="bgcolor" value="#000000" />
              <param name="allowScriptAccess" value="always" />
              <param name="allowFullScreen" value="true" />
              <param name="flashvars" value="embedType=directObjectTag&embedCode=#{@embed_code}"/>
              <embed src="http://player.ooyala.com/player.swf?embedCode=#{@embed_code}" bgcolor="#000000" width="#{width}" height="#{height}"
                     name="#{player_id}" align="middle" play="true" loop="false"
                     allowscriptaccess="always" allowfullscreen="true" type="application/x-shockwave-flash"
                     flashvars="&embedCode=#{@embed_code}" pluginspage =" http://www.adobe.com/go/getflashplayer">
              </embed>
            </object>
          </noscript>
          <h1>#{@title.to_s}</h1>
          <h2>#{@description.to_s}</h2>
          <h3>#{@metadata.to_s}</h3>
          #{labels_html}
        </div>
      )
    end
    

    private

    # Fetches title, description, labels and metadata from the Backlot API.
    def fetch_data()
      # a query to the backlot console is made
      xml_result = @api_client.query({ 'embedCode' => @embed_code,
                                       'fields' => 'labels,metadata' })
      
      # extract information
      doc = REXML::Document.new(xml_result)
      
      @title = doc.elements['list/item/title'].text
      @description = doc.elements['list/item/description'].text
      @labels = doc.get_elements('list/item/labels/label').collect { |l| l.text }.sort
      @metadata = ""
	  
	  if doc.elements["/list/item/metadata"].has_elements?()
		doc.get_elements("list/item/metadata/metadataItem").each do |node|
			@metadata << node.attributes['value'] + ", "
		end
		
		#removing the last comma from the metadata string
	    @metadata = @metadata[0...@metadata.rindex(',')]
	  end	
	  
    end
  end
end