#---------------------------------------------------------------#
#                                                               #  
#  (C) Copyright Rubysophic Inc. 2007-2008                      #
#  All rights reserved.                                         #
#                                                               #  
#  Use, duplication or disclosure of the code is not permitted  #
#  unless licensed.                                             #
#  Dynamic Application Discovery                                #                        
#                                                               #            
#  Last Updated: 6/03/08                                        #  
#---------------------------------------------------------------#
#                                                               #  
# RubyRunRSS provides the interfaces for creating RSS channel   #
# and adding items to it.                                       #
#                                                               #  
#---------------------------------------------------------------#

require 'rss/maker'

class RubyRunRSS
  RUBYRUN_RSS_VERSION                              = '2.0'
  RUBYRUN_RSS_CHANNEL_URL                          = 'http://www.rubysophic.com'
  RUBYRUN_RSS_IMAGE_TITLE                          = 'Learn more about RubyRun from Rubysophic'
  RUBYRUN_RSS_IMAGE_URL                            = 'http://www.rubysophic.com/images/logo.jpg'
  RUBYRUN_RSS_FOLDER                               = 'rubyrun_rss'
  RUBYRUN_RSS_PERF_SUMMARY_CHANNEL_TITLE           = 'RubyRun: %s Performance Summary'
  RUBYRUN_RSS_PERF_SUMMARY_CHANNEL_ITEM_FILENAME   = 'perf_summary_item'
  RUBYRUN_RSS_PERF_SUMMARY_CHANNEL_DESCRIPTION     = 'RubyRun delivers up-to-the-minute performance summary of your application.'
  RUBYRUN_RSS_PERF_SUMMARY_CHANNEL_FILENAME        = 'perf_summary.xml'
  RUBYRUN_RSS_PERF_SUMMARY_ITEM_TITLE              = 'Report for %s at %s'
  RUBYRUN_RSS_PERF_SUMMARY_ITEM_DESCRIPTION        = 'Performance summary of %s (%s) at %s'  
  
  # Constructor of the class.
  # RSS XML file and HTML files will be kept in the directory as specified                
  def initialize (title, description, directory, rss_filename, html_filename)
    @title = title
    @description = description
    @directory = directory
    @rss_filename = rss_filename
    @html_filename = html_filename
    @apps_name = Rails::Configuration.new.root_path.split('/').last
    @rss_xml_destination = "#{@directory}/#{@rss_filename}"
    create_channel_content unless File::exists?(@rss_xml_destination)
    @rss = load_rss_content
  end

  # Create the RSS channel
  def create_channel_content
    content = RSS::Maker.make(RUBYRUN_RSS_VERSION) do |m|
      m.channel.title = sprintf(@title, @apps_name)
      m.channel.link = RUBYRUN_RSS_CHANNEL_URL
      m.channel.description = @description
      m.items.do_sort = true # sort items by date
      m.image.title = RUBYRUN_RSS_IMAGE_TITLE
      m.image.width = 140
      m.image.height = 25
      m.image.url = RUBYRUN_RSS_IMAGE_URL
    end
    File.open(@rss_xml_destination,"w") do |f|
      f.write(content)
    end
    content.to_s
  end

  # Add an item to the RSS channel
  def add_item (title, description, html_content)
    filename = "#{@html_filename}_#{Time.now.to_i}#{rand(1000000)}.html"
    File.open("#{@directory}/#{filename}", 'w') { |file| file.puts html_content }
    item = RSS::Rss::Channel::Item.new
    item.title = sprintf(title, "#{$rubyrun_startup_id_type} #{$rubyrun_startup_id}",Time.now.strftime("%H:%M:%S"))
    item.description = sprintf(description, @apps_name, "#{$rubyrun_startup_id_type} #{$rubyrun_startup_id}", Time.now.strftime("%H:%M:%S"))
    item.link = "http://#{$rubyrun_host_with_port}/#{RUBYRUN_RSS_FOLDER}/#{filename}"
    sleep(rand(3))
    @rss = load_rss_content    
    remove_old_item(@rss) if @rss.items.length == $rubyrun_report_shift_age
    @rss.items << item
    File.open(@rss_xml_destination,"w") do |f|
      f.write(@rss)
    end    
  end
  
  private
  
  # Load the existing RSS XML file. Create a new channel if the channel is blank
  def load_rss_content
    content = "" # raw content of rss feed will be loaded here
    open(@rss_xml_destination) do |s| content = s.read end
    content = create_channel_content if content == ''
    RSS::Parser.parse(content, false)    
  end
  
  # Remove the last item in the RSS channel
  def remove_old_item(rss)
    item = rss.items.shift
    filename = "#{@directory}/#{item.link.split('/').last}"
    File.delete(filename) if File.exists?(filename)
  end  
  
end