analyze_page_ads.rb

require 'yaml'

ads = YAML.load_file 'config/page_ads.yml'

class PageAds
  attr :anchors
  attr :positions

  class Anchor

    attr :name
    attr :positions

    def self.from_yaml_line(line)
       #"anchor : &ad_set_30 [\"rich_media\", \"top_rail\", \"right_rail\"]",
       line =~ /:\W+&(\w+)\W(.*)$/
       pos = self.instance_eval $2
       Anchor.new($1, pos)
    end

    def initialize(name, positions)
     @name = name
     @positions = positions 
    end

    def inspect
     %Q{<#{self.class.to_s.inspect} name=#{@name.inspect} positions=#{@positions.inspect}>}
    end
  end
  class Position
    attr :name 
    attr :positions
    attr :anchor_name
    def initialize(name, anchor_reference, optional)
      @name = name
      @anchor_name = anchor_reference.strip! if anchor_reference
      @positions = []
      @optional = optional 
    end

    def optional?
      @optional
    end
    def to_s
      inspect
    end
    def inspect
     "<#{self.class.to_s}> name=#{@name.inspect} positions=#{@positions.inspect} anchor_ref=#{@anchor_name.inspect} optional=#{@optional.inspect}>"
    end
  end

  def initialize(io)
    @io = io
    @positions = []
    @anchors = []
    crack_that_whip
    @positions.reject!{|p| p == ""}
  end
  def crack_that_whip
    position_definition = ""
    @io.readlines.each do |line|
      case line
      when /^anchor/ then
        @anchors << Anchor.from_yaml_line(line.chomp)
        #puts "ANCHOR: #{line}"
      when /^[A-Z0-9_]+:/ then
        if position_definition.size == 3
          if position_definition.detect{|e| e.nil?}
            puts "ERROR NIL POS: #{position_definition.inspect}"
            next
          end
          anchor_ref = position_definition.detect{|i| i.include?("position")}.split(":")[1]
          #puts "ERROR ANCH POS: #{position_definition.inspect}" unless anchor_ref
          optional = position_definition.detect{|i| i.include?("optional")}.split(":")[1]
          @positions << Position.new(position_definition[0].strip.chop, anchor_ref, optional)
          puts "ERROR OPTS POS: #{position_definition.inspect}" unless optional 
          #puts position_definition.inspect
        end
        position_definition = [] 
        position_definition << line.chomp
      when /^\s{2}/ then
        position_definition << line.chomp
      else
        #puts "OTHER: #{line}"
      end

    end
  end
end
pa = PageAds.new(File.new(ARGV[0],'r'))

target_for_change = pa.positions.detect{|p| p.name == ARGV[1] }
shared_anchor = pa.anchors.detect{|a| target_for_change.anchor_name.include?(a.name) }

also_affected = pa.positions.select{|p| p.anchor_name == target_for_change.anchor_name}
puts "Target for change is:"
puts "\t\t#{target_for_change.inspect}"
puts "Changing it affects:"
puts also_affected.map{ |p| "\t#{p.inspect}\n" }.join("")
puts "The shared anchor has the following positions:\n\t#{shared_anchor.inspect}\n"
exit