class ActionView::DependencyTracker::ERBTracker

def self.call(name, template)
  new(name, template).dependencies
end

def dependencies
  render_dependencies + explicit_dependencies
end

def directory
  name.split("/")[0..-2].join("/")
end

def explicit_dependencies
  source.scan(EXPLICIT_DEPENDENCY).flatten.uniq
end

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

def render_dependencies
  source.scan(RENDER_DEPENDENCY).
    collect(&:second).uniq.
    # render(@topic)         => render("topics/topic")
    # render(topics)         => render("topics/topic")
    # render(message.topics) => render("topics/topic")
    collect { |name| name.sub(/\A@?([a-z_]+\.)*([a-z_]+)\z/) { "#{$2.pluralize}/#{$2.singularize}" } }.
    # render("headline") => render("message/headline")
    collect { |name| name.include?("/") ? name : "#{directory}/#{name}" }.
    # replace quotes from string renders
    collect { |name| name.gsub(/["']/, "") }
end

def source
  template.source
end