class ActionView::Partials::PartialRenderer

def collection
  if @object.respond_to?(:to_ary)
    @object
  elsif @options.key?(:collection)
    @options[:collection] || []
  end
end

def collection_with_template(template = @template)
  segments, locals, template = [], @locals, @template
  if @options[:as]
    as = @options[:as]
    counter = "#{as}_counter".to_sym
  else
    as = template.variable_name
    counter = template.counter_name
  end
  locals[counter] = -1
  @collection.each do |object|
    locals[counter] += 1
    locals[as] = object
    segments << template.render(@view, locals)
  end
  segments
end

def collection_without_template(collection_paths = @collection_paths)
  segments, locals = [], @locals
  index, template  = -1, nil
  if @options[:as]
    as = @options[:as]
    counter = "#{as}_counter"
  end
  @collection.each_with_index do |object, i|
    template = find_template(collection_paths[i])
    locals[as || template.variable_name] = object
    locals[counter || template.counter_name] = (index += 1)
    segments << template.render(@view, locals)
  end
  @template = template
  segments
end

def find_template(path=@path)
  return path unless path.is_a?(String)
  prefix = @view.controller_path unless path.include?(?/)
  @view.find_template(path, prefix, true)
end

def initialize(view_context, options, block)
  @view           = view_context
  @partial_names  = PARTIAL_NAMES[@view.controller.class.name]
  setup(options, block)
end

def partial_path(object = @object)
  @partial_names[object.class.name] ||= begin
    object = object.to_model if object.respond_to?(:to_model)
    object.class.model_name.partial_path.dup.tap do |partial|
      path = @view.controller_path
      partial.insert(0, "#{File.dirname(path)}/") if partial.include?(?/) && path.include?(?/)
    end
  end
end

def render
  identifier = ((@template = find_template) ? @template.identifier : @path)
  if @collection
    ActiveSupport::Notifications.instrument("render_collection.action_view",
      :identifier => identifier || "collection", :count => @collection.size) do
      render_collection
    end
  else
    content = ActiveSupport::Notifications.instrument("render_partial.action_view",
      :identifier => identifier) do
      render_partial
    end
    if !@block && (layout = @options[:layout])
      content = @view._render_layout(find_template(layout), @locals){ content }
    end
    content
  end
end

def render_collection
  return nil if @collection.blank?
  if @options.key?(:spacer_template)
    spacer = find_template(@options[:spacer_template]).render(@view, @locals)
  end
  result = @template ? collection_with_template : collection_without_template
  result.join(spacer).html_safe
end

def render_partial(object = @object)
  locals, view, template = @locals, @view, @template
  object ||= locals[template.variable_name]
  locals[@options[:as] || template.variable_name] = object
  template.render(view, locals) do |*name|
    view._layout_for(*name, &@block)
  end
end

def setup(options, block)
  partial = options[:partial]
  @options = options
  @locals  = options[:locals] || {}
  @block   = block
  if String === partial
    @object     = options[:object]
    @path       = partial
    @collection = collection
  else
    @object = partial
    if @collection = collection
      paths = @collection_paths = @collection.map { |o| partial_path(o) }
      @path = paths.uniq.size == 1 ? paths.first : nil
    else
      @path = partial_path
    end
  end
end