module Middleman::SmushPngs

def self.included(base)
  base.supported_formats << "png"
end

def optimized_image_data_for(file)
  # I leave these urls here, just in case it stops working again...
  # url = "http://smush.it/ws.php" # original, redirects to somewhere else..
  url = 'http://ws1.adq.ac4.yahoo.com/ysmush.it/ws.php'
  # url = "http://developer.yahoo.com/yslow/smushit/ws.php" # official but does not work
  # url = "http://smushit.com/ysmush.it/ws.php" # used at the new page but does not hande uploads
  # url = "http://smushit.eperf.vip.ac4.yahoo.com/ysmush.it/ws.php" # used at the new page but does not hande uploads
  response = HTTPClient.post url, { 'files[]' => File.new(file) }
  response = JSON.parse(response.body.content)
  raise "smush.it: #{response['error']}" if response['error']
  image_url = response['dest']
  raise "no dest path found" unless image_url
  open(image_url) { |source| source.read() }
end

def render_path(file)
  if File.extname(file) == ".png"
    file = File.join(options.public, file)
    optimized = optimized_image_data_for(file)
    begin
      raise "Error: got larger" if size(file) < optimized.size
      raise "Error: empty file downloaded" if optimized.size < 20
      optimized
    rescue
      File.read(file)
    end
  else
    super
  end
end

def size(file)
  File.exist?(file) ? File.size(file) : 0
end