module Compass::SassExtensions::Functions::InlineImage

def compute_mime_type(path, mime_type)
  return mime_type if mime_type
  case path
  when /\.png$/i
    'image/png'
  when /\.jpe?g$/i
    'image/jpeg'
  when /\.gif$/i
    'image/gif'
  when /\.otf$/i
    'font/opentype'
  when /\.ttf$/i
    'font/truetype'
  when /\.woff$/i
    'font/woff'
  when /\.off$/i
    'font/openfont'
  when /\.([a-zA-Z]+)$/
    "image/#{Regexp.last_match(1).downcase}"
  else
    raise Compass::Error, "A mime type could not be determined for #{path}, please specify one explicitly."
  end
end

def data(real_path)
  if File.readable?(real_path)
    Base64.encode64(File.read(real_path)).gsub("\n","")
  else
    raise Compass::Error, "File not found or cannot be read: #{real_path}"
  end
end

def inline_font_files(*args)
  raise Sass::SyntaxError, "An even number of arguments must be passed to font_files()" unless args.size % 2 == 0
  path = path.value
  files = []
  while args.size > 0
    path = args.shift.value
    real_path = File.join(Compass.configuration.fonts_path, path)
    url = "url('data:#{compute_mime_type(path,mime_type)};base64,#{data(real_path)}')"
    files << "#{url} format('#{args.shift}')"
  end
  Sass::Script::String.new(files.join(", "))
end

def inline_image(path, mime_type = nil)
  path = path.value
  real_path = File.join(Compass.configuration.images_path, path)
  url = "url('data:#{compute_mime_type(path,mime_type)};base64,#{data(real_path)}')"
  Sass::Script::String.new(url)
end