class CopyTunerClient::CopyrayMiddleware

def append_css(html)
  html.sub(/<body[^>]*>/) { "#{Regexp.last_match}\n#{css_tag}" }
end

def append_js(html)
  html.sub(%r{</body>}) do
   "#{helpers.javascript_include_tag(:copyray)}\n#{Regexp.last_match}"
  end
end

def append_translation_logs(html)
  if CopyTunerClient::TranslationLog.initialized?
    json = CopyTunerClient::TranslationLog.translations.to_json
    # Use block to avoid back reference \?
    html.sub('</body>') { "<div id='copy-tuner-data' data-copy-tuner-translation-log='#{ERB::Util.html_escape json}' data-copy-tuner-url='#{CopyTunerClient.configuration.project_url}'></div></body>" }
  else
    html
  end
end

def call(env)
  CopyTunerClient::TranslationLog.clear
  status, headers, response = @app.call(env)
  if html_headers?(status, headers) && body = response_body(response)
    body = append_css(body)
    body = append_js(body)
    body = append_translation_logs(body)
    body = inject_copy_tuner_bar(body)
    content_length = body.bytesize.to_s
    headers['Content-Length'] = content_length
    # maintains compatibility with other middlewares
    if defined?(ActionDispatch::Response::RackBody) && ActionDispatch::Response::RackBody === response
      ActionDispatch::Response.new(status, headers, [body]).to_a
    else
      [status, headers, [body]]
    end
  else
    [status, headers, response]
  end
end

def css_tag
  helpers.stylesheet_link_tag :copyray
end

def file?(headers)
  headers["Content-Transfer-Encoding"] == "binary"
end

def helpers
  ActionController::Base.helpers
end

def html_headers?(status, headers)
  status == 200 &&
  headers['Content-Type'] &&
  headers['Content-Type'].include?('text/html') &&
  !file?(headers)
end

def initialize(app)
  @app = app
end

def inject_copy_tuner_bar(html)
  html.sub(/<body[^>]*>/) { "#{Regexp.last_match}\n#{render_copy_tuner_bar}" }
end

def render_copy_tuner_bar
  if ApplicationController.respond_to?(:render)
    # Rails 5
    ApplicationController.render(:partial => "/copy_tuner_bar").html_safe
  else
    # Rails <= 4.2
    ac = ActionController::Base.new
    ac.render_to_string(:partial => '/copy_tuner_bar').html_safe
  end
end

def response_body(response)
  body = ''
  response.each { |s| body << s.to_s }
  body
end