class API < Sinatra::Base

  use Rack::OAuth2Utils::Middleware do |access_token|
    AccessToken.find_by_token(access_token).try :account_id
  end
  
  helpers do
      
    def authorized?
      !!identity
    end
    
    def identity
     requets.env['oauth.identity']
    end
    
    def current_account
     Account.find(identity) if authorized?
    end
     
  end
  
  get '/private' do
    if authorized?
      content_type 'application/json'
      current_account.to_json
    else
      halt 403, 'Access forbidden'
    end
  end
  
end

STORE = Rack::OAuth2Utils::TestStore.new('tmp/access_tokens.store')

STORE['foobar'] = 'some_identity'

use Rack::OAuth2Utils::Middleware do |access_token|
  STORE[access_token]
end