class Doorkeeper::OAuth::RefreshTokenRequest

def authorize
  validate
  @response = if valid?
    revoke_and_create_access_token
    OAuth::TokenResponse.new access_token
  else
    OAuth::ErrorResponse.from_request(self)
  end
end

def create_access_token
  @access_token = Doorkeeper::AccessToken.create!({
    :application_id    => refresh_token.application_id,
    :resource_owner_id => refresh_token.resource_owner_id,
    :scopes            => refresh_token.scopes_string,
    :expires_in        => server.access_token_expires_in,
    :use_refresh_token => true
  })
end

def initialize(server, refresh_token, client)
  @server        = server
  @refresh_token = refresh_token
  @client        = client
end

def revoke_and_create_access_token
  refresh_token.revoke
  create_access_token
end

def valid?
  self.error.nil?
end

def validate_client
  client.present? && refresh_token.application_id == client.id
end

def validate_token
  refresh_token.present? && !refresh_token.revoked?
end