module Doorkeeper
  module OAuth
    class RefreshTokenRequest
      include Doorkeeper::Validations
      include Doorkeeper::OAuth::Helpers

      validate :token,        :error => :invalid_request
      validate :client,       :error => :invalid_client
      validate :client_match, :error => :invalid_grant
      validate :scope,        :error => :invalid_scope

      attr_accessor :server, :refresh_token, :credentials, :access_token
      attr_accessor :client

      def initialize(server, refresh_token, credentials, parameters = {})
        @server           = server
        @refresh_token    = refresh_token
        @credentials      = credentials
        @requested_scopes = parameters[:scopes]

        @client = Doorkeeper::Application.authenticate(credentials.uid, credentials.secret) if credentials
      end

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

      def valid?
        self.error.nil?
      end

      def scopes
        @scopes ||= if @requested_scopes.present?
          Scopes.from_string @requested_scopes
        else
          refresh_token.scopes
        end
      end

    private

      def revoke_and_create_access_token
        refresh_token.revoke
        create_access_token
      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            => scopes.to_s,
          :expires_in        => server.access_token_expires_in,
          :use_refresh_token => true
        })
      end

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

      def validate_client
        (!credentials || !!client)
      end

      def validate_client_match
        !client || refresh_token.application_id == client.id
      end

      def validate_scope
        if @requested_scopes.present?
          ScopeChecker.valid?(@requested_scopes, refresh_token.scopes)
        else
          true
        end
      end
    end
  end
end