package com.atlassian.asap.core.server.filter;
   
   import com.atlassian.asap.api.server.http.RequestAuthenticator;
   import com.atlassian.asap.core.server.AuthenticationContext;
   import com.atlassian.asap.core.server.http.RequestAuthenticatorImpl;
   import com.atlassian.asap.core.validator.JwtValidator;
   import com.atlassian.asap.core.validator.JwtValidatorImpl;
   
   import javax.servlet.FilterConfig;
  import java.util.Optional;
  
  /**
   * Implements {@link AbstractRequestAuthenticationFilter} as a Java bean to make
   * it easier to wire this filter using Spring.
   */
  public class RequestAuthenticationFilterBean extends AbstractRequestAuthenticationFilter {
      private final Optional<RequestAuthenticator> requestAuthenticator;
  
      /**
       * Using this constructor will try to automatically fetch your configuration from Spring.
       * You must have defined a bean of type {@link AuthenticationContext}.
       */
      public RequestAuthenticationFilterBean() {
          this.requestAuthenticator = Optional.empty();
      }
  
      /**
       * Using this constructor you must specify your own already configured RequestAuthenticator.
       * Consider using one of the convenient {@link #createDefault} factory methods below.
       */
      public RequestAuthenticationFilterBean(RequestAuthenticator requestAuthenticator) {
          this.requestAuthenticator = Optional.of(requestAuthenticator);
      }
  
      /**
       * A factory to instantiate the filter with minimal configuration.
       *
       * @param audience             the audience this filter will accept requests for
       * @param publicKeyRepoBaseUrl the base URL of the public key repository
       * @return a web filter
       */
      public static RequestAuthenticationFilterBean createDefault(String audience, String publicKeyRepoBaseUrl) {
          AuthenticationContext authContext = new AuthenticationContext(audience, publicKeyRepoBaseUrl);
          JwtValidator jwtValidator = JwtValidatorImpl.createDefault(authContext);
          RequestAuthenticator requestAuthenticator = new RequestAuthenticatorImpl(jwtValidator);
          return new RequestAuthenticationFilterBean(requestAuthenticator);
      }
  
      @Override
      protected RequestAuthenticator getRequestAuthenticator(final FilterConfig filterConfig) {
          return requestAuthenticator.orElseGet(new SpringRequestAuthenticatorSupplier(filterConfig));
      }
  
  }