package com.atlassian.asap.feign;
   
   import com.atlassian.asap.api.Jwt;
   import com.atlassian.asap.api.JwtBuilder;
   import com.atlassian.asap.api.client.http.AuthorizationHeaderGenerator;
   import com.atlassian.asap.api.exception.CannotRetrieveKeyException;
   import com.atlassian.asap.api.exception.InvalidTokenException;
   import feign.RequestInterceptor;
   import feign.RequestTemplate;
  
  import java.util.Objects;
  
  /**
   * Decorates a Feign request with ASAP credentials.
   */
  public class AsapInterceptor implements RequestInterceptor {
      private final AuthorizationHeaderGenerator authorizationHeaderGenerator;
      private final Jwt jwtPrototype;
  
      public AsapInterceptor(AuthorizationHeaderGenerator authorizationHeaderGenerator, Jwt jwtPrototype) {
          this.authorizationHeaderGenerator = Objects.requireNonNull(authorizationHeaderGenerator);
          this.jwtPrototype = Objects.requireNonNull(jwtPrototype);
      }
  
      @Override
      public void apply(RequestTemplate requestTemplate) {
          Jwt jwt = JwtBuilder.newFromPrototype(jwtPrototype).build();
          try {
              requestTemplate.header("Authorization", authorizationHeaderGenerator.generateAuthorizationHeader(jwt));
          } catch (InvalidTokenException e) {
              throw new RuntimeException("Invalid prototype token", e);
          } catch (CannotRetrieveKeyException e) {
              e.printStackTrace();
          }
      }
  }