package com.atlassian.asap.service.core.impl;
   
   import com.atlassian.asap.service.api.TokenValidator;
   import com.atlassian.asap.service.core.spi.AsapConfiguration;
   import com.google.common.base.MoreObjects;
   import com.google.common.collect.ImmutableSet;
   
   import java.util.Set;
   
  import static java.util.Objects.requireNonNull;
  
  /**
   * Implements the builder logic for a token validator.
   */
  @SuppressWarnings("WeakerAccess")
  public abstract class AbstractTokenValidator implements TokenValidator {
      private final AsapConfiguration config;
  
      /**
       * The issuers that are <strong>authorized</strong> to use this resource as 'root'.
       */
      private Set<String> authorizedIssuers;
  
      /**
       * The issuers that are <strong>authorized</strong> to use this resource.
       */
      private Set<String> impersonationAuthorizedIssuers;
  
      /**
       * The effective subjects that are <strong>authorized</strong> to use this resource.
       */
      private Set<String> authorizedSubjects;
  
      /**
       * The audience values that may be specified when creating a token for this resource.
       */
      private Set<String> acceptableAudienceValues;
  
      /**
       * True if the token's subject value is going to be interpreted as a user to impersonate.
       *
       * @see TokenValidator#subject(String...)
       */
      private boolean subjectImpersonation;
  
      /**
       * The validation policy to apply when validating the token.
       */
      private Policy policy = Policy.REQUIRE;
  
  
      @SuppressWarnings("WeakerAccess")
      protected AbstractTokenValidator(AsapConfiguration config) {
          this.config = requireNonNull(config, "config");
          this.authorizedIssuers = ImmutableSet.of();
          this.impersonationAuthorizedIssuers = ImmutableSet.of();
          this.authorizedSubjects = ImmutableSet.of();
          this.acceptableAudienceValues = ImmutableSet.of(config.audience());
      }
  
      @Override
      public TokenValidator issuer(Iterable<String> authorizedIssuers) {
          this.authorizedIssuers = ImmutableSet.copyOf(authorizedIssuers);
          return this;
      }
  
      @Override
      public TokenValidator impersonationIssuer(Iterable<String> impersonationIssuers) {
          this.impersonationAuthorizedIssuers = ImmutableSet.copyOf(impersonationIssuers);
          return this;
      }
  
      /**
       * @param subjectImpersonation {@code true} to use subject impersonation
       * @return {@code this}
       * @deprecated move/copy issuers that are allowed to impersonate users from the 'issuer' to the 'impersonationIssuer' list
       */
      @Override
      @Deprecated
      public TokenValidator subjectImpersonation(boolean subjectImpersonation) {
          this.subjectImpersonation = subjectImpersonation;
          return this;
      }
  
      @Override
      public TokenValidator subject(Iterable<String> authorizedSubjects) {
          this.authorizedSubjects = ImmutableSet.copyOf(authorizedSubjects);
          return this;
      }
  
      @Override
      public TokenValidator audience(Iterable<String> additionalAudienceValues) {
          this.acceptableAudienceValues = ImmutableSet.<String>builder()
                  .add(config.audience())
                  .addAll(additionalAudienceValues)
                  .build();
          return this;
      }
  
     @Override
     public TokenValidator policy(Policy policy) {
         this.policy = requireNonNull(policy, "policy");
         return this;
     }
 
     protected Set<String> authorizedIssuers() {
         return authorizedIssuers;
     }
 
     protected Set<String> impersonationAuthorizedIssuers() {
         return impersonationAuthorizedIssuers;
     }
 
     protected Set<String> authorizedSubjects() {
         return authorizedSubjects;
     }
 
     protected Set<String> acceptableAudienceValues() {
         return acceptableAudienceValues;
     }
 
     protected boolean subjectImpersonation() {
         return subjectImpersonation;
     }
 
     protected Policy policy() {
         return policy;
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(this)
                 .add("config", config)
                 .add("authorizedIssuers", authorizedIssuers)
                 .add("impersonationAuthorizedIssuers", impersonationAuthorizedIssuers)
                 .add("authorizedSubjects", authorizedSubjects)
                 .add("acceptableAudienceValues", acceptableAudienceValues)
                 .add("subjectImpersonation", subjectImpersonation)
                 .add("policy", policy)
                 .toString();
     }
 }