package org.oxerr.spring.cache.redis.scored;
   
   import java.util.Optional;
   
   import org.oxerr.spring.cache.redis.scored.score.resolver.ScoreResolver;
   import org.springframework.cache.Cache;
   import org.springframework.cache.interceptor.CacheInterceptor;
   import org.springframework.lang.NonNull;
   import org.springframework.lang.Nullable;
  
  /**
   * Resolves the score of the caching value by the {@link ScoreResolver},
   * and stores to the {@link ScoreHolder},
   * and then the {@link ScoredRedisCacheWriter} could read the score
   * from the {@link ScoreHolder}
   */
  public class ScoredRedisCacheInterceptor extends CacheInterceptor {
  
  	private static final long serialVersionUID = 2021082001L;
  
  	private final ScoreResolver scoreResolver;
  	private final ScoreHolder scoreHolder;
  
  	public ScoredRedisCacheInterceptor(
  		@NonNull ScoreResolver scoreResolver,
  		@NonNull ScoreHolder scoreHolder
  	) {
  		this.scoreResolver = scoreResolver;
  		this.scoreHolder = scoreHolder;
  	}
  
  	@Override
  	protected void doPut(Cache cache, Object key, @Nullable Object result) {
  		try {
  			this.setScore(result);
  			super.doPut(cache, key, result);
  		} finally {
  			this.clearScore();
  		}
  	}
  
  	private void setScore(@Nullable Object result) {
  		Optional<Double> score = this.scoreResolver.resolveScore(result);
  		this.scoreHolder.set(score.orElse(null));
  	}
  
  	private void clearScore() {
  		this.scoreHolder.remove();
  	}
  
  }