package org.oxerr.spring.cache.redis.scored.example.spring.data.redis.cache;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import org.springframework.boot.CommandLineRunner;
   import org.springframework.cache.Cache;
   import org.springframework.cache.CacheManager;
   import org.springframework.stereotype.Component;
   
  @Component
  public class AppRunner implements CommandLineRunner {
  
  	private static final Logger logger = LoggerFactory.getLogger(AppRunner.class);
  
  	private final Cache cache;
  
  	private final BookRepository bookRepository;
  
  	public AppRunner(CacheManager cacheManager, BookRepository bookRepository) {
  		this.bookRepository = bookRepository;
  
  		this.cache = cacheManager.getCache("books");
  	}
  
  	@Override
  	public void run(String... args) throws Exception {
  		// Clear cache before test.
  		cache.clear();
  
  		logger.info(".... Testing");
  		logger.info("Cache type: {}", cache.getClass());
  
  		final String isbn = "isbn-1234";
  		final String key = isbn;
  
  		final Book book  = bookRepository.saveBook(new Book(isbn, "version 1"));
  		logger.info("Book: {}", book);
  
  		// 1. The cached data is expired.
  		// Clear cache to mock the cached data is expired.
  		logger.info("1. The cached data is expired.");
  		cache.clear();
  
  		// Request A querying data.
  		final Thread threadA = new Thread(() -> {
  
  			// 2. Request A queries data from persistence layer, got old data(version 1).
  			logger.info("2. Request A queries data from persistence layer, got old data(version 1).");
  			Book oldData = bookRepository.getByIsbn(isbn);
  			logger.info("2. Request A queries data from persistence layer, got old data(version 1). Old data: {}", oldData);
  
  			// 5. Request A puts old data(version 1) into cache.
  			logger.info("5. Request A puts old data(version 1) into cache.");
  			Cache.ValueWrapper cachedData = cache.get(key);
  			logger.info("5. Request A puts old data(version 1) into cache. Cached data is stale: {}", cachedData.get());
  
  		}, "Request A");
  
  		// Request B updating data.
  		final Thread threadB = new Thread(() -> {
  
  			// 3. Request B writes new data(version 2) into persistence layer.
  			logger.info("3. Request B writes new data(version 2) into persistence layer.");
  			Book newData = bookRepository.saveBook(new Book(isbn, "version 2"));
  			logger.info("3. Request B writes new data(version 2) into persistence layer. New data: {}", newData);
  
  			// 4. Request B evicts old data from cache.
  			logger.info("4. Request B evicts old data from cache.");
  			Cache.ValueWrapper cachedData = cache.get(key);
  			logger.info("4. Request B evicts old data from cache. Cached data is null: {}", cachedData);
  
  		}, "Request B");
  
  		threadA.start();
  		Thread.sleep(1000);
  		threadB.start();
  
  		threadA.join();
  		threadB.join();
  
  		// Now we have the old data(version 1) in cache.
  		logger.info(".... Now we have the old data(version 1) in cache.");
  		logger.info("Stale data returned: {}", bookRepository.getByIsbn(isbn));
  	}
  
  }