package org.infinispan.stream;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import org.infinispan.configuration.cache.CacheMode;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.container.entries.CacheEntry;
import org.infinispan.filter.Converter;
import org.infinispan.manager.EmbeddedCacheManager;
import org.infinispan.marshall.core.ExternalPojo;
import org.infinispan.metadata.Metadata;
import org.infinispan.test.MultipleCacheManagersTest;
import org.infinispan.test.fwk.TestCacheManagerFactory;
import org.infinispan.transaction.TransactionMode;
import org.testng.annotations.Test;

/**
 * Base class used solely for setting up cluster configuration for use with stream iterators
 *
 * @author wburns
 * @since 8.0
 */
@Test(groups = "functional", testName = "stream.BaseSetupStreamIteratorTest")
public abstract class BaseSetupStreamIteratorTest extends MultipleCacheManagersTest {
   protected final String CACHE_NAME = getClass().getName();
   protected ConfigurationBuilder builderUsed;
   protected final boolean tx;
   protected final CacheMode cacheMode;

   public BaseSetupStreamIteratorTest(boolean tx, CacheMode mode) {
      this.tx = tx;
      cacheMode = mode;
   }

   protected void enhanceConfiguration(ConfigurationBuilder builder) {
      // Do nothing to config by default, used by people who extend this
   }

   @Override
   protected void createCacheManagers() throws Throwable {
      builderUsed = new ConfigurationBuilder();
      builderUsed.clustering().cacheMode(cacheMode);
      if (tx) {
         builderUsed.transaction().transactionMode(TransactionMode.TRANSACTIONAL);
      }
      if (cacheMode.isClustered()) {
         builderUsed.clustering().hash().numOwners(2);
         builderUsed.clustering().stateTransfer().chunkSize(50);
         enhanceConfiguration(builderUsed);
         createClusteredCaches(3, CACHE_NAME, builderUsed);
      } else {
         enhanceConfiguration(builderUsed);
         EmbeddedCacheManager cm = TestCacheManagerFactory.createCacheManager(builderUsed);
         cacheManagers.add(cm);
         cm.defineConfiguration(CACHE_NAME, builderUsed.build());
      }
   }

   protected static <K, V> Map<K, V> mapFromIterator(Iterator<? extends Map.Entry<K, V>> iterator) {
      Map<K, V> map = new HashMap<K, V>();
      while (iterator.hasNext()) {
         Map.Entry<K, V> entry = iterator.next();
         map.put(entry.getKey(), entry.getValue());
      }
      return map;
   }

   protected static <K, V> Map<K, V> mapFromStream(Stream<CacheEntry<K, V>> stream) {
      return stream.collect(CacheCollectors.serializableCollector(
              () -> Collectors.toMap(e -> e.getKey(), e -> e.getValue())));
   }

   protected static class StringTruncator implements Converter<Object, String, String>, Serializable, ExternalPojo {
      private final int beginning;
      private final int length;

      public StringTruncator(int beginning, int length) {
         this.beginning = beginning;
         this.length = length;
      }

      @Override
      public String convert(Object key, String value, Metadata metadata) {
         if (value != null && value.length() > beginning + length) {
            return value.substring(beginning, beginning + length);
         } else {
            throw new IllegalStateException("String should be longer than truncation size!  Possible double conversion performed!");
         }
      }
   }
}