package org.infinispan.lucene.profiling;

import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.StringField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.infinispan.Cache;
import org.infinispan.configuration.cache.CacheMode;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.lucene.directory.DirectoryBuilder;
import org.infinispan.lucene.testutils.LuceneSettings;
import org.infinispan.manager.EmbeddedCacheManager;
import org.infinispan.test.AbstractCacheTest;
import org.infinispan.test.MultipleCacheManagersTest;
import org.infinispan.test.TestingUtil;
import org.infinispan.test.fwk.TransportFlags;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
import org.jgroups.protocols.DISCARD;
import org.testng.annotations.Test;

/**
 * @author Sanne Grinovero &lt;sanne@infinispan.org&gt; (C) 2011 Red Hat Inc.
 */
@SuppressWarnings("deprecation")
@Test(groups = "profiling", testName = "lucene.profiling.DynamicTopologyStressTest", sequential = true)
public class DynamicTopologyStressTest extends MultipleCacheManagersTest {

   private static final Log log = LogFactory.getLog(DynamicTopologyStressTest.class);

   private static final boolean KEEP_GOING = false;
   private static final boolean VISUAL_PROGRESS_FEEDBACK = false;

   /** Number of seconds the test will run. Should run for some minutes **/
   private static final int SECONDS_TOTAL = 15;

   /** How many Documents to write in each second **/
   private static final int WRITES_PER_SECOND = 100;

   /** Number of Terms written in the index **/
   private static final int INITIAL_INDEX_TERMS = 2000;

   private static final String INDEX_NAME = "unstableIndex";
   private static final String FIELDNAME = "fieldname";

   /** Number of reading nodes **/
   private static final int READERS = 5;

   private final AtomicBoolean failed = new AtomicBoolean(false);
   private volatile int lastWrittenTermId = 0;

   /** Registry of clustered CacheManagers used as readers **/
   private EmbeddedCacheManager[] readers = new EmbeddedCacheManager[READERS];
   private DISCARD[] discardPerNode = new DISCARD[READERS];
   private EmbeddedCacheManager writingNode;

   @Override
   protected void createCacheManagers() throws Throwable {
      ConfigurationBuilder cb = AbstractCacheTest.getDefaultClusteredCacheConfig(CacheMode.DIST_SYNC, false);
      cb.invocationBatching().disable();
      TransportFlags transportFlags = new TransportFlags().withMerge(true);

      writingNode = addClusterEnabledCacheManager(cb, transportFlags);
      for (int i = 0; i < READERS; i++) {
         readers[i] = addClusterEnabledCacheManager(cb, transportFlags);
         Cache<Object, Object> cache = readers[i].getCache();
         discardPerNode[i] = TestingUtil.getDiscardForCache(readers[i]);
         TestingUtil.setDelayForCache(cache, 1, 1);
         TestingUtil.blockUntilViewReceived(cache, i + 1);
      }
   }

   @Test
   void testDirectoryUnstableCluster() throws IOException {
      Directory masterDirectory = DirectoryBuilder.newDirectoryInstance(writingNode.getCache(),
            writingNode.getCache(), writingNode.getCache(), INDEX_NAME).create();
      SharedState sharedIndexState = IndexReadingStressTest.fillDirectory(masterDirectory, INITIAL_INDEX_TERMS);

      ExecutorService executor = Executors.newFixedThreadPool(READERS + 1);
      try {
         executor.execute(new ConstantWritingThread(masterDirectory, sharedIndexState));
         for (int i=0; i<READERS; i++) {
            executor.execute(new ConstantReadingThread(masterDirectory, sharedIndexState));
         }
         executor.shutdown();
         executor.awaitTermination(SECONDS_TOTAL * 2, TimeUnit.SECONDS); //wait for all jobs to finish
      } catch (InterruptedException e) {
         log.error(e);
         assert false : "unexpected interruption";
      }
      assert failed.get() == false;
   }

   private void failed(Exception e) {
      log.error(e);
      if (! KEEP_GOING) {
         failed.set(true);
      }
   }

   public class ConstantWritingThread implements Runnable {

      private final Directory masterDirectory;

      public ConstantWritingThread(Directory masterDirectory,
            SharedState sharedIndexState) {
         this.masterDirectory = masterDirectory;
      }

      @Override
      public void run() {
         while (lastWrittenTermId < (SECONDS_TOTAL * WRITES_PER_SECOND) && failed.get() == false) {
            IndexWriter writer = null;
            try {
               int toWrite = lastWrittenTermId + 1;
               writer = LuceneSettings.openWriter(masterDirectory, 3); // 3 or any low setting
               Document doc = new Document();
               Field field = new StringField(FIELDNAME, "HA" + toWrite, Store.YES);
               doc.add(field);
               writer.addDocument(doc);
               writer.commit();
               lastWrittenTermId = toWrite;
               if (VISUAL_PROGRESS_FEEDBACK) System.out.println("Written: " + doc);
               Thread.sleep(1000 / WRITES_PER_SECOND);
            } catch (IOException e) {
               failed(e);
               return;
            } catch (InterruptedException e) {
               failed(e);
               return;
            } finally {
               try {
                  if (writer != null) {
                     writer.close();
                  }
               } catch (IOException e) {
                  failed(e);
                  return;
               }
            }
         }
      }

   }

   public class ConstantReadingThread implements Runnable {

      private final Directory masterDirectory;

      public ConstantReadingThread(Directory masterDirectory, SharedState sharedIndexState) {
         this.masterDirectory = masterDirectory;
      }

      @Override
      public void run() {
         while (lastWrittenTermId < (SECONDS_TOTAL * WRITES_PER_SECOND) && failed.get() == false) {
            IndexReader indexReader = null;
            try {
               int i = lastWrittenTermId;
               indexReader = DirectoryReader.open(masterDirectory);
               IndexSearcher indexSearcher = new IndexSearcher(indexReader);
               if (i==0) continue; // nothing written yet
               String termValue = "HA" + i;
               Query query = new TermQuery(new Term( FIELDNAME, termValue));
               TopDocs docs = indexSearcher.search(query, 1);
               if (docs.totalHits != 1) {
                  failed.set(true);
                  log.error("String '" + termValue + "' should exist but was not found in index");
               }
               if (VISUAL_PROGRESS_FEEDBACK) System.out.print(".");
               Thread.sleep(1);
            } catch (IOException e) {
               failed(e);
               return;
            } catch (InterruptedException e) {
               failed(e);
               return;
            } finally {
               try {
                  if (indexReader != null) {
                     indexReader.close();
                  }
               } catch (IOException e) {
                  failed(e);
                  return;
               }
            }
         }
      }

   }

}
