/* 
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System;

using NUnit.Framework;

using Lucene.Net.Analysis;
using Lucene.Net.Documents;
using Lucene.Net.Store;
using Lucene.Net.Util;
using English = Lucene.Net.Util.English;
using LuceneTestCase = Lucene.Net.Util.LuceneTestCase;

namespace Lucene.Net.Index
{
	
    [TestFixture]
	public class TestTransactions:LuceneTestCase
	{
		private System.Random RANDOM;
		private static volatile bool doFail;
		
		private class RandomFailure:MockRAMDirectory.Failure
		{
			public RandomFailure(TestTransactions enclosingInstance)
			{
				InitBlock(enclosingInstance);
			}
			private void  InitBlock(TestTransactions enclosingInstance)
			{
				this.enclosingInstance = enclosingInstance;
			}
			private TestTransactions enclosingInstance;
			public TestTransactions Enclosing_Instance
			{
				get
				{
					return enclosingInstance;
				}
				
			}
			public override void  Eval(MockRAMDirectory dir)
			{
				if (TestTransactions.doFail && Enclosing_Instance.RANDOM.Next() % 10 <= 3)
					throw new System.IO.IOException("now failing randomly but on purpose");
			}
		}
		
		abstract public class TimedThread:SupportClass.ThreadClass
		{
			internal bool failed;
			private static int RUN_TIME_SEC = 6;
			private TimedThread[] allThreads;
			
			abstract public void  DoWork();
			
			internal TimedThread(TimedThread[] threads)
			{
				this.allThreads = threads;
			}
			
			override public void  Run()
			{
				long stopTime = (DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond) + 1000 * RUN_TIME_SEC;
				
				try
				{
					while ((DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond) < stopTime && !AnyErrors())
						DoWork();
				}
				catch (System.Exception e)
				{
					System.Console.Out.WriteLine(SupportClass.ThreadClass.Current() + ": exc");
					System.Console.Out.WriteLine(e.StackTrace);
					failed = true;
				}
			}
			
			private bool AnyErrors()
			{
				for (int i = 0; i < allThreads.Length; i++)
					if (allThreads[i] != null && allThreads[i].failed)
						return true;
				return false;
			}
		}
		
		private class IndexerThread:TimedThread
		{
			private void  InitBlock(TestTransactions enclosingInstance)
			{
				this.enclosingInstance = enclosingInstance;
			}
			private TestTransactions enclosingInstance;
			public TestTransactions Enclosing_Instance
			{
				get
				{
					return enclosingInstance;
				}
				
			}
			internal Directory dir1;
			internal Directory dir2;
			internal System.Object lock_Renamed;
			internal int nextID;
			
			public IndexerThread(TestTransactions enclosingInstance, System.Object lock_Renamed, Directory dir1, Directory dir2, TimedThread[] threads):base(threads)
			{
				InitBlock(enclosingInstance);
				this.lock_Renamed = lock_Renamed;
				this.dir1 = dir1;
				this.dir2 = dir2;
			}
			
			public override void  DoWork()
			{
				
				IndexWriter writer1 = new IndexWriter(dir1, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
				writer1.SetMaxBufferedDocs(3);
				writer1.SetMergeFactor(2);
				((ConcurrentMergeScheduler) writer1.GetMergeScheduler()).SetSuppressExceptions();
				
				IndexWriter writer2 = new IndexWriter(dir2, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
				// Intentionally use different params so flush/merge
				// happen @ different times
				writer2.SetMaxBufferedDocs(2);
				writer2.SetMergeFactor(3);
				((ConcurrentMergeScheduler) writer2.GetMergeScheduler()).SetSuppressExceptions();
				
				Update(writer1);
				Update(writer2);
				
				TestTransactions.doFail = true;
				try
				{
					lock (lock_Renamed)
					{
						try
						{
							writer1.PrepareCommit();
						}
						catch (System.Exception t)
						{
							writer1.Rollback();
							writer2.Rollback();
							return ;
						}
						try
						{
							writer2.PrepareCommit();
						}
						catch (System.Exception t)
						{
							writer1.Rollback();
							writer2.Rollback();
							return ;
						}
						
						writer1.Commit();
						writer2.Commit();
					}
				}
				finally
				{
					TestTransactions.doFail = false;
				}
				
				writer1.Close();
				writer2.Close();
			}
			
			public virtual void  Update(IndexWriter writer)
			{
				// Add 10 docs:
				for (int j = 0; j < 10; j++)
				{
					Document d = new Document();
					int n = Enclosing_Instance.RANDOM.Next();
					d.Add(new Field("id", System.Convert.ToString(nextID++), Field.Store.YES, Field.Index.NOT_ANALYZED));
					d.Add(new Field("contents", English.IntToEnglish(n), Field.Store.NO, Field.Index.ANALYZED));
					writer.AddDocument(d);
				}
				
				// Delete 5 docs:
				int deleteID = nextID - 1;
				for (int j = 0; j < 5; j++)
				{
					writer.DeleteDocuments(new Term("id", "" + deleteID));
					deleteID -= 2;
				}
			}
		}
		
		private class SearcherThread:TimedThread
		{
			internal Directory dir1;
			internal Directory dir2;
			internal System.Object lock_Renamed;
			
			public SearcherThread(System.Object lock_Renamed, Directory dir1, Directory dir2, TimedThread[] threads):base(threads)
			{
				this.lock_Renamed = lock_Renamed;
				this.dir1 = dir1;
				this.dir2 = dir2;
			}
			
			public override void  DoWork()
			{
				IndexReader r1, r2;
				lock (lock_Renamed)
				{
					r1 = IndexReader.Open(dir1);
					r2 = IndexReader.Open(dir2);
				}
				if (r1.NumDocs() != r2.NumDocs())
					throw new System.SystemException("doc counts differ: r1=" + r1.NumDocs() + " r2=" + r2.NumDocs());
				r1.Close();
				r2.Close();
			}
		}
		
		public virtual void  InitIndex(Directory dir)
		{
			IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
			for (int j = 0; j < 7; j++)
			{
				Document d = new Document();
				int n = RANDOM.Next();
				d.Add(new Field("contents", English.IntToEnglish(n), Field.Store.NO, Field.Index.ANALYZED));
				writer.AddDocument(d);
			}
			writer.Close();
		}
		
		[Test]
		public virtual void  TestTransactions_Rename()
		{
			RANDOM = NewRandom();
			MockRAMDirectory dir1 = new MockRAMDirectory();
			MockRAMDirectory dir2 = new MockRAMDirectory();
			dir1.SetPreventDoubleWrite(false);
			dir2.SetPreventDoubleWrite(false);
			dir1.FailOn(new RandomFailure(this));
			dir2.FailOn(new RandomFailure(this));
			
			InitIndex(dir1);
			InitIndex(dir2);
			
			TimedThread[] threads = new TimedThread[3];
			int numThread = 0;
			
			IndexerThread indexerThread = new IndexerThread(this, this, dir1, dir2, threads);
			threads[numThread++] = indexerThread;
			indexerThread.Start();
			
			SearcherThread searcherThread1 = new SearcherThread(this, dir1, dir2, threads);
			threads[numThread++] = searcherThread1;
			searcherThread1.Start();
			
			SearcherThread searcherThread2 = new SearcherThread(this, dir1, dir2, threads);
			threads[numThread++] = searcherThread2;
			searcherThread2.Start();
			
			for (int i = 0; i < numThread; i++)
				threads[i].Join();
			
			for (int i = 0; i < numThread; i++)
				Assert.IsTrue(!((TimedThread) threads[i]).failed);
		}
	}
}