/*
    * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.internal.storage.file;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertThrows;
  import static org.junit.Assert.fail;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import org.eclipse.jgit.errors.MissingObjectException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.internal.storage.file.PackIndex.MutableEntry;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.junit.Test;
  
  public abstract class PackIndexTestCase extends RepositoryTestCase {
  
  	PackIndex smallIdx;
  
  	PackIndex denseIdx;
  
  	@Override
  	public void setUp() throws Exception {
  		super.setUp();
  		smallIdx = PackIndex.open(getFileForPack34be9032());
  		denseIdx = PackIndex.open(getFileForPackdf2982f28());
  	}
  
  	/**
  	 * Return file with appropriate index version for prepared pack.
  	 *
  	 * @return file with index
  	 */
  	public abstract File getFileForPack34be9032();
  
  	/**
  	 * Return file with appropriate index version for prepared pack.
  	 *
  	 * @return file with index
  	 */
  	public abstract File getFileForPackdf2982f28();
  
  	/**
  	 * Return file with appropriate index version for bad fanout table test.
  	 *
  	 * @return file with index
  	 */
  	public abstract File getFileForBadFanoutTable();
  
  	/**
  	 * Verify CRC32 support.
  	 *
  	 * @throws MissingObjectException
  	 * @throws UnsupportedOperationException
  	 */
  	public abstract void testCRC32() throws MissingObjectException,
  			UnsupportedOperationException;
  
  	/**
  	 * Test contracts of Iterator methods and this implementation remove()
  	 * limitations.
  	 */
  	@Test
  	public void testIteratorMethodsContract() {
  		Iterator<PackIndex.MutableEntry> iter = smallIdx.iterator();
  		while (iter.hasNext()) {
  			iter.next();
  		}
  
  		try {
  			iter.next();
  			fail("next() unexpectedly returned element");
  		} catch (NoSuchElementException x) {
  			// expected
  		}
  
  		try {
  			iter.remove();
  			fail("remove() shouldn't be implemented");
  		} catch (UnsupportedOperationException x) {
  			// expected
  		}
  	}
  
  	/**
 	 * Test results of iterator comparing to content of well-known (prepared)
 	 * small index.
 	 */
 	@Test
 	public void testIteratorReturnedValues1() {
 		Iterator<PackIndex.MutableEntry> iter = smallIdx.iterator();
 		assertEquals("4b825dc642cb6eb9a060e54bf8d69288fbee4904", iter.next()
 				.name());
 		assertEquals("540a36d136cf413e4b064c2b0e0a4db60f77feab", iter.next()
 				.name());
 		assertEquals("5b6e7c66c276e7610d4a73c70ec1a1f7c1003259", iter.next()
 				.name());
 		assertEquals("6ff87c4664981e4397625791c8ea3bbb5f2279a3", iter.next()
 				.name());
 		assertEquals("82c6b885ff600be425b4ea96dee75dca255b69e7", iter.next()
 				.name());
 		assertEquals("902d5476fa249b7abc9d84c611577a81381f0327", iter.next()
 				.name());
 		assertEquals("aabf2ffaec9b497f0950352b3e582d73035c2035", iter.next()
 				.name());
 		assertEquals("c59759f143fb1fe21c197981df75a7ee00290799", iter.next()
 				.name());
 		assertFalse(iter.hasNext());
 	}
 
 	/**
 	 * Compare offset from iterator entries with output of findOffset() method.
 	 */
 	@Test
 	public void testCompareEntriesOffsetsWithFindOffsets() {
 		for (MutableEntry me : smallIdx) {
 			assertEquals(smallIdx.findOffset(me.toObjectId()), me.getOffset());
 		}
 		for (MutableEntry me : denseIdx) {
 			assertEquals(denseIdx.findOffset(me.toObjectId()), me.getOffset());
 		}
 	}
 
 	/**
 	 * Compare offset from iterator entries with output of getOffset() method.
 	 */
 	@Test
 	public void testCompareEntriesOffsetsWithGetOffsets() {
 		int i = 0;
 		for (MutableEntry me : smallIdx) {
 			assertEquals(smallIdx.getOffset(i++), me.getOffset());
 		}
 		int j = 0;
 		for (MutableEntry me : denseIdx) {
 			assertEquals(denseIdx.getOffset(j++), me.getOffset());
 		}
 	}
 
 	/**
 	 * Test partial results of iterator comparing to content of well-known
 	 * (prepared) dense index, that may need multi-level indexing.
 	 */
 	@Test
 	public void testIteratorReturnedValues2() {
 		Iterator<PackIndex.MutableEntry> iter = denseIdx.iterator();
 		while (!iter.next().name().equals(
 				"0a3d7772488b6b106fb62813c4d6d627918d9181")) {
 			// just iterating
 		}
 		assertEquals("1004d0d7ac26fbf63050a234c9b88a46075719d3", iter.next()
 				.name()); // same level-1
 		assertEquals("10da5895682013006950e7da534b705252b03be6", iter.next()
 				.name()); // same level-1
 		assertEquals("1203b03dc816ccbb67773f28b3c19318654b0bc8", iter.next()
 				.name());
 	}
 
 	@Test
 	public void testBadFanoutTable() {
 		IOException ex = assertThrows(IOException.class, () -> {
 			try (FileInputStream fis = new FileInputStream(
 					getFileForBadFanoutTable())) {
 				PackIndex.read(fis);
 			}
 		});
 		assertEquals(JGitText.get().indexFileIsTooLargeForJgit,
 				ex.getMessage());
 	}
 }