/*
 * Copyright (C) 2008, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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package org.eclipse.jgit.treewalk;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.security.MessageDigest;

import org.eclipse.jgit.api.Git;
import org.eclipse.jgit.dircache.DirCacheCheckout;
import org.eclipse.jgit.dircache.DirCacheEntry;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.RepositoryTestCase;
import org.eclipse.jgit.util.FileUtils;
import org.eclipse.jgit.util.RawParseUtils;
import org.junit.Before;
import org.junit.Test;

public class FileTreeIteratorTest extends RepositoryTestCase {
	private final String[] paths = { "a,", "a,b", "a/b", "a0b" };

	private long[] mtime;

	@Before
	public void setUp() throws Exception {
		super.setUp();

		// We build the entries backwards so that on POSIX systems we
		// are likely to get the entries in the trash directory in the
		// opposite order of what they should be in for the iteration.
		// This should stress the sorting code better than doing it in
		// the correct order.
		//
		mtime = new long[paths.length];
		for (int i = paths.length - 1; i >= 0; i--) {
			final String s = paths[i];
			writeTrashFile(s, s);
			mtime[i] = new File(trash, s).lastModified();
		}
	}

	@Test
	public void testEmptyIfRootIsFile() throws Exception {
		final File r = new File(trash, paths[0]);
		assertTrue(r.isFile());
		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
				db.getConfig().get(WorkingTreeOptions.KEY));
		assertTrue(fti.first());
		assertTrue(fti.eof());
	}

	@Test
	public void testEmptyIfRootDoesNotExist() throws Exception {
		final File r = new File(trash, "not-existing-file");
		assertFalse(r.exists());
		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
				db.getConfig().get(WorkingTreeOptions.KEY));
		assertTrue(fti.first());
		assertTrue(fti.eof());
	}

	@Test
	public void testEmptyIfRootIsEmpty() throws Exception {
		final File r = new File(trash, "not-existing-file");
		assertFalse(r.exists());
		FileUtils.mkdir(r);

		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
				db.getConfig().get(WorkingTreeOptions.KEY));
		assertTrue(fti.first());
		assertTrue(fti.eof());
	}

	@Test
	public void testSimpleIterate() throws Exception {
		final FileTreeIterator top = new FileTreeIterator(trash, db.getFS(),
				db.getConfig().get(WorkingTreeOptions.KEY));

		assertTrue(top.first());
		assertFalse(top.eof());
		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
		assertEquals(paths[0], nameOf(top));
		assertEquals(paths[0].length(), top.getEntryLength());
		assertEquals(mtime[0], top.getEntryLastModified());

		top.next(1);
		assertFalse(top.first());
		assertFalse(top.eof());
		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
		assertEquals(paths[1], nameOf(top));
		assertEquals(paths[1].length(), top.getEntryLength());
		assertEquals(mtime[1], top.getEntryLastModified());

		top.next(1);
		assertFalse(top.first());
		assertFalse(top.eof());
		assertEquals(FileMode.TREE.getBits(), top.mode);

		final ObjectReader reader = db.newObjectReader();
		final AbstractTreeIterator sub = top.createSubtreeIterator(reader);
		assertTrue(sub instanceof FileTreeIterator);
		final FileTreeIterator subfti = (FileTreeIterator) sub;
		assertTrue(sub.first());
		assertFalse(sub.eof());
		assertEquals(paths[2], nameOf(sub));
		assertEquals(paths[2].length(), subfti.getEntryLength());
		assertEquals(mtime[2], subfti.getEntryLastModified());

		sub.next(1);
		assertTrue(sub.eof());

		top.next(1);
		assertFalse(top.first());
		assertFalse(top.eof());
		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
		assertEquals(paths[3], nameOf(top));
		assertEquals(paths[3].length(), top.getEntryLength());
		assertEquals(mtime[3], top.getEntryLastModified());

		top.next(1);
		assertTrue(top.eof());
	}

	@Test
	public void testComputeFileObjectId() throws Exception {
		final FileTreeIterator top = new FileTreeIterator(trash, db.getFS(),
				db.getConfig().get(WorkingTreeOptions.KEY));

		final MessageDigest md = Constants.newMessageDigest();
		md.update(Constants.encodeASCII(Constants.TYPE_BLOB));
		md.update((byte) ' ');
		md.update(Constants.encodeASCII(paths[0].length()));
		md.update((byte) 0);
		md.update(Constants.encode(paths[0]));
		final ObjectId expect = ObjectId.fromRaw(md.digest());

		assertEquals(expect, top.getEntryObjectId());

		// Verify it was cached by removing the file and getting it again.
		//
		FileUtils.delete(new File(trash, paths[0]));
		assertEquals(expect, top.getEntryObjectId());
	}

	@Test
	public void testIsModifiedSymlink() throws Exception {
		File f = writeTrashFile("symlink", "content");
		Git git = new Git(db);
		git.add().addFilepattern("symlink").call();
		git.commit().setMessage("commit").call();

		// Modify previously committed DirCacheEntry and write it back to disk
		DirCacheEntry dce = db.readDirCache().getEntry("symlink");
		dce.setFileMode(FileMode.SYMLINK);
		DirCacheCheckout.checkoutEntry(db, f, dce);

		FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(), db
				.getConfig().get(WorkingTreeOptions.KEY));
		while (!fti.getEntryPathString().equals("symlink"))
			fti.next(1);
		assertFalse(fti.isModified(dce, false));
	}

	private static String nameOf(final AbstractTreeIterator i) {
		return RawParseUtils.decode(Constants.CHARSET, i.path, 0, i.pathLen);
	}
}