/*
    * Copyright (C) 2013, Axel Richard <axel.richard@obeo.fr>
    * 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.
   *
   * 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 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  package org.eclipse.jgit.symlinks;
  
  import static org.junit.Assert.assertEquals;
  
  import java.io.File;
  import java.util.List;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.diff.DiffEntry;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lib.FileMode;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.treewalk.FileTreeIterator;
  import org.eclipse.jgit.treewalk.FileTreeIterator.FileEntry;
  import org.eclipse.jgit.treewalk.TreeWalk;
  import org.eclipse.jgit.util.FS;
  import org.eclipse.jgit.util.FileUtils;
  import org.junit.Before;
  import org.junit.Test;
  
  public class SymlinksTest extends RepositoryTestCase {
  	@Before
  	public void beforeMethod() {
  		// If this assumption fails the tests are skipped. When running on a
  		// filesystem not supporting symlinks I don't want this tests
  		org.junit.Assume.assumeTrue(FS.DETECTED.supportsSymlinks());
  	}
  
  	/**
  	 * Steps: 1.Add file 'a' 2.Commit 3.Create branch '1' 4.Replace file 'a' by
  	 * symlink 'a' 5.Commit 6.Checkout branch '1'
  	 *
  	 * The working tree should contain 'a' with FileMode.REGULAR_FILE after the
  	 * checkout.
  	 *
  	 * @throws Exception
  	 */
  	@Test
  	public void fileModeTestFileThenSymlink() throws Exception {
  		Git git = new Git(db);
  		writeTrashFile("a", "Hello world a");
  		writeTrashFile("b", "Hello world b");
  		git.add().addFilepattern(".").call();
  		git.commit().setMessage("add files a & b").call();
  		Ref branch_1 = git.branchCreate().setName("branch_1").call();
  		git.rm().addFilepattern("a").call();
  		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "b");
  		git.add().addFilepattern("a").call();
  		git.commit().setMessage("add symlink a").call();
  
  		FileEntry entry = new FileTreeIterator.FileEntry(new File(
  				db.getWorkTree(), "a"), db.getFS());
  		assertEquals(FileMode.SYMLINK, entry.getMode());
  
  		git.checkout().setName(branch_1.getName()).call();
  
  		entry = new FileTreeIterator.FileEntry(new File(db.getWorkTree(), "a"),
  				db.getFS());
  		assertEquals(FileMode.REGULAR_FILE, entry.getMode());
  	}
  
 	/**
 	 * Steps: 1.Add symlink 'a' 2.Commit 3.Create branch '1' 4.Replace symlink
 	 * 'a' by file 'a' 5.Commit 6.Checkout branch '1'
 	 *
 	 * The working tree should contain 'a' with FileMode.SYMLINK after the
 	 * checkout.
 	 *
 	 * @throws Exception
 	 */
 	@Test
 	public void fileModeTestSymlinkThenFile() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("b", "Hello world b");
 		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "b");
 		git.add().addFilepattern(".").call();
 		git.commit().setMessage("add file b & symlink a").call();
 		Ref branch_1 = git.branchCreate().setName("branch_1").call();
 		git.rm().addFilepattern("a").call();
 		writeTrashFile("a", "Hello world a");
 		git.add().addFilepattern("a").call();
 		git.commit().setMessage("add file a").call();
 
 		FileEntry entry = new FileTreeIterator.FileEntry(new File(
 				db.getWorkTree(), "a"), db.getFS());
 		assertEquals(FileMode.REGULAR_FILE, entry.getMode());
 
 		git.checkout().setName(branch_1.getName()).call();
 
 		entry = new FileTreeIterator.FileEntry(new File(db.getWorkTree(), "a"),
 				db.getFS());
 		assertEquals(FileMode.SYMLINK, entry.getMode());
 	}
 
 	/**
 	 * Steps: 1.Add folder 'a' 2.Commit 3.Create branch '1' 4.Replace folder 'a'
 	 * by symlink 'a' 5.Commit 6.Checkout branch '1'
 	 *
 	 * The working tree should contain 'a' with FileMode.TREE after the
 	 * checkout.
 	 *
 	 * @throws Exception
 	 */
 	@Test
 	public void fileModeTestFolderThenSymlink() throws Exception {
 		Git git = new Git(db);
 		FileUtils.mkdirs(new File(db.getWorkTree(), "a"));
 		writeTrashFile("a/b", "Hello world b");
 		writeTrashFile("c", "Hello world c");
 		git.add().addFilepattern(".").call();
 		git.commit().setMessage("add folder a").call();
 		Ref branch_1 = git.branchCreate().setName("branch_1").call();
 		git.rm().addFilepattern("a").call();
 		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "c");
 		git.add().addFilepattern("a").call();
 		git.commit().setMessage("add symlink a").call();
 
 		FileEntry entry = new FileTreeIterator.FileEntry(new File(
 				db.getWorkTree(), "a"), db.getFS());
 		assertEquals(FileMode.SYMLINK, entry.getMode());
 
 		git.checkout().setName(branch_1.getName()).call();
 
 		entry = new FileTreeIterator.FileEntry(new File(db.getWorkTree(), "a"),
 				db.getFS());
 		assertEquals(FileMode.TREE, entry.getMode());
 	}
 
 	/**
 	 * Steps: 1.Add symlink 'a' 2.Commit 3.Create branch '1' 4.Replace symlink
 	 * 'a' by folder 'a' 5.Commit 6.Checkout branch '1'
 	 *
 	 * The working tree should contain 'a' with FileMode.SYMLINK after the
 	 * checkout.
 	 *
 	 * @throws Exception
 	 */
 	@Test
 	public void fileModeTestSymlinkThenFolder() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("c", "Hello world c");
 		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "c");
 		git.add().addFilepattern(".").call();
 		git.commit().setMessage("add symlink a").call();
 		Ref branch_1 = git.branchCreate().setName("branch_1").call();
 		git.rm().addFilepattern("a").call();
 		FileUtils.mkdirs(new File(db.getWorkTree(), "a"));
 		writeTrashFile("a/b", "Hello world b");
 		git.add().addFilepattern("a").call();
 		git.commit().setMessage("add folder a").call();
 
 		FileEntry entry = new FileTreeIterator.FileEntry(new File(
 				db.getWorkTree(), "a"), db.getFS());
 		assertEquals(FileMode.TREE, entry.getMode());
 
 		git.checkout().setName(branch_1.getName()).call();
 
 		entry = new FileTreeIterator.FileEntry(new File(db.getWorkTree(), "a"),
 				db.getFS());
 		assertEquals(FileMode.SYMLINK, entry.getMode());
 	}
 
 	/**
 	 * Steps: 1.Add file 'b' 2.Commit 3.Create branch '1' 4.Add symlink 'a'
 	 * 5.Commit 6.Checkout branch '1'
 	 *
 	 * The working tree should not contain 'a' -> FileMode.MISSING after the
 	 * checkout.
 	 *
 	 * @throws Exception
 	 */
 	@Test
 	public void fileModeTestMissingThenSymlink() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("b", "Hello world b");
 		git.add().addFilepattern(".").call();
 		RevCommit commit1 = git.commit().setMessage("add file b").call();
 		Ref branch_1 = git.branchCreate().setName("branch_1").call();
 		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "b");
 		git.add().addFilepattern("a").call();
 		RevCommit commit2 = git.commit().setMessage("add symlink a").call();
 
 		git.checkout().setName(branch_1.getName()).call();
 
 		TreeWalk tw = new TreeWalk(db);
 		tw.addTree(commit1.getTree());
 		tw.addTree(commit2.getTree());
 		List<DiffEntry> scan = DiffEntry.scan(tw);
 		assertEquals(1, scan.size());
 		assertEquals(FileMode.SYMLINK, scan.get(0).getNewMode());
 		assertEquals(FileMode.MISSING, scan.get(0).getOldMode());
 	}
 
 	/**
 	 * Steps: 1.Add symlink 'a' 2.Commit 3.Create branch '1' 4.Delete symlink
 	 * 'a' 5.Commit 6.Checkout branch '1'
 	 *
 	 * The working tree should contain 'a' with FileMode.SYMLINK after the
 	 * checkout.
 	 *
 	 * @throws Exception
 	 */
 	@Test
 	public void fileModeTestSymlinkThenMissing() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("b", "Hello world b");
 		FileUtils.createSymLink(new File(db.getWorkTree(), "a"), "b");
 		git.add().addFilepattern(".").call();
 		RevCommit commit1 = git.commit().setMessage("add file b & symlink a")
 				.call();
 		Ref branch_1 = git.branchCreate().setName("branch_1").call();
 		git.rm().addFilepattern("a").call();
 		RevCommit commit2 = git.commit().setMessage("delete symlink a").call();
 
 		git.checkout().setName(branch_1.getName()).call();
 
 		TreeWalk tw = new TreeWalk(db);
 		tw.addTree(commit1.getTree());
 		tw.addTree(commit2.getTree());
 		List<DiffEntry> scan = DiffEntry.scan(tw);
 		assertEquals(1, scan.size());
 		assertEquals(FileMode.MISSING, scan.get(0).getNewMode());
 		assertEquals(FileMode.SYMLINK, scan.get(0).getOldMode());
 	}
 
 	@Test
 	public void createSymlinkAfterTarget() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("a", "start");
 		git.add().addFilepattern("a").call();
 		RevCommit base = git.commit().setMessage("init").call();
 		writeTrashFile("target", "someData");
 		FileUtils.createSymLink(new File(db.getWorkTree(), "link"), "target");
 		git.add().addFilepattern("target").addFilepattern("link").call();
 		git.commit().setMessage("add target").call();
 		assertEquals(4, db.getWorkTree().list().length); // self-check
 		git.checkout().setName(base.name()).call();
 		assertEquals(2, db.getWorkTree().list().length); // self-check
 		git.checkout().setName("master").call();
 		assertEquals(4, db.getWorkTree().list().length);
 		String data = read(new File(db.getWorkTree(), "target"));
 		assertEquals(8, new File(db.getWorkTree(), "target").length());
 		assertEquals("someData", data);
 		data = read(new File(db.getWorkTree(), "link"));
 		assertEquals("target",
 				FileUtils.readSymLink(new File(db.getWorkTree(), "link")));
 		assertEquals("someData", data);
 	}
 
 	@Test
 	public void createFileSymlinkBeforeTarget() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("a", "start");
 		git.add().addFilepattern("a").call();
 		RevCommit base = git.commit().setMessage("init").call();
 		writeTrashFile("target", "someData");
 		FileUtils.createSymLink(new File(db.getWorkTree(), "tlink"), "target");
 		git.add().addFilepattern("target").addFilepattern("tlink").call();
 		git.commit().setMessage("add target").call();
 		assertEquals(4, db.getWorkTree().list().length); // self-check
 		git.checkout().setName(base.name()).call();
 		assertEquals(2, db.getWorkTree().list().length); // self-check
 		git.checkout().setName("master").call();
 		assertEquals(4, db.getWorkTree().list().length);
 		String data = read(new File(db.getWorkTree(), "target"));
 		assertEquals(8, new File(db.getWorkTree(), "target").length());
 		assertEquals("someData", data);
 		data = read(new File(db.getWorkTree(), "tlink"));
 		assertEquals("target",
 				FileUtils.readSymLink(new File(db.getWorkTree(), "tlink")));
 		assertEquals("someData", data);
 	}
 
 	@Test
 	public void createDirSymlinkBeforeTarget() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("a", "start");
 		git.add().addFilepattern("a").call();
 		RevCommit base = git.commit().setMessage("init").call();
 		FileUtils.createSymLink(new File(db.getWorkTree(), "link"), "target");
 		FileUtils.mkdir(new File(db.getWorkTree(), "target"));
 		writeTrashFile("target/file", "someData");
 		git.add().addFilepattern("target").addFilepattern("link").call();
 		git.commit().setMessage("add target").call();
 		assertEquals(4, db.getWorkTree().list().length); // self-check
 		git.checkout().setName(base.name()).call();
 		assertEquals(2, db.getWorkTree().list().length); // self-check
 		git.checkout().setName("master").call();
 		assertEquals(4, db.getWorkTree().list().length);
 		String data = read(new File(db.getWorkTree(), "target/file"));
 		assertEquals(8, new File(db.getWorkTree(), "target/file").length());
 		assertEquals("someData", data);
 		data = read(new File(db.getWorkTree(), "link/file"));
 		assertEquals("target",
 				FileUtils.readSymLink(new File(db.getWorkTree(), "link")));
 		assertEquals("someData", data);
 	}
 }