/*
    * Copyright (C) 2017 Thomas Wolf <thomas.wolf@paranor.ch> 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.attributes;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  import static org.junit.Assert.assertArrayEquals;
  import static org.junit.Assert.assertEquals;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedReader;
  import java.io.ByteArrayInputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.Set;
  
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.eclipse.jgit.treewalk.FileTreeIterator;
  import org.eclipse.jgit.treewalk.TreeWalk;
  import org.eclipse.jgit.treewalk.filter.NotIgnoredFilter;
  import org.eclipse.jgit.util.FS;
  import org.eclipse.jgit.util.FS.ExecutionResult;
  import org.eclipse.jgit.util.RawParseUtils;
  import org.eclipse.jgit.util.TemporaryBuffer;
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * Tests that verify that the attributes of files in a repository are the same
   * in JGit and in C-git.
   */
  public class CGitAttributesTest extends RepositoryTestCase {
  
  	@Before
  	public void initRepo() throws IOException {
  		// Because we run C-git, we must ensure that global or user exclude
  		// files cannot influence the tests. So we set core.excludesFile to an
  		// empty file inside the repository.
  		StoredConfig config = db.getConfig();
  		File fakeUserGitignore = writeTrashFile(".fake_user_gitignore", "");
  		config.setString("core", null, "excludesFile",
  				fakeUserGitignore.getAbsolutePath());
  		// Disable case-insensitivity -- JGit doesn't handle that yet.
  		config.setBoolean("core", null, "ignoreCase", false);
  		// And try to switch off the global attributes file, too.
  		config.setString("core", null, "attributesFile",
  				fakeUserGitignore.getAbsolutePath());
  		config.save();
  	}
  
  	private void createFiles(String... paths) throws IOException {
  		for (String path : paths) {
  			writeTrashFile(path, "x");
  		}
  	}
  
  	private String toString(TemporaryBuffer b) throws IOException {
  		return RawParseUtils.decode(b.toByteArray());
  	}
  
  	private Attribute fromString(String key, String value) {
  		if ("set".equals(value)) {
  			return new Attribute(key, Attribute.State.SET);
  		}
  		if ("unset".equals(value)) {
  			return new Attribute(key, Attribute.State.UNSET);
  		}
  		if ("unspecified".equals(value)) {
  			return new Attribute(key, Attribute.State.UNSPECIFIED);
  		}
  		return new Attribute(key, value);
  	}
  
  	private LinkedHashMap<String, Attributes> cgitAttributes(
  			Set<String> allFiles) throws Exception {
  		FS fs = db.getFS();
  		StringBuilder input = new StringBuilder();
  		for (String filename : allFiles) {
  			input.append(filename).append('\n');
  		}
  		ProcessBuilder builder = fs.runInShell("git",
  				new String[] { "check-attr", "--stdin", "--all" });
  		builder.directory(db.getWorkTree());
  		builder.environment().put("HOME", fs.userHome().getAbsolutePath());
  		ExecutionResult result = fs.execute(builder, new ByteArrayInputStream(
  				input.toString().getBytes(UTF_8)));
  		String errorOut = toString(result.getStderr());
  		assertEquals("External git failed", "exit 0\n",
 				"exit " + result.getRc() + '\n' + errorOut);
 		LinkedHashMap<String, Attributes> map = new LinkedHashMap<>();
 		try (BufferedReader r = new BufferedReader(new InputStreamReader(
 				new BufferedInputStream(result.getStdout().openInputStream()),
 				UTF_8))) {
 			r.lines().forEach(line -> {
 				// Parse the line and add to result map
 				int start = 0;
 				int i = line.indexOf(':');
 				String path = line.substring(0, i).trim();
 				start = i + 1;
 				i = line.indexOf(':', start);
 				String key = line.substring(start, i).trim();
 				String value = line.substring(i + 1).trim();
 				Attribute attr = fromString(key, value);
 				Attributes attrs = map.get(path);
 				if (attrs == null) {
 					attrs = new Attributes(attr);
 					map.put(path, attrs);
 				} else {
 					attrs.put(attr);
 				}
 			});
 		}
 		return map;
 	}
 
 	private LinkedHashMap<String, Attributes> jgitAttributes()
 			throws IOException {
 		// Do a tree walk and return a list of all files and directories with
 		// their attributes
 		LinkedHashMap<String, Attributes> result = new LinkedHashMap<>();
 		try (TreeWalk walk = new TreeWalk(db)) {
 			walk.addTree(new FileTreeIterator(db));
 			walk.setFilter(new NotIgnoredFilter(0));
 			while (walk.next()) {
 				String path = walk.getPathString();
 				if (walk.isSubtree() && !path.endsWith("/")) {
 					// git check-attr expects directory paths to end with a
 					// slash
 					path += '/';
 				}
 				Attributes attrs = walk.getAttributes();
 				if (attrs != null && !attrs.isEmpty()) {
 					result.put(path, attrs);
 				} else {
 					result.put(path, null);
 				}
 				if (walk.isSubtree()) {
 					walk.enterSubtree();
 				}
 			}
 		}
 		return result;
 	}
 
 	private void assertSameAsCGit() throws Exception {
 		LinkedHashMap<String, Attributes> jgit = jgitAttributes();
 		LinkedHashMap<String, Attributes> cgit = cgitAttributes(jgit.keySet());
 		// remove all without attributes
 		Iterator<Map.Entry<String, Attributes>> iterator = jgit.entrySet()
 				.iterator();
 		while (iterator.hasNext()) {
 			Map.Entry<String, Attributes> entry = iterator.next();
 			if (entry.getValue() == null) {
 				iterator.remove();
 			}
 		}
 		assertArrayEquals("JGit attributes differ from C git",
 				cgit.entrySet().toArray(), jgit.entrySet().toArray());
 	}
 
 	@Test
 	public void testBug508568() throws Exception {
 		createFiles("foo.xml/bar.jar", "sub/foo.xml/bar.jar");
 		writeTrashFile(".gitattributes", "*.xml xml\n" + "*.jar jar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testRelativePath() throws Exception {
 		createFiles("sub/foo.txt");
 		writeTrashFile("sub/.gitattributes", "sub/** sub\n" + "*.txt txt\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testRelativePaths() throws Exception {
 		createFiles("sub/foo.txt", "sub/sub/bar", "foo/sub/a.txt",
 				"foo/sub/bar/a.tmp");
 		writeTrashFile(".gitattributes", "sub/** sub\n" + "*.txt txt\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testNestedMatchNot() throws Exception {
 		createFiles("foo.xml/bar.jar", "foo.xml/bar.xml", "sub/b.jar",
 				"sub/b.xml");
 		writeTrashFile("sub/.gitattributes", "*.xml xml\n" + "*.jar jar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testNestedMatch() throws Exception {
 		// This is an interesting test. At the time of this writing, the
 		// gitignore documentation says: "In other words, foo/ will match a
 		// directory foo AND PATHS UNDERNEATH IT, but will not match a regular
 		// file or a symbolic link foo". (Emphasis added.) And gitattributes is
 		// supposed to follow the same rules. But the documentation appears to
 		// lie: C-git will *not* apply the attribute "xml" to *any* files in
 		// any subfolder "foo" here. It will only apply the "jar" attribute
 		// to the three *.jar files.
 		//
 		// The point is probably that ignores are handled top-down, and once a
 		// directory "foo" is matched (here: on paths "foo" and "sub/foo" by
 		// pattern "foo/"), the directory is excluded and the gitignore
 		// documentation also says: "It is not possible to re-include a file if
 		// a parent directory of that file is excluded." So once the pattern
 		// "foo/" has matched, it appears as if everything beneath would also be
 		// matched.
 		//
 		// But not so for gitattributes! The foo/ rule only matches the
 		// directory itself, but not anything beneath.
 		createFiles("foo/bar.jar", "foo/bar.xml", "sub/b.jar", "sub/b.xml",
 				"sub/foo/b.jar");
 		writeTrashFile(".gitattributes",
 				"foo/ xml\n" + "sub/foo/ sub\n" + "*.jar jar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testNestedMatchWithWildcard() throws Exception {
 		// See above.
 		createFiles("foo/bar.jar", "foo/bar.xml", "sub/b.jar", "sub/b.xml",
 				"sub/foo/b.jar");
 		writeTrashFile(".gitattributes",
 				"**/foo/ xml\n" + "*/foo/ sub\n" + "*.jar jar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testNestedMatchRecursive() throws Exception {
 		createFiles("foo/bar.jar", "foo/bar.xml", "sub/b.jar", "sub/b.xml",
 				"sub/foo/b.jar");
 		writeTrashFile(".gitattributes", "foo/** xml\n" + "*.jar jar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testStarMatchOnSlashNot() throws Exception {
 		createFiles("sub/a.txt", "foo/sext", "foo/s.txt");
 		writeTrashFile(".gitattributes", "s*xt bar");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testPrefixMatchNot() throws Exception {
 		createFiles("src/new/foo.txt");
 		writeTrashFile(".gitattributes", "src/new bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testComplexPathMatchNot() throws Exception {
 		createFiles("src/new/foo.txt", "src/ndw");
 		writeTrashFile(".gitattributes", "s[p-s]c/n[de]w bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testStarPathMatchNot() throws Exception {
 		createFiles("src/new/foo.txt", "src/ndw");
 		writeTrashFile(".gitattributes", "src/* bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubSimple() throws Exception {
 		createFiles("src/new/foo.txt", "foo/src/new/foo.txt", "sub/src/new");
 		writeTrashFile(".gitattributes", "src/new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursive() throws Exception {
 		createFiles("src/new/foo.txt", "foo/src/new/foo.txt", "sub/src/new");
 		writeTrashFile(".gitattributes", "**/src/new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack() throws Exception {
 		createFiles("src/new/foo.txt", "src/src/new/foo.txt");
 		writeTrashFile(".gitattributes", "**/src/new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack2() throws Exception {
 		createFiles("src/new/foo.txt", "src/src/new/foo.txt");
 		writeTrashFile(".gitattributes", "**/**/src/new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack3() throws Exception {
 		createFiles("src/new/src/new/foo.txt",
 				"foo/src/new/bar/src/new/foo.txt");
 		writeTrashFile(".gitattributes", "**/src/new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack4() throws Exception {
 		createFiles("src/src/src/new/foo.txt",
 				"foo/src/src/bar/src/new/foo.txt");
 		writeTrashFile(".gitattributes", "**/src/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack5() throws Exception {
 		createFiles("x/a/a/b/foo.txt", "x/y/z/b/a/b/foo.txt",
 				"x/y/a/a/a/a/b/foo.txt", "x/y/a/a/a/a/b/a/b/foo.txt");
 		writeTrashFile(".gitattributes", "**/*/a/b bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubRecursiveBacktrack6() throws Exception {
 		createFiles("x/a/a/b/foo.txt", "x/y/a/b/a/b/foo.txt");
 		writeTrashFile(".gitattributes", "**/*/**/a/b bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryWildmatchDoesNotMatchFiles1() throws Exception {
 		createFiles("a", "dir/b", "dir/sub/c");
 		writeTrashFile(".gitattributes", "**/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryWildmatchDoesNotMatchFiles2() throws Exception {
 		createFiles("a", "dir/b", "dir/sub/c");
 		writeTrashFile(".gitattributes", "**/**/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryWildmatchDoesNotMatchFiles3() throws Exception {
 		createFiles("a", "x/b", "sub/x/c", "sub/x/d/e");
 		writeTrashFile(".gitattributes", "x/**/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryWildmatchDoesNotMatchFiles4() throws Exception {
 		createFiles("a", "dir/x", "dir/sub1/x", "dir/sub2/x/y");
 		writeTrashFile(".gitattributes", "x/**/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatchSubComplex() throws Exception {
 		createFiles("src/new/foo.txt", "foo/src/new/foo.txt", "sub/src/new");
 		writeTrashFile(".gitattributes", "s[rs]c/n*/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testDirectoryMatch() throws Exception {
 		createFiles("src/new/foo.txt", "foo/src/new/foo.txt", "sub/src/new");
 		writeTrashFile(".gitattributes", "new/ bar\n");
 		assertSameAsCGit();
 	}
 
 	@Test
 	public void testBracketsInGroup() throws Exception {
 		createFiles("[", "]", "[]", "][", "[[]", "[]]", "[[]]");
 		writeTrashFile(".gitattributes", "[[]] bar1\n" + "[\\[]] bar2\n"
 				+ "[[\\]] bar3\n" + "[\\[\\]] bar4\n");
 		assertSameAsCGit();
 	}
 }