/*
 * Copyright (C) 2014, Obeo. 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.util.Arrays.asList;
import static org.hamcrest.CoreMatchers.hasItem;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.List;

import org.eclipse.jgit.attributes.Attribute.State;
import org.eclipse.jgit.junit.JGitTestUtil;
import org.eclipse.jgit.junit.RepositoryTestCase;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.treewalk.CanonicalTreeParser;
import org.eclipse.jgit.treewalk.FileTreeIterator;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.WorkingTreeIterator;
import org.junit.Test;

/**
 * Tests attributes node behavior on the local filesystem.
 */
public class AttributesNodeWorkingTreeIteratorTest extends RepositoryTestCase {

	private static final FileMode D = FileMode.TREE;

	private static final FileMode F = FileMode.REGULAR_FILE;

	private static Attribute EOL_LF = new Attribute("eol", "lf");

	private static Attribute DELTA_UNSET = new Attribute("delta", State.UNSET);

	@Test
	public void testRules() throws Exception {

		File customAttributeFile = File.createTempFile("tmp_",
				"customAttributeFile", null);
		customAttributeFile.deleteOnExit();

		JGitTestUtil.write(customAttributeFile, "*.txt custom=value");
		db.getConfig().setString("core", null, "attributesfile",
				customAttributeFile.getAbsolutePath());
		writeAttributesFile(".git/info/attributes", "windows* eol=crlf");

		writeAttributesFile(".gitattributes", "*.txt eol=lf");
		writeTrashFile("windows.file", "");
		writeTrashFile("windows.txt", "");
		writeTrashFile("global.txt", "");
		writeTrashFile("readme.txt", "");

		writeAttributesFile("src/config/.gitattributes", "*.txt -delta");
		writeTrashFile("src/config/readme.txt", "");
		writeTrashFile("src/config/windows.file", "");
		writeTrashFile("src/config/windows.txt", "");

		try (TreeWalk walk = beginWalk()) {
			assertIteration(walk, F, ".gitattributes");
			assertIteration(walk, F, "global.txt", asList(EOL_LF));
			assertIteration(walk, F, "readme.txt", asList(EOL_LF));

			assertIteration(walk, D, "src");

			assertIteration(walk, D, "src/config");
			assertIteration(walk, F, "src/config/.gitattributes");
			assertIteration(walk, F, "src/config/readme.txt",
					asList(DELTA_UNSET));
			assertIteration(walk, F, "src/config/windows.file", null);
			assertIteration(walk, F, "src/config/windows.txt",
					asList(DELTA_UNSET));

			assertIteration(walk, F, "windows.file", null);
			assertIteration(walk, F, "windows.txt", asList(EOL_LF));

			assertFalse("Not all files tested", walk.next());
		}
	}

	/**
	 * Checks that if there is no .gitattributes file in the repository
	 * everything still work fine.
	 *
	 * @throws Exception
	 */
	@Test
	public void testNoAttributes() throws Exception {
		writeTrashFile("l0.txt", "");
		writeTrashFile("level1/l1.txt", "");
		writeTrashFile("level1/level2/l2.txt", "");

		try (TreeWalk walk = beginWalk()) {
			assertIteration(walk, F, "l0.txt");

			assertIteration(walk, D, "level1");
			assertIteration(walk, F, "level1/l1.txt");

			assertIteration(walk, D, "level1/level2");
			assertIteration(walk, F, "level1/level2/l2.txt");

			assertFalse("Not all files tested", walk.next());
		}
	}

	/**
	 * Checks that empty .gitattribute files do not return incorrect value.
	 *
	 * @throws Exception
	 */
	@Test
	public void testEmptyGitAttributeFile() throws Exception {
		writeAttributesFile(".git/info/attributes", "");
		writeTrashFile("l0.txt", "");
		writeAttributesFile(".gitattributes", "");
		writeTrashFile("level1/l1.txt", "");
		writeTrashFile("level1/level2/l2.txt", "");

		try (TreeWalk walk = beginWalk()) {
			assertIteration(walk, F, ".gitattributes");
			assertIteration(walk, F, "l0.txt");

			assertIteration(walk, D, "level1");
			assertIteration(walk, F, "level1/l1.txt");

			assertIteration(walk, D, "level1/level2");
			assertIteration(walk, F, "level1/level2/l2.txt");

			assertFalse("Not all files tested", walk.next());
		}
	}

	@Test
	public void testNoMatchingAttributes() throws Exception {
		writeAttributesFile(".git/info/attributes", "*.java delta");
		writeAttributesFile(".gitattributes", "*.java -delta");
		writeAttributesFile("levelA/.gitattributes", "*.java eol=lf");
		writeAttributesFile("levelB/.gitattributes", "*.txt eol=lf");

		writeTrashFile("levelA/lA.txt", "");

		try (TreeWalk walk = beginWalk()) {
			assertIteration(walk, F, ".gitattributes");

			assertIteration(walk, D, "levelA");
			assertIteration(walk, F, "levelA/.gitattributes");
			assertIteration(walk, F, "levelA/lA.txt");

			assertIteration(walk, D, "levelB");
			assertIteration(walk, F, "levelB/.gitattributes");

			assertFalse("Not all files tested", walk.next());
		}
	}

	private void assertIteration(TreeWalk walk, FileMode type, String pathName)
			throws IOException {
		assertIteration(walk, type, pathName,
				Collections.<Attribute> emptyList());
	}

	private void assertIteration(TreeWalk walk, FileMode type, String pathName,
			List<Attribute> nodeAttrs)
			throws IOException {
		assertTrue("walk has entry", walk.next());
		assertEquals(pathName, walk.getPathString());
		assertEquals(type, walk.getFileMode(0));
		WorkingTreeIterator itr = walk.getTree(0, WorkingTreeIterator.class);
		assertNotNull("has tree", itr);

		AttributesNode attributesNode = itr.getEntryAttributesNode();
		assertAttributesNode(walk, pathName, attributesNode, nodeAttrs);
		if (D.equals(type))
			walk.enterSubtree();

	}

	private void assertAttributesNode(TreeWalk walk, String pathName,
			AttributesNode attributesNode, List<Attribute> nodeAttrs)
					throws IOException {
		if (attributesNode == null)
			assertTrue(nodeAttrs == null || nodeAttrs.isEmpty());
		else {

			Attributes entryAttributes = new Attributes();
			new AttributesHandler(walk,
					() -> walk.getTree(CanonicalTreeParser.class))
							.mergeAttributes(attributesNode, pathName, false,
									entryAttributes);

			if (nodeAttrs != null && !nodeAttrs.isEmpty()) {
				for (Attribute attribute : nodeAttrs) {
					assertThat(entryAttributes.getAll(),
							hasItem(attribute));
				}
			} else {
				assertTrue(
						"The entry "
								+ pathName
								+ " should not have any attributes. Instead, the following attributes are applied to this file "
								+ entryAttributes.toString(),
						entryAttributes.isEmpty());
			}
		}
	}

	private void writeAttributesFile(String name, String... rules)
			throws IOException {
		StringBuilder data = new StringBuilder();
		for (String line : rules)
			data.append(line + "\n");
		writeTrashFile(name, data.toString());
	}

	private TreeWalk beginWalk() {
		TreeWalk newWalk = new TreeWalk(db);
		newWalk.addTree(new FileTreeIterator(db));
		return newWalk;
	}
}