/*
    * Copyright (C) 2021, 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.lfs;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  
  import java.io.File;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.api.ResetCommand.ResetType;
  import org.eclipse.jgit.attributes.FilterCommandRegistry;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lfs.lib.Constants;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.junit.AfterClass;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  public class LfsGitTest extends RepositoryTestCase {
  
  	private static final String SMUDGE_NAME = org.eclipse.jgit.lib.Constants.BUILTIN_FILTER_PREFIX
  			+ Constants.ATTR_FILTER_DRIVER_PREFIX
  			+ org.eclipse.jgit.lib.Constants.ATTR_FILTER_TYPE_SMUDGE;
  
  	private static final String CLEAN_NAME = org.eclipse.jgit.lib.Constants.BUILTIN_FILTER_PREFIX
  			+ Constants.ATTR_FILTER_DRIVER_PREFIX
  			+ org.eclipse.jgit.lib.Constants.ATTR_FILTER_TYPE_CLEAN;
  
  	@BeforeClass
  	public static void installLfs() {
  		FilterCommandRegistry.register(SMUDGE_NAME, SmudgeFilter.FACTORY);
  		FilterCommandRegistry.register(CLEAN_NAME, CleanFilter.FACTORY);
  	}
  
  	@AfterClass
  	public static void removeLfs() {
  		FilterCommandRegistry.unregister(SMUDGE_NAME);
  		FilterCommandRegistry.unregister(CLEAN_NAME);
  	}
  
  	private Git git;
  
  	@Override
  	@Before
  	public void setUp() throws Exception {
  		super.setUp();
  		git = new Git(db);
  		// commit something
  		writeTrashFile("Test.txt", "Hello world");
  		git.add().addFilepattern("Test.txt").call();
  		git.commit().setMessage("Initial commit").call();
  		// prepare the config for LFS
  		StoredConfig config = git.getRepository().getConfig();
  		config.setString("filter", "lfs", "clean", CLEAN_NAME);
  		config.setString("filter", "lfs", "smudge", SMUDGE_NAME);
  		config.save();
  	}
  
  	@Test
  	public void checkoutNonLfsPointer() throws Exception {
  		String content = "size_t\nsome_function(void* ptr);\n";
  		File smallFile = writeTrashFile("Test.txt", content);
  		StringBuilder largeContent = new StringBuilder(
  				LfsPointer.SIZE_THRESHOLD * 4);
  		while (largeContent.length() < LfsPointer.SIZE_THRESHOLD * 4) {
  			largeContent.append(content);
  		}
  		File largeFile = writeTrashFile("large.txt", largeContent.toString());
  		fsTick(largeFile);
  		git.add().addFilepattern("Test.txt").addFilepattern("large.txt").call();
  		git.commit().setMessage("Text files").call();
  		writeTrashFile(".gitattributes", "*.txt filter=lfs");
  		git.add().addFilepattern(".gitattributes").call();
  		git.commit().setMessage("attributes").call();
  		assertTrue(smallFile.delete());
  		assertTrue(largeFile.delete());
  		// This reset will run the two text files through the smudge filter
  		git.reset().setMode(ResetType.HARD).call();
  		assertTrue(smallFile.exists());
  		assertTrue(largeFile.exists());
  		checkFile(smallFile, content);
  		checkFile(largeFile, largeContent.toString());
  		// Modify the large file
  		largeContent.append(content);
  		writeTrashFile("large.txt", largeContent.toString());
  		// This should convert largeFile to an LFS pointer
  		git.add().addFilepattern("large.txt").call();
  		git.commit().setMessage("Large modified").call();
 		String lfsPtr = "version https://git-lfs.github.com/spec/v1\n"
 				+ "oid sha256:d041ab19bd7edd899b3c0450d0f61819f96672f0b22d26c9753abc62e1261614\n"
 				+ "size 858\n";
 		assertEquals("[.gitattributes, mode:100644, content:*.txt filter=lfs]"
 				+ "[Test.txt, mode:100644, content:" + content + ']'
 						+ "[large.txt, mode:100644, content:" + lfsPtr + ']',
 				indexState(CONTENT));
 		// Verify the file has been saved
 		File savedFile = new File(db.getDirectory(), "lfs");
 		savedFile = new File(savedFile, "objects");
 		savedFile = new File(savedFile, "d0");
 		savedFile = new File(savedFile, "41");
 		savedFile = new File(savedFile,
 				"d041ab19bd7edd899b3c0450d0f61819f96672f0b22d26c9753abc62e1261614");
 		String saved = new String(Files.readAllBytes(savedFile.toPath()),
 				StandardCharsets.UTF_8);
 		assertEquals(saved, largeContent.toString());
 
 		assertTrue(smallFile.delete());
 		assertTrue(largeFile.delete());
 		git.reset().setMode(ResetType.HARD).call();
 		assertTrue(smallFile.exists());
 		assertTrue(largeFile.exists());
 		checkFile(smallFile, content);
 		checkFile(largeFile, largeContent.toString());
 		assertEquals("[.gitattributes, mode:100644, content:*.txt filter=lfs]"
 				+ "[Test.txt, mode:100644, content:" + content + ']'
 						+ "[large.txt, mode:100644, content:" + lfsPtr + ']',
 				indexState(CONTENT));
 		git.add().addFilepattern("Test.txt").call();
 		git.commit().setMessage("Small committed again").call();
 		String lfsPtrSmall = "version https://git-lfs.github.com/spec/v1\n"
 				+ "oid sha256:9110463275fb0e2f0e9fdeaf84e598e62915666161145cf08927079119cc7814\n"
 				+ "size 33\n";
 		assertEquals("[.gitattributes, mode:100644, content:*.txt filter=lfs]"
 				+ "[Test.txt, mode:100644, content:" + lfsPtrSmall + ']'
 						+ "[large.txt, mode:100644, content:" + lfsPtr + ']',
 				indexState(CONTENT));
 
 		assertTrue(git.status().call().isClean());
 	}
 }