/*
    * Copyright (C) 2010-2012 Christian Halstrick <christian.halstrick@sap.com> 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.lib;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.Collections;
  
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.junit.Test;
  
  public class MergeHeadMsgTest extends RepositoryTestCase {
  	private static final String mergeMsg = "merge a and b";
  
  	private static final String sampleId = "1c6db447abdbb291b25f07be38ea0b1bf94947c5";
  
  	@Test
  	public void testReadWriteMergeHeads() throws IOException {
  		assertEquals(db.readMergeHeads(), null);
  		db.writeMergeHeads(Arrays.asList(ObjectId.zeroId(),
  				ObjectId.fromString(sampleId)));
  		assertEquals(read(new File(db.getDirectory(), "MERGE_HEAD")), "0000000000000000000000000000000000000000\n1c6db447abdbb291b25f07be38ea0b1bf94947c5\n");
  		assertEquals(db.readMergeHeads().size(), 2);
  		assertEquals(db.readMergeHeads().get(0), ObjectId.zeroId());
  		assertEquals(db.readMergeHeads().get(1), ObjectId.fromString(sampleId));
  
  		// same test again, this time with lower-level io
  		try (FileOutputStream fos = new FileOutputStream(
  				new File(db.getDirectory(), "MERGE_HEAD"));) {
  			fos.write(
  					"0000000000000000000000000000000000000000\n1c6db447abdbb291b25f07be38ea0b1bf94947c5\n"
  							.getBytes(UTF_8));
  		}
  		assertEquals(db.readMergeHeads().size(), 2);
  		assertEquals(db.readMergeHeads().get(0), ObjectId.zeroId());
  		assertEquals(db.readMergeHeads().get(1), ObjectId.fromString(sampleId));
  		db.writeMergeHeads(Collections.<ObjectId> emptyList());
  		assertEquals(read(new File(db.getDirectory(), "MERGE_HEAD")), "");
  		assertEquals(db.readMergeHeads(), null);
  		try (FileOutputStream fos = new FileOutputStream(
  				new File(db.getDirectory(), "MERGE_HEAD"))) {
  			fos.write(sampleId.getBytes(UTF_8));
  		}
  		assertEquals(db.readMergeHeads().size(), 1);
  		assertEquals(db.readMergeHeads().get(0), ObjectId.fromString(sampleId));
  	}
  
  	@Test
  	public void testReadWriteMergeMsg() throws IOException {
  		assertEquals(db.readMergeCommitMsg(), null);
  		assertFalse(new File(db.getDirectory(), "MERGE_MSG").exists());
  		db.writeMergeCommitMsg(mergeMsg);
  		assertEquals(db.readMergeCommitMsg(), mergeMsg);
  		assertEquals(read(new File(db.getDirectory(), "MERGE_MSG")), mergeMsg);
  		db.writeMergeCommitMsg(null);
  		assertEquals(db.readMergeCommitMsg(), null);
  		assertFalse(new File(db.getDirectory(), "MERGE_MSG").exists());
  		try (FileOutputStream fos = new FileOutputStream(
  				new File(db.getDirectory(), Constants.MERGE_MSG))) {
  			fos.write(mergeMsg.getBytes(UTF_8));
  		}
  		assertEquals(db.readMergeCommitMsg(), mergeMsg);
  	}
  
  }