/*
    * Copyright (C) 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.internal.storage.file;
  
  import java.io.IOException;
  
  import org.eclipse.jgit.internal.storage.file.GC.RepoStatistics;
  import org.eclipse.jgit.junit.LocalDiskRepositoryTestCase;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.junit.TestRepository;
  import org.eclipse.jgit.junit.TestRepository.CommitBuilder;
  import org.eclipse.jgit.lib.AnyObjectId;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.junit.After;
  import org.junit.Before;
  
  public abstract class GcTestCase extends LocalDiskRepositoryTestCase {
  	protected TestRepository<FileRepository> tr;
  	protected FileRepository repo;
  	protected GC gc;
  	protected RepoStatistics stats;
  
  	@Override
  	@Before
  	public void setUp() throws Exception {
  		super.setUp();
  		repo = createWorkRepository();
  		tr = new TestRepository<>(repo, new RevWalk(repo),
  				mockSystemReader);
  		gc = new GC(repo);
  	}
  
  	@Override
  	@After
  	public void tearDown() throws Exception {
  		super.tearDown();
  	}
  
  	/**
  	 * Create a chain of commits of given depth.
  	 * <p>
  	 * Each commit contains one file named "a" containing the index of the
  	 * commit in the chain as its content. The created commit chain is
  	 * referenced from any ref.
  	 * <p>
  	 * A chain of depth = N will create 3*N objects in Gits object database. For
  	 * each depth level three objects are created: the commit object, the
  	 * top-level tree object and a blob for the content of the file "a".
  	 *
  	 * @param depth
  	 *            the depth of the commit chain.
  	 * @return the commit that is the tip of the commit chain
  	 * @throws Exception
  	 */
  	protected RevCommit commitChain(int depth) throws Exception {
  		if (depth <= 0)
  			throw new IllegalArgumentException("Chain depth must be > 0");
  		CommitBuilder cb = tr.commit();
  		RevCommit tip;
  		do {
  			--depth;
  			tip = cb.add("a", "" + depth).message("" + depth).create();
  			cb = cb.child();
  		} while (depth > 0);
  		return tip;
  	}
  
  	/**
  	 * Create a chain of commits of given depth with given number of added files
  	 * per commit.
  	 * <p>
  	 * Each commit contains {@code files} files as its content. The created
  	 * commit chain is referenced from any ref.
  	 * <p>
  	 * A chain will create {@code (2 + files) * depth} objects in Gits object
  	 * database. For each depth level the following objects are created: the
  	 * commit object, the top-level tree object and @code files} blobs for the
  	 * content of the file "a".
  	 *
  	 * @param depth
  	 *            the depth of the commit chain.
  	 * @param width
  	 *            number of files added per commit
  	 * @return the commit that is the tip of the commit chain
  	 * @throws Exception
  	 */
  	protected RevCommit commitChain(int depth, int width) throws Exception {
  		if (depth <= 0) {
  			throw new IllegalArgumentException("Chain depth must be > 0");
  		}
 		if (width <= 0) {
 			throw new IllegalArgumentException("Number of files per commit must be > 0");
 		}
 		CommitBuilder cb = tr.commit();
 		RevCommit tip = null;
 		do {
 			--depth;
 			for (int i=0; i < width; i++) {
 				String id = depth + "-" + i;
 				cb.add("a" + id, id).message(id);
 			}
 			tip = cb.create();
 			cb = cb.child();
 		} while (depth > 0);
 		return tip;
 	}
 
 	protected long lastModified(AnyObjectId objectId) {
 		return repo.getFS()
 				.lastModifiedInstant(repo.getObjectDatabase().fileFor(objectId))
 				.toEpochMilli();
 	}
 
 	protected static void fsTick() throws InterruptedException, IOException {
 		RepositoryTestCase.fsTick(null);
 	}
 }