// Copyright (C) 2008 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.server.git;

import static com.google.common.base.Preconditions.checkArgument;

import com.google.common.collect.Ordering;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.server.git.strategy.CommitMergeStatus;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.project.ChangeControl;
import java.io.IOException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;

/** Extended commit entity with code review specific metadata. */
public class CodeReviewCommit extends RevCommit {
  /**
   * Default ordering when merging multiple topologically-equivalent commits.
   *
   * <p>Operates only on these commits and does not take ancestry into account.
   *
   * <p>Use this in preference to the default order, which comes from {@link AnyObjectId} and only
   * orders on SHA-1.
   */
  public static final Ordering<CodeReviewCommit> ORDER =
      Ordering.natural()
          .onResultOf(
              (CodeReviewCommit c) ->
                  c.getPatchsetId() != null ? c.getPatchsetId().getParentKey().get() : null)
          .nullsFirst();

  public static CodeReviewRevWalk newRevWalk(Repository repo) {
    return new CodeReviewRevWalk(repo);
  }

  public static CodeReviewRevWalk newRevWalk(ObjectReader reader) {
    return new CodeReviewRevWalk(reader);
  }

  public static class CodeReviewRevWalk extends RevWalk {
    private CodeReviewRevWalk(Repository repo) {
      super(repo);
    }

    private CodeReviewRevWalk(ObjectReader reader) {
      super(reader);
    }

    @Override
    protected CodeReviewCommit createCommit(AnyObjectId id) {
      return new CodeReviewCommit(id);
    }

    @Override
    public CodeReviewCommit next()
        throws MissingObjectException, IncorrectObjectTypeException, IOException {
      return (CodeReviewCommit) super.next();
    }

    @Override
    public void markStart(RevCommit c)
        throws MissingObjectException, IncorrectObjectTypeException, IOException {
      checkArgument(c instanceof CodeReviewCommit);
      super.markStart(c);
    }

    @Override
    public void markUninteresting(final RevCommit c)
        throws MissingObjectException, IncorrectObjectTypeException, IOException {
      checkArgument(c instanceof CodeReviewCommit);
      super.markUninteresting(c);
    }

    @Override
    public CodeReviewCommit lookupCommit(AnyObjectId id) {
      return (CodeReviewCommit) super.lookupCommit(id);
    }

    @Override
    public CodeReviewCommit parseCommit(AnyObjectId id)
        throws MissingObjectException, IncorrectObjectTypeException, IOException {
      return (CodeReviewCommit) super.parseCommit(id);
    }
  }

  /**
   * Unique key of the PatchSet entity from the code review system.
   *
   * <p>This value is only available on commits that have a PatchSet represented in the code review
   * system.
   */
  private PatchSet.Id patchsetId;

  /** Change control for the change owner. */
  private ChangeControl control;

  /**
   * The result status for this commit.
   *
   * <p>Only valid if {@link #patchsetId} is not null.
   */
  private CommitMergeStatus statusCode;

  public CodeReviewCommit(final AnyObjectId id) {
    super(id);
  }

  public ChangeNotes notes() {
    return getControl().getNotes();
  }

  public CommitMergeStatus getStatusCode() {
    return statusCode;
  }

  public void setStatusCode(CommitMergeStatus statusCode) {
    this.statusCode = statusCode;
  }

  public PatchSet.Id getPatchsetId() {
    return patchsetId;
  }

  public void setPatchsetId(PatchSet.Id patchsetId) {
    this.patchsetId = patchsetId;
  }

  public void copyFrom(final CodeReviewCommit src) {
    control = src.control;
    patchsetId = src.patchsetId;
    statusCode = src.statusCode;
  }

  public Change change() {
    return getControl().getChange();
  }

  public ChangeControl getControl() {
    return control;
  }

  public void setControl(ChangeControl control) {
    this.control = control;
  }
}