// Copyright (C) 2013 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.acceptance;

import static com.google.common.truth.Truth.assertThat;
import static com.google.gerrit.acceptance.GitUtil.pushHead;

import com.google.common.base.Function;
import com.google.common.base.Strings;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.ApprovalsUtil;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Provider;
import com.google.inject.assistedinject.Assisted;
import com.google.inject.assistedinject.AssistedInject;

import org.eclipse.jgit.api.TagCommand;
import org.eclipse.jgit.junit.TestRepository;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.transport.PushResult;
import org.eclipse.jgit.transport.RemoteRefUpdate;
import org.eclipse.jgit.transport.RemoteRefUpdate.Status;

import java.util.Arrays;
import java.util.Set;

public class PushOneCommit {
  public static final String SUBJECT = "test commit";
  public static final String FILE_NAME = "a.txt";
  public static final String FILE_CONTENT = "some content";

  public interface Factory {
    PushOneCommit create(
        ReviewDb db,
        PersonIdent i,
        TestRepository<?> testRepo);

    PushOneCommit create(
        ReviewDb db,
        PersonIdent i,
        TestRepository<?> testRepo,
        @Assisted("subject") String subject,
        @Assisted("fileName") String fileName,
        @Assisted("content") String content);

    PushOneCommit create(
        ReviewDb db,
        PersonIdent i,
        TestRepository<?> testRepo,
        @Assisted("subject") String subject,
        @Assisted("fileName") String fileName,
        @Assisted("content") String content,
        @Assisted("changeId") String changeId);
  }

  public static class Tag {
    public String name;

    public Tag(String name) {
      this.name = name;
    }
  }

  public static class AnnotatedTag extends Tag {
    public String message;
    public PersonIdent tagger;

    public AnnotatedTag(String name, String message, PersonIdent tagger) {
      super(name);
      this.message = message;
      this.tagger = tagger;
    }
  }

  private final ChangeNotes.Factory notesFactory;
  private final ApprovalsUtil approvalsUtil;
  private final Provider<InternalChangeQuery> queryProvider;
  private final ReviewDb db;
  private final TestRepository<?> testRepo;

  private final String subject;
  private final String fileName;
  private final String content;
  private String changeId;
  private Tag tag;
  private boolean force;

  private final TestRepository<?>.CommitBuilder commitBuilder;

  @AssistedInject
  PushOneCommit(ChangeNotes.Factory notesFactory,
      ApprovalsUtil approvalsUtil,
      Provider<InternalChangeQuery> queryProvider,
      @Assisted ReviewDb db,
      @Assisted PersonIdent i,
      @Assisted TestRepository<?> testRepo) throws Exception {
    this(notesFactory, approvalsUtil, queryProvider,
        db, i, testRepo, SUBJECT, FILE_NAME, FILE_CONTENT);
  }

  @AssistedInject
  PushOneCommit(ChangeNotes.Factory notesFactory,
      ApprovalsUtil approvalsUtil,
      Provider<InternalChangeQuery> queryProvider,
      @Assisted ReviewDb db,
      @Assisted PersonIdent i,
      @Assisted TestRepository<?> testRepo,
      @Assisted("subject") String subject,
      @Assisted("fileName") String fileName,
      @Assisted("content") String content) throws Exception {
    this(notesFactory, approvalsUtil, queryProvider,
        db, i, testRepo, subject, fileName, content, null);
  }

  @AssistedInject
  PushOneCommit(ChangeNotes.Factory notesFactory,
      ApprovalsUtil approvalsUtil,
      Provider<InternalChangeQuery> queryProvider,
      @Assisted ReviewDb db,
      @Assisted PersonIdent i,
      @Assisted TestRepository<?> testRepo,
      @Assisted("subject") String subject,
      @Assisted("fileName") String fileName,
      @Assisted("content") String content,
      @Nullable @Assisted("changeId") String changeId) throws Exception {
    this.db = db;
    this.testRepo = testRepo;
    this.notesFactory = notesFactory;
    this.approvalsUtil = approvalsUtil;
    this.queryProvider = queryProvider;
    this.subject = subject;
    this.fileName = fileName;
    this.content = content;
    this.changeId = changeId;
    if (changeId != null) {
      commitBuilder = testRepo.amendRef("HEAD")
          .insertChangeId(changeId.substring(1));
    } else {
      commitBuilder = testRepo.branch("HEAD").commit().insertChangeId();
    }
    commitBuilder.message(subject).ident(i);
  }

  public Result to(String ref) throws Exception {
    commitBuilder.add(fileName, content);
    return execute(ref);
  }

  public Result rm(String ref) throws Exception {
    commitBuilder.rm(fileName);
    return execute(ref);
  }

  private Result execute(String ref) throws Exception {
    RevCommit c = commitBuilder.create();
    if (changeId == null) {
      changeId = GitUtil.getChangeId(testRepo, c).get();
    }
    if (tag != null) {
      TagCommand tagCommand = testRepo.git().tag().setName(tag.name);
      if (tag instanceof AnnotatedTag) {
        AnnotatedTag annotatedTag = (AnnotatedTag)tag;
        tagCommand.setAnnotated(true)
          .setMessage(annotatedTag.message)
          .setTagger(annotatedTag.tagger);
      } else {
        tagCommand.setAnnotated(false);
      }
      tagCommand.call();
    }
    return new Result(ref, pushHead(testRepo, ref, tag != null, force), c,
        subject);
  }

  public void setTag(final Tag tag) {
    this.tag = tag;
  }

  public void setForce(boolean force) {
    this.force = force;
  }

  public class Result {
    private final String ref;
    private final PushResult result;
    private final RevCommit commit;
    private final String resSubj;

    private Result(String ref, PushResult resSubj, RevCommit commit,
        String subject) {
      this.ref = ref;
      this.result = resSubj;
      this.commit = commit;
      this.resSubj = subject;
    }

    public ChangeData getChange() throws OrmException {
      return Iterables.getOnlyElement(
          queryProvider.get().byKeyPrefix(changeId));
    }

    public PatchSet getPatchSet() throws OrmException {
      return getChange().currentPatchSet();
    }

    public PatchSet.Id getPatchSetId() throws OrmException {
      return getChange().change().currentPatchSetId();
    }

    public String getChangeId() {
      return changeId;
    }

    public ObjectId getCommitId() {
      return commit;
    }

    public RevCommit getCommit() {
      return commit;
    }

    public void assertChange(Change.Status expectedStatus,
        String expectedTopic, TestAccount... expectedReviewers)
        throws OrmException {
      Change c = getChange().change();
      assertThat(resSubj).isEqualTo(c.getSubject());
      assertThat(expectedStatus).isEqualTo(c.getStatus());
      assertThat(expectedTopic).isEqualTo(Strings.emptyToNull(c.getTopic()));
      assertReviewers(c, expectedReviewers);
    }

    private void assertReviewers(Change c, TestAccount... expectedReviewers)
        throws OrmException {
      Set<Account.Id> expectedReviewerIds =
          Sets.newHashSet(Lists.transform(Arrays.asList(expectedReviewers),
              new Function<TestAccount, Account.Id>() {
                @Override
                public Account.Id apply(TestAccount a) {
                  return a.id;
                }
              }));

      for (Account.Id accountId
          : approvalsUtil.getReviewers(db, notesFactory.create(c)).values()) {
        assertThat(expectedReviewerIds.remove(accountId))
          .named("unexpected reviewer " + accountId)
          .isTrue();
      }
      assertThat((Iterable<?>)expectedReviewerIds)
        .named("missing reviewers: " + expectedReviewerIds)
        .isEmpty();
    }

    public void assertOkStatus() {
      assertStatus(Status.OK, null);
    }

    public void assertErrorStatus(String expectedMessage) {
      assertStatus(Status.REJECTED_OTHER_REASON, expectedMessage);
    }

    private void assertStatus(Status expectedStatus, String expectedMessage) {
      RemoteRefUpdate refUpdate = result.getRemoteUpdate(ref);
      assertThat(expectedStatus)
        .named(message(refUpdate))
        .isEqualTo(refUpdate.getStatus());
      assertThat(expectedMessage).isEqualTo(refUpdate.getMessage());
    }

    public void assertMessage(String expectedMessage) {
      RemoteRefUpdate refUpdate = result.getRemoteUpdate(ref);
      assertThat(message(refUpdate).toLowerCase())
        .named(message(refUpdate))
        .contains(expectedMessage.toLowerCase());
    }

    private String message(RemoteRefUpdate refUpdate) {
      StringBuilder b = new StringBuilder();
      if (refUpdate.getMessage() != null) {
        b.append(refUpdate.getMessage());
        b.append("\n");
      }
      b.append(result.getMessages());
      return b.toString();
    }
  }
}