// Copyright (C) 2014 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.server.change;

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

import com.google.gerrit.acceptance.AbstractDaemonTest;
import com.google.gerrit.acceptance.NoHttpd;
import com.google.gerrit.extensions.client.DiffPreferencesInfo.Whitespace;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.reviewdb.client.Patch;
import com.google.gerrit.reviewdb.client.Patch.ChangeType;
import com.google.gerrit.server.patch.PatchListCache;
import com.google.gerrit.server.patch.PatchListEntry;
import com.google.gerrit.server.patch.PatchListKey;
import com.google.gerrit.server.patch.PatchListNotAvailableException;
import com.google.inject.Inject;

import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.revwalk.RevCommit;
import org.junit.Test;

import java.util.List;

@NoHttpd
public class PatchListCacheIT extends AbstractDaemonTest {
  private static String SUBJECT_1 = "subject 1";
  private static String SUBJECT_2 = "subject 2";
  private static String SUBJECT_3 = "subject 3";
  private static String FILE_A = "a.txt";
  private static String FILE_B = "b.txt";
  private static String FILE_C = "c.txt";
  private static String FILE_D = "d.txt";

  @Inject
  private PatchListCache patchListCache;

  @Test
  public void listPatchesAgainstBase() throws Exception {
    commitBuilder()
        .add(FILE_D, "4")
        .message(SUBJECT_1)
        .create();
    pushHead(testRepo, "refs/heads/master", false);

    // Change 1, 1 (+FILE_A, -FILE_D)
    RevCommit c = commitBuilder()
        .add(FILE_A, "1")
        .rm(FILE_D)
        .message(SUBJECT_2)
        .insertChangeId()
        .create();
    String id = getChangeId(testRepo, c).get();
    pushHead(testRepo, "refs/for/master", false);

    // Compare Change 1,1 with Base (+FILE_A, -FILE_D)
    List<PatchListEntry> entries = getCurrentPatches(id);
    assertThat(entries).hasSize(3);
    assertAdded(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_A, entries.get(1));
    assertDeleted(FILE_D, entries.get(2));

    // Change 1,2 (+FILE_A, +FILE_B, -FILE_D)
    c = amendBuilder()
        .add(FILE_B, "2")
        .create();
    pushHead(testRepo, "refs/for/master", false);
    entries = getCurrentPatches(id);

    // Compare Change 1,2 with Base (+FILE_A, +FILE_B, -FILE_D)
    assertThat(entries).hasSize(4);
    assertAdded(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_A, entries.get(1));
    assertAdded(FILE_B, entries.get(2));
    assertDeleted(FILE_D, entries.get(3));
  }

  @Test
  public void listPatchesAgainstBaseWithRebase() throws Exception {
    commitBuilder()
        .add(FILE_D, "4")
        .message(SUBJECT_1)
        .create();
    pushHead(testRepo, "refs/heads/master", false);

    // Change 1,1 (+FILE_A, -FILE_D)
    RevCommit c = commitBuilder()
        .add(FILE_A, "1")
        .rm(FILE_D)
        .message(SUBJECT_2)
        .create();
    String id = getChangeId(testRepo, c).get();
    pushHead(testRepo, "refs/for/master", false);
    List<PatchListEntry> entries = getCurrentPatches(id);
    assertThat(entries).hasSize(3);
    assertAdded(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_A, entries.get(1));
    assertDeleted(FILE_D, entries.get(2));

    // Change 2,1 (+FILE_B)
    testRepo.reset("HEAD~1");
    commitBuilder()
        .add(FILE_B, "2")
        .message(SUBJECT_3)
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Change 1,2 (+FILE_A, -FILE_D))
    testRepo.cherryPick(c);
    pushHead(testRepo, "refs/for/master", false);

    // Compare Change 1,2 with Base (+FILE_A, -FILE_D))
    entries = getCurrentPatches(id);
    assertThat(entries).hasSize(3);
    assertAdded(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_A, entries.get(1));
    assertDeleted(FILE_D, entries.get(2));
  }

  @Test
  public void listPatchesAgainstOtherPatchSet() throws Exception {
    commitBuilder()
        .add(FILE_D, "4")
        .message(SUBJECT_1)
        .create();
    pushHead(testRepo, "refs/heads/master", false);

    // Change 1,1 (+FILE_A, +FILE_C, -FILE_D)
    RevCommit a = commitBuilder()
        .add(FILE_A, "1")
        .add(FILE_C, "3")
        .rm(FILE_D)
        .message(SUBJECT_2)
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Change 1,2 (+FILE_A, +FILE_B, -FILE_D)
    RevCommit b = amendBuilder()
        .add(FILE_B, "2")
        .rm(FILE_C)
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Compare Change 1,1 with Change 1,2 (+FILE_B, -FILE_C)
    List<PatchListEntry>  entries = getPatches(a, b);
    assertThat(entries).hasSize(3);
    assertModified(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_B, entries.get(1));
    assertDeleted(FILE_C, entries.get(2));

    // Compare Change 1,2 with Change 1,1 (-FILE_B, +FILE_C)
    List<PatchListEntry>  entriesReverse = getPatches(b, a);
    assertThat(entriesReverse).hasSize(3);
    assertModified(Patch.COMMIT_MSG, entriesReverse.get(0));
    assertDeleted(FILE_B, entriesReverse.get(1));
    assertAdded(FILE_C, entriesReverse.get(2));
  }

  @Test
  public void listPatchesAgainstOtherPatchSetWithRebase() throws Exception {
    commitBuilder()
        .add(FILE_D, "4")
        .message(SUBJECT_1)
        .create();
    pushHead(testRepo, "refs/heads/master", false);

    // Change 1,1 (+FILE_A, -FILE_D)
    RevCommit a = commitBuilder()
        .add(FILE_A, "1")
        .rm(FILE_D)
        .message(SUBJECT_2)
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Change 2,1 (+FILE_B)
    testRepo.reset("HEAD~1");
    commitBuilder()
        .add(FILE_B, "2")
        .message(SUBJECT_3)
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Change 1,2 (+FILE_A, +FILE_C, -FILE_D)
    testRepo.cherryPick(a);
    RevCommit b = amendBuilder()
        .add(FILE_C, "2")
        .create();
    pushHead(testRepo, "refs/for/master", false);

    // Compare Change 1,1 with Change 1,2 (+FILE_C)
    List<PatchListEntry>  entries = getPatches(a, b);
    assertThat(entries).hasSize(2);
    assertModified(Patch.COMMIT_MSG, entries.get(0));
    assertAdded(FILE_C, entries.get(1));

    // Compare Change 1,2 with Change 1,1 (-FILE_C)
    List<PatchListEntry>  entriesReverse = getPatches(b, a);
    assertThat(entriesReverse).hasSize(2);
    assertModified(Patch.COMMIT_MSG, entriesReverse.get(0));
    assertDeleted(FILE_C, entriesReverse.get(1));
  }

  private static void assertAdded(String expectedNewName, PatchListEntry e) {
    assertName(expectedNewName, e);
    assertThat(e.getChangeType()).isEqualTo(ChangeType.ADDED);
  }

  private static void assertModified(String expectedNewName, PatchListEntry e) {
    assertName(expectedNewName, e);
    assertThat(e.getChangeType()).isEqualTo(ChangeType.MODIFIED);
  }

  private static void assertDeleted(String expectedNewName, PatchListEntry e) {
    assertName(expectedNewName, e);
    assertThat(e.getChangeType()).isEqualTo(ChangeType.DELETED);
  }

  private static void assertName(String expectedNewName, PatchListEntry e) {
    assertThat(e.getNewName()).isEqualTo(expectedNewName);
    assertThat(e.getOldName()).isNull();
  }

  private List<PatchListEntry> getCurrentPatches(String changeId)
      throws PatchListNotAvailableException, RestApiException {
    return patchListCache
        .get(getKey(null, getCurrentRevisionId(changeId)), project)
        .getPatches();
  }

  private List<PatchListEntry> getPatches(ObjectId revisionIdA, ObjectId revisionIdB)
      throws PatchListNotAvailableException {
    return patchListCache.get(getKey(revisionIdA, revisionIdB), project)
        .getPatches();
  }

  private PatchListKey getKey(ObjectId revisionIdA, ObjectId revisionIdB) {
    return new PatchListKey(revisionIdA, revisionIdB, Whitespace.IGNORE_NONE);
  }

  private ObjectId getCurrentRevisionId(String changeId) throws RestApiException {
    return ObjectId.fromString(gApi.changes().id(changeId).get().currentRevision);
  }
}