// Copyright 2020 Google LLC
//
// 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
//
//     https://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.graphgeckos.dashboard.storage;

import com.google.cloud.datastore.Entity;
import com.google.cloud.datastore.StructuredQuery.OrderBy;
import com.google.cloud.datastore.StructuredQuery.PropertyFilter;
import com.google.cloud.datastore.TimestampValue;
import com.google.cloud.datastore.Query;
import com.google.cloud.Timestamp;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.Date;
import java.util.List;
import org.springframework.boot.SpringApplication;
import org.springframework.cloud.gcp.data.datastore.core.DatastoreTemplate;
import org.springframework.stereotype.Repository;

/**
 * Implementation of the DataRepository, with the purpose of providing I/O to the Google Cloud
 * Datastore. Each individual database entry is modeled by the {@link #BuildInfo BuildInfo} class.
 * The relevant fields for the database, which are described in that class are:
 *    - Kind: "revision"
 *    - Key: commit hash
 * The database indexes after all the BuildInfo fields, besides the {@code builders} list.
 * It is unfeasable to query after the list of builders, since it would not be possible to
 * replicate such a list without querying the database for it first, and the complexity
 * of the indexing and querying would be great, without any apparent value.
 *
 * Useful links:
 * - https://googleapis.dev/java/google-cloud-datastore/latest/index.html
 * - https://googleapis.dev/java/spring-cloud-gcp/1.2.2.RELEASE/index.html
 * - https://cloud.google.com/datastore/docs/concepts/
 * - https://spring.io/projects/spring-cloud-gcp#overview
 */
@Repository
public class GCDataRepository implements DataRepository {
  private DatastoreTemplate storage;

  /**
   * {@inheritDoc}
   */
  public void createRevisionEntry(ParsedGitData entryData) throws IllegalArgumentException {
    if (entryData == null) {
      throw new IllegalArgumentException("entryData cannot be null");
    } else if (!entryData.validCreateData()) {
      throw new IllegalArgumentException("entryData does not contain all necessary fields");
    }

    if (getRevisionEntry(entryData.getCommitHash()) == null) {
      storage.save(new BuildInfo(entryData););
    }
  }

  /**
   * {@inheritDoc}
   */
  public void updateRevisionEntry(ParsedBuildbotData updateData) throws IllegalArgumentException {
    if (updateData == null) {
      throw new IllegalArgumentException("entryData cannot be null");
    } else if (updateData.validUpdateData()) {
      throw new IllegalArgumentException("updateData does not contain all necessary fields");
    }

    BuildInfo associatedEntity = getRevisionEntry(updateData.getCommitHash());

    if (associatedEntity != null) {
      associatedEntity.addBuilder(updateData.toBuilder());

      storage.save(associatedEntity);
    }
  }

  /**
   * {@inheritDoc}
   */
  public void deleteRevisionEntry(String commitHash) throws IllegalArgumentException {
    if (commitHash == null) {
      throw new IllegalArgumentException("commitHash cannot be null");
    }

    BuildInfo toBeDeleted = getRevisionEntry(commitHash);

    if (toBeDeleted != null) {
      storage.delete(toBeDeleted);
    }
  }

  /**
   * {@inheritDoc}
   */
  public Iterable<BuildInfo> getLastRevisionEntries(int number, int offset)
                                                         throws IllegalArgumentException {
    if (number < 0 || offset < 0) {
      throw new IllegalArgumentException("Both number and offset must be >= 0");
    }

    Query<Entity> query = Query.newEntityQueryBuilder()
                               .setKind("revision")
                               .setOrderBy(OrderBy.desc("timestamp"))
                               .setOffset(offset)
                               .setLimit(number)
                               .build();

    Iterable<BuildInfo> results = storage.query(query, BuildInfo.class).getIterable();

    List<BuildInfo> toBeReturned = new ArrayList<BuildInfo>();

    for (BuildInfo entity : results) {
      toBeReturned.add(entity);
    }

    return toBeReturned;
  }

  /**
   * Queries the database for a given entry, that has the Id set to the provided commitHash.
   * Used to separate the usage from the actual Spring Datastore implementation.
   * Returns null when nothing was found.
   */
  private BuildInfo getRevisionEntry(String commitHash) {
    return storage.findById(commitHash, BuildInfo.class);
  }
}

@@ -1154,24 +1154,87 @@
 .util.List;%0A
+import org.springframework.beans.factory.annotation.Autowired;%0A
 import org.s
@@ -2429,16 +2429,29 @@
 itory %7B%0A
+  @Autowired%0A
   privat

add autowired annotation to storage