/*
 * SonarQube
 * Copyright (C) 2009-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.db.measure;

import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import java.util.Collection;
import java.util.List;
import java.util.Optional;
import org.apache.ibatis.session.ResultHandler;
import org.sonar.db.Dao;
import org.sonar.db.DbSession;
import org.sonar.db.component.ComponentDto;

import static java.util.Collections.emptyList;
import static org.sonar.db.DatabaseUtils.executeLargeInputs;

public class MeasureDao implements Dao {

  public Optional<MeasureDto> selectSingle(DbSession dbSession, MeasureQuery query) {
    List<MeasureDto> measures = selectByQuery(dbSession, query);
    return Optional.ofNullable(Iterables.getOnlyElement(measures, null));
  }

  /**
   * Selects the measures of either the last analysis (when {@link MeasureQuery#analysisUuid} is {@code null}) or of the
   * specified analysis (given by {@link MeasureQuery#analysisUuid}).
   * The components can be specified either as :
   * - A list of projects in {@link MeasureQuery#projectUuids}
   * - A list of components in {@link MeasureQuery#componentUuids} with one mandatory project in {@link MeasureQuery#projectUuids}
   * - One single component in  {@link MeasureQuery#componentUuids}
   * <p>
   * In addition, this method returns measures which are not associated to any developer, unless one is specified in
   * {@link MeasureQuery#personId}.
   * </p>
   * <p>
   * Returned measure can optionally be filtered metric (either by specifying {@link MeasureQuery#metricIds}
   * or {@link MeasureQuery#metricKeys}).
   * </p>
   */
  public List<MeasureDto> selectByQuery(DbSession dbSession, MeasureQuery query) {
    if (query.returnsEmpty()) {
      return emptyList();
    }
    if (query.isOnComponents()) {
      return executeLargeInputs(
        query.getComponentUuids(),
        componentUuids -> {
          MeasureQuery pageQuery = MeasureQuery.copyWithSubsetOfComponentUuids(query, componentUuids);
          return mapper(dbSession).selectByQueryOnComponents(pageQuery);
        });
    }
    if (query.isOnProjects()) {
      return executeLargeInputs(
        query.getProjectUuids(),
        projectUuids -> {
          MeasureQuery pageQuery = MeasureQuery.copyWithSubsetOfProjectUuids(query, projectUuids);
          return mapper(dbSession).selectByQueryOnProjects(pageQuery);
        });
    }
    return mapper(dbSession).selectByQueryOnSingleComponent(query);
  }

  public void selectTreeByQuery(DbSession dbSession, ComponentDto baseComponent, MeasureTreeQuery query, ResultHandler resultHandler) {
    if (query.returnsEmpty()) {
      return;
    }
    mapper(dbSession).selectTreeByQuery(query, baseComponent.uuid(), query.getUuidPath(baseComponent), resultHandler);
  }

  public List<PastMeasureDto> selectPastMeasures(DbSession dbSession, String componentUuid, String analysisUuid, Collection<Integer> metricIds) {
    if (metricIds.isEmpty()) {
      return emptyList();
    }
    return executeLargeInputs(
      metricIds,
      ids -> mapper(dbSession).selectPastMeasuresOnSingleAnalysis(componentUuid, analysisUuid, ids));
  }

  /**
   * Select measures of:
   * - one component
   * - for a list of metrics
   * - with analysis from a date (inclusive) - optional
   * - with analysis to a date (exclusive) - optional
   *
   * If no constraints on dates, all the history is returned
   */
  public List<MeasureDto> selectPastMeasures(DbSession dbSession, PastMeasureQuery query) {
    return mapper(dbSession).selectPastMeasuresOnSeveralAnalyses(query);
  }

  /**
   * Used by developer cockpit.
   */
  public List<MeasureDto> selectProjectMeasuresOfDeveloper(DbSession dbSession, long developerId, Collection<Integer> metricIds) {
    return executeLargeInputs(
      metricIds,
      ids -> mapper(dbSession).selectProjectMeasuresOfDeveloper(developerId, metricIds));
  }

  public List<MeasureDto> selectByComponentsAndMetrics(DbSession dbSession, List<String> componentUuids, List<Integer> metricIds) {
    return executeLargeInputs(componentUuids, partitionComponentUuids -> mapper(dbSession).selectByComponentsAndMetrics(partitionComponentUuids, metricIds));
  }

  public void insert(DbSession session, MeasureDto measureDto) {
    mapper(session).insert(measureDto);
  }

  public void insert(DbSession session, Collection<MeasureDto> items) {
    for (MeasureDto item : items) {
      insert(session, item);
    }
  }

  public void insert(DbSession session, MeasureDto item, MeasureDto... others) {
    insert(session, Lists.asList(item, others));
  }

  private static MeasureMapper mapper(DbSession session) {
    return session.getMapper(MeasureMapper.class);
  }
}