/*
 * Copyright 2000-2018 JetBrains s.r.o.
 *
 * 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 jetbrains.buildServer.usageStatistics.impl;

import com.intellij.openapi.diagnostic.Logger;
import java.io.File;
import java.io.IOException;
import jetbrains.buildServer.serverSide.ServerPaths;
import jetbrains.buildServer.util.FilePersisterUtil;
import jetbrains.buildServer.util.FileUtil;
import org.jdom.Document;
import org.jdom.Element;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

public class UsageStatisticsSettingsPersistor {
  @NotNull private static final Logger LOG = Logger.getInstance(UsageStatisticsSettingsPersistor.class.getName());
  @NotNull private static final String REPORTING_ENABLED = "reporting-enabled";
  @NotNull private final File myConfigFile;

  public UsageStatisticsSettingsPersistor(@NotNull final ServerPaths serverPaths) {
    myConfigFile = new File(serverPaths.getConfigDir(), "usage-statistics-config.xml");
  }

  public void saveSettings(@NotNull final UsageStatisticsSettings settings) {
    final Element element = new Element("usage-statistics-settings");
    element.setAttribute(REPORTING_ENABLED, String.valueOf(settings.isReportingEnabled()));
    synchronized (myConfigFile) {
      saveXml(element, myConfigFile);
    }
  }

  @NotNull
  public UsageStatisticsSettings loadSettings() {
    final UsageStatisticsSettings settings = new UsageStatisticsSettings();

    final Element element;
    synchronized (myConfigFile) {
      element = loadXml(myConfigFile);
    }
    if (element != null) {
      final String reportingEnabled = element.getAttributeValue(REPORTING_ENABLED);
      if (reportingEnabled != null) {
        settings.setReportingEnabled(Boolean.parseBoolean(reportingEnabled));
      }
    }

    return settings;
  }

  private static void saveXml(@NotNull final Element element, @NotNull final File file) {
    try {
      FilePersisterUtil.saveDocument(new Document(element), file);
    } catch (final IOException e) {
      LOG.warnAndDebugDetails("Failed to save usage statistics settings into file \"" + file.getAbsolutePath() + "\"", e);
    }
  }

  @Nullable
  private static Element loadXml(@NotNull final File file) {
    if (!file.exists() || !file.canRead()) return null;
    try {
      return FileUtil.parseDocument(file);
    } catch (final Exception e) {
      LOG.warnAndDebugDetails("Failed to load usage statistics settings from file \"" + file.getAbsolutePath() + "\"", e);
    }
    return null;
  }
}