/*
 * Copyright 2000-2017 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 com.intellij.internal.statistic.persistence;

import com.intellij.concurrency.JobScheduler;
import com.intellij.ide.AppLifecycleListener;
import com.intellij.internal.statistic.UsagesCollector;
import com.intellij.internal.statistic.beans.GroupDescriptor;
import com.intellij.internal.statistic.beans.UsageDescriptor;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.components.*;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.project.ProjectManager;
import com.intellij.openapi.project.ProjectManagerAdapter;
import com.intellij.openapi.util.text.StringUtil;
import gnu.trove.THashSet;
import org.jdom.Element;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;

@State(
  name = "StatisticsApplicationUsages",
  storages = @Storage(value = "statistics.application.usages.xml", roamingType = RoamingType.DISABLED)
)
public class ApplicationStatisticsPersistenceComponent extends ApplicationStatisticsPersistence implements ApplicationComponentAdapter, PersistentStateComponent<Element> {
  private boolean persistOnClosing = !ApplicationManager.getApplication().isUnitTestMode();

  private static final String TOKENIZER = ",";

  @NonNls
  private static final String GROUP_TAG = "group";
  @NonNls
  private static final String GROUP_NAME_ATTR = "name";

  @NonNls
  private static final String PROJECT_TAG = "project";
  @NonNls
  private static final String COLLECTION_TIME_TAG = "collectionTime";
  @NonNls
  private static final String PROJECT_ID_ATTR = "id";
  @NonNls
  private static final String VALUES_ATTR = "values";

  public static ApplicationStatisticsPersistenceComponent getInstance() {
    return ApplicationManager.getApplication().getComponent(ApplicationStatisticsPersistenceComponent.class);
  }

  @Override
  public void loadState(Element element) {
    for (Element groupElement : element.getChildren(GROUP_TAG)) {
      GroupDescriptor groupDescriptor = GroupDescriptor.create(groupElement.getAttributeValue(GROUP_NAME_ATTR));
      List<Element> projectsList = groupElement.getChildren(PROJECT_TAG);
      for (Element projectElement : projectsList) {
        String projectId = projectElement.getAttributeValue(PROJECT_ID_ATTR);
        String frameworks = projectElement.getAttributeValue(VALUES_ATTR);
        if (!StringUtil.isEmptyOrSpaces(projectId) && !StringUtil.isEmptyOrSpaces(frameworks)) {
          Set<UsageDescriptor> frameworkDescriptors = new THashSet<>();
          for (String key : StringUtil.split(frameworks, TOKENIZER)) {
            UsageDescriptor descriptor = getUsageDescriptor(key);
            if (descriptor != null) {
              frameworkDescriptors.add(descriptor);
            }
          }
          long collectionTime;
          try {
            collectionTime = Long.valueOf(projectElement.getAttributeValue(COLLECTION_TIME_TAG));
          } catch (NumberFormatException ignored) {
            collectionTime = 0;
          }
          getApplicationData(groupDescriptor).put(projectId, new CollectedUsages(frameworkDescriptors, collectionTime));
        }
      }
    }
  }

  @Override
  public Element getState() {
    Element element = new Element("state");

    for (Map.Entry<GroupDescriptor, Map<String, CollectedUsages>> appData : getApplicationData().entrySet()) {
      Element groupElement = new Element(GROUP_TAG);
      groupElement.setAttribute(GROUP_NAME_ATTR, appData.getKey().getId());
      boolean isEmptyGroup = true;

      for (Map.Entry<String, CollectedUsages> projectData : appData.getValue().entrySet()) {
        Element projectElement = new Element(PROJECT_TAG);
        projectElement.setAttribute(PROJECT_ID_ATTR, projectData.getKey());
        final CollectedUsages projectDataValue = projectData.getValue();
        if (!projectDataValue.usages.isEmpty()) {
          projectElement.setAttribute(VALUES_ATTR, joinUsages(projectDataValue.usages));
          projectElement.setAttribute(COLLECTION_TIME_TAG, String.valueOf(projectDataValue.collectionTime));
          groupElement.addContent(projectElement);
          isEmptyGroup = false;
        }
      }

      if (!isEmptyGroup) {
        element.addContent(groupElement);
      }
    }

    return element;
  }

  private static UsageDescriptor getUsageDescriptor(String usage) {
    // for instance, usage can be: "_foo"(equals "_foo=1") or "_foo=2"
    try {
      final int i = usage.indexOf('=');
      if (i > 0 && i < usage.length() - 1) {
        String key = usage.substring(0, i).trim();
        String value = usage.substring(i + 1).trim();
        if (!StringUtil.isEmptyOrSpaces(key) && !StringUtil.isEmptyOrSpaces(value)) {
          try {
            final int count = Integer.parseInt(value);
            if (count > 0) {
              return new UsageDescriptor(key, count);
            }
          }
          catch (NumberFormatException ignored) {
          }
        }
      }
      return new UsageDescriptor(usage, 1);
    }
    catch (AssertionError e) {
      //escape loading of invalid usages
    }
    return null;
  }

  private static String joinUsages(@NotNull Set<UsageDescriptor> usages) {
    // for instance, usage can be: "_foo"(equals "_foo=1") or "_foo=2"
    return StringUtil.join(usages, usageDescriptor -> {
      final String key = usageDescriptor.getKey();
      final int value = usageDescriptor.getValue();
      return value != 1 ? key + "=" + value : key;
    }, TOKENIZER);
  }

  @Override
  public void initComponent() {
    ApplicationManager.getApplication().getMessageBus().connect().subscribe(AppLifecycleListener.TOPIC, new AppLifecycleListener() {
      @Override
      public void appClosing() {
        persistOpenedProjects();
        persistOnClosing = false;
      }
    });

    ProjectManager.getInstance().addProjectManagerListener(new ProjectManagerAdapter() {
      @Override
      public void projectClosing(Project project) {
        if (persistOnClosing && project != null) {
          UsagesCollector.doPersistProjectUsages(project);
        }
      }
    });

    persistPeriodically();
  }

  private static void persistPeriodically() {
    JobScheduler.getScheduler().scheduleWithFixedDelay(ApplicationStatisticsPersistenceComponent::persistOpenedProjects, 1, 1, TimeUnit.DAYS);
  }

  private static void persistOpenedProjects() {
    for (Project project : ProjectManager.getInstance().getOpenProjects()) {
      UsagesCollector.doPersistProjectUsages(project);
    }
  }
}
