/*
 * Copyright 2000-2014 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.openapi.components.impl.stores;

import com.intellij.notification.Notification;
import com.intellij.notification.NotificationListener;
import com.intellij.notification.NotificationType;
import com.intellij.notification.NotificationsManager;
import com.intellij.openapi.application.*;
import com.intellij.openapi.components.*;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.DocumentRunnable;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.project.ProjectBundle;
import com.intellij.openapi.project.ex.ProjectEx;
import com.intellij.openapi.util.Couple;
import com.intellij.openapi.util.JDOMUtil;
import com.intellij.openapi.util.Pair;
import com.intellij.openapi.util.io.BufferExposingByteArrayOutputStream;
import com.intellij.openapi.util.io.FileUtil;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.openapi.vfs.CharsetToolkit;
import com.intellij.openapi.vfs.LocalFileSystem;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.util.SystemProperties;
import com.intellij.util.UniqueFileNamesProvider;
import com.intellij.util.containers.ContainerUtil;
import com.intellij.util.io.fs.IFile;
import com.intellij.util.ui.UIUtil;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.Parent;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import javax.swing.event.HyperlinkEvent;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

/**
 * @author mike
 */
public class StorageUtil {
  private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.components.impl.stores.StorageUtil");

  private static final boolean DUMP_COMPONENT_STATES = SystemProperties.getBooleanProperty("idea.log.externally.changed.component.states", false);
  @SuppressWarnings("SpellCheckingInspection")
  private static final SimpleDateFormat LOG_DIR_FORMAT = new SimpleDateFormat("yyyyMMdd-HHmmss");

  private StorageUtil() { }

  public static void notifyUnknownMacros(@NotNull TrackingPathMacroSubstitutor substitutor,
                                         @NotNull final Project project,
                                         @Nullable String componentName) {
    final LinkedHashSet<String> macros = new LinkedHashSet<String>(substitutor.getUnknownMacros(componentName));
    if (macros.isEmpty()) {
      return;
    }

    UIUtil.invokeLaterIfNeeded(new Runnable() {
      @Override
      public void run() {
        macros.removeAll(getMacrosFromExistingNotifications(project));

        if (!macros.isEmpty()) {
          String format = "<p><i>%s</i> %s undefined. <a href=\"define\">Fix it</a></p>";
          String productName = ApplicationNamesInfo.getInstance().getProductName();
          String content = String.format(format, StringUtil.join(macros, ", "), macros.size() == 1 ? "is" : "are") +
                           "<br>Path variables are used to substitute absolute paths " +
                           "in " + productName + " project files " +
                           "and allow project file sharing in version control systems.<br>" +
                           "Some of the files describing the current project settings contain unknown path variables " +
                           "and " + productName + " cannot restore those paths.";
          new UnknownMacroNotification("Load Error", "Load error: undefined path variables", content, NotificationType.ERROR,
                                       new NotificationListener() {
                                         @Override
                                         public void hyperlinkUpdate(@NotNull Notification notification, @NotNull HyperlinkEvent event) {
                                           ((ProjectEx)project).checkUnknownMacros(true);
                                         }
                                       }, macros).notify(project);
        }
      }
    });
  }

  private static List<String> getMacrosFromExistingNotifications(Project project) {
    List<String> notified = ContainerUtil.newArrayList();
    NotificationsManager manager = NotificationsManager.getNotificationsManager();
    for (final UnknownMacroNotification notification : manager.getNotificationsOfType(UnknownMacroNotification.class, project)) {
      notified.addAll(notification.getMacros());
    }
    return notified;
  }

  @Nullable
  static VirtualFile save(@NotNull IFile file, Parent element, Object requestor) throws StateStorageException {
    try {
      VirtualFile vFile = LocalFileSystem.getInstance().findFileByIoFile(file);
      Couple<String> pair = loadFile(vFile);
      String text = JDOMUtil.writeParent(element, pair.second);

      if (file.exists()) {
        if (text.equals(pair.first)) {
          return null;
        }
      }
      else {
        file.createParentDirs();
      }

      // mark this action as modifying the file which daemon analyzer should ignore
      AccessToken token = ApplicationManager.getApplication().acquireWriteActionLock(DocumentRunnable.IgnoreDocumentRunnable.class);
      try {
        VirtualFile virtualFile = getOrCreateVirtualFile(requestor, file);
        byte[] bytes = text.getBytes(CharsetToolkit.UTF8);
        virtualFile.setBinaryContent(bytes, -1, -1, requestor);
        return virtualFile;
      }
      finally {
        token.finish();
      }
    }
    catch (IOException e) {
      throw new StateStorageException(e);
    }
  }

  @NotNull
  static VirtualFile getOrCreateVirtualFile(final Object requestor, final IFile ioFile) throws IOException {
    VirtualFile vFile = getVirtualFile(ioFile);

    if (vFile == null) {
      vFile = LocalFileSystem.getInstance().refreshAndFindFileByIoFile(ioFile);
    }

    if (vFile == null) {
      final IFile parentFile = ioFile.getParentFile();
      final VirtualFile parentVFile =
        LocalFileSystem.getInstance().refreshAndFindFileByIoFile(parentFile); // need refresh if the directory has just been created
      if (parentVFile == null) {
        throw new IOException(ProjectBundle.message("project.configuration.save.file.not.found", parentFile.getPath()));
      }
      vFile = parentVFile.createChildData(requestor, ioFile.getName());
    }

    return vFile;
  }

  @Nullable
  static VirtualFile getVirtualFile(final IFile ioFile) {
    return LocalFileSystem.getInstance().findFileByIoFile(ioFile);
  }

  /**
   * @return pair.first - file contents (null if file does not exist), pair.second - file line separators
   */
  private static Couple<String> loadFile(@Nullable final VirtualFile file) throws IOException {
    if (file == null || !file.exists()) {
      return Couple.of(null, SystemProperties.getLineSeparator());
    }

    String fileText = new String(file.contentsToByteArray(), CharsetToolkit.UTF8);
    final int index = fileText.indexOf('\n');
    return Couple.of(fileText, index == -1
                               ? SystemProperties.getLineSeparator()
                               : index - 1 >= 0 ? fileText.charAt(index - 1) == '\r' ? "\r\n" : "\n" : "\n");
  }

  public static boolean contentEquals(@NotNull final Document document, @NotNull final VirtualFile file) {
    try {
      final Couple<String> pair = loadFile(file);
      return pair.first != null && pair.first.equals(JDOMUtil.writeDocument(document, pair.second));
    }
    catch (IOException e) {
      LOG.debug(e);
      return false;
    }
  }

  public static boolean contentEquals(@NotNull final Element element, @NotNull final VirtualFile file) {
    try {
      final Couple<String> pair = loadFile(file);
      return pair.first != null && pair.first.equals(printElement(element, pair.second));
    }
    catch (IOException e) {
      LOG.debug(e);
      return false;
    }
  }

  static String printElement(final Element element, final String lineSeparator) throws StateStorageException {
    return JDOMUtil.writeElement(element, lineSeparator);
  }

  @Nullable
  public static Document loadDocument(final byte[] bytes) {
    try {
      return bytes == null || bytes.length == 0 ? null : JDOMUtil.loadDocument(new ByteArrayInputStream(bytes));
    }
    catch (JDOMException e) {
      return null;
    }
    catch (IOException e) {
      return null;
    }
  }

  @Nullable
  public static Document loadDocument(@Nullable InputStream stream) {
    if (stream == null) {
      return null;
    }

    try {
      try {
        return JDOMUtil.loadDocument(stream);
      }
      finally {
        stream.close();
      }
    }
    catch (JDOMException e) {
      return null;
    }
    catch (IOException e) {
      return null;
    }
  }

  public static BufferExposingByteArrayOutputStream documentToBytes(@NotNull Document document, boolean useSystemLineSeparator) throws IOException {
    BufferExposingByteArrayOutputStream out = new BufferExposingByteArrayOutputStream(512);
    OutputStreamWriter writer = new OutputStreamWriter(out, CharsetToolkit.UTF8_CHARSET);
    try {
      JDOMUtil.writeDocument(document, writer, useSystemLineSeparator ? SystemProperties.getLineSeparator() : "\n");
      return out;
    }
    finally {
      writer.close();
    }
  }

  public static boolean sendContent(@NotNull StreamProvider provider, @NotNull String fileSpec, @NotNull Document copy, @NotNull RoamingType type, boolean async) {
    if (!provider.isApplicable(fileSpec, type)) {
      return false;
    }

    try {
      return doSendContent(provider, fileSpec, copy, type, async);
    }
    catch (IOException e) {
      LOG.warn(e);
      return false;
    }
  }

  public static void deleteContent(@NotNull StreamProvider provider, @NotNull String fileSpec, @NotNull RoamingType type) {
    if (provider.isApplicable(fileSpec, type)) {
      provider.deleteFile(fileSpec, type);
    }
  }

  /**
   * You must call {@link StreamProvider#isApplicable(String, com.intellij.openapi.components.RoamingType)} before
   */
  public static boolean doSendContent(StreamProvider provider, String fileSpec, Document copy, RoamingType type, boolean async) throws IOException {
    // we should use standard line-separator (\n) - stream provider can share file content on any OS
    BufferExposingByteArrayOutputStream content = documentToBytes(copy, false);
    return provider.saveContent(fileSpec, content.getInternalBuffer(), content.size(), type, async);
  }

  public static void logStateDiffInfo(Set<Pair<VirtualFile, StateStorage>> changedFiles, Set<String> componentNames) {
    if (componentNames.isEmpty() || !(DUMP_COMPONENT_STATES || ApplicationManager.getApplication().isInternal())) {
      return;
    }

    try {
      File logDirectory = createLogDirectory();
      if (!logDirectory.mkdirs()) {
        throw new IOException("Cannot create " + logDirectory);
      }

      for (Pair<VirtualFile, StateStorage> pair : changedFiles) {
        File file = new File(pair.first.getPath());
        StateStorage storage = pair.second;

        if (storage instanceof XmlElementStorage) {
          Document state = ((XmlElementStorage)storage).logComponents();
          if (state != null) {
            File logFile = new File(logDirectory, "prev_" + file.getName());
            JDOMUtil.writeDocument(state, logFile, "\n");
          }
        }

        if (file.exists()) {
          File logFile = new File(logDirectory, "new_" + file.getName());
          FileUtil.copy(file, logFile);
        }
      }

      File logFile = new File(logDirectory, "components.txt");
      FileUtil.writeToFile(logFile, componentNames.toString() + "\n");
    }
    catch (Throwable e) {
      LOG.info(e);
    }
  }

  private static File createLogDirectory() {
    UniqueFileNamesProvider namesProvider = new UniqueFileNamesProvider();

    File statesDir = new File(PathManager.getSystemPath(), "log/componentStates");
    File[] children = statesDir.listFiles();
    if (children != null) {
      if (children.length > 10) {
        File childToDelete = null;

        for (File child : children) {
          if (childToDelete == null || childToDelete.lastModified() > child.lastModified()) {
            childToDelete = child;
          }
        }

        if (childToDelete != null) {
          FileUtil.delete(childToDelete);
        }
      }

      for (File child : children) {
        namesProvider.reserveFileName(child.getName());
      }
    }

    String name = "state-" + LOG_DIR_FORMAT.format(new Date()) + "-" + ApplicationInfo.getInstance().getBuild().asString();
    return new File(statesDir, namesProvider.suggestName(name));
  }

  public static boolean isProjectOrModuleFile(@NotNull String fileSpec) {
    return StoragePathMacros.PROJECT_FILE.equals(fileSpec) || fileSpec.startsWith(StoragePathMacros.PROJECT_CONFIG_DIR) || fileSpec.equals("$MODULE_FILE$");
  }
}