/*
 * 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.psi.impl;

import com.intellij.lang.PsiBuilderFactory;
import com.intellij.openapi.Disposable;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.extensions.Extensions;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.progress.ProgressIndicatorProvider;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.roots.FileIndexFacade;
import com.intellij.openapi.util.Disposer;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.openapi.vfs.VirtualFileFilter;
import com.intellij.psi.*;
import com.intellij.psi.impl.file.impl.FileManager;
import com.intellij.psi.impl.file.impl.FileManagerImpl;
import com.intellij.psi.util.PsiModificationTracker;
import com.intellij.testFramework.LightVirtualFile;
import com.intellij.util.containers.ContainerUtil;
import com.intellij.util.messages.MessageBus;
import com.intellij.util.messages.Topic;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.annotations.TestOnly;

import java.util.Collections;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

public class PsiManagerImpl extends PsiManagerEx {
  private static final Logger LOG = Logger.getInstance("#com.intellij.psi.impl.PsiManagerImpl");

  private final Project myProject;
  private final FileIndexFacade myExcludedFileIndex;
  private final MessageBus myMessageBus;
  private final PsiModificationTracker myModificationTracker;

  private final FileManager myFileManager;

  private final List<PsiTreeChangePreprocessor> myTreeChangePreprocessors = ContainerUtil.createLockFreeCopyOnWriteList();
  private final List<PsiTreeChangeListener> myTreeChangeListeners = ContainerUtil.createLockFreeCopyOnWriteList();
  private boolean myTreeChangeEventIsFiring = false;

  private boolean myIsDisposed;

  private VirtualFileFilter myAssertOnFileLoadingFilter = VirtualFileFilter.NONE;

  private final AtomicInteger myBatchFilesProcessingModeCount = new AtomicInteger(0);

  public static final Topic<AnyPsiChangeListener> ANY_PSI_CHANGE_TOPIC =
    Topic.create("ANY_PSI_CHANGE_TOPIC", AnyPsiChangeListener.class, Topic.BroadcastDirection.TO_PARENT);

  public PsiManagerImpl(Project project,
                        FileDocumentManager fileDocumentManager,
                        PsiBuilderFactory psiBuilderFactory,
                        FileIndexFacade excludedFileIndex,
                        MessageBus messageBus,
                        PsiModificationTracker modificationTracker) {
    myProject = project;
    myExcludedFileIndex = excludedFileIndex;
    myMessageBus = messageBus;
    myModificationTracker = modificationTracker;

    //We need to initialize PsiBuilderFactory service so it won't initialize under PsiLock from ChameleonTransform
    @SuppressWarnings({"UnusedDeclaration", "UnnecessaryLocalVariable"}) Object used = psiBuilderFactory;

    boolean isProjectDefault = project.isDefault();

    myFileManager = isProjectDefault ? new EmptyFileManager(this) : new FileManagerImpl(this, fileDocumentManager, excludedFileIndex);

    myTreeChangePreprocessors.add((PsiTreeChangePreprocessor)modificationTracker);
    Collections.addAll(myTreeChangePreprocessors, Extensions.getExtensions(PsiTreeChangePreprocessor.EP_NAME, myProject));

    Disposer.register(project, new Disposable() {
      @Override
      public void dispose() {
        myIsDisposed = true;
      }
    });
  }

  @Override
  public boolean isDisposed() {
    return myIsDisposed;
  }

  @Override
  public void dropResolveCaches() {
    FileManager fileManager = myFileManager;
    if (fileManager instanceof FileManagerImpl) { // mock tests
      ((FileManagerImpl)fileManager).processQueue();
    }
    beforeChange(true);
    beforeChange(false);
  }

  @Override
  public boolean isInProject(@NotNull PsiElement element) {
    PsiFile file = element.getContainingFile();
    if (file != null && file.isPhysical() && file.getViewProvider().getVirtualFile() instanceof LightVirtualFile) return true;

    if (element instanceof PsiDirectoryContainer) {
      PsiDirectory[] dirs = ((PsiDirectoryContainer)element).getDirectories();
      for (PsiDirectory dir : dirs) {
        if (!isInProject(dir)) return false;
      }
      return true;
    }

    VirtualFile virtualFile = null;
    if (file != null) {
      virtualFile = file.getViewProvider().getVirtualFile();
    }
    else if (element instanceof PsiFileSystemItem) {
      virtualFile = ((PsiFileSystemItem)element).getVirtualFile();
    }

    if (virtualFile != null) {
      return myExcludedFileIndex.isInContent(virtualFile);
    }
    return false;
  }

  @TestOnly
  public void setAssertOnFileLoadingFilter(@NotNull VirtualFileFilter filter, @NotNull Disposable parentDisposable) {
    // Find something to ensure there's no changed files waiting to be processed in repository indices.
    myAssertOnFileLoadingFilter = filter;
    Disposer.register(parentDisposable, new Disposable() {
      @Override
      public void dispose() {
        myAssertOnFileLoadingFilter = VirtualFileFilter.NONE;
      }
    });
  }

  @Override
  public boolean isAssertOnFileLoading(@NotNull VirtualFile file) {
    return myAssertOnFileLoadingFilter.accept(file);
  }

  @Override
  @NotNull
  public Project getProject() {
    return myProject;
  }

  @Override
  @NotNull
  public FileManager getFileManager() {
    return myFileManager;
  }

  @Override
  public boolean areElementsEquivalent(PsiElement element1, PsiElement element2) {
    ProgressIndicatorProvider.checkCanceled(); // We hope this method is being called often enough to cancel daemon processes smoothly

    if (element1 == element2) return true;
    if (element1 == null || element2 == null) {
      return false;
    }

    return element1.equals(element2) || element1.isEquivalentTo(element2) || element2.isEquivalentTo(element1);
  }

  @Override
  public PsiFile findFile(@NotNull VirtualFile file) {
    return myFileManager.findFile(file);
  }

  @Override
  @Nullable
  public FileViewProvider findViewProvider(@NotNull VirtualFile file) {
    return myFileManager.findViewProvider(file);
  }

  @TestOnly
  public void cleanupForNextTest() {
    myFileManager.cleanupForNextTest();
    LOG.assertTrue(ApplicationManager.getApplication().isUnitTestMode());
  }

  @Override
  public PsiDirectory findDirectory(@NotNull VirtualFile file) {
    ProgressIndicatorProvider.checkCanceled();

    return myFileManager.findDirectory(file);
  }

  @Override
  public void reloadFromDisk(@NotNull PsiFile file) {
    myFileManager.reloadFromDisk(file);
  }

  @Override
  public void addPsiTreeChangeListener(@NotNull PsiTreeChangeListener listener) {
    myTreeChangeListeners.add(listener);
  }

  @Override
  public void addPsiTreeChangeListener(@NotNull final PsiTreeChangeListener listener, @NotNull Disposable parentDisposable) {
    addPsiTreeChangeListener(listener);
    Disposer.register(parentDisposable, new Disposable() {
      @Override
      public void dispose() {
        removePsiTreeChangeListener(listener);
      }
    });
  }

  @Override
  public void removePsiTreeChangeListener(@NotNull PsiTreeChangeListener listener) {
    myTreeChangeListeners.remove(listener);
  }

  @Override
  public void beforeChildAddition(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_CHILD_ADDITION);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "beforeChildAddition: parent = " + event.getParent()
      );
    }
    fireEvent(event);
  }

  @Override
  public void beforeChildRemoval(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_CHILD_REMOVAL);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "beforeChildRemoval: child = " + event.getChild()
        + ", parent = " + event.getParent()
      );
    }
    fireEvent(event);
  }

  @Override
  public void beforeChildReplacement(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_CHILD_REPLACEMENT);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "beforeChildReplacement: oldChild = " + event.getOldChild()
        + ", parent = " + event.getParent()
      );
    }
    fireEvent(event);
  }

  public void beforeChildrenChange(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_CHILDREN_CHANGE);
    if (LOG.isDebugEnabled()) {
      LOG.debug("beforeChildrenChange: parent = " + event.getParent());
    }
    fireEvent(event);
  }

  public void beforeChildMovement(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_CHILD_MOVEMENT);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "beforeChildMovement: child = " + event.getChild()
        + ", oldParent = " + event.getOldParent()
        + ", newParent = " + event.getNewParent()
      );
    }
    fireEvent(event);
  }

  public void beforePropertyChange(@NotNull PsiTreeChangeEventImpl event) {
    beforeChange(true);
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.BEFORE_PROPERTY_CHANGE);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "beforePropertyChange: element = " + event.getElement()
        + ", propertyName = " + event.getPropertyName()
        + ", oldValue = " + event.getOldValue()
      );
    }
    fireEvent(event);
  }

  public void childAdded(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.CHILD_ADDED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "childAdded: child = " + event.getChild()
        + ", parent = " + event.getParent()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void childRemoved(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.CHILD_REMOVED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "childRemoved: child = " + event.getChild() + ", parent = " + event.getParent()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void childReplaced(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.CHILD_REPLACED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "childReplaced: oldChild = " + event.getOldChild()
        + ", newChild = " + event.getNewChild()
        + ", parent = " + event.getParent()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void childMoved(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.CHILD_MOVED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "childMoved: child = " + event.getChild()
        + ", oldParent = " + event.getOldParent()
        + ", newParent = " + event.getNewParent()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void childrenChanged(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.CHILDREN_CHANGED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "childrenChanged: parent = " + event.getParent()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void propertyChanged(@NotNull PsiTreeChangeEventImpl event) {
    event.setCode(PsiTreeChangeEventImpl.PsiEventType.PROPERTY_CHANGED);
    if (LOG.isDebugEnabled()) {
      LOG.debug(
        "propertyChanged: element = " + event.getElement()
        + ", propertyName = " + event.getPropertyName()
        + ", oldValue = " + event.getOldValue()
        + ", newValue = " + event.getNewValue()
      );
    }
    fireEvent(event);
    afterChange(true);
  }

  public void addTreeChangePreprocessor(@NotNull PsiTreeChangePreprocessor preprocessor) {
    myTreeChangePreprocessors.add(preprocessor);
  }

  private void fireEvent(@NotNull PsiTreeChangeEventImpl event) {
    boolean isRealTreeChange = event.getCode() != PsiTreeChangeEventImpl.PsiEventType.PROPERTY_CHANGED
                               && event.getCode() != PsiTreeChangeEventImpl.PsiEventType.BEFORE_PROPERTY_CHANGE;

    PsiFile file = event.getFile();
    if (file == null || file.isPhysical()) {
      ApplicationManager.getApplication().assertWriteAccessAllowed();
    }
    if (isRealTreeChange) {
      LOG.assertTrue(!myTreeChangeEventIsFiring, "Changes to PSI are not allowed inside event processing");
      myTreeChangeEventIsFiring = true;
    }
    try {
      for (PsiTreeChangePreprocessor preprocessor : myTreeChangePreprocessors) {
        preprocessor.treeChanged(event);
      }

      for (PsiTreeChangeListener listener : myTreeChangeListeners) {
        try {
          switch (event.getCode()) {
            case BEFORE_CHILD_ADDITION:
              listener.beforeChildAddition(event);
              break;

            case BEFORE_CHILD_REMOVAL:
              listener.beforeChildRemoval(event);
              break;

            case BEFORE_CHILD_REPLACEMENT:
              listener.beforeChildReplacement(event);
              break;

            case BEFORE_CHILD_MOVEMENT:
              listener.beforeChildMovement(event);
              break;

            case BEFORE_CHILDREN_CHANGE:
              listener.beforeChildrenChange(event);
              break;

            case BEFORE_PROPERTY_CHANGE:
              listener.beforePropertyChange(event);
              break;

            case CHILD_ADDED:
              listener.childAdded(event);
              break;

            case CHILD_REMOVED:
              listener.childRemoved(event);
              break;

            case CHILD_REPLACED:
              listener.childReplaced(event);
              break;

            case CHILD_MOVED:
              listener.childMoved(event);
              break;

            case CHILDREN_CHANGED:
              listener.childrenChanged(event);
              break;

            case PROPERTY_CHANGED:
              listener.propertyChanged(event);
              break;
          }
        }
        catch (Exception e) {
          LOG.error(e);
        }
      }
    }
    finally {
      if (isRealTreeChange) {
        myTreeChangeEventIsFiring = false;
      }
    }
  }

  @Override
  public void registerRunnableToRunOnChange(@NotNull final Runnable runnable) {
    myMessageBus.connect().subscribe(ANY_PSI_CHANGE_TOPIC, new AnyPsiChangeListener() {
      @Override
      public void beforePsiChanged(boolean isPhysical) {
        if (isPhysical) runnable.run();
      }

      @Override
      public void afterPsiChanged(boolean isPhysical) {
      }
    });
  }

  @Override
  public void registerRunnableToRunOnAnyChange(@NotNull final Runnable runnable) { // includes non-physical changes
    myMessageBus.connect().subscribe(ANY_PSI_CHANGE_TOPIC, new AnyPsiChangeListener() {
      @Override
      public void beforePsiChanged(boolean isPhysical) {
        runnable.run();
      }

      @Override
      public void afterPsiChanged(boolean isPhysical) {
      }
    });
  }

  @Override
  public void registerRunnableToRunAfterAnyChange(@NotNull final Runnable runnable) { // includes non-physical changes
    myMessageBus.connect().subscribe(ANY_PSI_CHANGE_TOPIC, new AnyPsiChangeListener() {
      @Override
      public void beforePsiChanged(boolean isPhysical) {
      }

      @Override
      public void afterPsiChanged(boolean isPhysical) {
        runnable.run();
      }
    });
  }

  @Override
  public void beforeChange(boolean isPhysical) {
    myMessageBus.syncPublisher(ANY_PSI_CHANGE_TOPIC).beforePsiChanged(isPhysical);
  }

  @Override
  public void afterChange(boolean isPhysical) {
    myMessageBus.syncPublisher(ANY_PSI_CHANGE_TOPIC).afterPsiChanged(isPhysical);
  }

  @Override
  @NotNull
  public PsiModificationTracker getModificationTracker() {
    return myModificationTracker;
  }

  @Override
  public void startBatchFilesProcessingMode() {
    myBatchFilesProcessingModeCount.incrementAndGet();
  }

  @Override
  public void finishBatchFilesProcessingMode() {
    myBatchFilesProcessingModeCount.decrementAndGet();
    LOG.assertTrue(myBatchFilesProcessingModeCount.get() >= 0);
  }

  @Override
  public boolean isBatchFilesProcessingMode() {
    return myBatchFilesProcessingModeCount.get() > 0;
  }
}