/*
 * 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 org.jetbrains.plugins.groovy.editor;

import com.intellij.lang.Language;
import com.intellij.openapi.actionSystem.DataContext;
import com.intellij.openapi.actionSystem.DataKeys;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.actionSystem.EditorActionHandler;
import com.intellij.openapi.project.Project;
import com.intellij.psi.PsiDocumentManager;
import com.intellij.psi.PsiFile;
import com.intellij.psi.util.PsiUtilBase;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.plugins.groovy.GroovyLanguage;

/**
 * @author ilyas
 */
public class HandlerUtils {
  private HandlerUtils() {
  }

  public static boolean isEnabled(@NotNull final Editor editor, @NotNull final DataContext dataContext,
                                  @Nullable final EditorActionHandler originalHandler) {
    final Project project = getProject(dataContext);
    if (project != null) {
      final Language language = PsiUtilBase.getLanguageInEditor(editor, project);
      if (language == GroovyLanguage.INSTANCE) {
        return true;
      }
    }

    return originalHandler == null || originalHandler.isEnabled(editor, dataContext);
  }

  public static boolean isReadOnly(@NotNull final Editor editor) {
    if (editor.isViewer()) {
      return true;
    }
    Document document = editor.getDocument();
    return !document.isWritable();
  }

  public static boolean canBeInvoked(final Editor editor, final Project project) {
    if (isReadOnly(editor)) {
      return false;
    }
    if (getPsiFile(editor, project) == null) {
      return false;
    }

    return true;
  }

  public static PsiFile getPsiFile(@NotNull final Editor editor, @NotNull final DataContext dataContext) {
    return getPsiFile(editor, getProject(dataContext));
  }

  public static PsiFile getPsiFile(@NotNull final Editor editor, final Project project) {
    return PsiDocumentManager.getInstance(project).getPsiFile(editor.getDocument());
  }

  @Nullable
  public static Language getLanguage(@NotNull final DataContext dataContext) {
    return DataKeys.LANGUAGE.getData(dataContext);
  }

  @Nullable
  public static Project getProject(@NotNull final DataContext dataContext) {
    return DataKeys.PROJECT.getData(dataContext);
  }


}