/*
 * Copyright 2013-2017 consulo.io
 *
 * 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 consulo.csharp.ide.editor;

import org.jetbrains.annotations.NotNull;
import consulo.csharp.lang.doc.psi.CSharpDocRoot;
import com.intellij.codeInsight.editorActions.enter.EnterHandlerDelegateAdapter;
import com.intellij.openapi.actionSystem.DataContext;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.actionSystem.EditorActionHandler;
import com.intellij.openapi.util.Ref;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.PsiWhiteSpace;
import com.intellij.psi.util.PsiTreeUtil;

/**
 * @author VISTALL
 */
public class CSharpEnterInDocLineCommentHandler extends EnterHandlerDelegateAdapter
{
	private static final String DOC_LINE_START = "///";

	@Override
	public Result preprocessEnter(@NotNull final PsiFile file,
			@NotNull final Editor editor,
			@NotNull final Ref<Integer> caretOffsetRef,
			@NotNull final Ref<Integer> caretAdvance,
			@NotNull final DataContext dataContext,
			final EditorActionHandler originalHandler)
	{
		final int caretOffset = caretOffsetRef.get().intValue();
		final Document document = editor.getDocument();
		final PsiElement psiAtOffset = file.findElementAt(caretOffset);
		final PsiElement probablyDocComment = psiAtOffset instanceof PsiWhiteSpace && psiAtOffset.getText().startsWith("\n") ? psiAtOffset
				.getPrevSibling() : psiAtOffset == null && caretOffset > 0 && caretOffset == document.getTextLength() ? file.findElementAt
				(caretOffset - 1) : psiAtOffset;

		if(probablyDocComment != null &&
				probablyDocComment.getTextOffset() < caretOffset &&
				PsiTreeUtil.getParentOfType(probablyDocComment, CSharpDocRoot.class, false) != null)
		{
			document.insertString(caretOffset, DOC_LINE_START + " ");
			caretAdvance.set(4);
			return Result.Default;
		}

		return Result.Continue;
	}
}