/*
 * Copyright 2000-2013 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.jetbrains.python.codeInsight.editorActions.smartEnter.fixers;

import com.intellij.lang.ASTNode;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.psi.PsiElement;
import com.intellij.util.IncorrectOperationException;
import com.jetbrains.python.PyTokenTypes;
import com.jetbrains.python.codeInsight.editorActions.smartEnter.PySmartEnterProcessor;
import com.jetbrains.python.psi.PyElementType;
import com.jetbrains.python.psi.PyExpression;
import com.jetbrains.python.psi.PyWithItem;
import com.jetbrains.python.psi.PyWithStatement;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import static com.jetbrains.python.psi.PyUtil.sure;

/**
 * @author Mikhail Golubev
 */
public class PyWithFixer implements PyFixer {
  public void apply(Editor editor, PySmartEnterProcessor processor, PsiElement psiElement) throws IncorrectOperationException {
    if (psiElement instanceof PyWithStatement) {
      final PyWithStatement withStatement = (PyWithStatement)psiElement;
      final PsiElement colonToken = getFirstChildOfType(psiElement, PyTokenTypes.COLON);
      final PsiElement withToken = getFirstChildOfType(withStatement, PyTokenTypes.WITH_KEYWORD);
      final Document document = editor.getDocument();
      if (colonToken == null) {
        int insertAt = sure(withToken).getTextRange().getEndOffset();
        String textToInsert = ":";
        final PyWithItem[] withItems = withStatement.getWithItems();
        final PyWithItem lastItem = withItems.length != 0 ? withItems[withItems.length - 1] : null;
        if (lastItem == null || lastItem.getExpression() == null) {
          textToInsert = " :";
          processor.registerUnresolvedError(insertAt + 1);
        }
        else {
          final PyExpression expression = lastItem.getExpression();
          insertAt = expression.getTextRange().getEndOffset();
          final PsiElement asToken = getFirstChildOfType(lastItem, PyTokenTypes.AS_KEYWORD);
          if (asToken != null) {
            insertAt = asToken.getTextRange().getEndOffset();
            final PyExpression target = lastItem.getTarget();
            if (target != null) {
              insertAt = target.getTextRange().getEndOffset();
            }
            else {
              textToInsert = " :";
              processor.registerUnresolvedError(insertAt + 1);
            }
          }
        }
        document.insertString(insertAt, textToInsert);
      }
    }
  }

  @Nullable
  private static PsiElement getFirstChildOfType(@NotNull final PsiElement element, @NotNull PyElementType type) {
    final ASTNode child = element.getNode().findChildByType(type);
    return child != null ? child.getPsi() : null;
  }
}