SplitFilterAction.java

/*
 * Copyright 2000-2015 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.codeInsight.intention.impl;

import com.intellij.codeInsight.CodeInsightBundle;
import com.intellij.codeInsight.intention.PsiElementBaseIntentionAction;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.psi.util.PsiUtil;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NotNull;

import java.util.Collection;

import static com.intellij.codeInsight.intention.impl.SplitConditionUtil.getLOperands;
import static com.intellij.codeInsight.intention.impl.SplitConditionUtil.getROperands;

public class SplitFilterAction extends PsiElementBaseIntentionAction {
  private static final Logger LOG = Logger.getInstance(SplitFilterAction.class.getName());

  @Override
  public boolean isAvailable(@NotNull Project project, Editor editor, @NotNull PsiElement element) {
    final PsiPolyadicExpression expression = SplitConditionUtil.findCondition(element, true, false);
    if (expression == null || expression.getOperands().length < 2) return false;

    PsiElement parent = PsiUtil.skipParenthesizedExprUp(expression.getParent());
    if (!(parent instanceof PsiLambdaExpression)) return false;
    if (((PsiLambdaExpression)parent).getParameterList().getParametersCount() != 1) return false;
    parent = parent.getParent();

    if (!(parent instanceof PsiExpressionList)) return false;
    final PsiElement gParent = parent.getParent();
    if (!(gParent instanceof PsiMethodCallExpression)) return false;

    if (MergeFilterChainAction.isFilterCall((PsiMethodCallExpression)gParent)) {
      return true;
    }

    return false;
  }

  @NotNull
  @Override
  public String getText() {
    return CodeInsightBundle.message("intention.split.filter.text");
  }

  @Override
  @NotNull
  public String getFamilyName() {
    return CodeInsightBundle.message("intention.split.filter.family");
  }

  @Override
  public void invoke(@NotNull Project project, Editor editor, @NotNull PsiElement element) throws IncorrectOperationException {
    final PsiJavaToken token = (PsiJavaToken)element;
    final PsiPolyadicExpression expression = SplitConditionUtil.findCondition(element, true, false);

    final PsiLambdaExpression lambdaExpression = PsiTreeUtil.getParentOfType(expression, PsiLambdaExpression.class);
    LOG.assertTrue(lambdaExpression != null);
    final String lambdaParameterName = lambdaExpression.getParameterList().getParameters()[0].getName();

    final PsiMethodCallExpression methodCallExpression = PsiTreeUtil.getParentOfType(expression, PsiMethodCallExpression.class);
    LOG.assertTrue(methodCallExpression != null, expression);

    PsiExpression lOperand = getLOperands(expression, token);
    PsiExpression rOperand = getROperands(expression, token);

    final Collection<PsiComment> comments = PsiTreeUtil.findChildrenOfType(expression, PsiComment.class);

    final PsiMethodCallExpression chainedCall =
      (PsiMethodCallExpression)JavaPsiFacade.getElementFactory(project).createExpressionFromText("a.filter(" + lambdaParameterName + " -> x)", expression);
    final PsiExpression argExpression = chainedCall.getArgumentList().getExpressions()[0];
    final PsiElement rReplaced = ((PsiLambdaExpression)argExpression).getBody().replace(rOperand);

    final PsiExpression compoundArg = methodCallExpression.getArgumentList().getExpressions()[0];

    final int separatorOffset = token.getTextOffset();
    for (PsiComment comment : comments) {
      if (comment.getTextOffset() < separatorOffset) {
        compoundArg.getParent().add(comment);
      }
      else {
        rReplaced.getParent().add(comment);
      }
    }

    ((PsiLambdaExpression)compoundArg).getBody().replace(lOperand);

    chainedCall.getMethodExpression().getQualifierExpression().replace(methodCallExpression);
    methodCallExpression.replace(chainedCall);
  }

}