plugins/IntentionPowerPak/src/com/siyeh/ipp/varargs/ConvertVarargParameterToArrayIntention.java

/*
 * Copyright 2006-2011 Bas Leijdekkers
 *
 * 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.siyeh.ipp.varargs;

import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.codeStyle.CodeStyleManager;
import com.intellij.psi.codeStyle.JavaCodeStyleManager;
import com.intellij.psi.search.searches.ReferencesSearch;
import com.intellij.util.IncorrectOperationException;
import com.intellij.util.Query;
import com.siyeh.ipp.base.Intention;
import com.siyeh.ipp.base.PsiElementPredicate;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

public class ConvertVarargParameterToArrayIntention extends Intention {

  @NotNull
  protected PsiElementPredicate getElementPredicate() {
    return new ConvertVarargParameterToArrayPredicate();
  }

  protected void processIntention(@NotNull PsiElement element)
    throws IncorrectOperationException {
    final PsiParameterList parameterList = (PsiParameterList)element;
    convertVarargsToArray(parameterList);
  }

  private static void convertVarargsToArray(PsiParameterList parameterList)
    throws IncorrectOperationException {
    final PsiParameter[] parameters = parameterList.getParameters();
    if (parameters.length == 0) {
      return;
    }
    final PsiParameter lastParameter = parameters[parameters.length - 1];
    if (lastParameter == null || !lastParameter.isVarArgs()) {
      return;
    }
    final PsiEllipsisType type =
      (PsiEllipsisType)lastParameter.getType();
    final PsiMethod method = (PsiMethod)parameterList.getParent();
    final Query<PsiReference> query = ReferencesSearch.search(method);
    final PsiType componentType = type.getComponentType();
    final String typeText = componentType.getCanonicalText();
    final int parameterIndex =
      parameterList.getParameterIndex(lastParameter);
    for (PsiReference reference : query) {
      final PsiElement referenceElement = reference.getElement();
      if (!(referenceElement instanceof PsiReferenceExpression)) {
        continue;
      }
      final PsiReferenceExpression referenceExpression =
        (PsiReferenceExpression)referenceElement;
      final PsiMethodCallExpression methodCallExpression =
        (PsiMethodCallExpression)referenceExpression.getParent();
      modifyCall(methodCallExpression, typeText, parameterIndex);
    }
    final PsiType arrayType = type.toArrayType();
    final Project project = lastParameter.getProject();
    final PsiElementFactory factory =
      JavaPsiFacade.getElementFactory(project);
    final PsiTypeElement newTypeElement =
      factory.createTypeElement(arrayType);
    final PsiTypeElement typeElement =
      lastParameter.getTypeElement();
    typeElement.replace(newTypeElement);
  }

  public static void modifyCall(PsiMethodCallExpression methodCallExpression,
                                String arrayTypeText,
                                int indexOfFirstVarargArgument)
    throws IncorrectOperationException {
    final PsiExpressionList argumentList =
      methodCallExpression.getArgumentList();
    final PsiExpression[] arguments = argumentList.getExpressions();
    @NonNls final StringBuilder builder = new StringBuilder("new ");
    builder.append(arrayTypeText);
    builder.append("[]{");
    if (arguments.length > indexOfFirstVarargArgument) {
      final PsiExpression firstArgument =
        arguments[indexOfFirstVarargArgument];
      final String firstArgumentText = firstArgument.getText();
      builder.append(firstArgumentText);
      for (int i = indexOfFirstVarargArgument + 1;
           i < arguments.length; i++) {
        builder.append(',');
        builder.append(arguments[i].getText());
      }
    }
    builder.append('}');
    final Project project = methodCallExpression.getProject();
    final PsiElementFactory factory =
      JavaPsiFacade.getElementFactory(project);
    final PsiExpression arrayExpression =
      factory.createExpressionFromText(builder.toString(),
                                       methodCallExpression);
    if (arguments.length > indexOfFirstVarargArgument) {
      final PsiExpression firstArgument =
        arguments[indexOfFirstVarargArgument];
      argumentList.deleteChildRange(firstArgument,
                                    arguments[arguments.length - 1]);
      argumentList.add(arrayExpression);
    }
    else {
      argumentList.add(arrayExpression);
    }
    final JavaCodeStyleManager javaCodeStyleManager =
      JavaCodeStyleManager.getInstance(project);
    javaCodeStyleManager.shortenClassReferences(argumentList);
    final CodeStyleManager codeStyleManager =
      CodeStyleManager.getInstance(project);
    codeStyleManager.reformat(argumentList);
  }
}