plugins/IntentionPowerPak/src/com/siyeh/ipp/exceptions/ObscureThrownExceptionsIntention.java

/*
 * Copyright 2011-2012 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.exceptions;

import com.intellij.psi.*;
import com.intellij.util.IncorrectOperationException;
import com.siyeh.IntentionPowerPackBundle;
import com.siyeh.ipp.base.MutablyNamedIntention;
import com.siyeh.ipp.base.PsiElementPredicate;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.HashSet;
import java.util.Set;

public class ObscureThrownExceptionsIntention extends MutablyNamedIntention {

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

  @Override
  protected void processIntention(@NotNull PsiElement element) throws IncorrectOperationException {
    if (!(element instanceof PsiReferenceList)) {
      return;
    }
    final PsiReferenceList referenceList = (PsiReferenceList)element;
    final PsiClassType[] types = referenceList.getReferencedTypes();
    final PsiClass commonSuperClass = findCommonSuperClass(types);
    if (commonSuperClass == null) {
      return;
    }
    final PsiElementFactory factory = JavaPsiFacade.getElementFactory(element.getProject());
    final PsiClassType classType = factory.createType(commonSuperClass);
    final PsiJavaCodeReferenceElement referenceElement = factory.createReferenceElementByType(classType);
    final PsiReferenceList newReferenceList = factory.createReferenceList(new PsiJavaCodeReferenceElement[]{referenceElement});
    referenceList.replace(newReferenceList);
  }

  @Nullable
  public static PsiClass findCommonSuperClass(PsiClassType... types) {
    if (types.length == 0) {
      return null;
    }
    final PsiClass firstClass = types[0].resolve();
    if (firstClass == null || types.length == 1) {
      return firstClass;
    }
    Set<PsiClass> sourceSet = new HashSet();
    PsiClass aClass = firstClass;
    while (aClass != null) {
      sourceSet.add(aClass);
      aClass = aClass.getSuperClass();
    }
    if (sourceSet.isEmpty()) {
      return null;
    }
    Set<PsiClass> targetSet = new HashSet();
    final int max = types.length - 1;
    for (int i = 1; i < max; i++) {
      final PsiClassType classType = types[i];
      PsiClass aClass1 = classType.resolve();
      while (aClass1 != null) {
        if (sourceSet.contains(aClass1)) {
          targetSet.add(aClass1);
        }
        aClass1 = aClass1.getSuperClass();
      }
      sourceSet = targetSet;
      targetSet = new HashSet();
    }
    PsiClass aClass1 = types[max].resolve();
    while (aClass1 != null && !sourceSet.contains(aClass1)) {
      aClass1 = aClass1.getSuperClass();
    }
    return aClass1;
  }

  @Override
  protected String getTextForElement(PsiElement element) {
    final PsiReferenceList referenceList = (PsiReferenceList)element;
    final PsiClassType[] types = referenceList.getReferencedTypes();
    final PsiClass commonSuperClass = findCommonSuperClass(types);
    if (commonSuperClass == null) {
      return null;
    }
    return IntentionPowerPackBundle.message("obscure.thrown.exceptions.intention.name", commonSuperClass.getName());
  }
}