plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/performance/CollectionContainsUrlInspection.java

/*
 * Copyright 2007-2010 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.ig.performance;

import com.intellij.psi.*;
import com.intellij.psi.util.PsiTreeUtil;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

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

public class CollectionContainsUrlInspection extends BaseInspection {

  @Override
  @NotNull
  public String getDisplayName() {
    return InspectionGadgetsBundle.message(
      "collection.contains.url.display.name");
  }

  @Override
  @NotNull
  protected String buildErrorString(Object... infos) {
    final ClassType type = (ClassType)infos[0];
    return InspectionGadgetsBundle.message(
      "collection.contains.url.problem.decriptor", type);
  }

  @Override
  public BaseInspectionVisitor buildVisitor() {
    return new CollectionContainsUrlVisitor();
  }

  private static class CollectionContainsUrlVisitor
    extends BaseInspectionVisitor {

    @Override
    public void visitVariable(PsiVariable variable) {
      super.visitVariable(variable);
      final PsiTypeElement typeElement = variable.getTypeElement();
      if (typeElement == null) {
        return;
      }
      final PsiType type = typeElement.getType();
      if (!(type instanceof PsiClassType)) {
        return;
      }
      final PsiJavaCodeReferenceElement referenceElement =
        typeElement.getInnermostComponentReferenceElement();
      if (referenceElement == null) {
        return;
      }
      final PsiClassType classType = (PsiClassType)type;
      final PsiClass aClass = classType.resolve();

      final ClassType collectionType = getClassType(aClass);
      if (collectionType == ClassType.OTHER) {
        return;
      }
      final PsiReferenceParameterList parameterList =
        referenceElement.getParameterList();
      if (parameterList == null ||
          parameterList.getTypeParameterElements().length == 0) {
        final PsiMember member =
          PsiTreeUtil.getParentOfType(variable, PsiMember.class);
        if (member == null) {
          return;
        }
        final UrlAddedVisitor visitor =
          new UrlAddedVisitor(variable, collectionType);
        member.accept(visitor);
        if (visitor.isUrlAdded()) {
          registerVariableError(variable, collectionType);
        }
        return;
      }
      final PsiType[] typeArguments = parameterList.getTypeArguments();
      boolean containsUrl = false;
      for (PsiType typeArgument : typeArguments) {
        if (typeArgument.equalsToText("java.net.URL")) {
          containsUrl = true;
          break;
        }
      }
      if (!containsUrl) {
        return;
      }
      registerVariableError(variable, collectionType);
    }

    private static ClassType getClassType(@Nullable PsiClass aClass) {
      return isMapOrSet(aClass, new HashSet());
    }

    private static ClassType isMapOrSet(
      @Nullable PsiClass aClass, Set<PsiClass> visitedClasses) {
      if (aClass == null) {
        return ClassType.OTHER;
      }
      if (!visitedClasses.add(aClass)) {
        return ClassType.OTHER;
      }
      @NonNls final String className = aClass.getQualifiedName();
      if (CommonClassNames.JAVA_UTIL_SET.equals(className)) {
        return ClassType.SET;
      }
      else if (CommonClassNames.JAVA_UTIL_MAP.equals(className)) {
        return ClassType.MAP;
      }
      final PsiClass[] supers = aClass.getSupers();
      for (PsiClass aSuper : supers) {
        final ClassType classType =
          isMapOrSet(aSuper, visitedClasses);
        if (classType != ClassType.OTHER) {
          return classType;
        }
      }
      return ClassType.OTHER;
    }
  }

  private static class UrlAddedVisitor
    extends JavaRecursiveElementVisitor {

    private boolean urlAdded = false;
    private final PsiVariable variable;
    private final ClassType collectionType;

    UrlAddedVisitor(PsiVariable variable,
                    ClassType collectionType) {
      this.variable = variable;
      this.collectionType = collectionType;
    }

    @Override
    public void visitMethodCallExpression(
      PsiMethodCallExpression expression) {
      if (urlAdded) {
        return;
      }
      super.visitMethodCallExpression(expression);
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      final PsiExpression qualifierExpression =
        methodExpression.getQualifierExpression();
      if (!(qualifierExpression instanceof PsiReferenceExpression)) {
        return;
      }
      final PsiReferenceExpression referenceExpression =
        (PsiReferenceExpression)qualifierExpression;
      @NonNls final String methodName =
        methodExpression.getReferenceName();
      if (collectionType == ClassType.SET &&
          !"add".equals(methodName)) {
        return;
      }
      if (collectionType == ClassType.MAP &&
          !"put".equals(methodName)) {
        return;
      }
      final PsiExpressionList argumentList = expression.getArgumentList();
      final PsiExpression[] arguments = argumentList.getExpressions();
      if (arguments.length != 1) {
        return;
      }
      final PsiExpression argument = arguments[0];
      final PsiType argumentType = argument.getType();
      if (argumentType == null ||
          !argumentType.equalsToText("java.net.URL")) {
        return;
      }
      final PsiElement element = referenceExpression.resolve();
      if (!variable.equals(element)) {
        return;
      }
      urlAdded = true;
    }

    public boolean isUrlAdded() {
      return urlAdded;
    }
  }

  enum ClassType {

    SET, MAP, OTHER;

    public String toString() {
      final String string = super.toString();
      return string.charAt(0) + string.substring(1).toLowerCase();
    }
  }
}