plugins/groovy/groovy-psi/src/org/jetbrains/plugins/groovy/codeInspection/confusing/DelegatesToInspection.java

/*
 * Copyright 2000-2014 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 org.jetbrains.plugins.groovy.codeInspection.confusing;

import com.intellij.codeInspection.LocalQuickFix;
import com.intellij.codeInspection.ProblemHighlightType;
import com.intellij.psi.PsiAnnotation;
import com.intellij.psi.PsiAnnotationMemberValue;
import com.intellij.psi.PsiElement;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.plugins.groovy.codeInspection.BaseInspection;
import org.jetbrains.plugins.groovy.codeInspection.BaseInspectionVisitor;
import org.jetbrains.plugins.groovy.codeInspection.GroovyInspectionBundle;
import org.jetbrains.plugins.groovy.lang.psi.api.auxiliary.modifiers.annotation.GrAnnotation;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.params.GrParameter;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.params.GrParameterList;
import org.jetbrains.plugins.groovy.lang.psi.impl.GrAnnotationUtil;
import org.jetbrains.plugins.groovy.lang.psi.util.GroovyCommonClassNames;

/**
 * @author Max Medvedev
 */
public class DelegatesToInspection extends BaseInspection {
  @NotNull
  @Override
  protected BaseInspectionVisitor buildVisitor() {
    return new BaseInspectionVisitor() {
      @Override
      public void visitAnnotation(GrAnnotation annotation) {
        checkTarget(annotation);
        checkDelegatesTo(annotation);
      }

      private void checkTarget(GrAnnotation annotation) {
        if (!GroovyCommonClassNames.GROOVY_LANG_DELEGATES_TO_TARGET.equals(annotation.getQualifiedName())) return;


        final PsiElement owner = annotation.getParent().getParent();
        if (!(owner instanceof GrParameter)) return;


        final boolean isTargetDeclared = annotation.findDeclaredAttributeValue("value") != null;
        String targetName = GrAnnotationUtil.inferStringAttribute(annotation, "value");

        final GrParameterList parameterList = DefaultGroovyMethods.asType(owner.getParent(), GrParameterList.class);
        for (GrParameter parameter : parameterList.getParameters()) {
          final PsiAnnotation delegatesTo = parameter.getModifierList().findAnnotation(GroovyCommonClassNames.GROOVY_LANG_DELEGATES_TO);
          if (delegatesTo != null) {
            if (isTargetDeclared) {
              final String curTarget = GrAnnotationUtil.inferStringAttribute(delegatesTo, "target");
              if (curTarget != null && curTarget.equals(targetName)) {
                return; //target is used
              }
            }
            else {
              if (delegatesTo.findDeclaredAttributeValue("target") == null && delegatesTo.findDeclaredAttributeValue("value") == null) {
                return; // target is used
              }
            }
          }
        }

        registerError(annotation.getClassReference(), GroovyInspectionBundle.message("target.annotation.is.unused"),
                      LocalQuickFix.EMPTY_ARRAY, ProblemHighlightType.GENERIC_ERROR_OR_WARNING);
      }

      private void checkDelegatesTo(GrAnnotation annotation) {
        if (!GroovyCommonClassNames.GROOVY_LANG_DELEGATES_TO.equals(annotation.getQualifiedName())) return;

        final PsiElement owner = annotation.getParent().getParent();
        if (!(owner instanceof GrParameter)) return;

        final PsiAnnotationMemberValue targetPair = annotation.findDeclaredAttributeValue("target");
        if (targetPair == null) return;

        String targetName = GrAnnotationUtil.inferStringAttribute(annotation, "target");

        final GrParameterList parameterList = DefaultGroovyMethods.asType(owner.getParent(), GrParameterList.class);
        for (GrParameter parameter : parameterList.getParameters()) {
          final PsiAnnotation target = parameter.getModifierList().findAnnotation(GroovyCommonClassNames.GROOVY_LANG_DELEGATES_TO_TARGET);
          if (target != null) {
            final String curTarget = GrAnnotationUtil.inferStringAttribute(target, "value");
            if (curTarget != null && curTarget.equals(targetName)) {
              return; //target is used
            }
          }
        }

        registerError(targetPair, GroovyInspectionBundle.message("target.0.does.not.exist", targetName != null ? targetName : "?"),
                      LocalQuickFix.EMPTY_ARRAY, ProblemHighlightType.GENERIC_ERROR_OR_WARNING);
      }
    };
  }
}