/*
 * 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.configSlurper;

import com.intellij.psi.CommonClassNames;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiType;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.plugins.groovy.extensions.GroovyMapContentProvider;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrMethodCall;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression;
import org.jetbrains.plugins.groovy.lang.psi.impl.GrMapType;
import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyPsiManager;
import org.jetbrains.plugins.groovy.lang.psi.typeEnhancers.GrReferenceTypeEnhancer;

/**
 * @author Sergey Evdokimov
 */
public class GroovyMapValueTypeEnhancer extends GrReferenceTypeEnhancer {
  @Override
  public PsiType getReferenceType(GrReferenceExpression ref, @Nullable PsiElement resolved) {
    if (resolved != null) return null;

    GrExpression qualifierExpression = ref.getQualifierExpression();
    if (qualifierExpression == null) return null;

    PsiType mapType = qualifierExpression.getType();

    if (!GroovyPsiManager.isInheritorCached(mapType, CommonClassNames.JAVA_UTIL_MAP)) {
      return null;
    }

    PsiElement qResolved;

    if (qualifierExpression instanceof GrReferenceExpression) {
      qResolved = ((GrReferenceExpression)qualifierExpression).resolve();
    }
    else if (qualifierExpression instanceof GrMethodCall) {
      qResolved = ((GrMethodCall)qualifierExpression).resolveMethod();
    }
    else {
      return null;
    }

    String key = ref.getReferenceName();
    if (key == null) return null;

    for (GroovyMapContentProvider provider : GroovyMapContentProvider.EP_NAME.getExtensions()) {
      PsiType type = provider.getValueType(qualifierExpression, qResolved, key);
      if (type != null) {
        return type;
      }
    }

    if (mapType instanceof GrMapType) {
      return ((GrMapType)mapType).getTypeByStringKey(key);
    }

    return null;
  }
}