/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.codehaus.groovy.transform.sc.transformers;

import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.MethodNode;
import org.codehaus.groovy.ast.expr.AttributeExpression;
import org.codehaus.groovy.ast.expr.Expression;
import org.codehaus.groovy.ast.expr.MethodCallExpression;
import org.codehaus.groovy.ast.expr.PropertyExpression;
import org.codehaus.groovy.transform.sc.StaticCompilationMetadataKeys;
import org.codehaus.groovy.transform.stc.StaticTypesMarker;

import static org.apache.groovy.ast.tools.ExpressionUtils.isThisExpression;
import static org.codehaus.groovy.ast.tools.GeneralUtils.callX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.classX;

/**
 * Rewrites property expressions into direct field or accessor calls when metadata allows it.
 */
class PropertyExpressionTransformer {

    private final StaticCompilationTransformer scTransformer;

    /**
     * Creates a property-expression transformer backed by the owning static compilation transformer.
     *
     * @param scTransformer the shared transformer context
     */
    PropertyExpressionTransformer(final StaticCompilationTransformer scTransformer) {
        this.scTransformer = scTransformer;
    }

    /**
     * Rewrites a property expression when static compilation can target a direct access path.
     *
     * @param pe the property expression to transform
     * @return the transformed expression
     */
    Expression transformPropertyExpression(final PropertyExpression pe) {
        MethodNode dmct = pe.getNodeMetaData(StaticTypesMarker.DIRECT_METHOD_CALL_TARGET);
        // NOTE: BinaryExpressionTransformer handles the setter
        if (dmct != null && dmct.getParameters().length == 0) {
            MethodCallExpression mce = callX(scTransformer.transform(pe.getObjectExpression()), dmct.getName());
            mce.setImplicitThis(pe.isImplicitThis());
            mce.setMethodTarget(dmct);
            mce.setSourcePosition(pe);
            mce.setSpreadSafe(pe.isSpreadSafe());
            mce.setSafe(pe.isSafe());
            mce.copyNodeMetaData(pe);
            return mce;
        }

        FieldNode field = pe.getNodeMetaData(StaticTypesMarker.PV_FIELDS_ACCESS);
        if (field == null) {
            field = pe.getNodeMetaData(StaticTypesMarker.PV_FIELDS_MUTATION);
        }
        if (field != null) {
            AttributeExpression ae;
            if (field.isStatic()) {
                ae = new AttributeExpression(classX(field.getDeclaringClass()), pe.getProperty());
            } else if (!isThisExpression(pe.getObjectExpression())) {
                ae = new AttributeExpression(scTransformer.transform(pe.getObjectExpression()), pe.getProperty(), pe.isSafe());
            } else {
                ae = new AttributeExpression(new PropertyExpression(classX(field.getDeclaringClass()), "this"), pe.getProperty(), pe.isSafe());

                ae.getObjectExpression().putNodeMetaData(StaticCompilationMetadataKeys.PROPERTY_OWNER, field.getDeclaringClass());
                ae.getObjectExpression().putNodeMetaData(StaticTypesMarker.INFERRED_TYPE, field.getDeclaringClass());
            }
            ae.setSpreadSafe(pe.isSpreadSafe());
            ae.setSourcePosition(pe);
            ae.copyNodeMetaData(pe);
            return ae;
        }

        return scTransformer.superTransform(pe);
    }
}
