/*
 * 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.apache.tuscany.sca.implementation.java.introspect.impl;

import static org.apache.tuscany.sca.implementation.java.introspect.impl.JavaIntrospectionHelper.getBaseType;

import java.lang.annotation.ElementType;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.List;

import org.apache.tuscany.sca.assembly.AssemblyFactory;
import org.apache.tuscany.sca.implementation.java.IntrospectionException;
import org.apache.tuscany.sca.implementation.java.JavaImplementation;
import org.apache.tuscany.sca.implementation.java.impl.JavaElementImpl;
import org.apache.tuscany.sca.implementation.java.impl.JavaParameterImpl;
import org.apache.tuscany.sca.interfacedef.InvalidInterfaceException;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.interfacedef.java.JavaInterface;
import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceContract;
import org.apache.tuscany.sca.interfacedef.java.JavaInterfaceFactory;
import org.osoa.sca.annotations.Producer;

/**
 * Processes an {@link @Producer} annotation, updating the component type 
 * 
 * @version $$
 */
public class ProducerProcessor extends BaseJavaClassVisitor {
    private JavaInterfaceFactory javaFactory;

    public ProducerProcessor(AssemblyFactory assemblyFactory, JavaInterfaceFactory javaFactory) {
        super(assemblyFactory);
        this.javaFactory = javaFactory;
    }

    @Override
    public void visitMethod(Method method, JavaImplementation type) throws IntrospectionException {
        Producer annotation = method.getAnnotation(Producer.class);
        if (annotation == null) {
            return; // Not a producer annotation.
        }
        if (!JavaIntrospectionHelper.isSetter(method)) {
            throw new IllegalProducerException("Annotated method is not a setter: " + method, method);
        }
        String name = annotation.name();
        if ("".equals(name)) {
            name = JavaIntrospectionHelper.toPropertyName(method.getName());
        }
        JavaElementImpl prod = type.getReferenceMembers().get(name);
        // Setter override field
        if (prod != null && prod.getElementType() != ElementType.FIELD) {
            throw new DuplicateProducerException(name);
        }
        removeProducer(prod, type);

        JavaElementImpl element = new JavaElementImpl(method, 0);
        org.apache.tuscany.sca.assembly.Producer producer = createProducer(element, name);
        type.getProducers().add(producer);
        type.getReferenceMembers().put(name, element);
    }

    private boolean removeProducer(JavaElementImpl producer, JavaImplementation type) {
        if (producer == null) {
            return false;
        }
        List<org.apache.tuscany.sca.assembly.Producer> producers = type.getProducers();
        for (int i = 0; i < producers.size(); i++) {
            if (producers.get(i).getName().equals(producer.getName())) {
            	producers.remove(i);
                return true;
            }
        }
        return false;
    }

    @Override
    public void visitField(Field field, JavaImplementation type) throws IntrospectionException {
        Producer annotation = field.getAnnotation(Producer.class);
        if (annotation == null) {
            return;
        }
        String name = annotation.name();
        if ("".equals(name)) {
            name = field.getName();
        }
        JavaElementImpl prod = type.getReferenceMembers().get(name);
        if (prod != null && prod.getElementType() == ElementType.FIELD) {
            throw new DuplicateProducerException(name);
        }

        // Setter method override field
        if (prod == null) {
            JavaElementImpl element = new JavaElementImpl(field);
            org.apache.tuscany.sca.assembly.Producer producer = createProducer(element, name);
            type.getProducers().add(producer);
            type.getReferenceMembers().put(name, element);
        }
    }

    @Override
    public void visitConstructorParameter(JavaParameterImpl parameter, JavaImplementation type)
        throws IntrospectionException {
        Producer refAnnotation = parameter.getAnnotation(Producer.class);
        if (refAnnotation == null) {
            return;
        }
        String paramName = parameter.getName();
        String name = getProducerName(paramName, parameter.getIndex(), refAnnotation.name());
        JavaElementImpl prod = type.getReferenceMembers().get(name);

        // Setter override field
        if (prod != null && prod.getElementType() != ElementType.FIELD) {
            throw new DuplicateProducerException(name);
        }

        removeProducer(prod, type);
        org.apache.tuscany.sca.assembly.Producer producer = createProducer(parameter, name);
        type.getProducers().add(producer);
        type.getReferenceMembers().put(name, parameter);
        parameter.setClassifer(Producer.class);
        parameter.setName(name);
    }

    private String getProducerName(String paramName, int pos, String name) throws InvalidConstructorException {
        if ("".equals(name)) {
            name = paramName;
        }
        if ("".equals(name)) {
            return "_producer" + pos;
        }
        if (!"".equals(paramName) && !name.equals(paramName)) {
            throw new InvalidConstructorException("Mismatching names specified for producer parameter " + pos);
        } else {
            return name;
        }
    }

    private org.apache.tuscany.sca.assembly.Producer createProducer(JavaElementImpl element, String name)
        throws IntrospectionException {
    	
        org.apache.tuscany.sca.assembly.Producer producer = assemblyFactory.createProducer();
        JavaInterfaceContract interfaceContract = javaFactory.createJavaInterfaceContract();
        producer.setInterfaceContract(interfaceContract);
        producer.setName(name);
        Class<?> rawType = element.getType();
        Type genericType = element.getGenericType();
        Class<?> baseType = getBaseType(rawType, genericType);
        try {
            JavaInterface interfaze = javaFactory.createJavaInterface(baseType);
            producer.getInterfaceContract().setInterface(interfaze);
            
            for (Operation op : interfaze.getOperations()) {
            	op.setNonBlocking(true);
            }
        } catch (InvalidInterfaceException e) {
            throw new IntrospectionException(e);
        }
        return producer;
    }
}