/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.controller.config.manager.impl;

import java.lang.reflect.Constructor;
import java.util.Arrays;
import java.util.List;

import org.opendaylight.controller.config.api.DependencyResolver;
import org.opendaylight.controller.config.api.DynamicMBeanWithInstance;
import org.opendaylight.controller.config.api.annotations.AbstractServiceInterface;
import org.opendaylight.controller.config.spi.Module;
import org.opendaylight.controller.config.spi.ModuleFactory;

import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;

/**
 * Creates new Config beans by calling {@link Class#newInstance()} on provided
 * config bean class.
 *
 */
public class ClassBasedModuleFactory implements ModuleFactory {
    private final String implementationName;
    private final Class<? extends Module> configBeanClass;

    /**
     * @param implementationName
     * @param configBeanClass
     *            class that will be instantiated when createModule is called.
     *            This class must implement Module interface and all exported
     *            interfaces.
     */
    public ClassBasedModuleFactory(String implementationName,
            Class<? extends Module> configBeanClass) {
        this.implementationName = implementationName;
        this.configBeanClass = configBeanClass;
    }

    @Override
    public String getImplementationName() {
        return implementationName;
    }

    @Override
    public Module createModule(String instanceName,
            DependencyResolver dependencyResolver, DynamicMBeanWithInstance old)
            throws Exception {
        Preconditions.checkNotNull(dependencyResolver);
        Preconditions.checkNotNull(old);
        Constructor<? extends Module> declaredConstructor;
        try {
            declaredConstructor = configBeanClass
                    .getDeclaredConstructor(DynamicMBeanWithInstance.class);
        } catch (NoSuchMethodException e) {
            throw new IllegalStateException(
                    "Did not find constructor with parameters (DynamicMBeanWithInstance) in "
                            + configBeanClass, e);
        }
        Preconditions.checkState(declaredConstructor != null);
        return declaredConstructor.newInstance(old);
    }

    @Override
    public Module createModule(String instanceName,
            DependencyResolver dependencyResolver) {
        try {
            return configBeanClass.newInstance();
        } catch (Exception e) {
            throw Throwables.propagate(e);
        }
    }

    @Override
    public boolean isModuleImplementingServiceInterface(
            Class<? extends AbstractServiceInterface> serviceInterface) {
        Class<?>[] classes = configBeanClass.getInterfaces();
        List<Class<?>> ifc = Arrays.asList(classes);
        if (ifc.contains(serviceInterface)) {
            return true;
        }
        for (Class<?> c : classes) {
            ifc = Arrays.asList(c.getInterfaces());
            if (ifc.contains(serviceInterface)) {
                return true;
            }
        }
        return false;
    }
}