/* 
 * 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.felix.ipojo.junit4osgi.helpers;

import java.util.ArrayList;
import java.util.Dictionary;
import java.util.List;
import java.util.Properties;

import org.apache.felix.ipojo.ComponentInstance;
import org.apache.felix.ipojo.Factory;
import org.apache.felix.ipojo.Handler;
import org.apache.felix.ipojo.HandlerFactory;
import org.apache.felix.ipojo.ServiceContext;
import org.apache.felix.ipojo.architecture.Architecture;
import org.apache.felix.ipojo.junit4osgi.Helper;
import org.apache.felix.ipojo.junit4osgi.OSGiTestCase;
import org.apache.felix.ipojo.metadata.Element;
import org.apache.felix.ipojo.parser.ManifestMetadataParser;
import org.apache.felix.ipojo.parser.ParseException;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.service.cm.ManagedServiceFactory;

/**
 * iPOJO Helper.
 * This helper helps getting {@link Factory}, and managing
 * {@link ComponentInstance}.
 * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
 */
public class IPOJOHelper extends Helper {

    /**
     * The bundle context.
     */
    private BundleContext m_context;
    /**
     * The test case.
     */
    private OSGiTestCase m_testcase;

    /**
     * List of instances.
     */
    private List m_instances;

    /**
     * Creates a IPOJOHelper.
     * @param tc the OSGi Test Case
     */
    public IPOJOHelper(OSGiTestCase tc) {
        super(tc);
        m_testcase = tc;
        m_context = m_testcase.getBundleContext();
        m_instances = new ArrayList();
    }

    /**
     * Disposes created instances.
     * @see org.apache.felix.ipojo.junit4osgi.Helper#dispose()
     */
    public void dispose() {
        for (int i = 0; i < m_instances.size(); i++) {
            ((ComponentInstance) m_instances.get(i)).dispose();
        }
        m_instances.clear();
    }

    /**
     * Gets a created instance from the instance name.
     * @param name the instance name.
     * @return the created {@link ComponentInstance} or <code>null</code>
     * if the instance was not created during the session.
     */
    public ComponentInstance getInstanceByName(String name) {
        for (int i = 0; i < m_instances.size(); i++) {
            if (((ComponentInstance) m_instances.get(i)).getInstanceName()
                    .equals(name)) {
                return (ComponentInstance) m_instances.get(i);
            }
        }
        return null;
    }

    /**
     * Creates a new component instance with the given name (and empty
     * configuration), from the factory specified in the given bundle.
     * 
     * @param bundle the bundle from which the component factory is defined.
     * @param factoryName the name of the component factory, defined in the
     *            specified bundle.
     * @param instanceName the name of the component instance to create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(Bundle bundle,
            String factoryName, String instanceName) {

        // Create the instance configuration
        Properties configuration = new Properties();
        configuration.put("instance.name", instanceName);

        return createComponentInstance(bundle, factoryName, configuration);
    }

    /**
     * Creates a new component instance with the given configuration, from the
     * factory specified in the given bundle.
     * 
     * @param bundle the bundle from which the component factory is defined.
     * @param factoryName the name of the component factory, defined in the
     *            specified bundle.
     * @param configuration the configuration of the component instance to
     *            create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(Bundle bundle,
            String factoryName, Dictionary configuration) {

        // Retrieve the component factory.
        Factory fact = getFactory(bundle, factoryName);

        if (fact == null) {
            // Factory not found...
            throw new IllegalArgumentException(
                    "Cannot find the component factory (" + factoryName
                            + ") in the specified bundle ("
                            + bundle.getSymbolicName() + ").");
        }

        try {
            return fact.createComponentInstance(configuration);
        } catch (Exception e) {
            throw new IllegalArgumentException(
                    "Cannot create the component instance with the given configuration:"
                            + e.getMessage());
        }
    }

    /**
     * Creates a new component instance with the given name and configuration,
     * from the factory specified in the given bundle.
     * 
     * @param bundle the bundle from which the component factory is defined.
     * @param factoryName the name of the component factory, defined in the
     *            specified bundle.
     * @param instanceName the name of the component instance to create.
     * @param configuration the configuration of the instance to create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(Bundle bundle,
            String factoryName, String instanceName, Dictionary configuration) {

        // Add the instance name to the configuration
        configuration.put("instance.name", instanceName);

        return createComponentInstance(bundle, factoryName, configuration);
    }

    /**
     * Creates a new component instance with the given name (and an empty
     * configuration), from the factory specified in the given service context.
     * 
     * @param serviceContext the service context in which the component factory
     *            service is registered.
     * @param factoryName the name of the component factory, defined in the
     *            specified service context.
     * @param instanceName the name of the component instance to create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(
            ServiceContext serviceContext, String factoryName,
            String instanceName) {

        // Create the instance configuration
        Properties configuration = new Properties();
        configuration.put("instance.name", instanceName);

        return createComponentInstance(serviceContext, factoryName,
                configuration);
    }

    /**
     * Creates a new component instance with the given name and configuration,
     * from the factory specified in the given service context.
     * 
     * @param serviceContext the service context in which the component factory
     *            service is registered.
     * @param factoryName the name of the component factory, defined in the
     *            specified service context.
     * @param configuration the configuration of the instance to create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(
            ServiceContext serviceContext, String factoryName,
            Dictionary configuration) {

        // Retrieve the component factory.
        Factory fact = getFactory(serviceContext, factoryName);

        if (fact == null) {
            // Factory not found...
            throw new IllegalArgumentException(
                    "Cannot find the component factory (" + factoryName
                            + ") in the specified service context.");
        }

        try {
            return fact.createComponentInstance(configuration);
        } catch (Exception e) {
            throw new IllegalArgumentException(
                    "Cannot create the component instance with the given configuration: "
                            + e.getMessage());
        }
    }

    /**
     * Creates a new component instance with the given name and configuration,
     * from the factory specified in the given service context.
     * 
     * @param serviceContext the service context in which the component factory
     *            service is registered.
     * @param factoryName the name of the component factory, defined in the
     *            specified service context.
     * @param instanceName the name of the component instance to create.
     * @param configuration the configuration of the instance to create.
     * @return the newly created component instance.
     */
    public static ComponentInstance createComponentInstance(
            ServiceContext serviceContext, String factoryName,
            String instanceName, Dictionary configuration) {

        // Add the instance name to the configuration
        configuration.put("instance.name", instanceName);

        return createComponentInstance(serviceContext, factoryName,
                configuration);
    }

    /**
     * Creates a new component instance with the given name (and empty
     * configuration), from the factory specified in the local bundle.
     * 
     * @param factoryName the name of the component factory, defined in the
     *            local bundle.
     * @param instanceName the name of the component instance to create.
     * @return the newly created component instance.
     */
    public ComponentInstance createComponentInstance(String factoryName,
            String instanceName) {
        ComponentInstance ci = createComponentInstance(m_context.getBundle(),
                factoryName, instanceName);
        m_instances.add(ci);
        return ci;
    }

    /**
     * Creates a new component instance with the given configuration, from the
     * factory specified in the local bundle.
     * 
     * @param factoryName the name of the component factory, in the local
     *            bundle.
     * @param configuration the configuration of the component instance to
     *            create.
     * @return the newly created component instance.
     */
    public ComponentInstance createComponentInstance(String factoryName,
            Dictionary configuration) {
        ComponentInstance ci = createComponentInstance(m_context.getBundle(),
                factoryName, configuration);
        m_instances.add(ci);
        return ci;
    }

    /**
     * Creates a new component instance with no configuration, from the factory
     * specified in the local bundle.
     * 
     * @param factoryName the name of the component factory, in the local
     *            bundle.
     * @return the newly created component instance.
     */
    public ComponentInstance createComponentInstance(String factoryName) {
        ComponentInstance ci = createComponentInstance(m_context.getBundle(),
                factoryName, (Dictionary) null);
        m_instances.add(ci);
        return ci;
    }

    /**
     * Creates a new component instance with the given name and configuration,
     * from the factory specified in the given bundle.
     * 
     * @param factoryName the name of the component factory, defined in the
     *            specified bundle.
     * @param instanceName the name of the component instance to create.
     * @param configuration the configuration of the instance to create.
     * @return the newly created component instance.
     */
    public ComponentInstance createComponentInstance(String factoryName,
            String instanceName, Dictionary configuration) {
        ComponentInstance ci = createComponentInstance(m_context.getBundle(),
                factoryName, instanceName, configuration);
        m_instances.add(ci);
        return ci;
    }

    /**
     * Returns the component factory with the given name in the local bundle.
     * 
     * @param factoryName the name of the factory to retrieve.
     * @return the component factory with the given name in the local bundle, or
     *         {@code null} if not found.
     */
    public Factory getFactory(String factoryName) {
        return getFactory(m_context.getBundle(), factoryName);
    }

    /**
     * Returns the handler factory with the given name in the local bundle.
     * 
     * @param factoryName the name of the handler factory to retrieve.
     * @return the handler factory with the given name in the local bundle, or
     *         {@code null} if not found.
     */
    public HandlerFactory getHandlerFactory(String factoryName) {
        return getHandlerFactory(m_context.getBundle(), factoryName);
    }

    /**
     * Returns the metadata description of the component defined in this bundle.
     * 
     * @param component the name of the locally defined component.
     * @return the metadata description of the component with the given name,
     *         defined in this given bundle, or {@code null} if not found.
     */
    public Element getMetadata(String component) {
        return getMetadata(m_context.getBundle(), component);
    }

    /**
     * Returns the component factory with the given name in the given bundle.
     * 
     * @param bundle the bundle from which the component factory is defined.
     * @param factoryName the name of the defined factory.
     * @return the component factory with the given name in the given bundle, or
     *         {@code null} if not found.
     */
    public static Factory getFactory(Bundle bundle, String factoryName) {
        ServiceReference[] refs;
        try {
            // Retrieves the component factories services in the bundle.
            refs = bundle.getBundleContext().getServiceReferences(
                    Factory.class.getName(),
                    "(factory.name=" + factoryName + ")");
            if (refs != null) {
                return (Factory) bundle.getBundleContext().getService(refs[0]);
            }

            // Factory not found...
            return null;

        } catch (InvalidSyntaxException e) {
            throw new IllegalArgumentException(
                    "Cannot get the component factory services: "
                            + e.getMessage());
        }
    }

    /**
     * Returns the component factory with the given name, registered in the
     * given service context.
     * 
     * @param serviceContext the service context in which the factory service is
     *            defined.
     * @param factoryName the name of the factory.
     * @return the component factory with the given name, registered in the
     *         given service context.
     */
    public static Factory getFactory(ServiceContext serviceContext,
            String factoryName) {
        ServiceReference[] refs;
        try {
            // Retrieves the component factories services in the service
            // context.
            refs = serviceContext.getServiceReferences(Factory.class.getName(),
                    "(factory.name=" + factoryName + ")");
            if (refs != null) {
                return (Factory) serviceContext.getService(refs[0]);
            }
            return null;

        } catch (InvalidSyntaxException e) {
            System.err.println("Cannot get the factory " + factoryName + " : "
                    + e.getMessage());
            return null;
        }
    }

    /**
     * Returns the handler factory with the given name in the given bundle.
     * 
     * @param bundle the bundle from which the handler factory is defined.
     * @param factoryName the name of the handler factory to retrieve.
     * @return the handler factory with the given name in the given bundle, or
     *         {@code null} if not found.
     */
    public static HandlerFactory getHandlerFactory(Bundle bundle,
            String factoryName) {
        ServiceReference[] refs;
        try {
            // Retrieves the handler factories services in the bundle.
            refs = bundle.getBundleContext().getServiceReferences(
                    HandlerFactory.class.getName(),
                    "(" + Handler.HANDLER_NAME_PROPERTY + "=" + factoryName
                            + ")");
            if (refs != null) {
                return (HandlerFactory) bundle.getBundleContext().getService(
                        refs[0]);
            }

            // Factory not found...
            return null;
        } catch (InvalidSyntaxException e) {
            throw new IllegalArgumentException(
                    "Cannot get the handler factory services: "
                            + e.getMessage());
        }
    }

    /**
     * Returns the metadata description of the component with the given name,
     * defined in the given bundle.
     * 
     * @param bundle the bundle from which the component is defined.
     * @param component the name of the defined component.
     * @return the metadata description of the component with the given name,
     *         defined in the given bundle, or {@code null} if not found.
     */
    public static Element getMetadata(Bundle bundle, String component) {

        // Retrieves the component description from the bundle's manifest.
        String elem = (String) bundle.getHeaders().get("iPOJO-Components");
        if (elem == null) {
            throw new IllegalArgumentException(
                    "Cannot find iPOJO-Components descriptor in the specified bundle ("
                            + bundle.getSymbolicName()
                            + "). Not an iPOJO bundle.");
        }

        // Parses the retrieved description and find the component with the
        // given name.
        try {
            Element element = ManifestMetadataParser.parseHeaderMetadata(elem);
            Element[] childs = element.getElements("component");
            for (int i = 0; i < childs.length; i++) {
                String name = childs[i].getAttribute("name");
                String clazz = childs[i].getAttribute("classname");
                if (name != null && name.equalsIgnoreCase(component)) {
                    return childs[i];
                }
                if (clazz.equalsIgnoreCase(component)) {
                    return childs[i];
                }
            }

            // Component not found...
            return null;

        } catch (ParseException e) {
            throw new IllegalStateException(
                    "Cannot parse the components from specified bundle ("
                            + bundle.getSymbolicName() + "): " + e.getMessage());
        }
    }

    /**
     * Returns the service object of a service registered in the specified
     * service context, offering the specified interface and matching the given
     * filter.
     * 
     * @param serviceContext the service context in which the service is
     *            searched.
     * @param itf the interface provided by the searched service.
     * @param filter an additional filter (can be {@code null}).
     * @return the service object provided by the specified bundle, offering the
     *         specified interface and matching the given filter.
     */
    public static Object getServiceObject(ServiceContext serviceContext,
            String itf, String filter) {
        ServiceReference ref = getServiceReference(serviceContext, itf, filter);
        if (ref != null) {
            return serviceContext.getService(ref);
        } else {
            return null;
        }
    }

    /**
     * Returns the service objects of the services registered in the specified
     * service context, offering the specified interface and matching the given
     * filter.
     * 
     * @param serviceContext the service context in which services are searched.
     * @param itf the interface provided by the searched services.
     * @param filter an additional filter (can be {@code null}).
     * @return the service objects provided by the specified bundle, offering
     *         the specified interface and matching the given filter.
     */
    public static Object[] getServiceObjects(ServiceContext serviceContext,
            String itf, String filter) {
        ServiceReference[] refs = getServiceReferences(serviceContext, itf,
                filter);
        if (refs != null) {
            Object[] list = new Object[refs.length];
            for (int i = 0; i < refs.length; i++) {
                list[i] = serviceContext.getService(refs[i]);
            }
            return list;
        } else {
            return new Object[0];
        }
    }

    /**
     * Returns the service reference of a service registered in the specified
     * service context, offering the specified interface and matching the given
     * filter.
     * 
     * @param serviceContext the service context in which services are searched.
     * @param itf the interface provided by the searched service.
     * @param filter an additional filter (can be {@code null}).
     * @return a service reference registered in the specified service context,
     *         offering the specified interface and matching the given filter.
     *         If no service is found, {@code null} is returned.
     */
    public static ServiceReference getServiceReference(
            ServiceContext serviceContext, String itf, String filter) {
        ServiceReference[] refs = getServiceReferences(serviceContext, itf,
                filter);
        if (refs.length != 0) {
            return refs[0];
        } else {
            // No service found
            return null;
        }
    }

    /**
     * Returns the service reference of the service registered in the specified
     * service context, offering the specified interface and having the given
     * persistent ID.
     * 
     * @param serviceContext the service context in which services are searched.
     * @param itf the interface provided by the searched service.
     * @param pid the persistent ID of the searched service.
     * @return a service registered in the specified service context, offering
     *         the specified interface and having the given persistent ID.
     */
    public static ServiceReference getServiceReferenceByPID(
            ServiceContext serviceContext, String itf, String pid) {
        String filter = "(" + "service.pid" + "=" + pid + ")";
        ServiceReference[] refs = getServiceReferences(serviceContext, itf,
                filter);
        if (refs == null) {
            return null;
        } else if (refs.length == 1) {
            return refs[0];
        } else {
            throw new IllegalStateException(
                    "A service lookup by PID returned several providers ("
                            + refs.length + ")" + " for " + itf + " with pid="
                            + pid);
        }
    }

    /**
     * Returns the service reference of all the services registered in the
     * specified service context, offering the specified interface and matching
     * the given filter.
     * 
     * @param serviceContext the service context in which services are searched.
     * @param itf the interface provided by the searched services.
     * @param filter an additional filter (can be {@code null}).
     * @return all the service references registered in the specified service
     *         context, offering the specified interface and matching the given
     *         filter. If no service matches, an empty array is returned.
     */
    public static ServiceReference[] getServiceReferences(
            ServiceContext serviceContext, String itf, String filter) {
        ServiceReference[] refs = null;
        try {
            // Get all the service references
            refs = serviceContext.getServiceReferences(itf, filter);
        } catch (InvalidSyntaxException e) {
            throw new IllegalArgumentException(
                    "Cannot get service references: " + e.getMessage());
        }
        if (refs == null) {
            return new ServiceReference[0];
        } else {
            return refs;
        }
    }

    /**
     * Returns the service reference of a service registered in the specified
     * service context, offering the specified interface and having the given
     * name.
     * 
     * @param serviceContext the service context in which services are searched.
     * @param itf the interface provided by the searched service.
     * @param name the name of the searched service.
     * @return a service registered in the specified service context, offering
     *         the specified interface and having the given name.
     */
    public static ServiceReference getServiceReferenceByName(
            ServiceContext serviceContext, String itf, String name) {
        String filter = null;
        if (itf.equals(Factory.class.getName())
                || itf.equals(ManagedServiceFactory.class.getName())) {
            filter = "(" + "factory.name" + "=" + name + ")";
        } else if (itf.equals(Architecture.class.getName())) {
            filter = "(" + "architecture.instance" + "=" + name + ")";
        } else {
            filter = "(" + "instance.name" + "=" + name + ")";
        }
        return getServiceReference(serviceContext, itf, filter);
    }

    /**
     * Checks the availability of a service inside the given service context.
     * @param sc the service context
     * @param itf the service interface to found
     * @return <code>true</code> if the service is available in the service
     *         context, <code>false</code> otherwise.
     */
    public static boolean isServiceAvailable(ServiceContext sc, String itf) {
        ServiceReference ref = getServiceReference(sc, itf, null);
        return ref != null;
    }

    /**
     * Checks the availability of a service inside the given service context.
     * @param sc the service context
     * @param itf the service interface to found
     * @param name the service provider name
     * @return <code>true</code> if the service is available in the service
     *         context, <code>false</code> otherwise.
     */
    public static boolean isServiceAvailableByName(ServiceContext sc,
            String itf, String name) {
        ServiceReference ref = getServiceReferenceByName(sc, itf, name);
        return ref != null;
    }

    /**
     * Checks the availability of a service inside the given service context.
     * @param sc the service context
     * @param itf the service interface to found
     * @param pid the pid of the service
     * @return <code>true</code> if the service is available in the service
     *         context, <code>false</code> otherwise.
     */
    public static boolean isServiceAvailableByPID(ServiceContext sc,
            String itf, String pid) {
        ServiceReference ref = getServiceReferenceByPID(sc, itf, pid);
        return ref != null;
    }

    /**
     * Returns the service reference of a service provided by the specified
     * bundle, offering the specified interface and having the given name.
     * 
     * @param bundle the bundle from which the service is searched.
     * @param itf the interface provided by the searched service.
     * @param name the name of the searched service.
     * @return a service provided by the specified bundle, offering the
     *         specified interface and having the given name.
     */
    public static ServiceReference getServiceReferenceByName(Bundle bundle,
            String itf, String name) {
        String filter = null;
        if (itf.equals(Factory.class.getName())
                || itf.equals(ManagedServiceFactory.class.getName())) {
            filter = "(" + "factory.name" + "=" + name + ")";
        } else if (itf.equals(Architecture.class.getName())) {
            filter = "(" + "architecture.instance" + "=" + name + ")";
        } else {
            filter = "(" + "instance.name" + "=" + name + ")";
        }
        return OSGiTestCase.getServiceReference(bundle, itf, filter);
    }

    /**
     * Returns the service reference of a service provided by the local bundle,
     * offering the specified interface and having the given name.
     * 
     * @param itf the interface provided by the searched service.
     * @param name the name of the searched service.
     * @return a service provided by the specified bundle, offering the
     *         specified interface and having the given name.
     */
    public ServiceReference getServiceReferenceByName(String itf, String name) {
        return getServiceReferenceByName(m_context.getBundle(), itf, name);
    }

    /**
     * Checks if the service is available.
     * @param itf the service interface
     * @param name the service provider name
     * @return <code>true</code> if the service is available, <code>false</code>
     *         otherwise.
     */
    public boolean isServiceAvailableByName(String itf, String name) {
        ServiceReference ref = getServiceReferenceByName(itf, name);
        return ref != null;
    }

}