/*
* 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.node.impl;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;

import org.apache.tuscany.sca.assembly.AssemblyFactory;
import org.apache.tuscany.sca.assembly.Component;
import org.apache.tuscany.sca.assembly.ComponentService;
import org.apache.tuscany.sca.assembly.Composite;
import org.apache.tuscany.sca.assembly.CompositeService;
import org.apache.tuscany.sca.contribution.Contribution;
import org.apache.tuscany.sca.contribution.ContributionFactory;
import org.apache.tuscany.sca.contribution.ContributionMetadata;
import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessorExtensionPoint;
import org.apache.tuscany.sca.contribution.service.ContributionService;
import org.apache.tuscany.sca.contribution.service.util.FileHelper;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.UtilityExtensionPoint;
import org.apache.tuscany.sca.core.assembly.ActivationException;
import org.apache.tuscany.sca.core.assembly.CompositeActivator;
import org.apache.tuscany.sca.host.embedded.impl.ReallySmallRuntime;
import org.apache.tuscany.sca.implementation.node.ConfiguredNodeImplementation;
import org.apache.tuscany.sca.implementation.node.NodeImplementationFactory;
import org.apache.tuscany.sca.monitor.Monitor;
import org.apache.tuscany.sca.monitor.MonitorFactory;
import org.apache.tuscany.sca.monitor.Problem;
import org.apache.tuscany.sca.monitor.Problem.Severity;
import org.apache.tuscany.sca.node.SCAClient;
import org.apache.tuscany.sca.node.SCAContribution;
import org.apache.tuscany.sca.node.SCANode2;
import org.apache.tuscany.sca.runtime.RuntimeComponent;
import org.apache.tuscany.sca.runtime.RuntimeComponentContext;
import org.osoa.sca.CallableReference;
import org.osoa.sca.ServiceReference;
import org.osoa.sca.ServiceRuntimeException;

/**
 * A local representation of the SCADomain running on a single node
 * 
 * @version $Rev$ $Date$
 */
public class NodeImpl implements SCANode2, SCAClient {

    private static final Logger logger = Logger.getLogger(NodeImpl.class.getName());

    // The node configuration name, used for logging
    private String configurationName;

    // The Tuscany runtime that does the hard work
    private ReallySmallRuntime runtime;
    private CompositeActivator compositeActivator;
    private XMLInputFactory inputFactory;
    private ModelFactoryExtensionPoint modelFactories;
    private StAXArtifactProcessorExtensionPoint artifactProcessors;
    private Monitor monitor;

    private ContributionMetadata metadata;

    // The composite loaded into this node
    private Composite composite;

    /** 
     * Constructs a new SCA node.
     *  
     * @param configuration the the node configuration information.
     */
    NodeImpl(ConfiguredNodeImplementation configuration) {
        configurationName = configuration.getURI();
        logger.log(Level.INFO, "Creating node: " + configuration.getURI());

        try {
            // Initialize the runtime
            initRuntime();

            URL configurationURL = new URL(configuration.getURI());

            // Resolve contribution URLs
            for (Contribution contribution : configuration.getContributions()) {
                URL contributionURL = new URL(configurationURL, contribution.getLocation());
                contribution.setLocation(contributionURL.toString());
            }

            // Resolve composite URL
            URL compositeURL = new URL(configurationURL, configuration.getComposite().getURI());
            configuration.getComposite().setURI(compositeURL.toString());

            // Configure the node
            configureNode(configuration);

        } catch (Exception e) {
            throw new ServiceRuntimeException(e);
        }
    }

    /** 
     * Constructs a new SCA node.
     *  
     * @param configurationURI the URI of the node configuration information.
     */
    NodeImpl(String configurationURI) {
        configurationName = configurationURI;
        logger.log(Level.INFO, "Creating node: " + configurationName);

        try {
            // Initialize the runtime
            initRuntime();

            // Read the node configuration feed
            StAXArtifactProcessor<ConfiguredNodeImplementation> configurationProcessor =
                artifactProcessors.getProcessor(ConfiguredNodeImplementation.class);
            URL configurationURL = new URL(configurationURI);
            InputStream is = configurationURL.openStream();
            XMLStreamReader reader = inputFactory.createXMLStreamReader(is);
            reader.nextTag();
            ConfiguredNodeImplementation configuration = configurationProcessor.read(reader);
            is.close();

            // Resolve contribution URLs
            for (Contribution contribution : configuration.getContributions()) {
                URL contributionURL = new URL(configurationURL, contribution.getLocation());
                contribution.setLocation(contributionURL.toString());
            }

            // Resolve composite URL
            URL compositeURL = new URL(configurationURL, configuration.getComposite().getURI());
            configuration.getComposite().setURI(compositeURL.toString());

            // Configure the node
            configureNode(configuration);

        } catch (Exception e) {
            throw new ServiceRuntimeException(e);
        }
    }

    NodeImpl(ClassLoader classLoader, String compositeURI) {
        configurationName = compositeURI;
        logger.log(Level.INFO, "Creating node: " + configurationName);

        try {
            // Initialize the runtime
            initRuntime();

            ConfiguredNodeImplementation config = findNodeConfiguration(compositeURI, classLoader);
            configureNode(config);
        } catch (Throwable e) {
            throw new ServiceRuntimeException(e);
        }
    }

    private ConfiguredNodeImplementation findNodeConfiguration(final String compositeURI, ClassLoader classLoader)
        throws Exception {
        NodeImplementationFactory nodeImplementationFactory =
            modelFactories.getFactory(NodeImplementationFactory.class);
        ConfiguredNodeImplementation config = nodeImplementationFactory.createConfiguredNodeImplementation();

        if (classLoader == null) {
            classLoader = Thread.currentThread().getContextClassLoader();
        }
        String contributionArtifactPath = compositeURI;
        URL contributionArtifactURL = null;
        if (compositeURI != null) {
            contributionArtifactURL = getResource(classLoader, compositeURI);
            if (contributionArtifactURL == null) {
                throw new IllegalArgumentException("Composite not found: " + contributionArtifactPath);
            }
            composite = createComposite(contributionArtifactURL.toString());
            config.setComposite(composite);
        } else {

            // Here the SCADomain was started without any reference to a composite file
            // We are going to look for an sca-contribution.xml or sca-contribution-generated.xml

            // Look for META-INF/sca-contribution.xml
            contributionArtifactPath = Contribution.SCA_CONTRIBUTION_META;
            contributionArtifactURL = getResource(classLoader, contributionArtifactPath);

            // Look for META-INF/sca-contribution-generated.xml
            if (contributionArtifactURL == null) {
                contributionArtifactPath = Contribution.SCA_CONTRIBUTION_GENERATED_META;
                contributionArtifactURL = getResource(classLoader, contributionArtifactPath);
            }

            // Look for META-INF/sca-deployables directory
            if (contributionArtifactURL == null) {
                contributionArtifactPath = Contribution.SCA_CONTRIBUTION_DEPLOYABLES;
                contributionArtifactURL = getResource(classLoader, contributionArtifactPath);
            } else {
                StAXArtifactProcessor<ContributionMetadata> processor =
                    artifactProcessors.getProcessor(ContributionMetadata.class);
                XMLStreamReader reader = inputFactory.createXMLStreamReader(contributionArtifactURL.openStream());
                metadata = processor.read(reader);
                reader.close();
                if (metadata.getDeployables().isEmpty()) {
                    throw new IllegalArgumentException(
                                                       "No deployable composite is declared in " + contributionArtifactPath);
                }
            }
        }

        if (contributionArtifactURL == null) {
            throw new IllegalArgumentException(
                                               "Can't determine contribution deployables. Either specify a composite file, or use an sca-contribution.xml file to specify the deployables.");
        }

        Contribution c = getContribution(contributionArtifactURL, contributionArtifactPath);
        config.getContributions().add(c);

        return config;
    }

    private Contribution getContribution(URL contributionArtifactURL, String contributionArtifactPath) {
        URL contributionURL = getContributionURL(contributionArtifactURL, contributionArtifactPath);

        ContributionFactory contributionFactory = modelFactories.getFactory(ContributionFactory.class);

        SCAContribution contribution = new SCAContribution(contributionURL.toString(), contributionURL.toString());
        Contribution c = createContribution(contributionFactory, contribution);
        return c;
    }

    private URL getContributionURL(URL contributionArtifactURL, String contributionArtifactPath) {
        URL contributionURL = null;
        // "jar:file://....../something.jar!/a/b/c/app.composite"
        try {
            String url = contributionArtifactURL.toExternalForm();
            String protocol = contributionArtifactURL.getProtocol();
            if ("file".equals(protocol)) {
                // directory contribution
                if (url.endsWith(contributionArtifactPath)) {
                    final String location = url.substring(0, url.lastIndexOf(contributionArtifactPath));
                    // workaround from evil URL/URI form Maven
                    // contributionURL = FileHelper.toFile(new URL(location)).toURI().toURL();
                    // Allow privileged access to open URL stream. Add FilePermission to added to
                    // security policy file.
                    try {
                        contributionURL = AccessController.doPrivileged(new PrivilegedExceptionAction<URL>() {
                            public URL run() throws IOException {
                                return FileHelper.toFile(new URL(location)).toURI().toURL();
                            }
                        });
                    } catch (PrivilegedActionException e) {
                        throw (MalformedURLException)e.getException();
                    }
                }

            } else if ("jar".equals(protocol)) {
                // jar contribution
                String location = url.substring(4, url.lastIndexOf("!/"));
                // workaround for evil URL/URI from Maven
                contributionURL = FileHelper.toFile(new URL(location)).toURI().toURL();

            } else if ("wsjar".equals(protocol)) {
                // See https://issues.apache.org/jira/browse/TUSCANY-2219
                // wsjar contribution 
                String location = url.substring(6, url.lastIndexOf("!/"));
                // workaround for evil url/uri from maven 
                contributionURL = FileHelper.toFile(new URL(location)).toURI().toURL();

            } else if (protocol != null && (protocol.equals("bundle") || protocol.equals("bundleresource"))) {
                contributionURL =
                    new URL(contributionArtifactURL.getProtocol(), contributionArtifactURL.getHost(),
                            contributionArtifactURL.getPort(), "/");
            }
        } catch (MalformedURLException mfe) {
            throw new IllegalArgumentException(mfe);
        }
        return contributionURL;
    }

    private static URL getResource(final ClassLoader classLoader, final String compositeURI) {
        return AccessController.doPrivileged(new PrivilegedAction<URL>() {
            public URL run() {
                return classLoader.getResource(compositeURI);
            }
        });
    }

    /** 
     * Constructs a new SCA node.
     *  
     * @param compositeURI
     * @param contributions
     */
    NodeImpl(String compositeURI, SCAContribution[] contributions) {
        configurationName = compositeURI;
        logger.log(Level.INFO, "Creating node: " + configurationName);

        try {
            // Initialize the runtime
            initRuntime();

            ConfiguredNodeImplementation configuration = null;
            if (contributions == null || contributions.length == 0) {
                configuration = findNodeConfiguration(compositeURI, null);
            } else {

                // Create a node configuration
                NodeImplementationFactory nodeImplementationFactory =
                    modelFactories.getFactory(NodeImplementationFactory.class);
                configuration = nodeImplementationFactory.createConfiguredNodeImplementation();

                Composite composite = createComposite(compositeURI);
                configuration.setComposite(composite);

                // Create contribution models
                ContributionFactory contributionFactory = modelFactories.getFactory(ContributionFactory.class);
                for (SCAContribution c : contributions) {
                    Contribution contribution = createContribution(contributionFactory, c);
                    configuration.getContributions().add(contribution);
                }
            }

            // Configure the node
            configureNode(configuration);

        } catch (Exception e) {
            throw new ServiceRuntimeException(e);
        }
    }

    private Composite createComposite(String compositeURI) {
        // Create composite model
        AssemblyFactory assemblyFactory = modelFactories.getFactory(AssemblyFactory.class);
        Composite composite = assemblyFactory.createComposite();
        composite.setURI(compositeURI);
        composite.setUnresolved(true);
        return composite;
    }

    /** 
     * Constructs a new SCA node.
     *  
     * @param compositeURI
     * @param compositeContent
     * @param contributions
     */
    NodeImpl(String compositeURI, String compositeContent, SCAContribution[] contributions) {
        configurationName = compositeURI;
        logger.log(Level.INFO, "Creating node: " + configurationName);

        try {
            // Initialize the runtime
            initRuntime();

            ConfiguredNodeImplementation configuration = null;
            if (contributions == null || contributions.length == 0) {
                configuration = findNodeConfiguration(compositeURI, null);
            } else {
                // Create a node configuration
                NodeImplementationFactory nodeImplementationFactory =
                    modelFactories.getFactory(NodeImplementationFactory.class);
                configuration = nodeImplementationFactory.createConfiguredNodeImplementation();

                // Read the composite model
                StAXArtifactProcessor<Composite> compositeProcessor = artifactProcessors.getProcessor(Composite.class);
                URL compositeURL = new URL(compositeURI);
                logger.log(Level.INFO, "Loading composite: " + compositeURL);
                XMLStreamReader reader = inputFactory.createXMLStreamReader(new StringReader(compositeContent));
                Composite composite = compositeProcessor.read(reader);
                reader.close();
                configuration.setComposite(composite);

                // Create contribution models
                ContributionFactory contributionFactory = modelFactories.getFactory(ContributionFactory.class);
                for (SCAContribution c : contributions) {
                    Contribution contribution = createContribution(contributionFactory, c);
                    configuration.getContributions().add(contribution);
                }
            }

            // Configure the node
            configureNode(configuration);

        } catch (Exception e) {
            throw new ServiceRuntimeException(e);
        }
    }

    private static Contribution createContribution(ContributionFactory contributionFactory, SCAContribution c) {
        Contribution contribution = contributionFactory.createContribution();
        contribution.setURI(c.getURI());
        contribution.setLocation(c.getLocation());
        contribution.setUnresolved(true);
        return contribution;
    }

    /**
     * Initialize the Tuscany runtime.
     * 
     * @throws Exception
     */
    private void initRuntime() throws Exception {

        // Create a node runtime
        runtime = new ReallySmallRuntime(Thread.currentThread().getContextClassLoader());
        runtime.start();

        // Get the various factories we need
        ExtensionPointRegistry registry = runtime.getExtensionPointRegistry();
        modelFactories = registry.getExtensionPoint(ModelFactoryExtensionPoint.class);
        inputFactory = modelFactories.getFactory(XMLInputFactory.class);

        // Create the required artifact processors
        artifactProcessors = registry.getExtensionPoint(StAXArtifactProcessorExtensionPoint.class);

        // Save the composite activator
        compositeActivator = runtime.getCompositeActivator();

        // save the monitor
        UtilityExtensionPoint utilities = registry.getExtensionPoint(UtilityExtensionPoint.class);
        MonitorFactory monitorFactory = utilities.getUtility(MonitorFactory.class);
        monitor = monitorFactory.createMonitor();
    }

    /**
     * Escape the space in URL string
     * @param uri
     * @return
     */
    private static URI createURI(String uri) {
        if (uri.indexOf(' ') != -1) {
            uri = uri.replace(" ", "%20");
        }
        return URI.create(uri);
    }
    
    private void configureNode(ConfiguredNodeImplementation configuration) throws Exception {

        // Find if any contribution JARs already available locally on the classpath
        Map<String, URL> localContributions = localContributions();

        // Load the specified contributions
        ContributionService contributionService = runtime.getContributionService();
        List<Contribution> contributions = new ArrayList<Contribution>();
        for (Contribution contribution : configuration.getContributions()) {
        	URI uri = createURI(contribution.getLocation());
            if (uri.getScheme() == null) {
                uri = new File(contribution.getLocation()).toURI();
            }
            URL contributionURL = uri.toURL();

            // Extract contribution file name
            String file = contributionURL.getPath();
            int i = file.lastIndexOf('/');
            if (i != -1 && i < file.length() - 1) {
                file = file.substring(i + 1);

                // If we find the local contribution file on the classpath, use it in
                // place of the original contribution URL
                URL localContributionURL = localContributions.get(file);
                if (localContributionURL != null) {
                    contributionURL = localContributionURL;
                }
            }

            // Load the contribution
            logger.log(Level.INFO, "Loading contribution: " + contributionURL);
            contributions.add(contributionService.contribute(contribution.getURI(), contributionURL, false));
            analyseProblems();
        }
        
        // Resolve the metadata within the context of the first contribution
        Contribution mainContribution = contributions.get(contributions.size() - 1);
        if (metadata != null) {
            StAXArtifactProcessor<ContributionMetadata> processor =
                artifactProcessors.getProcessor(ContributionMetadata.class);
            processor.resolve(metadata, mainContribution.getModelResolver());
            List<Composite> composites = metadata.getDeployables();
            configuration.setComposite(composites.get(0));
        }


        // Load the specified composite
        StAXArtifactProcessor<Composite> compositeProcessor = artifactProcessors.getProcessor(Composite.class);
        if (configuration.getComposite().getName() == null) {
        	URI uri = createURI(configuration.getComposite().getURI());
            if (uri.getScheme() == null) {
                uri = new File(configuration.getComposite().getURI()).toURI();
            }
            URL compositeURL = uri.toURL();
            logger.log(Level.INFO, "Loading composite: " + compositeURL);
            URLConnection connection = compositeURL.openConnection();
            connection.setDefaultUseCaches(false);
            connection.setUseCaches(false);
            InputStream is = connection.getInputStream();
            XMLStreamReader reader = inputFactory.createXMLStreamReader(is);
            composite = compositeProcessor.read(reader);
        } else {
            composite = configuration.getComposite();
        }

        analyseProblems();

        // Resolve it within the context of the first contribution
        compositeProcessor.resolve(composite, mainContribution.getModelResolver());

        analyseProblems();

        // Create a top level composite to host our composite
        // This is temporary to make the activator happy
        AssemblyFactory assemblyFactory = runtime.getAssemblyFactory();
        Composite tempComposite = assemblyFactory.createComposite();
        tempComposite.setName(new QName("http://tempuri.org", "temp"));
        tempComposite.setURI("http://tempuri.org");

        // Include the node composite in the top-level composite 
        tempComposite.getIncludes().add(composite);

        // set the top level composite on the composite activator as 
        // logic in callable reference resolution relies on this being 
        // available
        compositeActivator.setDomainComposite(tempComposite);

        // Build the composite
        runtime.buildComposite(composite);

        analyseProblems();
    }

    private void analyseProblems() throws Exception {

        for (Problem problem : monitor.getProblems()) {
            if ((problem.getSeverity() == Severity.ERROR) && (!problem.getMessageId().equals("SchemaError"))) {
                if (problem.getCause() != null) {
                    throw problem.getCause();
                } else {
                    throw new ServiceRuntimeException(problem.toString());
                }
            }
        }
    }

    public void start() {
        logger.log(Level.INFO, "Starting node: " + configurationName);

        try {

            // Activate the composite
            compositeActivator.activate(composite);

            // Start the composite
            compositeActivator.start(composite);

        } catch (ActivationException e) {
            throw new ServiceRuntimeException(e);
        }
    }

    public void stop() {
        logger.log(Level.INFO, "Stopping node: " + configurationName);

        try {

            // Stop the composite
            compositeActivator.stop(composite);

            // Deactivate the composite
            compositeActivator.deactivate(composite);

        } catch (ActivationException e) {
            throw new ServiceRuntimeException(e);
        }
    }

    public <B, R extends CallableReference<B>> R cast(B target) throws IllegalArgumentException {
        return (R)runtime.getProxyFactory().cast(target);
    }

    public <B> B getService(Class<B> businessInterface, String serviceName) {

        ServiceReference<B> serviceReference = getServiceReference(businessInterface, serviceName);
        if (serviceReference == null) {
            throw new ServiceRuntimeException("Service not found: " + serviceName);
        }
        return serviceReference.getService();
    }

    public <B> ServiceReference<B> getServiceReference(Class<B> businessInterface, String name) {

        // Extract the component name
        String componentName;
        String serviceName;
        int i = name.indexOf('/');
        if (i != -1) {
            componentName = name.substring(0, i);
            serviceName = name.substring(i + 1);

        } else {
            componentName = name;
            serviceName = null;
        }

        // Lookup the component 
        Component component = null;

        for (Component compositeComponent : composite.getComponents()) {
            if (compositeComponent.getName().equals(componentName)) {
                component = compositeComponent;
            }
        }

        if (component == null) {
            throw new ServiceRuntimeException("The service " + name + " has not been contributed to the domain");
        }
        RuntimeComponentContext componentContext = null;

        // If the component is a composite, then we need to find the
        // non-composite component that provides the requested service
        if (component.getImplementation() instanceof Composite) {
            for (ComponentService componentService : component.getServices()) {
                if (serviceName == null || serviceName.equals(componentService.getName())) {
                    CompositeService compositeService = (CompositeService)componentService.getService();
                    if (compositeService != null) {
                        if (serviceName != null) {
                            serviceName = "$promoted$." + component.getName() + "." + serviceName;
                        }
                        componentContext =
                            ((RuntimeComponent)compositeService.getPromotedComponent()).getComponentContext();
                        return componentContext.createSelfReference(businessInterface, compositeService
                            .getPromotedService());
                    }
                    break;
                }
            }
            // No matching service found
            throw new ServiceRuntimeException("Composite service not found: " + name);
        } else {
            componentContext = ((RuntimeComponent)component).getComponentContext();
            if (serviceName != null) {
                return componentContext.createSelfReference(businessInterface, serviceName);
            } else {
                return componentContext.createSelfReference(businessInterface);
            }
        }
    }

    /**
     * Returns the extension point registry used by this node.
     * 
     * @return
     */
    public ExtensionPointRegistry getExtensionPointRegistry() {
        return runtime.getExtensionPointRegistry();
    }

    /**
     * Returns the composite being run by this node.
     * 
     * @return
     */
    public Composite getComposite() {
        return composite;
    }

    /**
     * Returns contribution JARs available on the classpath.
     * 
     * @return
     */
    private static Map<String, URL> localContributions() {
        Map<String, URL> localContributions = new HashMap<String, URL>();
        collectJARs(localContributions, Thread.currentThread().getContextClassLoader());
        return localContributions;
    }

    /**
     * Collect JARs on the classpath of a URLClassLoader
     * @param urls
     * @param cl
     */
    private static void collectJARs(Map<String, URL> urls, ClassLoader cl) {
        if (cl == null) {
            return;
        }

        // Collect JARs from the URLClassLoader's classpath
        if (cl instanceof URLClassLoader) {
            URL[] jarURLs = ((URLClassLoader)cl).getURLs();
            if (jarURLs != null) {
                for (URL jarURL : jarURLs) {
                    String file = jarURL.getPath();
                    int i = file.lastIndexOf('/');
                    if (i != -1 && i < file.length() - 1) {
                        file = file.substring(i + 1);
                        urls.put(file, jarURL);
                    }
                }
            }
        }

        // Collect JARs from the parent ClassLoader
        collectJARs(urls, cl.getParent());
    }
}