/*
* 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 static java.lang.System.currentTimeMillis;
import static org.apache.tuscany.sca.definitions.util.SCADefinitionsUtil.aggregateSCADefinitions;
import static org.apache.tuscany.sca.node.impl.NodeUtil.contribution;
import static org.apache.tuscany.sca.node.impl.NodeUtil.createURI;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.InputStream;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
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.assembly.builder.CompositeBuilder;
import org.apache.tuscany.sca.assembly.builder.CompositeBuilderExtensionPoint;
import org.apache.tuscany.sca.contribution.Artifact;
import org.apache.tuscany.sca.contribution.Contribution;
import org.apache.tuscany.sca.contribution.ContributionFactory;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessorExtensionPoint;
import org.apache.tuscany.sca.contribution.processor.URLArtifactProcessor;
import org.apache.tuscany.sca.contribution.processor.URLArtifactProcessorExtensionPoint;
import org.apache.tuscany.sca.contribution.resolver.DefaultModelResolver;
import org.apache.tuscany.sca.contribution.resolver.ExtensibleModelResolver;
import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
import org.apache.tuscany.sca.contribution.resolver.ModelResolverExtensionPoint;
import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
import org.apache.tuscany.sca.core.DefaultExtensionPointRegistry;
import org.apache.tuscany.sca.core.ExtensionPointRegistry;
import org.apache.tuscany.sca.core.FactoryExtensionPoint;
import org.apache.tuscany.sca.core.ModuleActivator;
import org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint;
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.core.assembly.RuntimeAssemblyFactory;
import org.apache.tuscany.sca.core.invocation.ExtensibleProxyFactory;
import org.apache.tuscany.sca.core.invocation.ProxyFactory;
import org.apache.tuscany.sca.core.invocation.ProxyFactoryExtensionPoint;
import org.apache.tuscany.sca.definitions.SCADefinitions;
import org.apache.tuscany.sca.definitions.impl.SCADefinitionsImpl;
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.Client;
import org.apache.tuscany.sca.node.Node;
import org.apache.tuscany.sca.policy.Intent;
import org.apache.tuscany.sca.policy.IntentAttachPointType;
import org.apache.tuscany.sca.policy.PolicySet;
import org.apache.tuscany.sca.provider.SCADefinitionsProvider;
import org.apache.tuscany.sca.provider.SCADefinitionsProviderException;
import org.apache.tuscany.sca.provider.SCADefinitionsProviderExtensionPoint;
import org.apache.tuscany.sca.runtime.RuntimeComponent;
import org.apache.tuscany.sca.runtime.RuntimeComponentContext;
import org.apache.tuscany.sca.work.WorkScheduler;
import org.apache.tuscany.sca.workspace.Workspace;
import org.apache.tuscany.sca.workspace.WorkspaceFactory;
import org.apache.tuscany.sca.workspace.builder.ContributionBuilder;
import org.apache.tuscany.sca.workspace.builder.ContributionBuilderExtensionPoint;
import org.osoa.sca.CallableReference;
import org.osoa.sca.ServiceReference;
import org.osoa.sca.ServiceRuntimeException;

/**
 * Represents an SCA runtime node.
 * 
 * @version $Rev$ $Date$
 */
public class NodeImpl implements Node, Client {

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

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

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

    private ExtensionPointRegistry extensionPoints;
    private Monitor monitor;
    private URLArtifactProcessor<Contribution> contributionProcessor;
    private ModelResolverExtensionPoint modelResolvers;
    private FactoryExtensionPoint modelFactories;
    private WorkspaceFactory workspaceFactory;
    private ContributionFactory contributionFactory;
    private AssemblyFactory assemblyFactory;
    private XMLInputFactory inputFactory;
    private ContributionBuilder contributionDependencyBuilder;
    private CompositeBuilder compositeBuilder;
    private StAXArtifactProcessorExtensionPoint xmlProcessors;
    private StAXArtifactProcessor<Composite> compositeProcessor; 
    private ProxyFactory proxyFactory;
    private List<ModuleActivator> moduleActivators = new ArrayList<ModuleActivator>();
    private CompositeActivator compositeActivator;
    private WorkScheduler workScheduler;
    private SCADefinitions systemDefinitions;

    /** 
     * 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
            init();

            // Read the node configuration feed
            StAXArtifactProcessor<ConfiguredNodeImplementation> configurationProcessor = xmlProcessors.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);
        }
    }

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

        try {
            // Initialize the runtime
            init();

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

            if (compositeURI != null) {
                Composite composite = assemblyFactory.createComposite();
                composite.setURI(compositeURI);
                composite.setUnresolved(true);
                configuration.setComposite(composite);
            }
  
                // Create contribution models
            for (org.apache.tuscany.sca.node.Contribution c : contributions) {
                Contribution contribution = contribution(contributionFactory, c);
                configuration.getContributions().add(contribution);
            }

            // Configure the node
            configureNode(configuration);

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

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

        try {
            // Initialize the runtime
            init();

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

            // Read the composite model
            logger.log(Level.INFO, "Loading composite: " + compositeURI);

            XMLStreamReader reader = inputFactory.createXMLStreamReader(new ByteArrayInputStream(compositeContent.getBytes("UTF-8")));
            reader.nextTag();
            
            // Read the composite model
            composite = (Composite)compositeProcessor.read(reader);
            if (composite != null) {
                composite.setURI(compositeURI);
            }
            analyzeProblems();

            configuration.setComposite(composite);

            // Create contribution models
            for (org.apache.tuscany.sca.node.Contribution c : contributions) {
                Contribution contribution = contribution(contributionFactory, c);
                configuration.getContributions().add(contribution);
            }

            // Configure the node
            configureNode(configuration);

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

    private void init() {
        long start = currentTimeMillis();
        
        // Create extension point registry 
        extensionPoints = new DefaultExtensionPointRegistry();
        
        // Create a monitor
        UtilityExtensionPoint utilities = extensionPoints.getExtensionPoint(UtilityExtensionPoint.class);
        MonitorFactory monitorFactory = utilities.getUtility(MonitorFactory.class);
        monitor = monitorFactory.createMonitor(); 
        
        // Initialize the Tuscany module activators
        ModuleActivatorExtensionPoint activators = extensionPoints.getExtensionPoint(ModuleActivatorExtensionPoint.class);
        for (ModuleActivator moduleActivator: activators.getModuleActivators()) {
            moduleActivator.start(extensionPoints);
            moduleActivators.add(moduleActivator);
        }

        // Get XML input/output factories
        modelFactories = extensionPoints.getExtensionPoint(FactoryExtensionPoint.class);
        inputFactory = modelFactories.getFactory(XMLInputFactory.class);
        
        // Get contribution workspace and assembly model factories
        contributionFactory = modelFactories.getFactory(ContributionFactory.class);
        workspaceFactory = modelFactories.getFactory(WorkspaceFactory.class); 
        assemblyFactory = modelFactories.getFactory(AssemblyFactory.class);

        // Use the runtime-enabled assembly factory 
        assemblyFactory = new RuntimeAssemblyFactory();
        modelFactories.addFactory(assemblyFactory);
        
        // Create XML artifact processors
        xmlProcessors = extensionPoints.getExtensionPoint(StAXArtifactProcessorExtensionPoint.class);
        compositeProcessor = xmlProcessors.getProcessor(Composite.class);
        
        // Create contribution content processor
        URLArtifactProcessorExtensionPoint docProcessorExtensions = extensionPoints.getExtensionPoint(URLArtifactProcessorExtensionPoint.class);
        contributionProcessor = docProcessorExtensions.getProcessor(Contribution.class);
        
        // Get the model resolvers
        modelResolvers = extensionPoints.getExtensionPoint(ModelResolverExtensionPoint.class);
        
        // Get a contribution dependency builder
        ContributionBuilderExtensionPoint contributionBuilders = extensionPoints.getExtensionPoint(ContributionBuilderExtensionPoint.class);
        contributionDependencyBuilder = contributionBuilders.getContributionBuilder("org.apache.tuscany.sca.workspace.builder.ContributionDependencyBuilder");
        
        // Get composite builders
        CompositeBuilderExtensionPoint compositeBuilders = extensionPoints.getExtensionPoint(CompositeBuilderExtensionPoint.class);
        compositeBuilder = compositeBuilders.getCompositeBuilder("org.apache.tuscany.sca.assembly.builder.CompositeBuilder");
        
        // Initialize runtime

        // Get proxy factory
        ProxyFactoryExtensionPoint proxyFactories = extensionPoints.getExtensionPoint(ProxyFactoryExtensionPoint.class);
        proxyFactory = new ExtensibleProxyFactory(proxyFactories);

        // Get the composite activator
        compositeActivator = utilities.getUtility(CompositeActivator.class);

        workScheduler = utilities.getUtility(WorkScheduler.class);

        // This is not right, the aggregate algorithm is not right, adding policies to
        // a resolver like that is not correct as these policies won't be seen by the resolvers
        // used by the contributions, and we shouldn't have to use the doc processor to do
        // the resolution, so commenting out for now as it's not critical to get working in
        // the Equinox environment initially
        
//        // Load the system definitions.xml
//        SCADefinitionsProviderExtensionPoint definitionsProviders = extensionPoints.getExtensionPoint(SCADefinitionsProviderExtensionPoint.class);
//        systemDefinitions = new SCADefinitionsImpl();
//        try {
//            for (SCADefinitionsProvider definitionsProvider : definitionsProviders.getSCADefinitionsProviders()) {
//                aggregateSCADefinitions(definitionsProvider.getSCADefinition(), systemDefinitions);
//            }
//        } catch (SCADefinitionsProviderException e) {
//            throw new IllegalStateException(e);
//        }
//
//        // Configure a resolver for the system definitions
//        ModelResolver definitionsResolver = new DefaultModelResolver();
//        for (Intent intent : systemDefinitions.getPolicyIntents()) {
//            definitionsResolver.addModel(intent);
//        }
//        for (PolicySet policySet : systemDefinitions.getPolicySets()) {
//            definitionsResolver.addModel(policySet);
//        }
//        for (IntentAttachPointType bindingType : systemDefinitions.getBindingTypes()) {
//            definitionsResolver.addModel(bindingType);
//        }
//        for (IntentAttachPointType implementationType : systemDefinitions.getImplementationTypes()) {
//            definitionsResolver.addModel(implementationType);
//        }
//
//        // Now that all system sca definitions have been read, let's resolve them
//        URLArtifactProcessorExtensionPoint documentProcessors = extensionPoints.getExtensionPoint(URLArtifactProcessorExtensionPoint.class);
//        URLArtifactProcessor<SCADefinitions> definitionsProcessor = documentProcessors.getProcessor(SCADefinitions.class);
//        try {
//            definitionsProcessor.resolve(systemDefinitions, definitionsResolver);
//        } catch (ContributionResolveException e) {
//            throw new IllegalStateException(e);
//        }

        if (logger.isLoggable(Level.FINE)) {
            long end = currentTimeMillis();
            logger.fine("The tuscany runtime started in " + (end - start) + " ms.");
        }
    }
    
    private void configureNode(ConfiguredNodeImplementation configuration) throws Exception {

        // Create workspace model
        Workspace workspace = workspaceFactory.createWorkspace();
        workspace.setModelResolver(new ExtensibleModelResolver(workspace, modelResolvers, modelFactories));

        // Load the specified contributions
        for (Contribution c : configuration.getContributions()) {
            URI contributionURI = URI.create(c.getURI());
            
            URI uri = createURI(c.getLocation());
            if (uri.getScheme() == null) {
                uri = new File(c.getLocation()).toURI();
            }
            URL contributionURL = uri.toURL();

            // Load the contribution
            logger.log(Level.INFO, "Loading contribution: " + contributionURL);
            Contribution contribution = contributionProcessor.read(null, contributionURI, contributionURL);
            workspace.getContributions().add(contribution);
            analyzeProblems();
        }

        // Build the contribution dependencies
        Set<Contribution> resolved = new HashSet<Contribution>();
        for (Contribution contribution: workspace.getContributions()) {
            contributionDependencyBuilder.build(contribution, workspace, monitor);
            
            // Resolve contributions
            for (Contribution dependency: contribution.getDependencies()) {
                if (!resolved.contains(dependency)) {
                    resolved.add(dependency);
                    contributionProcessor.resolve(dependency, workspace.getModelResolver());
                }
            }
        }
        
        composite = configuration.getComposite();
        
        // Find the composite in the given contributions
        boolean found = false;
        Artifact compositeFile = contributionFactory.createArtifact();
        compositeFile.setUnresolved(true);
        compositeFile.setURI(composite.getURI());
        for (Contribution contribution: workspace.getContributions()) {
            ModelResolver resolver = contribution.getModelResolver();
            Artifact resolvedArtifact = resolver.resolveModel(Artifact.class, compositeFile);
            if (!resolvedArtifact.isUnresolved() && resolvedArtifact.getModel() instanceof Composite) {
                
                if (!composite.isUnresolved()) {
                    
                    // The composite content was passed into the node and read into a composite model,
                    // don't use the composite found in the contribution, use that composite, but just resolve
                    // it within the context of the contribution
                    compositeProcessor.resolve(composite, resolver);
                    
                } else {
                    
                    // Use the resolved composite we've found in the contribution
                    composite = (Composite)resolvedArtifact.getModel();
                }
                found = true;
                break;
            }
        }
        if (!found) {
            throw new IllegalArgumentException("Composite not found: " + composite.getURI());
        }

        // Build an aggregated SCA definitions model
        SCADefinitions definitions = systemDefinitions;
        //definitions = new SCADefinitionsImpl();
        //for (SCADefinitions definition : ((List<SCADefinitions>)policyDefinitions)) {
        //    SCADefinitionsUtil.aggregateSCADefinitions(definition, definitions);
        //}
        
        // Build the composite and wire the components included in it
        compositeBuilder.build(composite, definitions, monitor);
        analyzeProblems();
        
        // Create a top level composite to host our composite
        // This is temporary to make the activator happy
        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);
    }

    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 IllegalStateException(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 IllegalStateException(e);
        }

    }
    
    public void destroy() {
        // Stop the runtime modules
        for (ModuleActivator moduleActivator: moduleActivators) {
            moduleActivator.stop(extensionPoints);
        }

        // Stop and destroy the work manager
        workScheduler.destroy();
    }

    public <B, R extends CallableReference<B>> R cast(B target) throws IllegalArgumentException {
        return (R)proxyFactory.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() + "$slash$" + 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);
            }
        }
    }

    /**
     * Analyze problems reported by the artifact processors and builders.
     * 
     * @throws Exception
     */
    private void analyzeProblems() 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());
                }
            }
        }
    }

}