/*
 * 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.assembly.xml;

import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;

import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.apache.tuscany.sca.assembly.AssemblyFactory;
import org.apache.tuscany.sca.assembly.Binding;
import org.apache.tuscany.sca.assembly.Callback;
import org.apache.tuscany.sca.assembly.Component;
import org.apache.tuscany.sca.assembly.ComponentProperty;
import org.apache.tuscany.sca.assembly.ComponentReference;
import org.apache.tuscany.sca.assembly.ComponentService;
import org.apache.tuscany.sca.assembly.Composite;
import org.apache.tuscany.sca.assembly.CompositeReference;
import org.apache.tuscany.sca.assembly.CompositeService;
import org.apache.tuscany.sca.assembly.ConstrainingType;
import org.apache.tuscany.sca.assembly.Contract;
import org.apache.tuscany.sca.assembly.Implementation;
import org.apache.tuscany.sca.assembly.Property;
import org.apache.tuscany.sca.assembly.Reference;
import org.apache.tuscany.sca.assembly.Service;
import org.apache.tuscany.sca.assembly.Wire;
import org.apache.tuscany.sca.contribution.ContributionFactory;
import org.apache.tuscany.sca.contribution.DeployedArtifact;
import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
import org.apache.tuscany.sca.contribution.service.ContributionReadException;
import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
import org.apache.tuscany.sca.interfacedef.InterfaceContract;
import org.apache.tuscany.sca.interfacedef.InterfaceContractMapper;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.policy.PolicyFactory;
import org.apache.tuscany.sca.policy.PolicySetAttachPoint;
import org.apache.tuscany.sca.policy.util.PolicyValidationException;
import org.w3c.dom.Document;

/**
 * A component processor.
 * 
 * @version $Rev$ $Date$
 */
public class MetaComponentProcessor extends BaseAssemblyProcessor implements
        StAXArtifactProcessor<Component> {

    /**
     * Construct a new composite processor
     * 
     * @param contributionFactory
     * @param assemblyFactory
     * @param policyFactory
     * @param extensionProcessor
     */
    private Composite composite = null;
    private Component generatedComponent = null;

    public MetaComponentProcessor(ContributionFactory contributionFactory,
            AssemblyFactory factory, PolicyFactory policyFactory,
            InterfaceContractMapper interfaceContractMapper,
            StAXArtifactProcessor extensionProcessor) {
        super(contributionFactory, factory, policyFactory, extensionProcessor);
    }

    /**
     * Construct a new composite processor
     * 
     * @param assemblyFactory
     * @param policyFactory
     * @param extensionProcessor
     *                public CompositeProcessor(AssemblyFactory factory,
     *                PolicyFactory policyFactory, InterfaceContractMapper
     *                interfaceContractMapper, StAXArtifactProcessor
     *                extensionProcessor) { super(factory, policyFactory,
     *                extensionProcessor); }
     */
    public void setComposite(Composite c) {
        composite = c;
    }

    public Component getParsedComponent() {
        return this.generatedComponent;
    }

    public Composite getParsedComposite() {
        return this.composite;
    }

    public Component read(XMLStreamReader reader)
            throws ContributionReadException, XMLStreamException {
        Composite include = null;
        Component component = null;
        Property property = null;
        ComponentService componentService = null;
        ComponentReference componentReference = null;
        ComponentProperty componentProperty = null;
        CompositeService compositeService = null;
        CompositeReference compositeReference = null;
        Contract contract = null;
        Wire wire = null;
        Callback callback = null;
        QName name = null;

        // Read the component scdl

        while (reader.hasNext()) {
            int event = reader.getEventType();
            switch (event) {
            case START_ELEMENT:
                QName itemName = reader.getName();
                if (!itemName.getNamespaceURI().equals(SCA10_NS))
                    name = new QName(SCA10_NS, itemName.getLocalPart());
                else
                    name = itemName;

                if (SERVICE_QNAME.equals(name)) {
                    if (component != null) {

                        // Read a <component><service>
                        componentService = assemblyFactory
                                .createComponentService();
                        contract = componentService;
                        componentService.setName(getString(reader, NAME));
                        component.getServices().add(componentService);
                        policyProcessor.readPolicies(contract, reader);
                    }

                } else if (REFERENCE_QNAME.equals(name)) {
                    if (component != null) {
                        // Read a <component><reference>
                        componentReference = assemblyFactory
                                .createComponentReference();
                        contract = componentReference;
                        componentReference.setName(getString(reader, NAME));
                        readMultiplicity(componentReference, reader);
                        if (isSet(reader, AUTOWIRE)) {
                            componentReference.setAutowire(getBoolean(reader,
                                    AUTOWIRE));
                        }
                        readTargets(componentReference, reader);
                        componentReference.setWiredByImpl(getBoolean(reader,
                                WIRED_BY_IMPL));
                        component.getReferences().add(componentReference);
                        policyProcessor.readPolicies(contract, reader);
                    }

                } else if (PROPERTY_QNAME.equals(name)) {
                    if (component != null) {

                        // Read a <component><property>
                        componentProperty = assemblyFactory
                                .createComponentProperty();
                        property = componentProperty;
                        componentProperty.setSource(getString(reader, SOURCE));
                        componentProperty.setFile(getString(reader, FILE));
                        policyProcessor.readPolicies(property, reader);
                        readAbstractProperty(componentProperty, reader);

                        // Read the property value
                        Document value = readPropertyValue(property
                                .getXSDElement(), property.getXSDType(), reader);
                        property.setValue(value);

                        component.getProperties().add(componentProperty);
                    }
                } else if (COMPONENT_QNAME.equals(name)) {

                    // Read a <component>
                    component = assemblyFactory.createComponent();
                    component.setName(getString(reader, NAME));
                    if (isSet(reader, AUTOWIRE)) {
                        component.setAutowire(getBoolean(reader, AUTOWIRE));
                    }
                    if (isSet(reader, URI)) {
                        component.setURI(getString(reader, URI));
                    }
                    component.setConstrainingType(readConstrainingType(reader));
                    composite.getComponents().add(component);
                    policyProcessor.readPolicies(component, reader);

                } else if (WIRE_QNAME.equals(name)) {

                    // Read a <wire>
                    wire = assemblyFactory.createWire();
                    ComponentReference source = assemblyFactory
                            .createComponentReference();
                    source.setUnresolved(true);
                    source.setName(getString(reader, SOURCE));
                    wire.setSource(source);

                    ComponentService target = assemblyFactory
                            .createComponentService();
                    target.setUnresolved(true);
                    target.setName(getString(reader, TARGET));
                    wire.setTarget(target);

                    composite.getWires().add(wire);
                    policyProcessor.readPolicies(wire, reader);

                } else if (CALLBACK_QNAME.equals(name)) {

                    // Read a <callback>
                    callback = assemblyFactory.createCallback();
                    contract.setCallback(callback);
                    policyProcessor.readPolicies(callback, reader);

                } else if (OPERATION_QNAME.equals(name)) {

                    // Read an <operation>
                    Operation operation = assemblyFactory.createOperation();
                    operation.setName(getString(reader, NAME));
                    operation.setUnresolved(true);
                    if (callback != null) {
                        policyProcessor.readPolicies(callback, operation,
                                reader);
                    } else {
                        policyProcessor.readPolicies(contract, operation,
                                reader);
                    }
                } else if (IMPLEMENTATION_COMPOSITE_QNAME.equals(name)) {

                    // Read an implementation.composite
                    Composite implementation = assemblyFactory
                            .createComposite();
                    implementation.setName(getQName(reader, NAME));
                    implementation.setUnresolved(true);
                    component.setImplementation(implementation);
                    policyProcessor.readPolicies(implementation, reader);
                } else {

                    // Read an extension element
                    Object extension = extensionProcessor.read(reader);
                    if (extension != null) {
                        if (extension instanceof InterfaceContract) {

                            // <service><interface> and
                            // <reference><interface>
                            if (contract != null) {
                                contract
                                        .setInterfaceContract((InterfaceContract) extension);
                            } else {
                                if (name.getNamespaceURI().equals(SCA10_NS)) {
                                    throw new ContributionReadException(
                                            "Unexpected <interface> element found. It should appear inside a <service> or <reference> element");
                                } else {
                                    composite.getExtensions().add(extension);
                                }
                            }

                        } else if (extension instanceof Binding) {
                            // <service><binding> and
                            // <reference><binding>
                            if (callback != null) {
                                callback.getBindings().add((Binding) extension);
                            } else {
                                if (contract != null) {
                                    contract.getBindings().add(
                                            (Binding) extension);
                                } else {
                                    if (name.getNamespaceURI().equals(SCA10_NS)) {
                                        throw new ContributionReadException(
                                                "Unexpected <binding> element found. It should appear inside a <service> or <reference> element");
                                    } else {
                                        composite.getExtensions()
                                                .add(extension);
                                    }
                                }
                            }

                        } else if (extension instanceof Implementation) {

                            // <component><implementation>
                            if (component != null) {
                                component
                                        .setImplementation((Implementation) extension);
                            } else {
                                if (name.getNamespaceURI().equals(SCA10_NS)) {
                                    throw new ContributionReadException(
                                            "Unexpected <implementation> element found. It should appear inside a <component> element");
                                } else {
                                    composite.getExtensions().add(extension);
                                }
                            }
                        } else {

                            // Add the extension element to the current
                            // element
                            if (callback != null) {
                                callback.getExtensions().add(extension);
                            } else if (contract != null) {
                                contract.getExtensions().add(extension);
                            } else if (property != null) {
                                property.getExtensions().add(extension);
                            } else if (component != null) {
                                component.getExtensions().add(extension);
                            } else {
                                composite.getExtensions().add(extension);
                            }
                        }
                    }
                }
                break;

            case XMLStreamConstants.CHARACTERS:
                break;

            case END_ELEMENT:
                name = reader.getName();

                // Clear current state when reading reaching end element
                if (SERVICE_QNAME.equals(name)) {
                    componentService = null;
                    compositeService = null;
                    contract = null;
                } else if (INCLUDE_QNAME.equals(name)) {
                    include = null;
                } else if (REFERENCE_QNAME.equals(name)) {
                    componentReference = null;
                    compositeReference = null;
                    contract = null;
                } else if (PROPERTY_QNAME.equals(name)) {
                    componentProperty = null;
                    property = null;
                } else if (COMPONENT_QNAME.equals(name)) {
                    // component = null;
                } else if (WIRE_QNAME.equals(name)) {
                    wire = null;
                } else if (CALLBACK_QNAME.equals(name)) {
                    callback = null;
                }
                break;
            }

            // Read the next element
            if (reader.hasNext()) {
                reader.next();
            }
        }
        this.generatedComponent = component;
        return component;
    }

    public void write(Composite composite, XMLStreamWriter writer)
            throws ContributionWriteException, XMLStreamException {

        // Write <composite> element
        writeStartDocument(writer, COMPOSITE, writeConstrainingType(composite),
                new XAttr(TARGET_NAMESPACE, composite.getName()
                        .getNamespaceURI()), new XAttr(NAME, composite
                        .getName().getLocalPart()), new XAttr(AUTOWIRE,
                        composite.getAutowire()), policyProcessor
                        .writePolicies(composite));

        // Write <service> elements
        for (Service service : composite.getServices()) {
            CompositeService compositeService = (CompositeService) service;
            Component promotedComponent = compositeService
                    .getPromotedComponent();
            ComponentService promotedService = compositeService
                    .getPromotedService();
            String promote;
            if (promotedService != null) {
                if (promotedService.getName() != null) {
                    promote = promotedComponent.getName() + '/'
                            + promotedService.getService();
                } else {
                    promote = promotedComponent.getName();
                }
            } else {
                promote = null;
            }
            writeStart(writer, SERVICE, new XAttr(NAME, service.getName()),
                    new XAttr(PROMOTE, promote), policyProcessor
                            .writePolicies(service));

            // Write service interface
            extensionProcessor.write(service.getInterfaceContract(), writer);

            // Write bindings
            for (Binding binding : service.getBindings()) {
                extensionProcessor.write(binding, writer);
            }

            // Write <callback> element
            if (service.getCallback() != null) {
                Callback callback = service.getCallback();
                writeStart(writer, CALLBACK, policyProcessor
                        .writePolicies(callback));

                // Write callback bindings
                for (Binding binding : callback.getBindings()) {
                    extensionProcessor.write(binding, writer);
                }

                // Write extensions
                for (Object extension : callback.getExtensions()) {
                    extensionProcessor.write(extension, writer);
                }

                writeEnd(writer);
            }

            // Write extensions
            for (Object extension : service.getExtensions()) {
                extensionProcessor.write(extension, writer);
            }

            writeEnd(writer);
        }

        // Write <component> elements
        for (Component component : composite.getComponents()) {
            writeStart(writer, COMPONENT, new XAttr(NAME, component.getName()),
                    new XAttr(URI, component.getURI()), new XAttr(AUTOWIRE,
                            component.getAutowire()), policyProcessor
                            .writePolicies(component));

            // Write <service> elements
            for (ComponentService service : component.getServices()) {
                writeStart(writer, SERVICE, new XAttr(NAME, service.getName()),
                        policyProcessor.writePolicies(service));

                // Write service interface
                extensionProcessor
                        .write(service.getInterfaceContract(), writer);

                // Write bindings
                for (Binding binding : service.getBindings()) {
                    extensionProcessor.write(binding, writer);
                }

                // Write <callback> element
                if (service.getCallback() != null) {
                    Callback callback = service.getCallback();
                    writeStart(writer, CALLBACK, policyProcessor
                            .writePolicies(callback));

                    // Write bindings
                    for (Binding binding : callback.getBindings()) {
                        extensionProcessor.write(binding, writer);
                    }

                    // Write extensions
                    for (Object extension : callback.getExtensions()) {
                        extensionProcessor.write(extension, writer);
                    }

                    writeEnd(writer);
                }

                // Write extensions
                for (Object extension : service.getExtensions()) {
                    extensionProcessor.write(extension, writer);
                }

                writeEnd(writer);
            }

            // Write <reference> elements
            for (ComponentReference reference : component.getReferences()) {
                writeStart(writer, REFERENCE, new XAttr(NAME, reference
                        .getName()), new XAttr(AUTOWIRE, reference
                        .getAutowire()), writeTargets(reference),
                        policyProcessor.writePolicies(reference));

                // Write reference interface
                extensionProcessor.write(reference.getInterfaceContract(),
                        writer);

                // Write bindings
                for (Binding binding : reference.getBindings()) {
                    extensionProcessor.write(binding, writer);
                }

                // Write callback
                if (reference.getCallback() != null) {
                    Callback callback = reference.getCallback();
                    writeStart(writer, CALLBACK, policyProcessor
                            .writePolicies(callback));

                    // Write callback bindings
                    for (Binding binding : callback.getBindings()) {
                        extensionProcessor.write(binding, writer);
                    }

                    // Write extensions
                    for (Object extensions : callback.getExtensions()) {
                        extensionProcessor.write(extensions, writer);
                    }

                    writeEnd(writer);
                }

                // Write extensions
                for (Object extensions : reference.getExtensions()) {
                    extensionProcessor.write(extensions, writer);
                }

                writeEnd(writer);
            }

            // Write <property> elements
            for (ComponentProperty property : component.getProperties()) {
                writeStart(writer, PROPERTY,
                        new XAttr(NAME, property.getName()), new XAttr(
                                MUST_SUPPLY, property.isMustSupply()),
                        new XAttr(MANY, property.isMany()), new XAttr(TYPE,
                                property.getXSDType()), new XAttr(ELEMENT,
                                property.getXSDElement()), new XAttr(SOURCE,
                                property.getSource()), new XAttr(FILE, property
                                .getFile()), policyProcessor
                                .writePolicies(property));

                // Write property value
                writePropertyValue(property.getValue(), property
                        .getXSDElement(), property.getXSDType(), writer);

                // Write extensions
                for (Object extension : property.getExtensions()) {
                    extensionProcessor.write(extension, writer);
                }

                writeEnd(writer);
            }

            // Write the component implementation
            Implementation implementation = component.getImplementation();
            if (implementation instanceof Composite) {
                writeStart(writer, IMPLEMENTATION_COMPOSITE, new XAttr(NAME,
                        composite.getName()));
                writeEnd(writer);
            } else {
                extensionProcessor.write(component.getImplementation(), writer);
            }

            writeEnd(writer);
        }

        // Write <reference> elements
        for (Reference reference : composite.getReferences()) {
            CompositeReference compositeReference = (CompositeReference) reference;

            // Write list of promoted references
            List<String> promote = new ArrayList<String>();
            for (ComponentReference promoted : compositeReference
                    .getPromotedReferences()) {
                promote.add(promoted.getName());
            }

            // Write <reference> element
            writeStart(writer, REFERENCE, new XAttr(NAME, reference.getName()),
                    new XAttr(PROMOTE, promote), policyProcessor
                            .writePolicies(reference));

            // Write reference interface
            extensionProcessor.write(reference.getInterfaceContract(), writer);

            // Write bindings
            for (Binding binding : reference.getBindings()) {
                extensionProcessor.write(binding, writer);
            }

            // Write <callback> element
            if (reference.getCallback() != null) {
                Callback callback = reference.getCallback();
                writeStart(writer, CALLBACK);

                // Write callback bindings
                for (Binding binding : callback.getBindings()) {
                    extensionProcessor.write(binding, writer);
                }

                // Write extensions
                for (Object extension : callback.getExtensions()) {
                    extensionProcessor.write(extension, writer);
                }

                writeEnd(writer);
            }

            // Write extensions
            for (Object extension : reference.getExtensions()) {
                extensionProcessor.write(extension, writer);
            }

            writeEnd(writer);
        }

        // Write <property> elements
        for (Property property : composite.getProperties()) {
            writeStart(writer, PROPERTY, new XAttr(NAME, property.getName()),
                    new XAttr(MUST_SUPPLY, property.isMustSupply()), new XAttr(
                            MANY, property.isMany()), new XAttr(TYPE, property
                            .getXSDType()), new XAttr(ELEMENT, property
                            .getXSDElement()), policyProcessor
                            .writePolicies(property));

            // Write property value
            writePropertyValue(property.getValue(), property.getXSDElement(),
                    property.getXSDType(), writer);

            // Write extensions
            for (Object extension : property.getExtensions()) {
                extensionProcessor.write(extension, writer);
            }

            writeEnd(writer);
        }

        // Write <wire> elements
        for (Wire wire : composite.getWires()) {
            writeStart(writer, WIRE, new XAttr(SOURCE, wire.getSource()
                    .getName()), new XAttr(TARGET, wire.getTarget().getName()));

            // Write extensions
            for (Object extension : wire.getExtensions()) {
                extensionProcessor.write(extension, writer);
            }
            writeEnd(writer);
        }

        for (Object extension : composite.getExtensions()) {
            extensionProcessor.write(extension, writer);
        }

        writeEndDocument(writer);
    }

    public void resolve(Composite composite, ModelResolver resolver)
            throws ContributionResolveException, PolicyValidationException {

        // Resolve constraining type
        ConstrainingType constrainingType = composite.getConstrainingType();
        if (constrainingType != null) {
            constrainingType = resolver.resolveModel(ConstrainingType.class,
                    constrainingType);
            composite.setConstrainingType(constrainingType);
        }

        // Resolve includes in the composite
        for (int i = 0, n = composite.getIncludes().size(); i < n; i++) {
            Composite include = composite.getIncludes().get(i);
            if (include != null) {
                include = resolver.resolveModel(Composite.class, include);
                composite.getIncludes().set(i, include);
            }
        }

        // Resolve extensions
        for (Object extension : composite.getExtensions()) {
            if (extension != null) {
                extensionProcessor.resolve(extension, resolver);
            }
        }

        // Resolve component implementations, services and references
        for (Component component : composite.getComponents()) {
            constrainingType = component.getConstrainingType();
            if (constrainingType != null) {
                constrainingType = resolver.resolveModel(
                        ConstrainingType.class, constrainingType);
                component.setConstrainingType(constrainingType);
            }

            Implementation implementation = component.getImplementation();
            if (implementation != null) {
                implementation = resolveImplementation(implementation, resolver);
                component.setImplementation(implementation);
            }

            for (ComponentProperty componentProperty : component
                    .getProperties()) {
                if (componentProperty.getFile() != null) {
                    DeployedArtifact deployedArtifact = contributionFactory
                            .createDeployedArtifact();
                    deployedArtifact.setURI(componentProperty.getFile());
                    deployedArtifact = resolver.resolveModel(
                            DeployedArtifact.class, deployedArtifact);
                    if (deployedArtifact.getLocation() != null) {
                        componentProperty.setFile(deployedArtifact
                                .getLocation());
                    }
                }
            }
            resolveIntents(component.getRequiredIntents(), resolver);
            resolvePolicySets(component.getPolicySets(), resolver);
            resolveContracts(component.getServices(), resolver);
            resolveContracts(component.getReferences(), resolver);
        }

        // Resolve composite services and references
        resolveContracts(composite.getServices(), resolver);
        resolveContracts(composite.getReferences(), resolver);
        if (composite instanceof PolicySetAttachPoint) {
            resolveIntents(((PolicySetAttachPoint) composite)
                    .getRequiredIntents(), resolver);
            resolvePolicySets(((PolicySetAttachPoint) composite)
                    .getPolicySets(), resolver);
        }
    }

    public void write(Component model, XMLStreamWriter writer)
            throws ContributionWriteException, XMLStreamException {
        write(this.composite, writer);

    }

    public void resolve(Component component, ModelResolver resolver)
            throws ContributionResolveException {
        // Resolve component implementations, services and references
        ConstrainingType constrainingType = component.getConstrainingType();
        if (constrainingType != null) {
            constrainingType = resolver.resolveModel(ConstrainingType.class,
                    constrainingType);
            component.setConstrainingType(constrainingType);
        }

        Implementation implementation = component.getImplementation();
        if (implementation != null) {
            implementation = resolveImplementation(implementation, resolver);
            component.setImplementation(implementation);
        }

        for (ComponentProperty componentProperty : component.getProperties()) {
            if (componentProperty.getFile() != null) {
                DeployedArtifact deployedArtifact = contributionFactory
                        .createDeployedArtifact();
                deployedArtifact.setURI(componentProperty.getFile());
                deployedArtifact = resolver.resolveModel(
                        DeployedArtifact.class, deployedArtifact);
                if (deployedArtifact.getLocation() != null) {
                    componentProperty.setFile(deployedArtifact.getLocation());
                }
            }
        }
        resolveIntents(component.getRequiredIntents(), resolver);
        resolvePolicySets(component.getPolicySets(), resolver);
        resolveContracts(component.getServices(), resolver);
        resolveContracts(component.getReferences(), resolver);
    }

    public void resolveReference(ComponentReference reference,
            ModelResolver resolver) throws ContributionResolveException {
        resolveIntents(reference.getRequiredIntents(), resolver);
        resolvePolicySets(reference.getPolicySets(), resolver);
        List<ComponentReference> contracts = new ArrayList<ComponentReference>();
        contracts.add(reference);
        resolveContracts(contracts, resolver);
    }

    public QName getArtifactType() {
        return COMPONENT_QNAME;
    }

    public Class<Component> getModelType() {

        return Component.class;
    }

}