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 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package com.sun.xml.internal.bind.v2.runtime.reflect;

import java.io.IOException;

import java.util.concurrent.Callable;

import javax.xml.bind.JAXBException;

import javax.xml.bind.annotation.XmlValue;

import javax.xml.stream.XMLStreamException;

import com.sun.istack.internal.NotNull;

import com.sun.istack.internal.Nullable;

import com.sun.istack.internal.SAXException2;

import com.sun.xml.internal.bind.WhiteSpaceProcessor;

import com.sun.xml.internal.bind.api.AccessorException;

import com.sun.xml.internal.bind.v2.model.core.ID;

import com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder;

import com.sun.xml.internal.bind.v2.model.runtime.RuntimeNonElementRef;

import com.sun.xml.internal.bind.v2.model.runtime.RuntimePropertyInfo;

import com.sun.xml.internal.bind.v2.runtime.Name;

import com.sun.xml.internal.bind.v2.runtime.Transducer;

import com.sun.xml.internal.bind.v2.runtime.XMLSerializer;

import com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl;

import com.sun.xml.internal.bind.v2.runtime.reflect.opt.OptimizedTransducedAccessorFactory;

import com.sun.xml.internal.bind.v2.runtime.unmarshaller.Patcher;

import com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext;

import com.sun.xml.internal.bind.v2.runtime.unmarshaller.LocatorEx;

import org.xml.sax.SAXException;

/**

 * {@link Accessor} and {@link Transducer} combined into one object.

 *

 * <p>

 * This allows efficient conversions between primitive values and

 * String without using boxing.

 *

 * <p>

 * This abstraction only works for a single-value property.

 *

 * <p>

 * An instance of {@link TransducedAccessor} implicitly holds a

 * field of the {@code BeanT} that the accessors access.

 *

 * @author Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)

 */

public abstract class TransducedAccessor<BeanT> {

    /**

     * @see Transducer#useNamespace()

     */

    public boolean useNamespace() {

        return false;

    }

    /**

     * Obtain the value of the field and declares the namespace URIs used in

     * the value.

     *

     * @see Transducer#declareNamespace(Object, XMLSerializer)

     */

    public void declareNamespace( BeanT o, XMLSerializer w ) throws AccessorException, SAXException {

    }

    /**

     * Prints the responsible field of the given bean to the writer.

     *

     * <p>

     * Use {@link XMLSerializer#getInstance()} to access to the namespace bindings

     *

     * @return

     *      if the accessor didn't yield a value, return null.

     */

    public abstract @Nullable CharSequence print(@NotNull BeanT o) throws AccessorException, SAXException;

    /**

     * Parses the text value into the responsible field of the given bean.

     *

     * <p>

     * Use {@link UnmarshallingContext#getInstance()} to access to the namespace bindings

     *

     * @throws AccessorException

     *      if the transducer is used to parse an user bean that uses {@link XmlValue},

     *      then this exception may occur when it tries to set the leaf value to the bean.

     * @throws RuntimeException

     *      if the lexical form is incorrect. The method may throw a RuntimeException,

     *      but it shouldn't cause the entire unmarshalling to fail.

     * @throws SAXException

     *      if the parse method found an error, the error is reported, and then

     *      the processing is aborted.

     */

    public abstract void parse(BeanT o, CharSequence lexical) throws AccessorException, SAXException;

    /**

     * Checks if the field has a value.

     */

    public abstract boolean hasValue(BeanT o) throws AccessorException;

    /**

     * Gets the {@link TransducedAccessor} appropriately configured for

     * the given property.

     *

     * <p>

     * This allows the implementation to use an optimized code.

     */

    public static <T> TransducedAccessor<T> get(JAXBContextImpl context, RuntimeNonElementRef ref) {

        Transducer xducer = RuntimeModelBuilder.createTransducer(ref);

        RuntimePropertyInfo prop = ref.getSource();

        if(prop.isCollection()) {

            return new ListTransducedAccessorImpl(xducer,prop.getAccessor(),

        }

        if(prop.id()==ID.IDREF)

            return new IDREFTransducedAccessorImpl(prop.getAccessor());

        if(xducer.isDefault() && context != null && !context.fastBoot) {

            TransducedAccessor xa = OptimizedTransducedAccessorFactory.get(prop);

            if(xa!=null)    return xa;

        }

        if(xducer.useNamespace())

            return new CompositeContextDependentTransducedAccessorImpl( context, xducer, prop.getAccessor() );

        else

            return new CompositeTransducedAccessorImpl( context, xducer, prop.getAccessor() );

    }

    /**

     * Convenience method to write the value as a text inside an element

     * without any attributes.

     * Can be overridden for improved performance.

     *

     * <p>

     * The callee assumes that there's an associated value in the field.

     * No @xsi:type handling is expected.

     */

    public abstract void writeLeafElement(XMLSerializer w, Name tagName, BeanT o, String fieldName) throws SAXException, AccessorException, IOException, XMLStreamException;

    /**

     * Invokes one of the {@link XMLSerializer#text(String, String)} method

     * with the representation of data bested suited for this transduced accessor.

     */

    public abstract void writeText(XMLSerializer w, BeanT o, String fieldName) throws AccessorException, SAXException, IOException, XMLStreamException;

    static class CompositeContextDependentTransducedAccessorImpl<BeanT,ValueT> extends CompositeTransducedAccessorImpl<BeanT,ValueT> {

        public CompositeContextDependentTransducedAccessorImpl(JAXBContextImpl context,Transducer<ValueT> xducer, Accessor<BeanT,ValueT> acc) {

            super(context,xducer,acc);

            assert xducer.useNamespace();

        }

        @Override

        public boolean useNamespace() {

            return true;

        }

        @Override

        public void declareNamespace(BeanT bean, XMLSerializer w) throws AccessorException {

            ValueT o = acc.get(bean);

            if(o!=null)

                xducer.declareNamespace(o,w);

        }

        @Override

        public void writeLeafElement(XMLSerializer w, Name tagName, BeanT o, String fieldName) throws SAXException, AccessorException, IOException, XMLStreamException {

            w.startElement(tagName,null);

            declareNamespace(o,w);

            w.endNamespaceDecls(null);

            w.endAttributes();

            xducer.writeText(w,acc.get(o),fieldName);

            w.endElement();

        }

    }

    /**

     * Implementation of {@link TransducedAccessor} that

     * simply combines a {@link Transducer} and {@link Accessor}.

     */

    public static class CompositeTransducedAccessorImpl<BeanT,ValueT> extends TransducedAccessor<BeanT> {

        protected final Transducer<ValueT> xducer;

        protected final Accessor<BeanT,ValueT> acc;

        public CompositeTransducedAccessorImpl(JAXBContextImpl context, Transducer<ValueT> xducer, Accessor<BeanT,ValueT> acc) {

            this.xducer = xducer;

            this.acc = acc.optimize(context);

        }

        public CharSequence print(BeanT bean) throws AccessorException {

            ValueT o = acc.get(bean);

            if(o==null)     return null;

            return xducer.print(o);

        }

        public void parse(BeanT bean, CharSequence lexical) throws AccessorException, SAXException {

            acc.set(bean,xducer.parse(lexical));

        }

        public boolean hasValue(BeanT bean) throws AccessorException {

            return acc.getUnadapted(bean)!=null;

        }

        @Override

        public void writeLeafElement(XMLSerializer w, Name tagName, BeanT o, String fieldName) throws SAXException, AccessorException, IOException, XMLStreamException {

            xducer.writeLeafElement(w,tagName,acc.get(o),fieldName);

        }

        @Override

        public void writeText(XMLSerializer w, BeanT o, String fieldName) throws AccessorException, SAXException, IOException, XMLStreamException {

            xducer.writeText(w,acc.get(o),fieldName);

        }

    }

    /**

     * {@link TransducedAccessor} for IDREF.

     *

     * BeanT: the type of the bean that contains this the IDREF field.

     * TargetT: the type of the bean pointed by IDREF.

     */

    private static final class IDREFTransducedAccessorImpl<BeanT,TargetT> extends DefaultTransducedAccessor<BeanT> {

        private final Accessor<BeanT,TargetT> acc;

        /**

         * The object that an IDREF resolves to should be

         * assignable to this type.

         */

        private final Class<TargetT> targetType;

        public IDREFTransducedAccessorImpl(Accessor<BeanT, TargetT> acc) {

            this.acc = acc;

            this.targetType = acc.getValueType();

        }

        public String print(BeanT bean) throws AccessorException, SAXException {

            TargetT target = acc.get(bean);

            if(target==null)    return null;

            XMLSerializer w = XMLSerializer.getInstance();

            try {

                String id = w.grammar.getBeanInfo(target,true).getId(target,w);

                if(id==null)

                    w.errorMissingId(target);

                return id;

            } catch (JAXBException e) {

                w.reportError(null,e);

                return null;

            }

        }

        private void assign( BeanT bean, TargetT t, UnmarshallingContext context ) throws AccessorException {

            if(!targetType.isInstance(t))

                context.handleError(Messages.UNASSIGNABLE_TYPE.format(targetType,t.getClass()));

            else

                acc.set(bean,t);

        }

        public void parse(final BeanT bean, CharSequence lexical) throws AccessorException, SAXException {

            final String idref = WhiteSpaceProcessor.trim(lexical).toString();

            final UnmarshallingContext context = UnmarshallingContext.getInstance();

            final Callable callable = context.getObjectFromId(idref,acc.valueType);

            if(callable==null) {

                // the IDResolver decided to abort it now

                context.errorUnresolvedIDREF(bean,idref,context.getLocator());

                return;

            }

            TargetT t;

            try {

                t = (TargetT)callable.call();

            } catch (SAXException e) {// from callable.call

                throw e;

            } catch (RuntimeException e) {// from callable.call

                throw e;

            } catch (Exception e) {// from callable.call

                throw new SAXException2(e);

            }

            if(t!=null) {

                assign(bean,t,context);

            } else {

                // try again later

                final LocatorEx loc = new LocatorEx.Snapshot(context.getLocator());

                context.addPatcher(new Patcher() {

                    public void run() throws SAXException {

                        try {

                            TargetT t = (TargetT)callable.call();

                            if(t==null) {

                                context.errorUnresolvedIDREF(bean,idref,loc);

                            } else {

                                assign(bean,t,context);

                            }

                        } catch (AccessorException e) {

                            context.handleError(e);

                        } catch (SAXException e) {// from callable.call

                            throw e;

                        } catch (RuntimeException e) {// from callable.call

                            throw e;

                        } catch (Exception e) {// from callable.call

                            throw new SAXException2(e);

                        }

                    }

                });

            }

        }

        public boolean hasValue(BeanT bean) throws AccessorException {

            return acc.get(bean)!=null;

        }

    }

}