/*

 * Copyright (c) 1997, 2010, 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.unmarshaller;

import javax.xml.namespace.QName;

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

import com.sun.xml.internal.bind.v2.WellKnownNamespace;

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

import com.sun.istack.internal.Nullable;

import java.util.Collection;

import java.util.Collections;

import java.util.HashSet;

import org.xml.sax.Attributes;

import org.xml.sax.SAXException;

/**

 * Looks at @xsi:type and forwards to the right {@link Loader}.

 *

 * @author Kohsuke Kawaguchi

 */

public class XsiTypeLoader extends Loader {

    /**

     * Use this when no @xsi:type was found.

     */

    private final JaxBeanInfo defaultBeanInfo;

    public XsiTypeLoader(JaxBeanInfo defaultBeanInfo) {

        super(true);

        this.defaultBeanInfo = defaultBeanInfo;

    }

    public void startElement(UnmarshallingContext.State state, TagName ea) throws SAXException {

        JaxBeanInfo beanInfo = parseXsiType(state,ea,defaultBeanInfo);

        if(beanInfo==null)

            beanInfo = defaultBeanInfo;

        Loader loader = beanInfo.getLoader(null,false);

        state.loader = loader;

        loader.startElement(state,ea);

    }

    /*pacakge*/ static JaxBeanInfo parseXsiType(UnmarshallingContext.State state, TagName ea, @Nullable JaxBeanInfo defaultBeanInfo) throws SAXException {

        UnmarshallingContext context = state.getContext();

        JaxBeanInfo beanInfo = null;

        // look for @xsi:type

        Attributes atts = ea.atts;

        int idx = atts.getIndex(WellKnownNamespace.XML_SCHEMA_INSTANCE,"type");

        if(idx>=0) {

            // we'll consume the value only when it's a recognized value,

            // so don't consume it just yet.

            String value = atts.getValue(idx);

            QName type = DatatypeConverterImpl._parseQName(value,context);

            if(type==null) {

                reportError(Messages.NOT_A_QNAME.format(value),true);

            } else {

                if(defaultBeanInfo!=null && defaultBeanInfo.getTypeNames().contains(type))

                    // if this xsi:type is something that the default type can already handle,

                    // let it do so. This is added as a work around to bug https://jax-ws.dev.java.net/issues/show_bug.cgi?id=195

                    // where a redundant xsi:type="xs:dateTime" causes JAXB to unmarshal XMLGregorianCalendar,

                    // where Date is expected.

                    // this is not a complete fix, as we still won't be able to handle simple type substitution in general,

                    // but none-the-less

                    return defaultBeanInfo;

                beanInfo = context.getJAXBContext().getGlobalType(type);

                }

                // TODO: resurrect the following check

        //                    else

        //                    if(!target.isAssignableFrom(actual)) {

        //                        reportError(context,

        //                            Messages.UNSUBSTITUTABLE_TYPE.format(value,actual.getName(),target.getName()),

        //                            true);

        //                        actual = targetBeanInfo;  // ditto

        //                    }

            }

        }

        return beanInfo;

    }

    static final QName XsiTypeQNAME = new QName(WellKnownNamespace.XML_SCHEMA_INSTANCE,"type");

    @Override

    public Collection<QName> getExpectedAttributes() {

        final Collection<QName> expAttrs =  new HashSet<QName>();

        expAttrs.addAll(super.getExpectedAttributes());

        expAttrs.add(XsiTypeQNAME);

        return Collections.unmodifiableCollection(expAttrs);

    }

}