/*

 * Copyright (c) 2015, 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 javax.xml.catalog;

import com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl;

import java.io.StringReader;

import java.net.URL;

import java.util.Iterator;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParserFactory;

import javax.xml.transform.Source;

import javax.xml.transform.sax.SAXSource;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

/**

 * A SAX EntityResolver/JAXP URIResolver that uses catalogs.

 * <p>

 * This class implements both a SAX EntityResolver and a JAXP URIResolver.

 *

 *

 * @since 9

 */

final class CatalogUriResolverImpl implements CatalogUriResolver {

    Catalog catalog;

    CatalogResolverImpl entityResolver;

    /**

     * Construct an instance of the CatalogResolver from a Catalog.

     *

     * @param catalog A Catalog.

     */

    public CatalogUriResolverImpl(Catalog catalog) {

        this.catalog = catalog;

    }

    @Override

    public Source resolve(String href, String base) {

        if (href == null) return null;

        CatalogImpl c = (CatalogImpl)catalog;

        String uri = Normalizer.normalizeURI(href);

        String result;

        //remove fragment if any.

        int hashPos = uri.indexOf("#");

        if (hashPos >= 0) {

            uri = uri.substring(0, hashPos);

        }

        //search the current catalog

        result = resolve(c, uri);

        if (result == null) {

            GroupEntry.ResolveType resolveType = c.getResolve();

            switch (resolveType) {

                case IGNORE:

                    return new SAXSource(new InputSource(new StringReader("")));

                case STRICT:

                    CatalogMessages.reportError(CatalogMessages.ERR_NO_URI_MATCH,

                            new Object[]{href, base});

            }

            try {

                URL url = null;

                if (base == null) {

                    url = new URL(uri);

                    result = url.toString();

                } else {

                    URL baseURL = new URL(base);

                    url = (href.length() == 0 ? baseURL : new URL(baseURL, uri));

                    result = url.toString();

                }

            } catch (java.net.MalformedURLException mue) {

                    CatalogMessages.reportError(CatalogMessages.ERR_CREATING_URI,

                            new Object[]{href, base});

            }

        }

        SAXSource source = new SAXSource();

        source.setInputSource(new InputSource(result));

        setEntityResolver(source);

        return source;

    }

    /**

     * Resolves the publicId or systemId to one specified in the catalog.

     * @param catalog the catalog

     * @param href an href attribute, which may be relative or absolute

     * @return the resolved systemId if a match is found, null otherwise

     */

    String resolve(CatalogImpl catalog, String href) {

        String result = null;

        //search the current catalog

        catalog.reset();

        if (href != null) {

            result = catalog.matchURI(href);

        }

        //mark the catalog as having been searched before trying alternatives

        catalog.markAsSearched();

        //search alternative catalogs

        if (result == null) {

            Iterator<Catalog> iter = catalog.catalogs().iterator();

            while (iter.hasNext()) {

                result = resolve((CatalogImpl)iter.next(), href);

                if (result != null) {

                    break;

                }

            }

        }

        return result;

    }

    /**

     * Establish an entityResolver for newly resolved URIs.

     * <p>

     * This is called from the URIResolver to set an EntityResolver on the SAX

     * parser to be used for new XML documents that are encountered as a result

     * of the document() function, xsl:import, or xsl:include. This is done

     * because the XSLT processor calls out to the SAXParserFactory itself to

     * create a new SAXParser to parse the new document. The new parser does not

     * automatically inherit the EntityResolver of the original (although

     * arguably it should). Quote from JAXP specification on Class

     * SAXTransformerFactory:

     * <p>

     * {@code If an application wants to set the ErrorHandler or EntityResolver

     * for an XMLReader used during a transformation, it should use a URIResolver

     * to return the SAXSource which provides (with getXMLReader) a reference to

     * the XMLReader}

     *

     */

    private void setEntityResolver(SAXSource source) {

        XMLReader reader = source.getXMLReader();

        if (reader == null) {

            SAXParserFactory spFactory = new SAXParserFactoryImpl();

            spFactory.setNamespaceAware(true);

            try {

                reader = spFactory.newSAXParser().getXMLReader();

            } catch (ParserConfigurationException | SAXException ex) {

                CatalogMessages.reportRunTimeError(CatalogMessages.ERR_PARSER_CONF, ex);

            }

        }

        if (entityResolver != null) {

            entityResolver = new CatalogResolverImpl(catalog);

        }

        reader.setEntityResolver(entityResolver);

        source.setXMLReader(reader);

    }

}