/**
 * 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.cxf.jaxrs.provider.aegis;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.Provider;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import org.w3c.dom.Document;

import org.apache.cxf.aegis.AegisContext;
import org.apache.cxf.aegis.AegisWriter;
import org.apache.cxf.aegis.type.AegisType;
import org.apache.cxf.jaxrs.provider.json.utils.JSONUtils;
import org.apache.cxf.jaxrs.provider.json.utils.PrefixCollectingXMLStreamWriter;
import org.apache.cxf.jaxrs.utils.ExceptionUtils;
import org.apache.cxf.jaxrs.utils.HttpUtils;
import org.apache.cxf.staxutils.StaxUtils;
import org.apache.cxf.staxutils.W3CDOMStreamWriter;
import org.codehaus.jettison.mapped.Configuration;

@Provider
@Produces({"application/json" })
@Consumes({"application/json" })
public final class AegisJSONProvider<T> extends AegisElementProvider<T> {

    private List<String> arrayKeys;
    private boolean serializeAsArray;
    private boolean dropRootElement;
    private boolean ignoreNamespaces;
        
    private ConcurrentHashMap<String, String> namespaceMap = new ConcurrentHashMap<String, String>();

    public AegisJSONProvider() {
    }

    public void setIgnoreNamespaces(boolean ignoreNamespaces) {
        this.ignoreNamespaces = ignoreNamespaces;
    }
    
    public void setDropRootElement(boolean dropRootElement) {
        this.dropRootElement = dropRootElement;
    }

    public void setArrayKeys(List<String> keys) {
        this.arrayKeys = keys;
    }

    public void setSerializeAsArray(boolean asArray) {
        this.serializeAsArray = asArray;
    }

    @Override
    public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mt) {
        return true;
    }

    public void setNamespaceMap(Map<String, String> nsMap) {
        this.namespaceMap = new ConcurrentHashMap<String, String>(nsMap);
    }

    @Override
    public void writeTo(T obj, Class<?> type, Type genericType, Annotation[] anns, MediaType m,
                        MultivaluedMap<String, Object> headers, OutputStream os) throws IOException {
        if (type == null) {
            type = obj.getClass();
        }
        if (genericType == null) {
            genericType = type;
        }
        AegisContext context = getAegisContext(type, genericType);
        AegisType aegisType = context.getTypeMapping().getType(genericType);
        AegisWriter<XMLStreamWriter> aegisWriter = context.createXMLStreamWriter();
        try {
            W3CDOMStreamWriter w3cStreamWriter = new W3CDOMStreamWriter();
            XMLStreamWriter spyingWriter = new PrefixCollectingXMLStreamWriter(w3cStreamWriter,
                                                                               namespaceMap);
            spyingWriter.writeStartDocument();
            // use type qname as element qname?
            aegisWriter.write(obj, aegisType.getSchemaType(), false, spyingWriter, aegisType);
            spyingWriter.writeEndDocument();
            spyingWriter.close();
            Document dom = w3cStreamWriter.getDocument();
            // ok, now the namespace map has all the prefixes.
            
            String enc = HttpUtils.getSetEncoding(m, headers, "UTF-8");
            
            XMLStreamWriter xmlStreamWriter = createStreamWriter(aegisType.getSchemaType(), enc, os);
            xmlStreamWriter.writeStartDocument();
            StaxUtils.copy(dom, xmlStreamWriter);
            // Jettison needs, and StaxUtils.copy doesn't do it.
            xmlStreamWriter.writeEndDocument();
            xmlStreamWriter.flush();
            xmlStreamWriter.close();
        } catch (Exception e) {
            throw ExceptionUtils.toInternalServerErrorException(e, null);
        }
    }

    @Override
    protected XMLStreamWriter createStreamWriter(QName typeQName, String enc, OutputStream os) throws Exception {
        
        Configuration config = 
            JSONUtils.createConfiguration(namespaceMap, 
                                          writeXsiType && !ignoreNamespaces, false, null);
        XMLStreamWriter writer = JSONUtils.createStreamWriter(os, typeQName, 
             writeXsiType && !ignoreNamespaces, config, serializeAsArray, arrayKeys, dropRootElement, enc);
        return JSONUtils.createIgnoreNsWriterIfNeeded(writer, ignoreNamespaces, !writeXsiType);
    }

    @Override
    protected XMLStreamReader createStreamReader(AegisType typeToRead, InputStream is) throws Exception {
        // the namespace map. Oh, the namespace map.
        // This is wrong, but might make unit tests pass until we redesign.
        if (typeToRead != null) {
            String pfx = "ns1";
            int count = 1;
            while (namespaceMap.containsValue(pfx)) {
                count++;
                pfx = "ns" + count;
            }
            namespaceMap.putIfAbsent(typeToRead.getSchemaType().getNamespaceURI(), pfx);
        }
        return JSONUtils.createStreamReader(is, readXsiType, namespaceMap);
    }


}
