/**
 * 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.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.WeakHashMap;

import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;

import org.apache.cxf.aegis.AegisContext;

public abstract class AbstractAegisProvider<T> 
    implements MessageBodyReader<T>, MessageBodyWriter<T> {
    
    private static Map<java.lang.reflect.Type, AegisContext> classContexts      
        = new WeakHashMap<java.lang.reflect.Type, AegisContext>();
    
    protected boolean writeXsiType = true;
    protected boolean readXsiType = true;
    @Context 
    protected ContextResolver<AegisContext> resolver;
    
    public void setWriteXsiType(boolean write) {
        writeXsiType = write;
    }
    
    public void setReadXsiType(boolean read) {
        readXsiType = read;
    }
    
    public boolean isWriteable(Class<?> type, Type genericType, Annotation[] anns, MediaType mt) {
        return isSupported(type, genericType, anns);
    }
    
    public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mt) {
        return isSupported(type, genericType, annotations);
    }

    public long getSize(T o, Class<?> type, Type genericType, Annotation[] annotations, MediaType mt) {
        return -1;
    }

    protected AegisContext getAegisContext(Class<?> plainClass, Type genericType) {
        
        if (resolver != null) {
            /* wierdly, the JAX-RS API keys on Class, not AegisType, so it can't possibly
             * keep generics straight. Should we ignore the resolver?
             */
            AegisContext context = resolver.getContext(plainClass);
            // it's up to the resolver to keep its contexts in a map
            if (context != null) {
                return context;
            }
        }
        
        if (genericType == null) {
            genericType = plainClass;
        }
        return getClassContext(genericType);
    }
    
    
    private AegisContext getClassContext(Type reflectionType) {
        synchronized (classContexts) {
            AegisContext context = classContexts.get(reflectionType);
            if (context == null) {
                context = new AegisContext();
                context.setWriteXsiTypes(writeXsiType); 
                context.setReadXsiTypes(readXsiType);
                Set<java.lang.reflect.Type> rootClasses = new HashSet<java.lang.reflect.Type>();
                rootClasses.add(reflectionType);
                context.setRootClasses(rootClasses);
                context.initialize();
                classContexts.put(reflectionType, context);
            }
            return context;
        }
    }
    
    /**
     * For Aegis, it's not obvious to me how we'd decide that a type was hopeless.
     * @param type
     * @param genericType
     * @param annotations
     * @return
     */
    protected boolean isSupported(Class<?> type, Type genericType, Annotation[] annotations) {
        return true;
    }
    
    static void clearContexts() {
        classContexts.clear();
    }
}
