/**
 * Copyright 2005-2014 The Kuali Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
 *
 * 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.kuali.rice.ksb.messaging.serviceexporters;

import org.apache.commons.lang.StringUtils;
import org.apache.cxf.Bus;
import org.apache.cxf.endpoint.ServerRegistry;
import org.kuali.rice.core.api.config.property.Config;
import org.kuali.rice.core.api.config.property.ConfigContext;
import org.kuali.rice.ksb.api.bus.ServiceDefinition;

import javax.xml.namespace.QName;
import java.net.URI;
import java.net.URL;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

public class ServiceExportManagerImpl implements ServiceExportManager {

        private final ConcurrentMap<QName, ExportedServiceHolder> exportedServices;
        private final ServiceNameFinder serviceNameFinder;
        
        private Bus cxfBus;

        public ServiceExportManagerImpl() {
                this.exportedServices = new ConcurrentHashMap<QName, ExportedServiceHolder>();
                this.serviceNameFinder = new ServiceNameFinder();
        }
        
        @Override
        public QName getServiceName(String endpointUrl) {
                return getServiceNameFinder().lookup(endpointUrl);
        }
        
        protected ServiceNameFinder getServiceNameFinder() {
                return serviceNameFinder;
        }
        
        @Override
        public Object getService(QName serviceName) {
                ExportedServiceHolder holder = exportedServices.get(serviceName);
                if (holder == null) {
                        return null;
                }
                return holder.getExportedService();
        }
        
        @Override
        public void exportService(ServiceDefinition serviceDefinition) {
                if (serviceDefinition == null) {
                        throw new IllegalArgumentException("serviceDefinition was null");
                }
                ServiceExporter serviceExporter = ServiceExporterFactory.getServiceExporter(serviceDefinition, cxfBus);
                Object exportedService = serviceExporter.exportService(serviceDefinition);
                exportedServices.put(serviceDefinition.getServiceName(), new ExportedServiceHolder(exportedService, serviceDefinition));
                getServiceNameFinder().register(serviceDefinition);
        }

        @Override
        public void removeService(QName serviceName) {
                ExportedServiceHolder exportedServiceHolder = exportedServices.remove(serviceName);
                getServiceNameFinder().remove(exportedServiceHolder.getServiceDefinition().getEndpointUrl());
        }
                
        protected ConcurrentMap<QName, ExportedServiceHolder> getExportedServices() {
                return exportedServices;
        }
        
        public void setCxfBus(Bus cxfBus) {
                this.cxfBus = cxfBus;
        }

    /**
     * @deprecated setting ServerRegistry here has no effect, the ServerRegistry extension on the CXF Bus is used instead
     */
    @Deprecated
        public void setCxfServerRegistry(ServerRegistry cxfServerRegistry) {
        // no-op, see deprecation information
        }
        
        protected static class ExportedServiceHolder {
                
                private final Object exportedService;
                private final ServiceDefinition serviceDefinition;
                
                ExportedServiceHolder(Object exportedService, ServiceDefinition serviceDefinition) {
                        this.exportedService = exportedService;
                        this.serviceDefinition = serviceDefinition;
                }
                
                public Object getExportedService() {
                        return exportedService;
                }
                
                public ServiceDefinition getServiceDefinition() {
                        return serviceDefinition;
                }
                
        }
        
        /**
         * Looks up service QNameS based on URL StringS.  API is Map-like, but non-service specific portions of the
         * URL are trimmed prior to accessing its internal Map.
         * 
         * @author Kuali Rice Team (rice.collab@kuali.org)
         *
         */
        protected static class ServiceNameFinder {
            
                /**
                 * A service path to service QName map
                 */
                private ConcurrentMap<String, QName> servicePathToQName = new ConcurrentHashMap<String, QName>();
                

                /**
                 * This method trims the endpoint url base ({@link Config#getEndPointUrl()}) base off of the full service URL, e.g.
                 * "http://kuali.edu/kr-dev/remoting/SomeService" -> "SomeService".  It makes an effort to do so even if the host
                 * and ip don't match what is in {@link Config#getEndPointUrl()} by stripping host/port info.
                 * 
                 * If the service URL contains the configured subpath for RESTful service, additional trimming is done to
                 * isolate the service name from the rest of the url.
                 * 
                 * @param url
                 * @return the service specific suffix.  If fullServiceUrl doesn't contain the endpoint url base,
                 * fullServiceUrl is returned unmodified.  
                 */
                private String trimServiceUrlBase(String url) {
                        String trimmedUrl = StringUtils.removeStart(url, ConfigContext.getCurrentContextConfig().getEndPointUrl());
                        
                        if (trimmedUrl.length() == url.length()) { // it didn't contain the endpoint url base.
                                // Perhaps the incoming url has a different host (or the ip) or a different port.
                                // Trim off the host & port, then trim off the common base.
                                URI serviceUri = URI.create(url);
                                URI endpointUrlBase = URI.create(ConfigContext.getCurrentContextConfig().getEndPointUrl());
                                
                                String reqPath = serviceUri.getPath();
                                String basePath = endpointUrlBase.getPath();
                                
                                trimmedUrl = StringUtils.removeStart(reqPath, basePath);
                        }
                        
                        return trimmedUrl;
                }
                
                /**
                 * adds a mapping from the service specific portion of the service URL to the service name.
                 */
                public void register(ServiceDefinition serviceDefinition) {
                        String serviceUrlBase = trimServiceUrlBase(serviceDefinition.getEndpointUrl().toExternalForm());
                        if (serviceUrlBase.endsWith("/")) {
                                serviceUrlBase = StringUtils.chop(serviceUrlBase);
                        }
                        servicePathToQName.put(serviceUrlBase, serviceDefinition.getServiceName());
                }
                
                /**
                 * removes the mapping (if one exists) for the service specific portion of this url.
                 */
                public void remove(URL endpointUrl) {
                        servicePathToQName.remove(trimServiceUrlBase(endpointUrl.toExternalForm()));
                }
                
                /**
                 * gets the QName for the service
                 * 
                 * @param serviceUrl
                 * @return
                 */
                public QName lookup(String serviceUrl) {
                        String serviceUrlBase = trimServiceUrlBase(serviceUrl);

                        // First, make sure we don't have any query params
                        if (serviceUrlBase.length() > 0 && serviceUrlBase.lastIndexOf('?') != -1) {
                                serviceUrlBase = serviceUrlBase.substring(0, serviceUrlBase.lastIndexOf('?'));
                        }

                        QName qname = null;
                        // Now, iterate backwards through the url, stripping off pieces until you match -- this should work for rest too
                        while (qname == null) {
                                qname = servicePathToQName.get(serviceUrlBase);

                                int lastSeparatorIndex = serviceUrlBase.lastIndexOf('/');
                                if (lastSeparatorIndex == -1)
                                        break;
                                serviceUrlBase = serviceUrlBase.substring(0, lastSeparatorIndex);
                        }

                        return qname;
                }

        }

}