/**
 * 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.dosgi.dsw.handlers;

import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.cxf.dosgi.dsw.util.ClassUtils;
import org.apache.cxf.dosgi.dsw.util.OsgiUtils;
import org.apache.cxf.jaxrs.model.UserResource;
import org.apache.cxf.jaxrs.provider.aegis.AegisElementProvider;
import org.apache.cxf.jaxrs.utils.ResourceUtils;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class JaxRSUtils {

    public static final String MODEL_FOLDER = "/OSGI-INF/cxf/jaxrs/";
    public static final String DEFAULT_MODEL = "/OSGI-INF/cxf/jaxrs/model.xml";
    public static final String PROVIDERS_FILTER = "(|"
            + "(objectClass=javax.ws.rs.ext.MessageBodyReader)"
            + "(objectClass=javax.ws.rs.ext.MessageBodyWriter)"
            + "(objectClass=javax.ws.rs.ext.ExceptionMapper)"
            + "(objectClass=org.apache.cxf.jaxrs.ext.RequestHandler)"
            + "(objectClass=org.apache.cxf.jaxrs.ext.ResponseHandler)"
            + "(objectClass=org.apache.cxf.jaxrs.ext.ParameterHandler)"
            + "(objectClass=org.apache.cxf.jaxrs.ext.ResponseExceptionMapper)"
            + ")";
    private static final Logger LOG = LoggerFactory.getLogger(JaxRSUtils.class);

    private JaxRSUtils() {
        // never constructed
    }

    static List<Object> getProviders(BundleContext callingContext, Map<String, Object> sd) {
        List<Object> providers = new ArrayList<Object>();
        if ("aegis".equals(sd.get(org.apache.cxf.dosgi.dsw.Constants.RS_DATABINDING_PROP_KEY))) {
            providers.add(new AegisElementProvider());
        }

        providers.addAll(ClassUtils.loadProviderClasses(callingContext,
                                                        sd,
                                                        org.apache.cxf.dosgi.dsw.Constants.RS_PROVIDER_PROP_KEY));

        Object globalQueryProp = sd.get(org.apache.cxf.dosgi.dsw.Constants.RS_PROVIDER_GLOBAL_PROP_KEY);
        boolean globalQueryRequired = globalQueryProp == null || OsgiUtils.toBoolean(globalQueryProp);
        if (!globalQueryRequired) {
            return providers;
        }

        boolean cxfProvidersOnly = OsgiUtils.getBooleanProperty(sd,
                org.apache.cxf.dosgi.dsw.Constants.RS_PROVIDER_EXPECTED_PROP_KEY);

        try {
            ServiceReference[] refs = callingContext.getServiceReferences((String)null, PROVIDERS_FILTER);
            if (refs != null) {
                for (ServiceReference ref : refs) {
                    if (!cxfProvidersOnly
                        || OsgiUtils.toBoolean(ref
                            .getProperty(org.apache.cxf.dosgi.dsw.Constants.RS_PROVIDER_PROP_KEY))) {
                        providers.add(callingContext.getService(ref));
                    }
                }
            }
        } catch (Exception ex) {
            LOG.debug("Problems finding JAXRS providers " + ex.getMessage(), ex);
        }
        return providers;
    }

    static List<UserResource> getModel(BundleContext callingContext, Class<?> iClass) {
        String classModel = MODEL_FOLDER + iClass.getSimpleName() + "-model.xml";
        List<UserResource> list = getModel(callingContext, iClass, classModel);
        return list != null ? list : getModel(callingContext, iClass, DEFAULT_MODEL);
    }

    private static List<UserResource> getModel(BundleContext callingContext, Class<?> iClass, String name) {
        InputStream r = iClass.getClassLoader().getResourceAsStream(name);
        if (r == null) {
            URL u = callingContext.getBundle().getResource(name);
            if (u != null) {
                try {
                    r = u.openStream();
                } catch (Exception ex) {
                    LOG.info("Problems opening a user model resource at " + u.toString());
                }
            }
        }
        if (r != null) {
            try {
                return ResourceUtils.getUserResources(r);
            } catch (Exception ex) {
                LOG.info("Problems reading a user model, it will be ignored");
            }
        }
        return null;
    }
}