/*
 * 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.sling.testing.mock.sling;

import java.util.Dictionary;
import java.util.Hashtable;

import org.apache.sling.api.adapter.AdapterManager;
import org.apache.sling.testing.mock.osgi.MockOsgi;
import org.jetbrains.annotations.NotNull;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Wrapper for {@link MockAdapterManager} which makes sure multiple unit tests
 * running in parallel do not get in conflict with each other. Instead, a
 * different {@link MockAdapterManager} is used per thread.
 */
class ThreadsafeMockAdapterManagerWrapper implements AdapterManager {

    private static final Logger log = LoggerFactory.getLogger(ThreadsafeMockAdapterManagerWrapper.class);

    private static final InheritableThreadLocal<AdapterManagerBundleContextFactory> THREAD_LOCAL =
            new InheritableThreadLocal<AdapterManagerBundleContextFactory>() {
                @Override
                protected AdapterManagerBundleContextFactory initialValue() {
                    return new AdapterManagerBundleContextFactory();
                }
            };

    @Override
    @SuppressWarnings("null")
    public <AdapterType> AdapterType getAdapter(
            @NotNull final Object adaptable, @NotNull final Class<AdapterType> type) {
        AdapterManager adapterManager = THREAD_LOCAL.get().getAdapterManager();
        return adapterManager.getAdapter(adaptable, type);
    }

    /**
     * Sets bundle context.
     * @param bundleContext Bundle context
     */
    public void setBundleContext(@NotNull final BundleContext bundleContext) {
        AdapterManagerBundleContextFactory adapterManager = THREAD_LOCAL.get();
        adapterManager.setBundleContext(bundleContext);
    }

    /**
     * Removes bundle context reference.
     */
    public void clearBundleContext() {
        AdapterManagerBundleContextFactory adapterManager = THREAD_LOCAL.get();
        adapterManager.clearBundleContext();
    }

    private static class AdapterManagerBundleContextFactory {

        private BundleContext bundleContext;

        public void setBundleContext(@NotNull final BundleContext bundleContext) {
            log.debug("Set bundle context for AdapterManager, bundleContext={}", bundleContext);
            this.bundleContext = bundleContext;

            // register adapter manager
            MockAdapterManagerImpl adapterManagerImpl = new MockAdapterManagerImpl();
            Dictionary<String, Object> properties = new Hashtable<String, Object>();
            MockOsgi.injectServices(adapterManagerImpl, bundleContext);
            MockOsgi.activate(adapterManagerImpl, bundleContext, properties);
            bundleContext.registerService(AdapterManager.class.getName(), adapterManagerImpl, properties);
        }

        public void clearBundleContext() {
            this.bundleContext = null;
        }

        @SuppressWarnings("null")
        public synchronized AdapterManager getAdapterManager() {
            if (bundleContext == null) {
                BundleContext newBundleContext = MockOsgi.newBundleContext();
                log.warn(
                        "Create new bundle context for adapter manager because it was null, bundleContext={}",
                        bundleContext);
                setBundleContext(newBundleContext);
            }
            ServiceReference<AdapterManager> serviceReference = bundleContext.getServiceReference(AdapterManager.class);
            if (serviceReference != null) {
                return bundleContext.getService(serviceReference);
            } else {
                throw new RuntimeException("AdapterManager not registered in bundle context.");
            }
        }
    }
}