/**
 * 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.bus.spring;

import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.cxf.Bus;
import org.apache.cxf.bus.extension.ExtensionManagerImpl;
import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.common.util.ReflectionUtil;
import org.apache.cxf.configuration.ConfiguredBeanLocator;
import org.springframework.beans.Mergeable;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.TypedStringValue;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ConfigurableApplicationContext;

/**
 *
 */
public class SpringBeanLocator implements ConfiguredBeanLocator {
    private static final Logger LOG = LogUtils.getL7dLogger(SpringBeanLocator.class);

    ApplicationContext context;
    ConfiguredBeanLocator orig;
    Set<String> passThroughs = new HashSet<>();
    Object bundleContext;
    boolean osgi = true;

    public SpringBeanLocator(ApplicationContext ctx) {
        this(ctx, null);
    }
    public SpringBeanLocator(ApplicationContext ctx, Bus bus) {
        context = ctx;
        if (bus != null) {
            orig = bus.getExtension(ConfiguredBeanLocator.class);
            if (orig instanceof ExtensionManagerImpl) {
                List<String> names = new ArrayList<>();
                for (String s : ctx.getBeanDefinitionNames()) {
                    names.add(s);
                    for (String s2 : ctx.getAliases(s)) {
                        names.add(s2);
                    }
                }

                ((ExtensionManagerImpl)orig).removeBeansOfNames(names);
            }
        }
        loadOSGIContext(bus);
    }

    private void loadOSGIContext(Bus b) {
        bundleContext = findBundleContext(context, b);
        if (bundleContext == null) {
            osgi = false;
        }
    }

    private Object findBundleContext(ApplicationContext applicationContext, Bus b) {
        Object answer = null;
        ApplicationContext aContext = applicationContext;
        // try to find out the bundleContext by going through the parent context
        while (aContext != null && answer == null) {
            answer = getBundleContext(aContext, b);
            aContext = aContext.getParent();
        }
        return answer;
    }

    private Object getBundleContext(ApplicationContext applicationContext, Bus b) {
        try {
            //use a little reflection to allow this to work without the spring-dm jars
            //for the non-osgi cases
            Method m = applicationContext.getClass().getMethod("getBundleContext");
            Object o = m.invoke(applicationContext);
            if (o != null && b != null) {
                @SuppressWarnings("unchecked")
                Class<Object> cls = (Class<Object>)m.getReturnType();
                b.setExtension(o, cls);
            }
            return o;
        } catch (Throwable t) {
            // do nothing here
        }
        return null;
    }

    public <T> T getBeanOfType(String name, Class<T> type) {
        T t = null;
        try {
            t = type.cast(context.getBean(name, type));
        } catch (NoSuchBeanDefinitionException nsbde) {
            //ignore
        }
        if (t == null) {
            t = orig.getBeanOfType(name, type);
        }
        return t;
    }

    /** {@inheritDoc}*/
    public List<String> getBeanNamesOfType(Class<?> type) {
        Set<String> s = new LinkedHashSet<String>(Arrays.asList(context.getBeanNamesForType(type,
                                                                                         false,
                                                                                         false)));
        s.removeAll(passThroughs);
        s.addAll(orig.getBeanNamesOfType(type));
        return new ArrayList<>(s);
    }

    /** {@inheritDoc}*/
    public <T> Collection<? extends T> getBeansOfType(Class<T> type) {
        Set<String> s = new LinkedHashSet<String>(Arrays.asList(context.getBeanNamesForType(type,
                                                                                            false,
                                                                                            false)));
        s.removeAll(passThroughs);
        List<T> lst = new LinkedList<T>();
        for (String n : s) {
            lst.add(type.cast(context.getBean(n, type)));
        }
        lst.addAll(orig.getBeansOfType(type));
        if (lst.isEmpty()) {
            tryOSGI(lst, type);
        }
        return lst;
    }
    private <T> void tryOSGI(Collection<T> lst, Class<T> type) {
        if (!osgi) {
            return;
        }
        try {
            //use a little reflection to allow this to work without the spring-dm jars
            //for the non-osgi cases
            Class<?> contextClass = findContextClass(bundleContext.getClass());

            Method m = contextClass.getMethod("getServiceReference", String.class);
            ReflectionUtil.setAccessible(m);
            Object o = m.invoke(bundleContext, type.getName());
            if (o != null) {
                m = contextClass.getMethod("getService", m.getReturnType());
                ReflectionUtil.setAccessible(m);
                o = m.invoke(bundleContext, o);
                lst.add(type.cast(o));
            }
        } catch (NoSuchMethodException e) {
            osgi = false;
            //not using OSGi
        } catch (Throwable e) {
            //ignore
            LOG.log(Level.WARNING, "Could not get service for " + type.getName(), e);
        }
    }
    private Class<?> findContextClass(Class<?> cls) {
        for (Class<?> c : cls.getInterfaces()) {
            if (c.getName().equals("org.osgi.framework.BundleContext")) {
                return c;
            }
        }
        for (Class<?> c : cls.getInterfaces()) {
            Class<?> c2 = findContextClass(c);
            if (c2 != null) {
                return c2;
            }
        }
        Class<?> c2 = findContextClass(cls.getSuperclass());
        if (c2 != null) {
            return c2;
        }

        return cls;
    }


    public <T> boolean loadBeansOfType(Class<T> type,
                                       BeanLoaderListener<T> listener) {
        List<String> list = new ArrayList<>(Arrays.asList(context.getBeanNamesForType(type,
                                                                                            false,
                                                                                            false)));
        list.removeAll(passThroughs);
        Collections.reverse(list);
        boolean loaded = false;
        for (String s : list) {
            Class<?> beanType = context.getType(s);
            Class<? extends T> t = beanType.asSubclass(type);
            if (listener.loadBean(s, t)) {
                Object o = context.getBean(s);
                if (listener.beanLoaded(s, type.cast(o))) {
                    return true;
                }
                loaded = true;
            }
        }
        return loaded || orig.loadBeansOfType(type, listener);
    }

    public boolean hasConfiguredPropertyValue(String beanName, String propertyName, String searchValue) {
        if (context.containsBean(beanName) && !passThroughs.contains(beanName)) {
            ConfigurableApplicationContext ctxt = (ConfigurableApplicationContext)context;
            BeanDefinition def = ctxt.getBeanFactory().getBeanDefinition(beanName);
            if (!ctxt.getBeanFactory().isSingleton(beanName) || def.isAbstract()) {
                return false;
            }
            Collection<?> ids = null;
            PropertyValue pv = def.getPropertyValues().getPropertyValue(propertyName);

            if (pv != null) {
                Object value = pv.getValue();
                if (!(value instanceof Collection)) {
                    throw new RuntimeException("The property " + propertyName + " must be a collection!");
                }

                if (value instanceof Mergeable) {
                    if (!((Mergeable)value).isMergeEnabled()) {
                        ids = (Collection<?>)value;
                    }
                } else {
                    ids = (Collection<?>)value;
                }
            }

            if (ids != null) {
                for (Iterator<?> itr = ids.iterator(); itr.hasNext();) {
                    Object o = itr.next();
                    if (o instanceof TypedStringValue) {
                        if (searchValue.equals(((TypedStringValue) o).getValue())) {
                            return true;
                        }
                    } else {
                        if (searchValue.equals(o)) {
                            return true;
                        }
                    }
                }
            }
        }
        return orig.hasConfiguredPropertyValue(beanName, propertyName, searchValue);
    }

    public <T> List<T> getOSGiServices(Class<T> type) {
        List<T> lst = new ArrayList<>();
        if (!osgi) {
            return lst;
        }

        Class<?> contextClass = findContextClass(bundleContext.getClass());
        try {
            Method m = contextClass.getMethod("getServiceReference", String.class);
            Class<?> servRefClass = m.getReturnType();
            m = contextClass.getMethod("getServiceReferences", String.class, String.class);

            Object o = ReflectionUtil.setAccessible(m).invoke(bundleContext, type.getName(), null);
            if (o != null) {
                m = contextClass.getMethod("getService", servRefClass);
                ReflectionUtil.setAccessible(m);
                for (int x = 0; x < Array.getLength(o); x++) {
                    Object ref = Array.get(o, x);
                    Object o2 = m.invoke(bundleContext, ref);
                    if (o2 != null) {
                        lst.add(type.cast(o2));
                    }
                }
            }
        } catch (NoSuchMethodException e) {
            //not using OSGi apparently
            e.printStackTrace();
        } catch (Throwable e) {
            //ignore
            e.printStackTrace();
            LOG.log(Level.FINE, "Could not get services for " + type.getName(), e);
        }
        return lst;
    }

    public boolean hasBeanOfName(String name) {
        if (context.containsBean(name)) {
            return true;
        }
        return orig.hasBeanOfName(name);
    }

}
