EDIT

// $Id$

/**

* Copyright (C) 2015 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.api.application;

import java.io.File;

import java.io.IOException;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.lang.reflect.Type;

import java.net.URISyntaxException;

import java.net.URL;

import java.util.Dictionary;

import java.util.jar.Attributes;

import java.util.jar.JarFile;

import java.util.jar.Manifest;

import org.eclipse.core.runtime.FileLocator;

import org.eclipse.core.runtime.Platform;

import org.eclipse.osgi.util.ManifestElement;

import org.osgi.framework.Bundle;

import org.osgi.framework.BundleException;

import org.osgi.framework.Constants;

import org.springframework.security.core.context.SecurityContext;

import eu.etaxonomy.cdm.api.cache.CdmServiceCacher;

import eu.etaxonomy.cdm.api.service.ICommonService;

import eu.etaxonomy.cdm.api.service.IService;

import eu.etaxonomy.cdm.api.service.ITestService;

import eu.etaxonomy.cdm.io.service.IIOService;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.taxeditor.service.ICachedCommonService;

import eu.etaxonomy.taxeditor.session.DefaultNewEntityListener;

/**

 * @author cmathew

 * @date 17 Jun 2015

 *

 */

public class CdmApplicationState {

    private static CdmApplicationState cdmApplicationState;

    private ICdmApplicationConfiguration appConfig;

    private ICdmDataChangeService dataChangeService;

    private SecurityContext securityContext;

    private static CdmServiceCacher cdmServiceCacher;

    private static String cdmlibVersion = null;

    private static String cdmlibLastModified = null;

    public static CdmApplicationState getInstance() {

        if(cdmApplicationState == null) {

            cdmApplicationState = new CdmApplicationState();

        }

        return cdmApplicationState;

    }

    public void setAppConfig(ICdmApplicationConfiguration appConfig) {

        this.appConfig = appConfig;

        if(appConfig instanceof CdmApplicationRemoteController) {

            CdmBase.setNewEntityListener(new DefaultNewEntityListener());

        } else {

            CdmBase.setNewEntityListener(null);

        }

    }

    public ICdmApplicationConfiguration getAppConfig() {

        return appConfig;

    }

    public static void setCurrentAppConfig(ICdmApplicationConfiguration appConfig) {

        getInstance().setAppConfig(appConfig);

    }

    public static ICdmApplicationConfiguration getCurrentAppConfig() {

        return getInstance().getAppConfig();

    }

    /**

     * @return the dataChangeService

     */

    public ICdmDataChangeService getDataChangeService() {

        return dataChangeService;

    }

    /**

     * @param dataChangeService the dataChangeService to set

     */

    public void setDataChangeService(ICdmDataChangeService dataChangeService) {

        this.dataChangeService = dataChangeService;

    }

    public static ICdmDataChangeService getCurrentDataChangeService() {

        return getInstance().getDataChangeService();

    }

    public static void setCurrentDataChangeService(ICdmDataChangeService dataChangeService) {

        getInstance().setDataChangeService(dataChangeService);

    }

    /**

     * @return the securityContext

     */

    public SecurityContext getSecurityContext() {

        return securityContext;

    }

    /**

     * @param securityContext the securityContext to set

     */

    public void setSecurityContext(SecurityContext securityContext) {

        this.securityContext = securityContext;

    }

    /**

     * @return the securityContext

     */

    public static SecurityContext getCurrentSecurityContext() {

        return getInstance().getSecurityContext();

    }

    /**

     * @param securityContext the securityContext to set

     */

    public static void setCurrentSecurityContext(SecurityContext securityContext) {

        getInstance().setSecurityContext(securityContext);

    }

    public static void dispose() {

        getInstance().setCurrentDataChangeService(null);

        getInstance().setAppConfig(null);

        getInstance().setSecurityContext(null);

        cdmApplicationState = null;

        cdmServiceCacher = null;

        cdmlibVersion = null;

        cdmlibLastModified = null;

    }

    /**

     * Generic method that will scan the getters of {@link ICdmApplicationConfiguration} for the given service

     * interface. If a matching getter is found the according service implementation is returned by

     * invoking the getter otherwise the method returns <code>null</code>.

     *

     * @param <T>

     * @param serviceClass

     * @return the configured implementation of <code>serviceClass</code> or <code>null</code>

     * @throws CdmApplicationException

     */

    public static <T extends IService> T getService(Class<T> serviceClass) throws CdmApplicationException {

        ICdmApplicationConfiguration configuration = getCurrentAppConfig();

        Method[] methods = ICdmApplicationConfiguration.class.getDeclaredMethods();

        T service = null;

        for (Method method : methods) {

            Type type = method.getGenericReturnType();

            if (type.equals(serviceClass)) {

                try {

                    service = (T) method.invoke(configuration, null);

                    break;

                } catch (IllegalArgumentException iae) {

                    throw new CdmApplicationException(iae);

                } catch (IllegalAccessException iae) {

                    throw new CdmApplicationException(iae);

                } catch (InvocationTargetException ite) {

                    throw new CdmApplicationException(ite);

                }

            }

        }

        return service;

    }

    /**

     * @see #getService(Class)

     * As ICommonService is not extending IService we need a specific request here

     */

    public static ICommonService getCommonService() {

        ICdmApplicationConfiguration configuration = getCurrentAppConfig();

        return configuration.getCommonService();

    }

    public static IIOService getIOService() {

        ICdmApplicationConfiguration configuration = getCurrentAppConfig();

        return ((CdmApplicationRemoteController)configuration).getIOService();

    }

    public static ITestService getTestService() {

        ICdmApplicationConfiguration configuration = getCurrentAppConfig();

        return ((CdmApplicationRemoteController)configuration).getTestService();

    }

    public static ICachedCommonService getCachedCommonService() {

        ICdmApplicationConfiguration configuration = getCurrentAppConfig();

        return ((CdmApplicationRemoteController)configuration).getCachedCommonService();

    }

    public static CdmServiceCacher getCdmServiceCacher() {

        return cdmServiceCacher;

    }

    public static void setCdmServiceCacher(CdmServiceCacher cacher) {

        cdmServiceCacher = cacher;

    }

    public static void updateCdmlibManifestInfo() {

        cdmlibVersion = null;

        cdmlibLastModified = null;

        String cdmlibPathPrefix = "lib/cdmlib-services-";

        String jarSuffix = ".jar";

        Bundle bundle = Platform.getBundle("eu.etaxonomy.taxeditor.cdmlib");

        Dictionary<String, String> headers = bundle.getHeaders();

        String bundleClasspath = headers.get(Constants.BUNDLE_CLASSPATH);

        try {

            ManifestElement[] elements = ManifestElement.parseHeader(Constants.BUNDLE_CLASSPATH, bundleClasspath);

            for (ManifestElement manifestElement : elements) {

                String jar =  manifestElement.getValue();

                if(jar.startsWith(cdmlibPathPrefix) && jar.endsWith(jarSuffix)) {

                    URL fileURL = bundle.getEntry(jar);

                    File file = null;

                    try {

                        file = new File(FileLocator.resolve(fileURL).toURI());

                        JarFile jarFile = new JarFile(file);

                        Manifest manifest = jarFile.getManifest();

                        Attributes attributes = manifest.getMainAttributes();

                        // from the OSGI spec the LastModified value is " the number of milliseconds

                        // since midnight Jan. 1, 1970 UTC with the condition that a change must

                        // always result in a higher value than the previous last modified time

                        // of any bundle"

                        cdmlibVersion = attributes.getValue("Bundle-Version");

                        cdmlibLastModified = attributes.getValue("Bnd-LastModified");

                        if(cdmlibVersion == null || cdmlibLastModified == null) {

                            throw new IllegalStateException("Invalid cdmlib manifest info");

                        }

                    } catch (URISyntaxException urise) {

                        throw new IllegalStateException(urise);

                    } catch (IOException ioe) {

                        throw new IllegalStateException(ioe);

                    }

                }

            }

        } catch (BundleException e) {

            throw new IllegalStateException(e);

        }

    }

    public static String getCdmlibVersion() {

        if(cdmlibVersion == null) {

            updateCdmlibManifestInfo();

        }

        return cdmlibVersion;

    }

    public static String getCdmlibLastModified() {

        if(cdmlibLastModified == null) {

            updateCdmlibManifestInfo();

        }

        return cdmlibLastModified;

    }

}