src/main/java/de/ids_mannheim/korap/config/BeanConfiguration.java

package de.ids_mannheim.korap.config;

import de.ids_mannheim.korap.interfaces.AuthenticationIface;
import de.ids_mannheim.korap.interfaces.AuthenticationManagerIface;
import de.ids_mannheim.korap.interfaces.EncryptionIface;
import de.ids_mannheim.korap.interfaces.db.*;
import de.ids_mannheim.korap.web.utils.KustvaktResponseHandler;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

/**
 * User: hanl
 * Date: 10/9/13
 * Time: 11:20 AM
 */
public class BeanConfiguration {

    private static final String CONFIG_FILE = "light-config.xml";
    public static final String KUSTVAKT_DB = "kustvakt_db";

    public static final String KUSTVAKT_ENCRYPTION = "kustvakt_encryption";
    public static final String KUSTVAKT_AUDITING = "kustvakt_auditing";
    public static final String KUSTVAKT_CONFIG = "kustvakt_config";

    public static final String KUSTVAKT_AUTHENTICATION_MANAGER = "kustvakt_authenticationmanager";
    public static final String KUSTVAKT_USERDB = "kustvakt_userdb";
    public static final String KUSTVAKT_POLICIES = "kustvakt_policies";

    private static BeanHolderHelper beans;

    //todo: allow this for external plugin systems that are not kustvakt specific
    @Deprecated
    public static void setCustomBeansHolder(BeanHolderHelper holder) {
        ApplicationContext context = beans.context;
        holder.context = context;
        BeanConfiguration.beans = holder;
    }

    public static BeanHolderHelper getBeans() {
        return BeanConfiguration.beans;
    }

    @Deprecated
    public static void loadAuthenticationProviders() {
        Set<Class<? extends AuthenticationIface>> set = KustvaktClassLoader
                .loadSubTypes(AuthenticationIface.class);
        Set<AuthenticationIface> set2 = new HashSet<>();
        for (Class<? extends AuthenticationIface> i : set) {
            try {
                set2.add(i.newInstance());
            }catch (InstantiationException | IllegalAccessException e) {
                e.printStackTrace();
            }
        }
        try {
            getBeans().getAuthenticationManager().setProviders(set2);
        }catch (RuntimeException e) {
            // do nothing
        }
    }

    public static boolean hasContext() {
        return beans != null && beans.context != null;
    }

    public static void loadClasspathContext(String... files) {
        if (hasContext())
            closeApplication();

        ApplicationContext context;
        if (files.length == 0)
            context = new ClassPathXmlApplicationContext(CONFIG_FILE);
        else
            context = new ClassPathXmlApplicationContext(files);

        BeanConfiguration.beans = new BeanHolderHelper(context);
        setManualBeans();

    }

    private static void setManualBeans() {
        if (getBeans().getPolicyDbProvider() != null
                && getBeans().getEncryption() != null
                && getBeans().getResourceProvider() != null)
            de.ids_mannheim.korap.security.ac.SecurityManager
                    .setProviders(getBeans().getPolicyDbProvider(),
                            getBeans().getEncryption(),
                            Arrays.asList(getBeans().getResourceProvider()));
    }

    public static void loadFileContext(String filepath) {
        if (!hasContext()) {
            ApplicationContext context = new FileSystemXmlApplicationContext(
                    "file:" + filepath);
            BeanConfiguration.beans = new BeanHolderHelper(context);
        }
    }

    public static void closeApplication() {
        if (hasContext())
            beans.finish();
        beans = null;
    }

    //todo: set response handler
    @Deprecated
    public static KustvaktResponseHandler getResponseHandler() {
        return null;
    }

    public static class BeanHolderHelper {

        private ApplicationContext context = null;
        private DefaultHandler handler;

        private BeanHolderHelper(ApplicationContext context) {
            this.handler = new DefaultHandler();
            this.context = context;
            // todo: better method?!
            KustvaktResponseHandler.init(getAuditingProvider());
        }

        protected <T> T getBean(Class<T> clazz) {
            if (context != null) {
                try {
                    return context.getBean(clazz);
                }catch (NoSuchBeanDefinitionException e) {
                    // do nothing
                }
            }
            return this.handler.getDefault(clazz);
        }

        protected <T> T getBean(String name) {
            if (context != null) {
                try {
                    return (T) context.getBean(name);
                }catch (NoSuchBeanDefinitionException e) {
                    // do nothing
                }
            }
            return (T) this.handler.getDefault(name);
        }

        public AuditingIface getAuditingProvider() {
            return (AuditingIface) getBean(KUSTVAKT_AUDITING);
        }

        public <T extends KustvaktConfiguration> T getConfiguration() {
            return (T) getBean(KUSTVAKT_CONFIG);
        }

        public PersistenceClient getPersistenceClient() {
            return getBean(KUSTVAKT_DB);
        }

        //        public AuthenticationManagerIface getAuthenticationManager() {
        //            throw new RuntimeException("!Stub");
        //        }

        //        public EntityHandlerIface getUserDBHandler() {
        //            throw new RuntimeException("!Stub");
        //        }

        public EncryptionIface getEncryption() {
            return getBean(KUSTVAKT_ENCRYPTION);
        }

        public AuthenticationManagerIface getAuthenticationManager() {
            return getBean(KUSTVAKT_AUTHENTICATION_MANAGER);
        }

        public EntityHandlerIface getUserDBHandler() {
            return getBean(KUSTVAKT_USERDB);
        }

        public PolicyHandlerIface getPolicyDbProvider() {
            return getBean(KUSTVAKT_POLICIES);
        }

        // todo: !!!!!!!!!!!!!!!!!!!!!!!!!!
        // todo: more specific --> collection provider, document provider, etc.
        public ResourceOperationIface getResourceProvider() {
            return getBean("resourceProvider");
        }

        private void finish() {
            this.getAuditingProvider().finish();
            context = null;
        }

    }
}