package de.mpiwg.itgroup.annotations.restlet;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.Properties;

import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.servlet.ServletContext;

import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.kernel.AbstractGraphDatabase;
import org.neo4j.server.WrappingNeoServerBootstrapper;
import org.restlet.Application;
import org.restlet.Context;
import org.restlet.Restlet;
import org.restlet.routing.Router;

import de.mpiwg.itgroup.annotations.neo4j.AnnotationStore;

public class RestServer extends Application {

    public static Logger logger = Logger.getLogger(RestServer.class);

    /**
     * Properties holding consumer keys and secrets
     */
    private Properties consumerKeys;
    public String CONSUMER_KEYS_PATH = "WEB-INF/consumerkeys.property";

    private Properties serverConfig;
    public String CONFIG_PROPS_PATH = "WEB-INF/serverconfig.property";

    private GraphDatabaseService graphDb;
    public static final String GRAPHDB_KEY = "annotationmanager.graphdb";
    public static final String GRAPHDB_PATH_KEY = "annotationmanager.graphdb.path";
    public String graphdbPath = "WEB-INF/neo4j-annotation-db";

    private WrappingNeoServerBootstrapper srv;
    public static final String GRAPHDBSRV_KEY = "annotationmanager.graphdb.srv";
    
    private AnnotationStore store;
    public static final String ANNSTORE_KEY = "annotationmanager.store";

    private String ldapServerUrl;
    public static final String LDAP_SERVER_KEY = "annotationmanager.ldapserver.url";

    /**
     * constructor
     * 
     * @param parentContext
     */
    public RestServer(Context parentContext) {
        super(parentContext);
        // TODO: is this the right place to run the log4j configurator?
        BasicConfigurator.configure();

        ServletContext sc = (ServletContext) getContext().getServerDispatcher().getContext().getAttributes()
                .get("org.restlet.ext.servlet.ServletContext");
        if (sc != null) {
            /*
             * read config from webapp
             */
            serverConfig = new Properties();
            InputStream ps1 = getResourceAsStream(sc, CONFIG_PROPS_PATH);
            if (ps1 != null) {
                logger.debug("loading config from " + CONFIG_PROPS_PATH);
                try {
                    serverConfig.load(ps1);
                    /*
                     * read serverconfig options
                     */
                    graphdbPath = serverConfig.getProperty(GRAPHDB_PATH_KEY, graphdbPath);
                    ldapServerUrl =  serverConfig.getProperty(LDAP_SERVER_KEY, null);
                } catch (IOException e) {
                    logger.warn("Error loading server config: ", e);
                }
                logger.debug("config: " + serverConfig);
            } else {
                logger.error("Unable to get resource " + CONFIG_PROPS_PATH);
            }
            // look for database service in context
            graphDb = (GraphDatabaseService) sc.getAttribute(GRAPHDB_KEY);
            if (graphDb == null) {
                /*
                 * open database
                 */
                String dbFn = getResourcePath(sc, graphdbPath);
                if (dbFn != null) {
                    logger.debug("opening DB " + dbFn);
                    graphDb = new GraphDatabaseFactory().newEmbeddedDatabase(dbFn);
                    registerShutdownHook(graphDb);
                    // store in context
                    sc.setAttribute(GRAPHDB_KEY, graphDb);
                    // AnnotationStore
                    store = new AnnotationStore(graphDb);
                    sc.setAttribute(ANNSTORE_KEY, store);
                    // admin server
                    srv = new WrappingNeoServerBootstrapper((AbstractGraphDatabase) graphDb);
                    logger.debug("Starting DB admin server...");
                    // store in context
                    sc.setAttribute(GRAPHDBSRV_KEY, srv);
                    srv.start();
                } else {
                    logger.error("Unable to get resource " + dbFn);
                }
            }
            /*
             * read consumerKeys from webapp
             */
            consumerKeys = new Properties();
            InputStream ps2 = getResourceAsStream(sc, CONSUMER_KEYS_PATH);
            if (ps2 != null) {
                logger.debug("loading consumer keys from " + CONSUMER_KEYS_PATH);
                try {
                    consumerKeys.load(ps2);
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                logger.debug("consumer keys: " + consumerKeys);
            } else {
                logger.error("Unable to get resource " + CONSUMER_KEYS_PATH);
            }
        } else {
            logger.error("Unable to get ServletContext!");
        }

    }

    /**
     * returns consumer secret for consumer key. returns null if consumer key
     * doesn't exist.
     * 
     * @param consumerKey
     * @return
     */
    public String getConsumerSecret(String consumerKey) {
        return consumerKeys.getProperty(consumerKey);
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.restlet.Application#createInboundRoot()
     */
    @Override
    public Restlet createInboundRoot() {
        // this.authenticator = createAuthenticator();

        Router router = new Router(getContext());

        router.attach("/annotator/annotations", AnnotatorAnnotations.class);
        router.attach("/annotator/annotations/{id}", AnnotatorAnnotations.class);
        router.attach("/annotator/search", AnnotatorSearch.class);

        // router.attach("",redirector); router.attach("/annotator",
        // ExtendedAnnotationInput.class);

        router.attach("/", AnnotatorInfo.class);
        // authenticator.setNext(router);
        // return authenticator;

        return router;
    }

    /**
     * Hole den vollen Benutzernamen aus dem LDAP
     * 
     * @param creator
     * @return
     */
    public String getFullNameFromLdap(String creator) {
        String retString = creator; // falls nichts gefunden wird einfach den
                                    // creator zurueckgeben
        if (ldapServerUrl == null) {
        	return retString;
        }
        Hashtable<String, String> env = new Hashtable<String, String>();
        String sp = "com.sun.jndi.ldap.LdapCtxFactory";
        env.put(javax.naming.Context.INITIAL_CONTEXT_FACTORY, sp);

        env.put(javax.naming.Context.PROVIDER_URL, ldapServerUrl);

        DirContext dctx;
        try {
            dctx = new InitialDirContext(env);
        } catch (NamingException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
            return retString;
        }

        String base = "ou=people";

        SearchControls sc = new SearchControls();
        String[] attributeFilter = { "cn", "mail" };
        sc.setReturningAttributes(attributeFilter);
        sc.setSearchScope(SearchControls.SUBTREE_SCOPE);

        String filter = "(uid=" + creator + ")";

        try {
            NamingEnumeration<SearchResult> results = dctx.search(base, filter, sc);
            while (results.hasMore()) {
                SearchResult sr = (SearchResult) results.next();
                javax.naming.directory.Attributes attrs = sr.getAttributes();

                Attribute attr = attrs.get("cn");
                retString = (String) attr.get();
            }
        } catch (NamingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            dctx.close();
        } catch (NamingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return retString;
    }

    /**
     * returns resource from path (in webapp) as InputStream.
     * 
     * @param sc
     * @param path
     * @return
     */
    protected InputStream getResourceAsStream(ServletContext sc, String path) {
        InputStream ps = sc.getResourceAsStream(path);
        if (ps == null) {
            // try as file
            File pf = new File(sc.getRealPath(path));
            if (pf != null) {
                logger.debug("trying file for: " + pf);
                try {
                    ps = new FileInputStream(pf);
                } catch (FileNotFoundException e) {
                    logger.error(e);
                }
            }
        }
        return ps;
    }

    /**
     * get a real file name for a web app file pathname.
     * 
     * If filename starts with "/" its treated as absolute else the path is
     * appended to the base directory of the web-app.
     * 
     * @param filename
     * @param sc
     * @return
     */
    public static String getResourcePath(ServletContext sc, String filename) {
        File f = new File(filename);
        // is the filename absolute?
        if (!f.isAbsolute()) {
            // relative path -> use getRealPath to resolve in webapp
            filename = sc.getRealPath(filename);
        }
        return filename;
    }

    /* (non-Javadoc)
     * @see org.restlet.Application#stop()
     */
    @Override
    public synchronized void stop() throws Exception {
        /*
         * trying to clean up databases, nur sure if this is the right way...
         */
        if (srv != null) {
            logger.debug("Stopping DB admin server...");
            srv.stop();
            srv = null;
        }
        if (graphDb != null) {
            logger.debug("Stopping DB...");
            graphDb.shutdown();
            graphDb = null;
        }
        super.stop();
    }

    private static void registerShutdownHook(final GraphDatabaseService graphDb) {
        // Registers a shutdown hook for the Neo4j instance so that it
        // shuts down nicely when the VM exits (even if you "Ctrl-C" the
        // running example before it's completed)
        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                graphDb.shutdown();
            }
        });
    }
   
    
}