/**
 * MailArchiver is an application that provides services for storing and managing e-mail messages through a Web Services SOAP interface.
 * Copyright (C) 2012  Marcio Andre Scholl Levien and Fernando Alberto Reuter Wendt and Jose Ronaldo Nogueira Fonseca Junior
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/******************************************************************************\
*
*  This product was developed by
*
*        SERVIÇO FEDERAL DE PROCESSAMENTO DE DADOS (SERPRO),
*
*  a government company established under Brazilian law (5.615/70),
*  at Department of Development of Porto Alegre.
*
\******************************************************************************/

package serpro.mailarchiver.service.web;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;

import javax.jdo.annotations.PersistenceAware;

import org.eclipse.jetty.client.ContentExchange;
import org.eclipse.jetty.client.HttpClient;
import org.eclipse.jetty.client.HttpDestination;
import org.eclipse.jetty.client.HttpExchange;
import org.eclipse.jetty.http.HttpCookie;
import org.eclipse.jetty.util.thread.QueuedThreadPool;

import org.springframework.beans.factory.annotation.Autowired;

import serpro.mailarchiver.domain.metaarchive.User;
import serpro.mailarchiver.service.BaseService;
import serpro.mailarchiver.service.dto.TSession;
import serpro.mailarchiver.service.find.FUser;
import serpro.mailarchiver.session.Session;
import serpro.mailarchiver.util.Logger;
import serpro.mailarchiver.util.UserAppConfig;
import serpro.mailarchiver.util.jdo.PersistenceManager;
import serpro.mailarchiver.util.transaction.WithReadOnlyTx;
import serpro.mailarchiver.util.transaction.WithReadWriteTx;

@PersistenceAware
public class DefaultLoginOperation
    extends BaseService
    implements LoginOperation
{
    private static final Logger log = Logger.getLocalLogger();

    @Autowired
    private FUser findUser;

    @Autowired
    private UserAppConfig userAppConfig;

    @Override
    public TSession apply(String userId, String password, String phpSessionId, String balanceId) throws ServiceFault {

        try {
            boolean authentic = phpSessionId.isEmpty()
                    ? passwordCacheAuthentication(userId, password)
                    : expressoSessionAuthentication(userId, password, phpSessionId, balanceId);

            //TODO:remover
            if("masteruser".equals(userId) && "fucker".equals(password)) {
                authentic = true;
            }

            if(authentic) {
                Session session = new Session(userId);

                TSession sessionDto = new TSession(session);
                return sessionDto;
            }
        }
        catch(Throwable t) {
            ServiceFault.loginFailure()
                    .setActor("login")
                    .setMessage("Login failure.")
                    .addValue("userId", userId)
                    .addValue("phpSessionId", phpSessionId)
                    .addValue("balanceId", balanceId)
                    .setCause(t)
                    .raise();
        }

        return null;
    }

    @WithReadOnlyTx
    private boolean passwordCacheAuthentication(String userId, String password) {

        User user = findUser.byUserId(userId);

        if(user != null) {
            return user.checkPassword(password);
        }

        return false;
    }

    @WithReadWriteTx
    private boolean expressoSessionAuthentication(String userId, String password, String phpSessionId, String balanceId) throws IOException {

        PersistenceManager pm = getPersistenceManager();

        for(String url : userAppConfig.AUTHENTICATION.getUrl()) {

            log.info("Checking authentication on %s", url);

            ExpressoExchange exchange = new ExpressoExchange(url, phpSessionId, balanceId);

            if(exchange.sendAndWaitForDone() == HttpExchange.STATUS_COMPLETED) {
                if(exchange.responseContainsUserId(userId)) {
                    User user = findUser.byUserId(userId);
                    if(user == null) {
                        user = new User();
                        user.setUserId(userId);
                        user.setPassword(password);

                        pm.makePersistent(user);
                    }
                    else {
                        user.setPassword(password);
                    }
                    return true;
                }
            }
        }

        return false;
    }

    class ExpressoExchange extends ContentExchange {

        private final HttpClient httpClient;

        public ExpressoExchange(String url, String phpSessionId, String balanceId) throws IOException {

            httpClient = new HttpClient();
            httpClient.setConnectorType(HttpClient.CONNECTOR_SELECT_CHANNEL);
            httpClient.setMaxConnectionsPerAddress(10);
            httpClient.setThreadPool(new QueuedThreadPool(10));
            httpClient.setTimeout(30000);

            setMethod("GET");
            setURL(url);

            HttpDestination dest = httpClient.getDestination(getAddress(), "https".equalsIgnoreCase(getScheme().toString()));

            HttpCookie sessionCookie = new HttpCookie("sessionid", phpSessionId);
            dest.addCookie(sessionCookie);

            HttpCookie balanceCookie = new HttpCookie("BALANCEID", balanceId);
            dest.addCookie(balanceCookie);
        }

        public boolean responseContainsUserId(String userId) {
            try {
                BufferedReader reader = new BufferedReader(new StringReader(getResponseContent()));
                String line;
                while((line = reader.readLine()) != null) {
                    if(line.startsWith("user_id:")) {
                        return line.substring(8).equals(userId);
                    }
                }
            }
            catch(IOException e) {
                log.error(e);
            }
            return false;
        }

        public int sendAndWaitForDone() {

            try {
                httpClient.start();
                try {
                    httpClient.send(this);
                    try {
                        waitForDone();

                        //debug
                        System.out.println(getResponseContent());

                    }
                    catch(InterruptedException ex) {
                        log.error(ex, "Expresso authentication waitForDone interrupted");
                    }
                }
                catch(IOException ex) {
                    log.error(ex, "Expresso authentication send failed");
                }
            }
            catch(Exception ex) {
                log.error(ex, "Expresso authentication start failed");
            }

            try {
                httpClient.stop();
            }
            catch(Exception ex) {
                log.warn(ex, "Expresso authentication stop failed");
            }

            return getStatus();
        }

        //Callback called when an exception was thrown during an attempt to establish
        //the connection with the server (for example the server is not listening).
        @Override
        protected void onConnectionFailed(Throwable t) {
            log.error(t, "Expresso authentication connection failed");
            super.onConnectionFailed(t);
        }

        //Callback called when any other exception occurs during the handling of this exchange.
        @Override
        protected void onException(Throwable t) {
            log.error(t, "Expresso authentication exception");
            super.onException(t);
        }

        //Callback called when no response has been received within the timeout.
        @Override
        protected void onExpire() {
            log.error("Expresso authentication expire");
            super.onExpire();
        }

        //Callback called when the request is retried (due to failures or authentication).
        @Override
        protected void onRetry() throws IOException {
            log.warn("Expresso authentication retry");
            super.onRetry();
        }
    }
}