/*
 * Juick
 * Copyright (C) 2013, Ugnich Anton
 *
 * 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/>.
 */
package com.juick;

import com.google.android.gcm.server.Message;
import com.google.android.gcm.server.MulticastResult;
import com.google.android.gcm.server.Result;
import com.google.android.gcm.server.Sender;
import com.juick.json.MessageSerializer;
import com.juick.server.PushQueries;
import com.juick.server.MessagesQueries;
import com.juick.xmpp.JID;
import com.juick.xmpp.Message.MessageListener;
import com.juick.xmpp.utils.XmlUtils;
import com.juick.xmpp.Stream;
import com.juick.xmpp.StreamComponent;
import com.juick.xmpp.extensions.JuickMessage;
import com.notnoop.apns.APNS;
import com.notnoop.apns.ApnsService;
import org.apache.http.Consts;
import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.apache.http.util.TextUtils;
import org.json.JSONObject;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.Socket;
import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;

/**
 *
 * @author Ugnich Anton
 */
public class PushComponent implements ServletContextListener, Stream.StreamListener, MessageListener {

    private static Logger logger = Logger.getLogger(PushComponent.class.getName());

    private ExecutorService executorService;
    String wns_application_sip;
    String wns_client_secret;
    Connection sql;
    Socket socket;
    Stream xmpp;
    Sender GCMSender;

    @Override
    public void contextInitialized(final ServletContextEvent sce) {
        logger.info("component initialized");
        executorService = Executors.newSingleThreadExecutor();
        executorService.submit(new Runnable() {
            @Override
            public void run() {
                Properties conf = new Properties();
                try {
                    conf.load(sce.getServletContext().getResourceAsStream("WEB-INF/juick.conf"));
                    LogManager.getLogManager().readConfiguration(
                            sce.getServletContext().getResourceAsStream("WEB-INF/logging.properties"));
                    wns_application_sip = conf.getProperty("wns_application_sip", "");
                    wns_client_secret = conf.getProperty("wns_client_secret", "");
                    GCMSender = new Sender(conf.getProperty("gcm_key"));

                    setupSql(conf.getProperty("mysql_host"), conf.getProperty("mysql_username"),
                            conf.getProperty("mysql_password", ""), conf.getProperty("mysql_database", ""));
                    setupXmppComponent(new JID("", conf.getProperty("push_jid"), ""), conf.getProperty("xmpp_host", "localhost"),
                            Integer.parseInt(conf.getProperty("xmpp_port", "5347")), conf.getProperty("push_xmpp_password", ""));
                } catch (IOException e) {
                    logger.log(Level.SEVERE, e.getMessage(), e);
                }
            }
        });
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        // Now deregister JDBC drivers in this context's ClassLoader:
        // Get the webapp's ClassLoader
        ClassLoader cl = Thread.currentThread().getContextClassLoader();
        // Loop through all drivers
        Enumeration<Driver> drivers = DriverManager.getDrivers();
        while (drivers.hasMoreElements()) {
            Driver driver = drivers.nextElement();
            if (driver.getClass().getClassLoader() == cl) {
                // This driver was registered by the webapp's ClassLoader, so deregister it:
                try {
                    logger.info(String.format("Deregistering JDBC driver %s", driver.toString()));
                    DriverManager.deregisterDriver(driver);
                } catch (SQLException ex) {
                    logger.log(Level.SEVERE, String.format("Error deregistering JDBC driver %s", driver), ex);
                }
            } else {
                // driver was not registered by the webapp's ClassLoader and may be in use elsewhere
                logger.log(Level.SEVERE, String.format("Not deregistering JDBC driver %s as it does not belong to this webapp's ClassLoader", driver));
            }
        }
        executorService.shutdown();
        logger.info("component destroyed");
    }

    public void setupSql(String host, String username, String password, String database) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            sql = DriverManager.getConnection(
                    String.format("jdbc:mysql://%s/%s?autoReconnect=true&user=%s&password=%s",
                            host, database, username, password));
        } catch (SQLException e) {
            logger.log(Level.SEVERE, e.getMessage(), e);
        } catch (ClassNotFoundException e) {
            logger.log(Level.SEVERE, e.getMessage(), e);
        }
    }

    public void setupXmppComponent(JID jid, String host, int port, String password) {
        try {
            socket = new Socket(host, port);
            xmpp = new StreamComponent(jid, socket.getInputStream(), socket.getOutputStream(), password);
            xmpp.addChildParser(new JuickMessage());
            xmpp.addListener((Stream.StreamListener) this);
            xmpp.addListener((MessageListener) this);
            xmpp.startParsing();
        } catch (IOException e) {
            logger.log(Level.SEVERE, e.getMessage(), e);
        }
    }

    @Override
    public void onStreamReady() {
        logger.info("XMPP STREAM READY");
    }

    @Override
    public void onStreamFail(Exception e) {logger.log(Level.SEVERE, "XMPP STREAM FAIL", e);}

    @Override
    public void onMessage(com.juick.xmpp.Message msg) {
        JuickMessage jmsg = (JuickMessage) msg.getChild(JuickMessage.XMLNS);
        if (jmsg == null) {
            return;
        }
        logger.info("Message to push: " + msg.toString());

        boolean isPM = jmsg.getMID() == 0;
        boolean isReply = jmsg.getRID() > 0;
        int senderID = 0, recipientID = 0;
        // reply pushed to original sender
        if (isReply) {
            com.juick.Message op = MessagesQueries.getMessage(sql, jmsg.getMID());
            senderID = op.getUser().getUID();
            // do not notify self
            if (jmsg.getUser().getUID() == op.getUser().getUID()) {
                return;
            }
        }
        if (isPM) {
            // PM
            try {
                recipientID = Integer.parseInt(msg.to.Username);
            } catch (NumberFormatException e) {
                logger.info("Wrong PM recipient: " + msg.to.Username);
                return;
            }
        }

        /*** ANDROID ***/
        List<String> regids;
        if (isPM) {
            regids = new ArrayList<String>();
            String targetId = PushQueries.getAndroidRegID(sql, recipientID);
            if (targetId != null && !targetId.isEmpty()) {
                regids.add(targetId);
            }
        } else {
            regids = PushQueries.getAndroidSubscribers(sql, senderID);
        }

        if (!regids.isEmpty()) {
            MessageSerializer messageSerializer = new MessageSerializer();
            String json = messageSerializer.serialize(jmsg).toString();
            logger.info(json);
            Message message = new Message.Builder().addData("message", json).build();
            try {
                MulticastResult result = GCMSender.send(message, regids, 3);
                List<Result> results = result.getResults();
                for (int i = 0; i < results.size(); i++) {
                    logger.info("RES " + i + ": " + results.get(i).toString());
                }
            } catch (IOException e) {
                logger.log(Level.SEVERE, e.getMessage(), e);
            } catch (IllegalArgumentException err) {
                logger.warning("Android: Invalid API Key");
            }
        } else {
            logger.info("GMS: no recipients");
        }

        /*** WinPhone ***/
        List<String> urls;
        if (isPM) {
            urls = new ArrayList<String>();
            String targetURL = PushQueries.getWinPhoneURL(sql, recipientID);
            if (targetURL != null && !targetURL.isEmpty()) {
                urls.add(targetURL);
            }
        } else {
            urls = PushQueries.getWinPhoneSubscribers(sql, senderID);
        }


        if (urls.isEmpty()) {
            logger.info("WNS: no recipients");
        } else {
            try {
                String wnsToken = getWnsAccessToken();
                String text1 = "@" + jmsg.getUser().getUName();
                if (!jmsg.Tags.isEmpty()) {
                    text1 += ":" + XmlUtils.escape(jmsg.getTagsString());
                }
                String text2 = XmlUtils.escape(jmsg.getText());
                String xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?>"
                        + "<toast>"
                        + "<visual>"
                        + "<binding template=\"ToastImageAndText02\">"
                        + "<image id=\"1\" src=\"http://i.juick.com/as/" + jmsg.getUser().getUID() + ".png\" />"
                        + "<text id=\"1\">" + text1 + "</text>"
                        + "<text id=\"2\">" + text2 + "</text>"
                        + "</binding>"
                        + "</visual>"
                        + "<commands>"
                        + "<command arguments=\"?mid=" + jmsg.getMID() + "\" />"
                        + "</commands>"
                        + "</toast>";
                logger.fine(xml);
                for (int i = 0; i < urls.size(); i++) {
                    String url = urls.get(i);
                    logger.info("WNS: " + url);
                    sendWNS(wnsToken, url, xml);
                }
            } catch (IOException e) {
                logger.log(Level.SEVERE, "WNS: ", e);
            } catch (IllegalStateException e) {
                logger.log(Level.SEVERE, "WNS: ", e);
            }
        }

        /*** iOS ***/
        List<String> tokens;
        if (isPM) {
            tokens = new ArrayList<String>();
            String targetToken = PushQueries.getAPNSToken(sql, recipientID);
            if (targetToken != null && !targetToken.isEmpty()) {
                tokens.add(targetToken);
            }
        } else {
            tokens = PushQueries.getAPNSSubscribers(sql, senderID);
        }
        if (!tokens.isEmpty()) {
            ApnsService service = APNS.newService().withCert("/etc/juick/ios.p12", "juick")
                    .withSandboxDestination().build();
            for (String token : tokens) {
                String payload = APNS.newPayload().alertTitle("@" + jmsg.getUser().getUName()).alertBody(jmsg.getText()).build();
                logger.info("APNS: " + token);
                service.push(token, payload);
            }
        } else {
            logger.info("APNS: no recipients");
        }
    }

    String getWnsAccessToken() throws IOException, IllegalStateException {
        if(TextUtils.isEmpty(wns_application_sip)) {
            throw new IllegalStateException("'wns_application_sip' is not initialized");
        }
        if(TextUtils.isEmpty(wns_client_secret)) {
            throw new IllegalStateException("'wns_client_secret' is not initialized");
        }
        HttpClient client = HttpClientBuilder.create().build();
        String url = "https://login.live.com/accesstoken.srf";
        List<NameValuePair> formParams = new ArrayList<NameValuePair>();
        formParams.add(new BasicNameValuePair("grant_type", "client_credentials"));
        formParams.add(new BasicNameValuePair("client_id", wns_application_sip));
        formParams.add(new BasicNameValuePair("client_secret", wns_client_secret));
        formParams.add(new BasicNameValuePair("scope", "notify.windows.com"));
        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, Consts.UTF_8);
        HttpPost httppost = new HttpPost(url);
        httppost.setEntity(entity);
        HttpResponse response = client.execute(httppost);
        int statusCode = response.getStatusLine().getStatusCode();
        String responseContent = EntityUtils.toString(response.getEntity(), Consts.UTF_8);
        JSONObject json = new JSONObject(responseContent);
        if(statusCode != 200) {
            throw new IOException(json.opt("error") + ": " + json.opt("error_description"));
        }
        String tokenType = (String)json.get("token_type");
        if(tokenType.length() >= 1) {
            tokenType = Character.toUpperCase(tokenType.charAt(0)) + tokenType.substring(1);
        }
        return tokenType + " " + json.get("access_token");
    }

    void sendWNS(String wnsToken, String url, String xml) throws IOException {
        HttpClient client = HttpClientBuilder.create().build();
        StringEntity entity = new StringEntity(xml, Consts.UTF_8);
        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("Content-Type", "text/xml");
        httpPost.setHeader("Authorization", wnsToken);
        httpPost.setHeader("X-WNS-Type", "wns/toast");
        httpPost.setEntity(entity);
        HttpResponse response = client.execute(httpPost);
        int statusCode = response.getStatusLine().getStatusCode();
        if(statusCode != 200) {
            String headersContent = stringifyWnsHttpHeaders(response.getAllHeaders());
            throw new IOException(headersContent);
        }
    }

    static String stringifyWnsHttpHeaders(Header[] allHeaders) {
        String[] wnsHeaders = Arrays.stream(allHeaders)
                .filter(x -> x.getName().startsWith("X-WNS-") || x.getName().startsWith("WWW-"))
                .map(x -> x.getName() + ": " + x.getValue())
                .toArray(String[]::new);
        return String.join("\n", wnsHeaders);
    }
}