/*
 * 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.components;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.android.gcm.server.*;
import com.juick.ExternalToken;
import com.juick.User;
import com.juick.formatters.PlainTextFormatter;
import com.juick.server.component.DisconnectedEvent;
import com.juick.util.MessageUtils;
import com.turo.pushy.apns.ApnsClient;
import com.turo.pushy.apns.PushNotificationResponse;
import com.turo.pushy.apns.util.ApnsPayloadBuilder;
import com.turo.pushy.apns.util.SimpleApnsPushNotification;
import com.turo.pushy.apns.util.concurrent.PushNotificationResponseListener;
import io.netty.util.concurrent.Future;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.text.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.PingMessage;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.ConcurrentWebSocketSessionDecorator;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import javax.annotation.Nonnull;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.Collectors;

/**
 * @author Ugnich Anton
 */
@Component
public class Notifications extends TextWebSocketHandler implements NotificationClientListener {
    private static Logger logger = LoggerFactory.getLogger(Notifications.class);

    @Inject
    private RestTemplate rest;
    @Inject
    private Sender GCMSender;

    @Inject
    private ObjectMapper jsonMapper;

    private final Set<String> invalidGCMTokens = Collections.synchronizedSet(new HashSet<>());
    private final Set<String> invalidMPNSTokens = Collections.synchronizedSet(new HashSet<>());
    private final Set<String> invalidAPNSTokens = Collections.synchronizedSet(new HashSet<>());

    @Inject
    private MPNSClient mpnsClient;
    @Inject
    private ApnsClient apns;
    @Value("${ios_app_id:}")
    private String topic;

    @PostConstruct
    public void init() {
        mpnsClient.setListener(this);
        closeFlag.set(false);
    }
    public void messageReceived(@Nonnull com.juick.Message jmsg) {
        if (jmsg.isService()) {
            serviceMessageReceived(jmsg);
            return;
        }
        User pmTo = jmsg.getTo();
        final List<User> users = new ArrayList<>();
        if (MessageUtils.isPM(jmsg)) {
            users.addAll(rest.exchange(String.format("http://api.juick.com/notifications?uid=%d",
                    pmTo.getUid()),
                    HttpMethod.GET, null, new ParameterizedTypeReference<List<User>>() {
                    }).getBody());
        } else if (MessageUtils.isReply(jmsg)) {
            users.addAll(rest.exchange(String.format("http://api.juick.com/notifications?uid=%d&mid=%d&rid=%d",
                    jmsg.getUser().getUid(), jmsg.getMid(), jmsg.getRid()),
                    HttpMethod.GET, null, new ParameterizedTypeReference<List<User>>() {
                    }).getBody());
        } else {
            users.addAll(rest.exchange(String.format("http://api.juick.com/notifications?uid=%s&mid=%s",
                    jmsg.getUser().getUid(), jmsg.getMid()),
                    HttpMethod.GET, null, new ParameterizedTypeReference<List<User>>() {
                    }).getBody());
        }

        // GCM
        List<String> regids = users.stream().flatMap(u -> u.getTokens().stream()).filter(d -> d.getType().equals("gcm"))
                .map(ExternalToken::getToken).collect(Collectors.toList());
        if (!regids.isEmpty()) {
            try {
                String json = jsonMapper.writeValueAsString(jmsg);
                logger.info(json);
                Message message = new Message.Builder().addData("message", json).build();
                MulticastResult result = GCMSender.send(message, regids, 3);
                List<Result> results = result.getResults();
                for (int i = 0; i < results.size(); i++) {
                    Result currentResult = results.get(i);
                    logger.info("RES {}: {}", i, currentResult);
                    List<String> errorCodes = Arrays.asList(Constants.ERROR_MISMATCH_SENDER_ID, Constants.ERROR_NOT_REGISTERED);
                    if (errorCodes.contains(currentResult.getErrorCodeName())) {
                        // assuming results are in order of regids
                        // http://stackoverflow.com/a/11594531/1097384
                        String currentId = regids.get(i);
                        logger.info("{} is scheduled to remove", currentId);
                        addInvalidGCMToken(currentId);
                    }
                }
            } catch (IOException ex) {
                logger.error(ex.getMessage(), ex);
            } catch (IllegalArgumentException err) {
                logger.warn("Android: Invalid API Key", err);
            }
        } else {
            logger.info("GMS: no recipients");
        }

        /*** WinPhone ***/
        List<String> urls = users.stream().flatMap(u -> u.getTokens().stream()).filter(d -> d.getType().equals("mpns"))
                .map(ExternalToken::getToken).collect(Collectors.toList());

        if (urls.isEmpty()) {
            logger.info("WNS: no recipients");
        } else {
            try {
                String text1 = "@" + jmsg.getUser().getName();
                if (!jmsg.getTags().isEmpty()) {
                    text1 += ":" + StringEscapeUtils.escapeXml11(MessageUtils.getTagsString(jmsg));
                }
                String text2 = StringEscapeUtils.escapeXml11(StringUtils.defaultString(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=\"/ThreadView.xaml?mid=" + jmsg.getMid() + "\" />"
                        + "</commands>"
                        + "</toast>";
                logger.trace(xml);
                for (String url : urls) {
                    logger.info("WNS: {}", url);
                    mpnsClient.sendNotification(url, xml);
                }
            } catch (IOException | IllegalStateException ex) {
                logger.error("WNS: ", ex);
            }
        }

        /*** iOS ***/
        ApnsPayloadBuilder apnsPayloadBuilder = new ApnsPayloadBuilder();
        apnsPayloadBuilder.addCustomProperty("mid", jmsg.getMid());
        apnsPayloadBuilder.addCustomProperty("uname", jmsg.getUser().getName());
        String post = PlainTextFormatter.formatPost(jmsg);
        String[] parts = post.split("\n", 2);
        apnsPayloadBuilder.setAlertTitle(parts[0]).setAlertBody(parts[1]);
        users.forEach( user -> {
            apnsPayloadBuilder.setBadgeNumber(user.getUnreadCount());
            String payload = apnsPayloadBuilder.buildWithDefaultMaximumLength();
            user.getTokens().stream().filter(t -> t.getType().equals("apns"))
                    .map(ExternalToken::getToken).forEach(token -> {
                Future<PushNotificationResponse<SimpleApnsPushNotification>> notification = apns.sendNotification(
                        new SimpleApnsPushNotification(token, topic, payload));
                notification.addListener((PushNotificationResponseListener<SimpleApnsPushNotification>) future -> {
                    if (future.isSuccess()) {
                        processAPNSResponse(token, future.getNow());
                    } else {
                        logger.warn("APNS error ", future.cause());
                    }
                });
            });
        });
    }
    private void serviceMessageReceived(@Nonnull com.juick.Message jmsg) {
        logger.info("Message read event from {} for {}", jmsg.getUser().getName(), jmsg.getMid());
        // iOS
        List<User> users = rest.exchange(String.format("http://api.juick.com/notifications?uid=%d",
                jmsg.getUser().getUid()),
                HttpMethod.GET, null, new ParameterizedTypeReference<List<User>>() {
                }).getBody();
        ApnsPayloadBuilder apnsPayloadBuilder = new ApnsPayloadBuilder();
        users.forEach(user -> {
            apnsPayloadBuilder.setBadgeNumber(user.getUnreadCount());
            String payload = apnsPayloadBuilder.buildWithDefaultMaximumLength();
            user.getTokens().stream().filter(t -> t.getType().equals("apns"))
                    .map(ExternalToken::getToken).forEach(token -> {
                Future<PushNotificationResponse<SimpleApnsPushNotification>> notification = apns.sendNotification(
                        new SimpleApnsPushNotification(token, topic, payload));
                notification.addListener((PushNotificationResponseListener<SimpleApnsPushNotification>) future -> {
                    if (future.isSuccess()) {
                        processAPNSResponse(token, future.getNow());
                    } else {
                        logger.warn("APNS error ", future.cause());
                    }
                });
            });
        });
    }

    private void processAPNSResponse(String token, PushNotificationResponse<SimpleApnsPushNotification> pushNotificationResponse) {
        if (!closeFlag.get()) {
            if (pushNotificationResponse.isAccepted()) {
                logger.info("APNS accepted: {}", token);
            } else {
                String reason = pushNotificationResponse.getRejectionReason();
                logger.info("APNS rejected: {}", reason);
                if (reason.equals("BadDeviceToken")) {
                    invalidAPNSTokens.add(token);
                }
            }
            Optional<Date> invalidationDate = Optional.ofNullable(
                    pushNotificationResponse.getTokenInvalidationTimestamp());
            invalidationDate.ifPresent(date -> {
                if (date.before(new Date())) {
                    logger.info("Token invalidated: {}", token);
                    invalidAPNSTokens.add(token);
                }
            });
        }
    }

    public void addInvalidGCMToken(String token) {
        synchronized (invalidGCMTokens) {
            invalidGCMTokens.add(token);
        }
    }
    public Set<String> getInvalidGCMTokens() {
        return invalidGCMTokens;
    }
    public void cleanupGCMTokens() {
        logger.info("removed {} GCM tokens", invalidGCMTokens.size());
        synchronized (invalidGCMTokens) {
            invalidGCMTokens.clear();
        }
    }
    public void addInvalidMPNSToken(String token) {
        synchronized (invalidMPNSTokens) {
            invalidMPNSTokens.add(token);
        }
    }
    public Set<String> getInvalidMPNSTokens() {
        return invalidMPNSTokens;
    }
    public void cleanupMPNSTokens() {
        logger.info("removed {} MPNS tokens", invalidMPNSTokens.size());
        synchronized (invalidMPNSTokens) {
            invalidMPNSTokens.clear();
        }
    }

    @Override
    public void invalidToken(String type, String token) {
        switch (type) {
            case "mpns":
                addInvalidMPNSToken(token);
                break;
            default:
                break;
        }
    }

    public Set<String> getInvalidAPNSTokens() {
        return invalidAPNSTokens;
    }
    @Inject
    private ApplicationEventPublisher applicationEventPublisher;

    private ConcurrentWebSocketSessionDecorator session;
    private final AtomicBoolean closeFlag = new AtomicBoolean(false);

    @Override
    public void afterConnectionEstablished(WebSocketSession session) {
        if (!closeFlag.get()) {
            logger.info("WebSocket connected");
            this.session = new ConcurrentWebSocketSessionDecorator(session, 60000, 65535);
        }
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) {
        if (!closeFlag.get()) {
            logger.info("WebSocket disconnected with code {}: {}", status.getCode(), status.getReason());
            applicationEventPublisher.publishEvent(new DisconnectedEvent(this));
        }
    }

    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage text) throws Exception {
        if (!closeFlag.get() && this.session.getDelegate().equals(session)) {
            com.juick.Message jmsg = jsonMapper.readValue(text.asBytes(), com.juick.Message.class);

            if (logger.isInfoEnabled()) // prevent writeValueAsString execution if logger disabled
                logger.info("got jmsg: {}", jsonMapper.writeValueAsString(jmsg));
            messageReceived(jmsg);
        }
    }

    @Scheduled(fixedRate = 30000, initialDelay = 30000)
    public void ping() throws IOException {
        if (!closeFlag.get()) {
            if (session != null && session.isOpen()) {
                logger.debug("Sending WebSocket ping");
                session.sendMessage(new PingMessage());
            } else {
                applicationEventPublisher.publishEvent(new DisconnectedEvent(this));
            }
        }
    }
    @PreDestroy
    public void close() {
        apns.close();
        closeFlag.set(true);
    }
    @Scheduled(fixedRate = 600000)
    public void cleanupTokens() {
        if (!closeFlag.get()) {
            logger.debug("initializing GCM tokens cleanup: {} tokens", getInvalidGCMTokens().size());
            deleteTokens("gcm", new ArrayList<>(getInvalidGCMTokens()));
            cleanupGCMTokens();
            logger.debug("initializing MPNS tokens cleanup: {} tokens", getInvalidMPNSTokens().size());
            deleteTokens("mpns", new ArrayList<>(getInvalidMPNSTokens()));
            cleanupMPNSTokens();
            logger.debug("initializing APNS tokens cleanup: {} tokens", getInvalidAPNSTokens().size());
            deleteTokens("apns", new ArrayList<>(getInvalidAPNSTokens()));
            cleanupMPNSTokens();
        }
    }
    private void deleteTokens(String type, List<String> devices) {
        if (devices.size() > 0) {
            List<ExternalToken> list = devices.stream()
                    .map(d -> new ExternalToken(null, type, d, null)).collect(Collectors.toList());
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
            rest.exchange("http://api.juick.com/notifications",
                    HttpMethod.DELETE, new HttpEntity<>(list, headers), new ParameterizedTypeReference<Void>() {
                    });
        }
    }
}