package com.juick.components;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutureCallback;
import com.google.api.core.ApiFutures;
import com.google.auth.oauth2.GoogleCredentials;
import com.google.firebase.FirebaseApp;
import com.google.firebase.FirebaseOptions;
import com.google.firebase.messaging.FirebaseMessaging;
import com.google.firebase.messaging.FirebaseMessagingException;
import com.google.firebase.messaging.Message;
import com.juick.ExternalToken;
import com.juick.User;
import com.juick.service.component.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.core.task.TaskExecutor;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import java.io.IOException;
import java.util.List;
import java.util.stream.Collectors;

public class FirebaseManager implements NotificationListener {
    private static Logger logger = LoggerFactory.getLogger(FirebaseManager.class);
    @Inject
    ObjectMapper jsonMapper;
    @Value("${fcm_database_url:}")
    private String fcmDatabaseUrl;
    @Inject
    private NotificationsManager notificationsManager;
    @Inject
    private TaskExecutor taskExecutor;

    @PostConstruct
    public void initialize() throws IOException {
        Resource serviceAccount =
                new ClassPathResource("serviceAccount.json");

        FirebaseOptions options = new FirebaseOptions.Builder()
                .setCredentials(GoogleCredentials.fromStream(serviceAccount.getInputStream()))
                .setDatabaseUrl(fcmDatabaseUrl)
                .build();

        FirebaseApp.initializeApp(options);
    }

    @Override
    public void processMessageEvent(MessageEvent messageEvent) {
        com.juick.Message jmsg = messageEvent.getMessage();
        List<User> users = messageEvent.getUsers();
        // 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()) {
            String json = null;
            try {
                json = jsonMapper.writeValueAsString(jmsg);
            } catch (JsonProcessingException e) {
                logger.warn("JSON exception", e);
            }
            logger.info(json);
            Message.Builder messageBuilder = Message.builder()
                    .putData("message", json);
            regids.forEach(token -> {
                messageBuilder.setToken(token);
                ApiFuture<String> response = FirebaseMessaging.getInstance().sendAsync(messageBuilder.build());
                ApiFutures.addCallback(response, new ApiFutureCallback<String>() {
                    @Override
                    public void onFailure(Throwable t) {
                        if (t instanceof FirebaseMessagingException) {
                            FirebaseMessagingException e = (FirebaseMessagingException) t;
                            if (e.getErrorCode().equals("messaging/invalid-argument")
                                    || e.getErrorCode().equals("messaging/registration-token-not-registered")
                                    || e.getErrorCode().equals("messaging/invalid-registration-token")) {
                                // invalid token
                                logger.info("{} is scheduled to remove", token);
                                notificationsManager.addInvalidGCMToken(token);
                            } else {
                                logger.warn("Unhandled FirebaseMessaging exception", t);
                            }
                        } else {
                            logger.warn("Unhandled FCM exception", t);
                        }
                    }

                    @Override
                    public void onSuccess(String result) {
                        logger.info("Successfully sent message: " + result);
                    }
                }, taskExecutor);
            });
        } else {
            logger.info("GMS: no recipients");
        }
    }

    @Override
    public void processSubscribeEvent(SubscribeEvent subscribeEvent) {

    }

    @Override
    public void processLikeEvent(LikeEvent likeEvent) {

    }

    @Override
    public void processPingEvent(PingEvent pingEvent) {

    }

    @Override
    public void processMessageReadEvent(MessageReadEvent messageReadEvent) {

    }

    @Override
    public void processTopEvent(TopEvent topEvent) {

    }
}