/*
 * Copyright (C) 2008-2017, Juick
 *
 * 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.api;

import com.juick.User;
import com.juick.server.component.MessageEvent;
import com.juick.server.util.HttpUtils;
import com.juick.service.MessagesService;
import com.juick.service.SubscriptionService;
import com.juick.service.TelegramService;
import com.juick.service.UserService;
import com.pengrad.telegrambot.BotUtils;
import com.pengrad.telegrambot.Callback;
import com.pengrad.telegrambot.TelegramBot;
import com.pengrad.telegrambot.model.Message;
import com.pengrad.telegrambot.model.MessageEntity;
import com.pengrad.telegrambot.model.PhotoSize;
import com.pengrad.telegrambot.model.Update;
import com.pengrad.telegrambot.model.request.ParseMode;
import com.pengrad.telegrambot.request.GetFile;
import com.pengrad.telegrambot.request.SendMessage;
import com.pengrad.telegrambot.request.SetWebhook;
import com.pengrad.telegrambot.response.GetFileResponse;
import com.pengrad.telegrambot.response.SendResponse;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;
import org.springframework.web.util.UriComponents;
import org.springframework.web.util.UriComponentsBuilder;

import javax.annotation.Nonnull;
import javax.annotation.PostConstruct;
import javax.inject.Inject;
import java.io.IOException;
import java.net.URL;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Optional;

import static com.juick.formatters.PlainTextFormatter.formatPost;
import static com.juick.formatters.PlainTextFormatter.formatUrl;

/**
 * Created by vt on 12/05/16.
 */
@Component
public class TelegramBotManager implements ApplicationListener<MessageEvent> {
    private static final Logger logger = LoggerFactory.getLogger(TelegramBotManager.class);

    private TelegramBot bot;

    @Value("${telegram_token}")
    private String telegramToken;
    @Inject
    private TelegramService telegramService;
    @Inject
    private MessagesService messagesService;
    @Inject
    private SubscriptionService subscriptionService;
    @Inject
    private UserService userService;
    @Inject
    private ApiServer apiServer;
    @Value("${upload_tmp_dir:/var/www/juick.com/i/tmp/}")
    private String tmpDir;

    private static final String MSG_LINK = "🔗";

    @PostConstruct
    public void init() {
        if (StringUtils.isBlank(telegramToken)) {
            logger.info("telegram token is not set, exiting");
            return;
        }
        bot = new TelegramBot(telegramToken);
        try {
            SetWebhook webhook = new SetWebhook().url("https://api.juick.com/tlgmbtwbhk");
            if (!bot.execute(webhook).isOk()) {
                logger.error("error setting webhook");
            }
        } catch (Exception e) {
            logger.warn("couldn't initialize telegram bot", e);
        }
    }

    public void processUpdate(String data) throws Exception {
        Update update = BotUtils.parseUpdate(data);
        Message message = update.message();
        if (update.message() == null) {
            message = update.editedMessage();
            if (message == null) {
                logger.error("error parsing telegram update: {}", update);
                return;
            }
        }
        User user_from = userService.getUserByUID(telegramService.getUser(message.chat().id())).orElse(new User());
        logger.info("Found juick user {}", user_from.getUid());

        List<Long> chats = telegramService.getChats();
        String username = message.from().username();
        if (username == null) {
            username = message.from().firstName();
        }
        if (!chats.contains(message.chat().id())) {
            telegramService.addChat(message.chat().id());
            logger.info("added chat with {}", username);
            telegramService.createTelegramUser(message.from().id(), username);
            telegramSignupNotify(message.from().id().longValue(), userService.getSignUpHashByTelegramID(message.from().id().longValue(), username));
        } else {
            if (user_from.getUid() == 0) {
                telegramSignupNotify(message.from().id().longValue(), userService.getSignUpHashByTelegramID(message.from().id().longValue(), username));
            } else {
                String attachment = StringUtils.EMPTY;
                if (message.photo() != null) {
                    String fileId = Arrays.stream(message.photo()).max(Comparator.comparingInt(PhotoSize::fileSize))
                            .orElse(new PhotoSize()).fileId();
                    if (StringUtils.isNotEmpty(fileId)) {
                        GetFile request = new GetFile(fileId);
                        GetFileResponse response = bot.execute(request);
                        logger.info("got file {}", response.file());
                        URL fileURL = new URL(bot.getFullFilePath(response.file()));
                        attachment = HttpUtils.downloadImage(fileURL, tmpDir);
                        logger.info("received {}", attachment);
                    }
                }
                String text = message.text();
                if (StringUtils.isBlank(text)) {
                    text = message.caption();
                }
                if (StringUtils.isBlank(text)) {
                    text = StringUtils.EMPTY;
                }
                if (StringUtils.isNotEmpty(text) || StringUtils.isNotEmpty(attachment)) {
                    if (text.equalsIgnoreCase("LOGIN")
                            || text.equalsIgnoreCase("PING")
                            || text.equalsIgnoreCase("HELP")
                            || text.equalsIgnoreCase("/login")
                            || text.equalsIgnoreCase("/start")
                            || text.equalsIgnoreCase("/help")) {
                        String msgUrl = "http://juick.com/login?hash=" + userService.getHashByUID(user_from.getUid());
                        String msg = String.format("Hi, %s!\nYou can post messages and images to Juick there.\n" +
                                "Tap to [log into website](%s) to get more info", user_from.getName(), msgUrl);
                        telegramNotify(message.from().id().longValue(), msg);
                    } else {
                        Message replyMessage = message.replyToMessage();
                        if (replyMessage != null) {
                            if (replyMessage.entities() != null) {
                                Optional<MessageEntity> juickLink = Arrays.stream(replyMessage.entities())
                                        .filter(this::isJuickLink)
                                        .findFirst();
                                if (juickLink.isPresent()) {
                                    if (StringUtils.isNotEmpty(juickLink.get().url())) {
                                        UriComponents uriComponents = UriComponentsBuilder.fromUriString(
                                                juickLink.get().url()).build();
                                        String path = uriComponents.getPath();
                                        if (StringUtils.isNotEmpty(path) && path.length() > 1) {
                                            int mid = Integer.valueOf(path.substring(1));
                                            String prefix = String.format("#%d ", mid);
                                            if (StringUtils.isNotEmpty(uriComponents.getFragment())) {
                                                int rid = Integer.valueOf(uriComponents.getFragment());
                                                prefix = String.format("#%d/%d ", mid, rid);
                                            }
                                            apiServer.processMessage(user_from, prefix + text, attachment);
                                            telegramNotify(message.from().id().longValue(), "Reply sent");
                                        } else {
                                            logger.warn("invalid path: {}", path);
                                        }
                                    } else {
                                        logger.warn("invalid entity: {}", juickLink);
                                    }
                                } else {
                                    telegramNotify(message.from().id().longValue(),
                                            "Can not reply to this message", replyMessage.messageId());
                                }
                            } else {
                                telegramNotify(message.from().id().longValue(),
                                        "Can not reply to this message", replyMessage.messageId());
                            }
                        } else {
                            apiServer.processMessage(user_from, text, attachment);
                            telegramNotify(message.from().id().longValue(), "Message sent");
                        }
                    }
                }
            }
        }
    }

    private boolean isJuickLink(MessageEntity e) {
        return e.offset() == 0 && e.type().equals(MessageEntity.Type.text_link) && e.length() == 2;
    }

    @Override
    public void onApplicationEvent(@Nonnull MessageEvent event) {
        com.juick.Message jmsg = event.getMessage();
        String msgUrl = formatUrl(jmsg);
        if (jmsg.getMid() > 0 && jmsg.getRid() == 0) {
            String msg = String.format("[%s](%s) %s", MSG_LINK, msgUrl, formatPost(jmsg, true));

            List<Long> users = telegramService.getTelegramIdentifiers(subscriptionService.getSubscribedUsers(jmsg.getUser().getUid(), jmsg.getMid()));
            List<Long> chats = telegramService.getChats();
            // registered subscribed users

            users.forEach(c -> telegramNotify(c, msg));
            // anonymous
            chats.stream().filter(u -> telegramService.getUser(u) == 0).forEach(c -> telegramNotify(c, msg));
        } else if (jmsg.getRid() > 0) {
            // get quote
            com.juick.Message msg = messagesService.getReply(jmsg.getMid(), jmsg.getRid());
            String fmsg = String.format("[%s](%s) %s", MSG_LINK, msgUrl, formatPost(msg, true));
            telegramService.getTelegramIdentifiers(
                    subscriptionService.getUsersSubscribedToComments(jmsg.getMid(), jmsg.getUser().getUid())
            ).forEach(c -> telegramNotify(c, fmsg));
        }
    }

    public void telegramNotify(Long chatId, String msg) {
        telegramNotify(chatId, msg, 0);
    }

    public void telegramNotify(Long chatId, String msg, Integer replyTo) {
        SendMessage telegramMessage = new SendMessage(chatId, msg);
        if (replyTo > 0) {
            telegramMessage.replyToMessageId(replyTo);
        }
        telegramMessage.parseMode(ParseMode.Markdown).disableWebPagePreview(true);
        bot.execute(telegramMessage, new Callback<SendMessage, SendResponse>() {
            @Override
            public void onResponse(SendMessage request, SendResponse response) {
                if (!response.isOk()) {
                    if (response.errorCode() == 403) {
                        // remove from anonymous chat
                        telegramService.getChats().stream().filter(c -> c.equals(chatId)).findFirst().ifPresent(
                                d -> {
                                    telegramService.deleteChat(d);
                                    logger.info("deleted {} chat", d);
                                }
                        );
                        int userId = telegramService.getUser(chatId);
                        if (userId > 0) {
                            User userToDelete = userService.getUserByUID(userId)
                                    .orElse(new User());
                            boolean status = telegramService.deleteTelegramUser(userToDelete.getUid());
                            logger.info("deleting telegram id of @{} : {}", userToDelete.getName(), status);
                            boolean chatStatus = telegramService.deleteChat(chatId);
                            logger.info("deleting telegram chat {} : {}", chatId, chatStatus);
                        }
                    } else {
                        logger.warn("error response, isOk: {}, errorCode: {}, description: {}",
                                response.isOk(), response.errorCode(), response.description());
                    }
                }
            }

            @Override
            public void onFailure(SendMessage request, IOException e) {
                logger.warn("telegram failure", e);
            }
        });
    }

    public void telegramSignupNotify(Long telegramId, String hash) {
        bot.execute(new SendMessage(telegramId,
                String.format("You are subscribed to all Juick messages. " +
                        "[Create or link](http://juick.com/signup?type=durov&hash=%s) " +
                        "an existing Juick account to get your subscriptions and ability to post messages", hash))
                .parseMode(ParseMode.Markdown), new Callback<SendMessage, SendResponse>() {
            @Override
            public void onResponse(SendMessage request, SendResponse response) {
                logger.info("got response: {}", response.message());
            }

            @Override
            public void onFailure(SendMessage request, IOException e) {
                logger.warn("telegram failure", e);
            }
        });
    }
}