/*
 * 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.server.protocol;

import com.juick.Message;
import com.juick.Tag;
import com.juick.User;
import com.juick.formatters.PlainTextFormatter;
import com.juick.server.protocol.annotation.UserCommand;
import com.juick.server.util.TagUtils;
import com.juick.service.*;
import org.apache.commons.lang3.math.NumberUtils;
import org.apache.commons.lang3.reflect.MethodUtils;

import javax.inject.Inject;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 * Created by oxpa on 22.03.16.
 */

public class JuickProtocol {

    private String baseUri;
    private ProtocolListener listener;

    @Inject
    UserService userService;
    @Inject
    TagService tagService;
    @Inject
    MessagesService messagesService;
    @Inject
    SubscriptionService subscriptionService;
    @Inject
    PMQueriesService pmQueriesService;
    @Inject
    PrivacyQueriesService privacyQueriesService;
    @Inject
    ShowQueriesService showQueriesService;

    public JuickProtocol(String baseUri) {
        this.baseUri = baseUri;
    }

    /**
     * find command by pattern and invoke
     * @param user who send command
     * @param userInput given by user
     * @return command result
     * @throws InvocationTargetException
     * @throws IllegalAccessException
     * @throws NoSuchMethodException
     */
    public String getReply(User user, String userInput) throws InvocationTargetException,
            IllegalAccessException, NoSuchMethodException {
        Optional<Method> cmd = MethodUtils.getMethodsListWithAnnotation(getClass(), UserCommand.class).stream()
                .filter(m -> Pattern.compile(m.getAnnotation(UserCommand.class).pattern(),
                        m.getAnnotation(UserCommand.class).patternFlags()).matcher(userInput).matches())
                .findFirst();
        if (!cmd.isPresent()) {
            // default command - post as new message
            return postMessage(user, userInput.trim());
        } else {
            Matcher matcher = Pattern.compile(cmd.get().getAnnotation(UserCommand.class).pattern(),
                    cmd.get().getAnnotation(UserCommand.class).patternFlags()).matcher(userInput.trim());
            List<String> groups = new ArrayList<>();
            while (matcher.find()) {
                for (int i = 1; i <= matcher.groupCount(); i++) {
                    groups.add(matcher.group(i));
                }
            }
            return (String) getClass().getMethod(cmd.get().getName(), User.class, String[].class)
                    .invoke(this, user, groups.toArray(new String[groups.size()]));
        }
    }

    public String postMessage(User user, String input) {
        List<Tag> tags = tagService.fromString(input, false);
        String body = input.substring(TagUtils.toString(tags).length());
        int mid = messagesService.createMessage(user.getUid(), body, null, tags);
        subscriptionService.subscribeMessage(mid, user.getUid());
        listener.messagePosted(messagesService.getMessage(mid));
        return "New message posted.\n#" + mid + " " + baseUri + mid;
    }




    @UserCommand(pattern = "^d\\s*\\#([0-9]+)$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "D #12345 - delete the message")
    public String commandDel(User user, String... args) {
        int mid = NumberUtils.toInt(args[0], 0);
        if (messagesService.deleteMessage(user.getUid(), mid)) {
            return String.format("Message %s deleted", mid);
        }
        return "Error";
    }


    @UserCommand(pattern = "^(#+)$", help = "# - Show last messages from your feed (## - second page, ...)")
    public String commandMyFeed(User user, String... arguments) {
        // number of # is the page count
        int page = arguments[0].length() - 1;
        List<Integer> mids = messagesService.getMyFeed(user.getUid(), page, false);
        List<Message> messages = messagesService.getMessages(mids);
        // TODO: add instructions for empty feed
        return "Your feed: \n" + String.join("\n",
                messages.stream().map(PlainTextFormatter::formatPost).collect(Collectors.toList()));
    }



    @UserCommand(pattern = "^#(\\d+)(\\+?)$", help = "#1234 - Show message (#1234+ - message with replies)")
    public String commandShow(User user, String... arguments) {
        boolean showReplies = arguments[1].length() > 0;
        int mid = NumberUtils.toInt(arguments[0], 0);
        if (mid == 0) {
            return "Error";
        }
        Message msg = messagesService.getMessage(mid);
        if (msg != null) {
            if (showReplies) {
                List<Message> replies = messagesService.getReplies(mid);
                replies.add(0, msg);
                return String.join("\n",
                        replies.stream().map(PlainTextFormatter::formatPost).collect(Collectors.toList()));
            }
            return PlainTextFormatter.formatPost(msg);
        }
        return "Message not found";
    }
    @UserCommand(pattern = "^(#|\\.)(\\d+)((\\.|\\-|\\/)(\\d+))?\\s([\\s\\S]+)",
    help = "#1234 *tag *tag2 - edit tags\n#1234 text - reply to message")
    public String EditOrReply(User user, String... args) {
        int mid = NumberUtils.toInt(args[1]);
        int rid = NumberUtils.toInt(args[4], 0);
        String txt = args[5];
        List<Tag> messageTags = tagService.fromString(txt, true);
        if (messageTags.size() > 0) {
            if (user.getUid() != messagesService.getMessageAuthor(mid).getUid()) {
                return "It is not your message";
            }
            tagService.updateTags(mid, messageTags);
            return "Tags are updated";
        } else {
            int newrid = messagesService.createReply(mid, rid, user.getUid(), txt, null);
            listener.messagePosted(messagesService.getReply(mid, newrid));
            return "Reply posted.\n#" + mid + "/" + newrid + " "
                    + baseUri + mid + "#" + newrid;
        }
    }


    @UserCommand(pattern = "^(s|u)\\s+\\@(\\S+)$", help = "S @user - subscribe to user's posts",
            patternFlags = Pattern.CASE_INSENSITIVE)
    public String commandSubscribeUser(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        User toUser = userService.getUserByName(args[1]);
        if (toUser.getUid() > 0) {
            if (subscribe) {
                if (subscriptionService.subscribeUser(user, toUser)) {
                    listener.userSubscribed(user, toUser);
                    return "Subscribed";
                    // TODO: already subscribed case
                }
            } else {
                if (subscriptionService.unSubscribeUser(user, toUser)) {
                    return "Unsubscribed from @" + toUser.getName();
                }
                return "You was not subscribed to @" + toUser.getName();
            }
        }
        return "Error";
    }

    public String getBaseUri() {
        return baseUri;
    }

    public ProtocolListener getListener() {
        return listener;
    }

    public void setListener(ProtocolListener listener) {
        this.listener = listener;
    }
}