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.helpers.TagStats;
import com.juick.server.protocol.annotation.UserCommand;
import com.juick.service.*;
import com.juick.util.TagUtils;
import org.apache.commons.lang3.StringUtils;
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.*;
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 = "^#\\+$", help = "#+ - Show last Juick messages")
    public String commandLast(User user, String... arguments) {
        List<Integer> mids = messagesService.getAll(user.getUid(), 0);
        List<Message> messages = messagesService.getMessages(mids);
        return "Last messages: \n"
                + messages.stream().sorted(Collections.reverseOrder()).map(PlainTextFormatter::formatPostSummary)
                .collect(Collectors.joining("\n\n"));
    }

    @UserCommand(pattern = "^bl$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL - Show your blacklist")
    public String commandBL(User user_from, String... arguments) {
        List<User> blusers;
        List<String> bltags;

        blusers = userService.getUserBLUsers(user_from.getUid());
        bltags = tagService.getUserBLTags(user_from.getUid());


        String txt = StringUtils.EMPTY;
        if (bltags.size() > 0) {
            for (String bltag : bltags) {
                txt += "*" + bltag + "\n";
            }

            if (blusers.size() > 0) {
                txt += "\n";
            }
        }
        if (blusers.size() > 0) {
            for (User bluser : blusers) {
                txt += "@" + bluser.getName() + "\n";
            }
        }
        if (txt.isEmpty()) {
            txt = "You don't have any users or tags in your blacklist.";
        }
        return txt;
    }

    @UserCommand(pattern = "^bl\\s+@([^\\s\\n\\+]+)", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL @username - add @username to your blacklist")
    public String blacklistUser(User from, String... arguments) {
        User blUser = userService.getUserByName(arguments[0]);
        if (blUser != null) {
            PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistUser(from, blUser);
            if (result == PrivacyQueriesService.PrivacyResult.Added) {
                return "User added to your blacklist";
            } else {
                return "User removed from your blacklist";
            }
        }
        return "User not found";
    }

    @UserCommand(pattern = "^bl\\s\\*(\\S+)$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "BL *tag - add *tag to your blacklist")
    public String blacklistTag(User from, String... arguments) {
        User blUser = userService.getUserByName(arguments[0]);
        if (blUser != null) {
            Tag tag = tagService.getTag(arguments[0], false);
            if (tag != null) {
                PrivacyQueriesService.PrivacyResult result = privacyQueriesService.blacklistTag(from, tag);
                if (result == PrivacyQueriesService.PrivacyResult.Added) {
                    return "Tag added to your blacklist";
                } else {
                    return "Tag removed from your blacklist";
                }
            }
        }
        return "Tag not found";
    }

    @UserCommand(pattern = "@", help = "@ - Show recommendations and popular personal blogs")
    public String commandUsers(User currentUser, String... args) {
        StringBuilder msg = new StringBuilder();
        msg.append("Recommended blogs");
        List<String> recommendedUsers = showQueriesService.getRecommendedUsers(currentUser);
        if (recommendedUsers.size() > 0) {
            for (String user : recommendedUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo recommendations now. Subscribe to more blogs. ;)");
        }
        msg.append("\n\nTop 10 personal blogs:");
        List<String> topUsers = showQueriesService.getTopUsers();
        if (topUsers.size() > 0) {
            for (String user : topUsers) {
                msg.append("\n@").append(user);
            }
        } else {
            msg.append("\nNo top users. Empty DB? ;)");
        }
        return msg.toString();
    }

    @UserCommand(pattern = "\\*", help = "* - Show your tags")
    public String commandTags(User currentUser, String... args) {
        List<TagStats> tags = tagService.getUserTagStats(currentUser.getUid());
        String msg = "Your tags: (tag - messages)\n" +
                tags.stream()
                        .map(t -> String.format("\n*%s - %d", t.getTag().getName(), t.getUsageCount())).collect(Collectors.joining());
        return msg;
    }

    @UserCommand(pattern = "S", help = "S - Show your subscriptions")
    public String commandSubscriptions(User currentUser, String... args) {
        List<User> friends = userService.getUserFriends(currentUser.getUid());
        List<String> tags = subscriptionService.getSubscribedTags(currentUser);
        String msg = friends.size() > 0 ? "You are subscribed to users:" + friends.stream().map(u -> "\n@" + u.getName())
                .collect(Collectors.joining())
                : "You are not subscribed to any user.";
        msg += tags.size() > 0 ? "\nYou are subscribed to tags:" + tags.stream().map(t -> "\n*" + t)
                .collect(Collectors.joining())
                : "\nYou are not subscribed to any tag.";
        return msg;
    }

    @UserCommand(pattern = "!", help = "! - Show your favorite messages")
    public String commandFavorites(User currentUser, String... args) {
        List<Integer> mids = messagesService.getUserRecommendations(currentUser.getUid(), 0);
        if (mids.size() > 0) {
            List<Message> messages = messagesService.getMessages(mids);
            return "Favorite messages: \n" + String.join("\n", messages.stream().map(PlainTextFormatter::formatPost)
                    .collect(Collectors.toList()));
        }
        return "No favorite messages, try to \"like\" something ;)";
    }

    @UserCommand(pattern = "^\\@([^\\s\\n\\+]+)(\\+?)$",
            help = "@username+ - Show user's info and last 10 messages (@username++ - second page, ..)")
    public String commandUser(User user, String... arguments) {
        User blogUser = userService.getUserByName(arguments[0]);
        int page = arguments[1].length();
        if (blogUser.getUid() > 0) {
            List<Integer> mids = messagesService.getUserBlog(blogUser.getUid(), 0, page);
            List<Message> messages = messagesService.getMessages(mids);
            return String.format("Last messages from @%s:\n%s", arguments[0],
                    String.join("\n", messages.stream()
                            .map(PlainTextFormatter::formatPost).collect(Collectors.toList())));
        }
        return "User not found";
    }

    @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 = "^login$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "LOGIN - log in to Juick website")
    public String commandLogin(User user, String... arguments) {
        return baseUri + "?" + userService.getHashByUID(user.getUid());
    }

    @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);
        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 = "^(on|off)$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "ON/OFF - Enable/disable subscriptions delivery")
    public String commandOnOff(User user, String[] input) {
        UserService.ActiveStatus newStatus;
        String retValUpdated;
        if (input[0].toLowerCase().equals("on")) {
            newStatus = UserService.ActiveStatus.Active;
            retValUpdated = "Notifications are activated for " + user.getJid();
        } else {
            newStatus = UserService.ActiveStatus.Inactive;
            retValUpdated = "Notifications are disabled for " + user.getJid();
        }

        if (userService.setActiveStatusForJID(user.getJid(), newStatus)) {
            return retValUpdated;
        } else {
            return String.format("Subscriptions status for %s was not changed", user.getJid());
        }
    }

    @UserCommand(pattern = "^ping$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "PING - returns you a PONG")
    public String commandPing(User user, String[] input) {
        return "PONG";
    }

    @UserCommand(pattern = "^\\@(\\S+)\\s+([\\s\\S]+)$", help = "@username message - send PM to username")
    public String commandPM(User user_from, String... arguments) {
        String user_to = arguments[0];
        String body = arguments[1];

        User toUser = userService.getUserByName(user_to);

        if (toUser.getUid() > 0) {
            if (!userService.isInBLAny(toUser.getUid(), user_from.getUid())) {
                if (pmQueriesService.createPM(user_from.getUid(), toUser.getUid(), body)) {
                    listener.privateMessage(user_from, toUser, body);
                    return "Private message sent";
                }
            }
        }
        return "Error";
    }

    @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+#(\\d+)$", help = "S #1234 - subscribe to comments",
            patternFlags = Pattern.CASE_INSENSITIVE)
    public String commandSubscribeMessage(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        int mid = NumberUtils.toInt(args[1], 0);
        if (messagesService.getMessage(mid) != null) {
            if (subscribe) {
                if (subscriptionService.subscribeMessage(mid, user.getUid())) {
                    return "Subscribed";
                }
            } else {
                if (subscriptionService.unSubscribeMessage(mid, user.getUid())) {
                    return "Unsubscribed from #" + mid;
                }
                return "You was not subscribed to #" + mid;
            }
        }
        return "Error";
    }
    @UserCommand(pattern = "^(s|u)\\s+\\@(\\S+)$", 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";
    }
    @UserCommand(pattern = "^(s|u)\\s+\\*(\\S+)$", help = "S *tag - subscribe to tag" +
            "\nU *tag - unsubscribe from tag", patternFlags = Pattern.CASE_INSENSITIVE)
    public String commandSubscribeTag(User user, String... args) {
        boolean subscribe = args[0].equalsIgnoreCase("s");
        Tag tag = tagService.getTag(args[1], true);
        if (subscribe) {
            if (subscriptionService.subscribeTag(user, tag)) {
                return "Subscribed";
            }
        } else {
            if (subscriptionService.unSubscribeTag(user, tag)) {
                return "Unsubscribed from " + tag.getName();
            }
            return "You was not subscribed to " + tag.getName();
        }
        return "Error";
    }

    @UserCommand(pattern = "^help$", patternFlags = Pattern.CASE_INSENSITIVE,
            help = "HELP - returns this help message")
    public String commandHelp(User user, String[] input) {
        return Arrays.stream(getClass().getDeclaredMethods())
                .filter(m -> m.isAnnotationPresent(UserCommand.class))
                .map(m -> m.getAnnotation(UserCommand.class).help())
                .collect(Collectors.joining("\n"));
    }

    public String getBaseUri() {
        return baseUri;
    }

    public ProtocolListener getListener() {
        return listener;
    }

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