const express = require('express');
const {
    getConnection,
    getChannel,
    getMessage,
    deleteMessage,
    addMention,
    getMentions,
    getUserByUsername,
    setHasReplies,
    addReply,
    getMessageReplies
} = require('../libs/mysql');
const rateLimit = require("express-rate-limit");
const slowDown = require("express-slow-down");
const { checkAuth } = require('../libs/middlewares');

const limiter = rateLimit({
    windowMs: 1 * 1000,
    max: 2,
});

const speedLimiter = slowDown({
    windowMs: 1 * 1000,
    delayAfter: 2,
    delayMs: () => 5000,
});

const router = express.Router();

async function getReplies(message, connection) {
    const replies = await getMessageReplies(connection, message.id);
    for (const reply of replies) {
        if (reply.has_replies) {
            const subReplies = await getReplies(reply, connection);
            reply.replies = subReplies;
        }
        if (reply.content.includes('@')) {
            const mentions = await getMentions(connection, reply.id);
            reply.mentions = mentions;
        } else {
            reply.mentions = [];
        }
    }
    return replies;
}

router.get('/:message_id', async (req, res) => {
    const message_id = req.params.message_id;
    const connection = await getConnection();
    const message = await getMessage(connection, message_id);
    if (!message[0]) {
        connection.end();
        return res.send({ error: 'No message found' });
    }

    if (message[0].content.includes('@')) {
        const mentions = await getMentions(connection, message.id);
        message[0].mentions = mentions;
    } else {
        message[0].mentions = [];
    }

    if (message[0].has_replies) {
        const replies = await getReplies(message[0], connection);
        message[0].replies = replies;
    } else {
        message[0].replies = [];
    }
    
    connection.end();
    res.send(message[0]);
});

router.post('/:message_id/reply', speedLimiter, limiter, checkAuth, async (req, res) => {
    const { message } = req.body;
    const { message_id } = req.params;
    const user = req.user;

    if (!message) {
        return res.status(400).send({ error: 'Missing parameters' });
    }

    const connection = await getConnection();

    const originalMessage = await getMessage(connection, message_id);
    if (!originalMessage[0]) {
        connection.end();
        return res.status(400).send({ error: 'No message found' });
    }

    const channel = await getChannel(connection, originalMessage[0].channel_name);
    const sent_message = await addReply(connection, channel[0].id, user.id, message.replace("\"", "'"), message_id);
    await setHasReplies(connection, message_id, true);
    const new_message_id = sent_message.insertId;

    for (const word of message.split(' ')) {
        if (word.startsWith('@')) {
            const username = word.substring(1);
            const mentionedUser = await getUserByUsername(connection, username);
            if (mentionedUser[0]) {
                await addMention(connection, new_message_id, mentionedUser[0].id);
            }
        }
    }

    connection.end();

    req.sockets.emit({
        type: 'new_message',
        channel_id: channel[0].id,
        user_id: user.id,
    });

    res.send({ message: 'Reply sent' });
});

router.post('/:message_id/delete', checkAuth, async (req, res) => {
    const { message_id } = req.params;
    const user = req.user;

    const connection = await getConnection();

    const message = await getMessage(connection, message_id);
    if (!message[0]) {
        connection.end();
        return res.status(400).send({ error: 'No message found' });
    }

    const channel = await getChannel(connection, message[0].channel_name);

    if (user.id !== channel[0].owner_id && user.id !== message[0].user_id && user.admin !== 1) {
        connection.end();
        return res.status(401).send({ error: 'Unauthorized' });
    }

    if (message[0].reply_to_id) {
        const replies = await getMessageReplies(connection, message[0].reply_to_id);
        if (replies.length === 1) {
            await setHasReplies(connection, replyToId, false);
        }
    }

    await deleteMessage(connection, message_id);
    connection.end();

    req.sockets.emit({
        type: 'delete_message',
        channel_id: channel[0].id,
        user_id: user.id,
    });

    res.send({ message: 'Message deleted' });
});

module.exports = router;