import {getClient} from "../utils/database.js";
import {query} from "express-validator";


export async function create(req, res) {
    const channel = {
        name: req.body.name,
        description: req.body.description,
        owner: req.body.owner,
    }

    const client = await getClient();

    const query = `INSERT INTO channels (name, description, owner) VALUES ($1, $2, $3)`;
    await client.query(query, [channel.name, channel.description, channel.owner]);

    const logger = req.body.logger;
    logger.action("try to create new channel with owner " + channel.owner + " and name " + channel.name);

    logger.write("Successfully created new channel with name " + channel.name, 200);
    client.end();
    res.status(200).json(channel);
}

export async function getById(req, res) {
    const id = req.params.id;

    const logger = req.body.logger;
    logger.action("try to get channel with id " + id);
    const client = await getClient();

    const query = `
        SELECT *
        FROM channels
        WHERE channels.id = $1
    `;

    const result = await client.query(query, [id]);

    const videoQuery = `
        SELECT v.*, COUNT(h.video) as views, COUNT(l.id) as likes, COUNT(c.id) as comments
        FROM videos v
            LEFT JOIN history h ON v.id = h.video
            LEFT JOIN likes l ON v.id = l.video
            LEFT JOIN comments c ON v.id = c.video
        WHERE v.channel = $1
        GROUP BY v.id, title, thumbnail, description, channel, visibility, file, slug, format, release_date
    `;
    const videoResult = await client.query(videoQuery, [id]);

    result.rows[0].videos = videoResult.rows;

    logger.write("Successfully get channel with id " + id, 200);
    client.end();
    res.status(200).json(result.rows[0]);

}

export async function getAll(req, res) {
    const logger = req.body.logger;
    logger.action("try to get all channels");
    const client = await getClient();

    const query = `SELECT * FROM channels`;
    const channels = await client.query(query);

    let result = []

    for (const channelNbr in channels.rows) {
        const channel = channels.rows[channelNbr];
        const subQuery = `SELECT * FROM subscriptions WHERE channel = $1`;
        const subResult = await client.query(subQuery, [channel.id]);
        if (subResult.rows.length > 0) {
            channel.subscriptions = subResult.rows.length;
            result.push(channel);
        } else {
            channel.subscriptions = 0;
            result.push(channel);
        }
    }

    result.sort((a, b) => {
        var keyA = a.subscriptions;
        var keyB = b.subscriptions;
        if (keyA > keyB) return 1;
        if (keyA < keyB) return -1;
    })

    logger.write("Successfully get all channels", 200);
    client.end();
    res.status(200).json(result);
}

export async function update(req, res) {
    const id = req.params.id;
    const channel = {
        name: req.body.name,
        description: req.body.description,
    }

    const client = await getClient();
    const logger = req.body.logger;
    logger.action("try to update channel with id " + req.params.id);

    const channelQuery = `SELECT * FROM channels WHERE id = $1`;
    const channelResult = await client.query(channelQuery, [req.params.id]);
    const channelInBase = channelResult.rows[0];

    if (channelInBase.name !== channel.name) {
        const nameQuery = `SELECT name FROM channels WHERE name = $1`;
        const nameResult = await client.query(nameQuery, [channel.name]);
        if (nameResult.rows.length > 0) {
            logger.write("failed to update channel because name already taken", 400);
            client.end();
            res.status(400).json({error: 'Name already used'});
            return
        }
    }

    const updateQuery = `UPDATE channels SET name = $1, description = $2 WHERE id = $3`;
    await client.query(updateQuery, [channel.name, channel.description, id]);
    logger.write("Successfully updated channel", 200);
    client.end();
    res.status(200).json(channel);

}

export async function del(req, res) {
    const id = req.params.id;
    const logger = req.body.logger;
    logger.action("try to delete channel with id " + id);
    const client = await getClient();
    const query = `DELETE FROM channels WHERE id = $1`;
    await client.query(query, [id]);
    logger.write("Successfully deleted channel", 200);
    client.end();
    res.status(200).json({message: 'Successfully deleted'});
}

export async function toggleSubscription(req, res) {
    const id = req.params.id;
    const userId = req.body.userId;
    const logger = req.body.logger;
    logger.action("try to toggle subscription for channel with id " + id);

    const client = await getClient();
    const query = `SELECT * FROM subscriptions WHERE channel = $1 AND owner = $2`;
    const result = await client.query(query, [id, userId]);

    if (result.rows.length > 0) {
        // Unsubscribe
        const deleteQuery = `DELETE FROM subscriptions WHERE channel = $1 AND owner = $2`;
        await client.query(deleteQuery, [id, userId]);

        // Send back the number of remaining subscriptions
        const countQuery = `SELECT COUNT(*) FROM subscriptions WHERE channel = $1`;
        const countResult = await client.query(countQuery, [id]);
        const remainingSubscriptions = countResult.rows[0].count;

        logger.write("Successfully unsubscribed from channel", 200);
        client.end();
        res.status(200).json({message: 'Unsubscribed successfully', subscriptions: remainingSubscriptions});
    } else {
        // Subscribe
        const insertQuery = `INSERT INTO subscriptions (channel, owner) VALUES ($1, $2)`;
        await client.query(insertQuery, [id, userId]);

        // Send back the number of subscriptions after subscribing
        const countQuery = `SELECT COUNT(*) FROM subscriptions WHERE channel = $1`;
        const countResult = await client.query(countQuery, [id]);
        const totalSubscriptions = countResult.rows[0].count;

        logger.write("Successfully subscribed to channel", 200);
        client.end();
        res.status(200).json({message: 'Subscribed successfully', subscriptions: totalSubscriptions});
    }
}

export async function getStats(req, res) {

    try {
        const id = req.params.id;

        const logger = req.body.logger;
        logger.action("try to get stats");

        const request = `
        SELECT
            (SELECT COUNT(*) FROM subscriptions WHERE channel = $1) as subscribers,
            (SELECT COUNT(*) FROM history h JOIN videos v ON h.video = v.id WHERE v.channel = $1) as views
        FROM channels
            LEFT JOIN public.subscriptions s on channels.id = s.channel
            LEFT JOIN public.videos v on channels.id = v.channel
            LEFT JOIN public.history h on v.id = h.video
        WHERE channels.id = $1
    `;
        const client = await getClient();
        const result = await client.query(request, [id]);
        logger.write("Successfully get stats", 200);
        client.end();
        res.status(200).json(result.rows[0]);
    } catch (error) {
        console.log(error);
        res.status(500).json({error: error.message});
    }

}