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 channels.*, u.username, u.picture, COUNT(s.id) as subscriptions
        FROM channels
                 JOIN public.users u ON channels.owner = u.id
                 LEFT JOIN public.subscriptions s ON channels.id = s.channel
        WHERE channels.id = $1
        GROUP BY channels.id, name, description, channels.owner, u.username, u.picture
    `;

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

    const videoQuery = `
        SELECT
            videos.id,
            videos.title,
            videos.description AS video_description,
            videos.thumbnail,
            videos.channel,
            videos.visibility,
            videos.file,
            videos.slug,
            videos.format,
            videos.release_date,
            channels.name AS name,
            channels.description AS description,
            users.picture AS profilePicture,
            COUNT(h.id) AS views,
            COUNT(likes.id) AS likes,
            COUNT(c.id) AS comments
        FROM public.videos
        LEFT JOIN public.channels ON videos.channel = channels.id
        LEFT JOIN public.users ON channels.OWNER = users.id
        LEFT JOIN public.history h ON h.video = videos.id
        LEFT JOIN public.likes ON likes.video = videos.id
        LEFT JOIN public.comments c ON c.video = videos.id
        WHERE videos.channel = $1 AND videos.visibility = 'public'
        GROUP BY videos.id, channels.name, channels.description, users.username, users.picture
    `;

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

    const videoReturn = [];

    for (const video of videoResult.rows) {
        video.creator = {
            name: video.name,
            profilePicture: video.profilepicture,
            description: video.video_description
        };
        delete video.name;
        delete video.profilepicture;
        delete video.video_description;
        videoReturn.push(video);
    }

    result.rows[0].videos = videoReturn;

    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});
    }

}