import {db} from '../databases/databases';
import {createMemoryCache} from '../utils/createMemoryCache';
import {config} from '../config';
import {Request, Response} from 'express';

const MILLISECONDS_IN_MINUTE = 60000;
const getTopUsersWithCache = createMemoryCache(generateTopUsersStats, config.getTopUsersCacheTimeMinutes * MILLISECONDS_IN_MINUTE);

async function generateTopUsersStats(sortBy: string, categoryStatsEnabled: boolean = false) {
    const userNames = [];
    const viewCounts = [];
    const totalSubmissions = [];
    const minutesSaved = [];
    const categoryStats: any[] = categoryStatsEnabled ? [] : undefined;

    let additionalFields = '';
    if (categoryStatsEnabled) {
        additionalFields += `SUM(CASE WHEN category = 'sponsor' THEN 1 ELSE 0 END) as "categorySponsor",
            SUM(CASE WHEN category = 'intro' THEN 1 ELSE 0 END) as "categorySumIntro",
            SUM(CASE WHEN category = 'outro' THEN 1 ELSE 0 END) as "categorySumOutro",
            SUM(CASE WHEN category = 'interaction' THEN 1 ELSE 0 END) as "categorySumInteraction",
            SUM(CASE WHEN category = 'selfpromo' THEN 1 ELSE 0 END) as "categorySelfpromo",
            SUM(CASE WHEN category = 'music_offtopic' THEN 1 ELSE 0 END) as "categoryMusicOfftopic", `;
    }

    const rows = await db.prepare('all', `SELECT COUNT(*) as "totalSubmissions", SUM(views) as "viewCount",
        SUM(("sponsorTimes"."endTime" - "sponsorTimes"."startTime") / 60 * "sponsorTimes"."views") as "minutesSaved",
        SUM("votes") as "userVotes", ` +
        additionalFields +
        `IFNULL("userNames"."userName", "sponsorTimes"."userID") as "userName" FROM "sponsorTimes" LEFT JOIN "userNames" ON "sponsorTimes"."userID"="userNames"."userID"
        LEFT JOIN "privateDB"."shadowBannedUsers" ON "sponsorTimes"."userID"="privateDB"."shadowBannedUsers"."userID"
        WHERE "sponsorTimes"."votes" > -1 AND "sponsorTimes"."shadowHidden" != 1 AND "privateDB"."shadowBannedUsers"."userID" IS NULL
        GROUP BY IFNULL("userName", "sponsorTimes"."userID") HAVING "userVotes" > 20
        ORDER BY "` + sortBy + `" DESC LIMIT 100`, []);

    for (let i = 0; i < rows.length; i++) {
        userNames[i] = rows[i].userName;

        viewCounts[i] = rows[i].viewCount;
        totalSubmissions[i] = rows[i].totalSubmissions;
        minutesSaved[i] = rows[i].minutesSaved;
        if (categoryStatsEnabled) {
            categoryStats[i] = [
                rows[i].categorySponsor,
                rows[i].categorySumIntro,
                rows[i].categorySumOutro,
                rows[i].categorySumInteraction,
                rows[i].categorySelfpromo,
                rows[i].categoryMusicOfftopic,
            ];
        }
    }

    return {
        userNames,
        viewCounts,
        totalSubmissions,
        minutesSaved,
        categoryStats,
    };
}

export async function getTopUsers(req: Request, res: Response) {
    const sortType = parseInt(req.query.sortType as string);
    const categoryStatsEnabled = req.query.categoryStats;

    if (sortType == undefined) {
        //invalid request
        res.sendStatus(400);
        return;
    }

    //setup which sort type to use
    let sortBy = '';
    if (sortType == 0) {
        sortBy = 'minutesSaved';
    } else if (sortType == 1) {
        sortBy = 'viewCount';
    } else if (sortType == 2) {
        sortBy = 'totalSubmissions';
    } else {
        //invalid request
        return res.sendStatus(400);
    }

    const stats = await getTopUsersWithCache(sortBy, categoryStatsEnabled);

    //send this result
    res.send(stats);
}