import { subMinutes } from 'date-fns';
import prisma from 'lib/prisma';
import clickhouse from 'lib/clickhouse';
import { runQuery, CLICKHOUSE, PRISMA, MONGODB } from 'lib/db';

export async function getActiveVisitors(...args: [websiteId: string]) {
  return runQuery({
    [PRISMA]: () => relationalQuery(...args),
    [MONGODB]: () => mongodbQuery(...args),
    [CLICKHOUSE]: () => clickhouseQuery(...args),
  });
}

async function relationalQuery(websiteId: string) {
  const { toUuid, rawQuery } = prisma;

  const date = subMinutes(new Date(), 5);
  const params: any = [websiteId, date];

  return rawQuery(
    `select count(distinct session_id) x
      from website_event
        join website
          on website_event.website_id = website.website_id
      where website.website_id = $1${toUuid()}
      and website_event.created_at >= $2`,
    params,
  );
}

async function clickhouseQuery(websiteId: string) {
  const { rawQuery } = clickhouse;
  const params = { websiteId, startAt: subMinutes(new Date(), 5) };

  return rawQuery(
    `select count(distinct session_id) x
    from website_event
    where website_id = {websiteId:UUID}
    and created_at >= {startAt:DateTime('UTC')}`,
    params,
  );
}

async function mongodbQuery(websiteId: string) {
  const { client } = prisma;

  const date = subMinutes(new Date(), 5);

  const result: any = await client.websiteEvent.aggregateRaw({
    pipeline: [
      {
        $match: {
          $expr: {
            $and: [
              {
                $eq: ['$website_id', websiteId],
              },
              {
                $gte: [
                  '$created_at',
                  {
                    $dateFromString: {
                      dateString: date.toISOString(),
                    },
                  },
                ],
              },
            ],
          },
        },
      },
      {
        $group: {
          _id: '$session_id',
        },
      },
      {
        $count: 'x',
      },
    ],
  });
  if (result.length > 0) {
    return { x: result[0].x };
  } else {
    return { x: 0 };
  }
}