import clickhouse from 'lib/clickhouse';
import { CLICKHOUSE, PRISMA, runQuery } from 'lib/db';
import prisma from 'lib/prisma';

export async function getPageviewFunnel(
  ...args: [
    websiteId: string,
    criteria: {
      windowMinutes: number;
      startDate: Date;
      endDate: Date;
      urls: string[];
    },
  ]
) {
  return runQuery({
    [PRISMA]: () => relationalQuery(...args),
    [CLICKHOUSE]: () => clickhouseQuery(...args),
  });
}

async function relationalQuery(
  websiteId: string,
  criteria: {
    windowMinutes: number;
    startDate: Date;
    endDate: Date;
    urls: string[];
  },
) {
  const { windowMinutes, startDate, endDate, urls } = criteria;
  const { rawQuery, getFunnelQuery, toUuid } = prisma;
  const { levelQuery, sumQuery, urlFilterQuery } = getFunnelQuery(urls, windowMinutes);

  const params: any = [websiteId, startDate, endDate, ...urls];

  return rawQuery(
    `WITH level0 AS (
        select session_id, url_path, created_at
        from website_event
        where url_path in (${urlFilterQuery})
            website_event.website_id = $1${toUuid()}
            and created_at between $2 and $3
    ),level1 AS (
        select session_id, url_path as level1_url, created_at as level1_created_at
        from level0
    )${levelQuery}
    
    SELECT ${sumQuery}
    from level3;
    `,
    params,
  );
}

async function clickhouseQuery(
  websiteId: string,
  criteria: {
    windowMinutes: number;
    startDate: Date;
    endDate: Date;
    urls: string[];
  },
) {
  const { windowMinutes, startDate, endDate, urls } = criteria;
  const { rawQuery, getBetweenDates, getFunnelQuery } = clickhouse;
  const { columnsQuery, conditionQuery, urlParams } = getFunnelQuery(urls);

  const params = {
    websiteId,
    window: windowMinutes * 60,
    ...urlParams,
  };

  return rawQuery(
    `
    SELECT level,
        count(*) AS count
    FROM (
    SELECT session_id,
            windowFunnel({window:UInt32}, 'strict_order')
            (
                created_at,
                ${columnsQuery}
            ) AS level
        FROM website_event
        WHERE website_id = {websiteId:UUID}
            and ${getBetweenDates('created_at', startDate, endDate)}             
            AND (url_path in [${conditionQuery}])
        GROUP BY 1
        )
    GROUP BY level
    ORDER BY level ASC;
    `,
    params,
  );
}