import clickhouse from 'lib/clickhouse';
import { CLICKHOUSE, PRISMA, runQuery } from 'lib/db';
import prisma from 'lib/prisma';
import { EVENT_TYPE } from 'lib/constants';
import { loadWebsite } from 'lib/query';

export async function getPageviewStats(
  ...args: [
    websiteId: string,
    criteria: {
      startDate: Date;
      endDate: Date;
      timezone?: string;
      unit?: string;
      count?: string;
      filters: object;
      sessionKey?: string;
    },
  ]
) {
  return runQuery({
    [PRISMA]: () => relationalQuery(...args),
    [CLICKHOUSE]: () => clickhouseQuery(...args),
  });
}

async function relationalQuery(
  websiteId: string,
  criteria: {
    startDate: Date;
    endDate: Date;
    timezone?: string;
    unit?: string;
    count?: string;
    filters: object;
    sessionKey?: string;
  },
) {
  const {
    startDate,
    endDate,
    timezone = 'utc',
    unit = 'day',
    count = '*',
    filters = {},
    sessionKey = 'session_id',
  } = criteria;
  const { getDatabaseType, toUuid, getDateQuery, parseFilters, rawQuery, client } = prisma;
  const db = getDatabaseType();
  const website = await loadWebsite(websiteId);
  const resetDate = new Date(website?.resetAt || website?.createdAt);
  const params: any = [websiteId, resetDate, startDate, endDate];
  const { filterQuery, joinSession } = parseFilters(filters, params);

  let sessionInclude = '';
  let sessionGroupAggregation: any = { $match: {} };
  let sessionProjectAggregation: any = { $match: {} };
  if (count !== '*') {
    sessionInclude = 'session_id : 1';
    sessionGroupAggregation = {
      $group: {
        _id: {
          t: '$t',
          session_id: '$session_id',
        },
      },
    };
    sessionProjectAggregation = {
      $project: {
        t: '$_id.t',
      },
    };
  }
  if (db === 'mongodb') {
    return await client.websiteEvent.aggregateRaw({
      pipeline: [
        {
          $match: {
            $expr: {
              $and: [
                {
                  $eq: ['$event_type', EVENT_TYPE.pageView],
                },
                {
                  $eq: ['$website_id', websiteId],
                },
                {
                  $gte: [
                    '$created_at',
                    {
                      $dateFromString: {
                        dateString: resetDate.toISOString(),
                      },
                    },
                  ],
                },
                {
                  $gte: [
                    '$created_at',
                    {
                      $dateFromString: {
                        dateString: startDate.toISOString(),
                      },
                    },
                  ],
                },
                {
                  $lte: [
                    '$created_at',
                    {
                      $dateFromString: {
                        dateString: endDate.toISOString(),
                      },
                    },
                  ],
                },
              ],
            },
          },
        },
        {
          $project: {
            t: {
              $dateTrunc: {
                date: '$created_at',
                unit: unit,
              },
            },
            sessionInclude,
          },
        },
        sessionGroupAggregation,
        sessionProjectAggregation,
        {
          $group: {
            _id: {
              t: '$t',
              session_id: '$session_id',
            },
            y: {
              $sum: 1,
            },
          },
        },
        {
          $project: {
            x: {
              $dateToString: {
                date: '$_id.t',
                format: getDateQuery('', unit, timezone),
                timezone: timezone,
              },
            },
            y: 1,
            _id: 0,
          },
        },
        {
          $sort: {
            x: 1,
          },
        },
      ],
    });
  } else {
    return rawQuery(
      `select ${getDateQuery('website_event.created_at', unit, timezone)} x,
        count(${count !== '*' ? `${count}${sessionKey}` : count}) y
      from website_event
        ${joinSession}
      where website_event.website_id = $1${toUuid()}
        and website_event.created_at >= $2
        and website_event.created_at between $3 and $4
        and event_type = ${EVENT_TYPE.pageView}
        ${filterQuery}
      group by 1`,
      params,
    );
  }
}

async function clickhouseQuery(
  websiteId: string,
  criteria: {
    startDate: Date;
    endDate: Date;
    timezone?: string;
    unit?: string;
    count?: string;
    filters: object;
    sessionKey?: string;
  },
) {
  const {
    startDate,
    endDate,
    timezone = 'UTC',
    unit = 'day',
    count = '*',
    filters = {},
  } = criteria;
  const {
    parseFilters,
    getDateFormat,
    rawQuery,
    getDateStringQuery,
    getDateQuery,
    getBetweenDates,
  } = clickhouse;
  const website = await loadWebsite(websiteId);
  const resetDate = new Date(website?.resetAt || website?.createdAt);
  const params = { websiteId };
  const { filterQuery } = parseFilters(filters, params);

  return rawQuery(
    `select
      ${getDateStringQuery('g.t', unit)} as x, 
      g.y as y
    from
      (select 
        ${getDateQuery('created_at', unit, timezone)} t,
        count(${count !== '*' ? 'distinct session_id' : count}) y
      from website_event
      where website_id = {websiteId:UUID}
        and event_type = ${EVENT_TYPE.pageView}
        and created_at >= ${getDateFormat(resetDate)}
        and ${getBetweenDates('created_at', startDate, endDate)}
        ${filterQuery}
      group by t) g
    order by t`,
    params,
  );
}