exports.up = (db, cb) => {
  db.runSql(`
        WITH user_events AS (
          SELECT
              DISTINCT CASE WHEN type = 'user-deleted' THEN pre_data ->> 'email' ELSE data ->> 'email' END AS email,
                       type,
                       created_at AS event_date
          FROM
              events
          WHERE
              type IN ('user-created', 'user-deleted')
        ),
        dates AS (
           WITH RECURSIVE generated_dates AS (
               SELECT
                   MIN(event_date):: timestamp AS date
               FROM
                   user_events
               UNION ALL
               SELECT
                   date + INTERVAL '1 day'
               FROM
                   generated_dates
               WHERE
                   date + INTERVAL '1 day' <= CURRENT_DATE
           )
           SELECT
               date :: date
           FROM
               generated_dates
        ),
        active_emails AS (
           SELECT
               d.date,
               ue.email,
               MAX(
                   CASE WHEN ue.type = 'user-created' THEN ue.event_date ELSE NULL END
               ) AS created_date,
               MAX(
                   CASE WHEN ue.type = 'user-deleted' THEN ue.event_date ELSE NULL END
               ) AS deleted_date
           FROM
               dates d
                   LEFT JOIN user_events ue ON ue.event_date <= d.date
           GROUP BY
               d.date,
               ue.email
        ),
        result AS (
            SELECT
                d.date,
                COALESCE(
                    COUNT(
                        DISTINCT CASE
                                     WHEN ae.deleted_date IS NULL
                                         OR ae.deleted_date >= d.date - INTERVAL '30 days'
                                         OR ae.deleted_date < ae.created_date
                                         THEN ae.email
                                     ELSE NULL
                        END
                    ),
                    0
                ) AS active_emails_count
            FROM
                dates d
                    LEFT JOIN active_emails ae ON d.date = ae.date
            GROUP BY
                d.date
            ORDER BY
                d.date
        ) INSERT INTO licensed_users (date, count)
            SELECT date, active_emails_count
            FROM result
            WHERE EXISTS (
                SELECT 1 FROM user_events
            )
        ON CONFLICT (date) DO NOTHING;
  `, cb);

};

exports.down = (db, cb) => {
  db.runSql(``, cb);
};