CREATE OR REPLACE FUNCTION GET_FLOW_POOL_MONTH_STAT(INT)
  RETURNS TABLE
          (
            pool_id       INT,
            members       NUMERIC,
            minimum_flows NUMERIC,
            minimum_price NUMERIC,
            excess_flows  NUMERIC,
            excess_price  NUMERIC
          )
AS
$$
DECLARE
  query TEXT;
BEGIN
    query := 'WITH settings AS (
        SELECT pool_id,
            json_array_elements(minimum_settings::json) ->> ''package_id'' AS package_id,
            json_array_elements(minimum_settings::json) ->> ''flows'' AS flows,
            json_array_elements(minimum_settings::json) ->> ''price'' AS price,
            gradient * pow(1024, gradient_unit) as gradient,
            gradient_price / pow(1024, gradient_unit) as gradient_price,
            start_at,
            end_at
        FROM virtual_flow_pool_settings
    ), pool_package AS (
        SELECT virtual_flow_pool_months.pool_id,
            virtual_flow_pool_months.package_id,
            COUNT(*) as members,
            SUM(settings.flows::NUMERIC) AS minimum_flows,
            SUM(settings.price::NUMERIC) AS minimum_price,
            SUM(virtual_flow_pool_months.mebibyte) AS total_flows,
            AVG(settings.gradient::int) AS gradient,
            AVG(settings.gradient_price::NUMERIC) AS gradient_price
        FROM virtual_flow_pool_months
        JOIN settings ON
            settings.package_id::int = virtual_flow_pool_months.package_id AND
            settings.pool_id::int = virtual_flow_pool_months.pool_id AND
            settings.start_at <= (overlay($1::text placing ''-'' from 5 for 0) || ''-01 00:00:00'')::TIMESTAMP AND
            (settings.end_at >= (overlay($1::text placing ''-'' from 5 for 0) || ''-01 23:59:59'')::TIMESTAMP OR settings.end_at IS NULL)
        WHERE virtual_flow_pool_months.month = $1
        GROUP BY virtual_flow_pool_months.pool_id, virtual_flow_pool_months.package_id
    )
        SELECT pool_id,
            SUM(members) as members,
            SUM(minimum_flows) as minimum_flows,
            SUM(minimum_price) as minimum_price,
            CASE WHEN SUM(total_flows) - SUM(minimum_flows) < 0 THEN 0 ELSE SUM(total_flows) - SUM(minimum_flows) END as excess_flows,
            CEIL((CASE WHEN SUM(total_flows) - SUM(minimum_flows) < 0 THEN 0 ELSE SUM(total_flows) - SUM(minimum_flows) END)/AVG(gradient))*AVG(gradient)*AVG(gradient_price) as excess_price
            FROM pool_package AS t GROUP BY pool_id
    ';

  RETURN QUERY EXECUTE query USING $1;
END;
$$ LANGUAGE plpgsql;