Jellystat/SQL Scripts/2. CREATE FUNCTIONS/CREATE FUNCTION fs_most_popular_items.sql

-- FUNCTION: public.fs_most_popular_items(integer, text)

-- DROP FUNCTION IF EXISTS public.fs_most_popular_items(integer, text);

CREATE OR REPLACE FUNCTION public.fs_most_popular_items(
	days integer,
	itemtype text)
    RETURNS TABLE(unique_viewers bigint, latest_activity_date timestamp with time zone, "Name" text, "Id" text) 
    LANGUAGE 'plpgsql'
    COST 100
    VOLATILE PARALLEL UNSAFE
    ROWS 1000

AS $BODY$
BEGIN
    RETURN QUERY
    SELECT 
        t.unique_viewers,
        t.latest_activity_date,
        i."Name",
        i."Id"
    FROM (
        SELECT 
            jf_playback_activity."NowPlayingItemId",
            count(DISTINCT jf_playback_activity."UserId") AS unique_viewers,
            latest_activity_date.latest_date AS latest_activity_date
        FROM 
            jf_playback_activity
            JOIN (
                SELECT 
                    jf_playback_activity_1."NowPlayingItemId",
                    max(jf_playback_activity_1."ActivityDateInserted") AS latest_date
                FROM 
                    jf_playback_activity jf_playback_activity_1
                GROUP BY jf_playback_activity_1."NowPlayingItemId"
            ) latest_activity_date 
            ON jf_playback_activity."NowPlayingItemId" = latest_activity_date."NowPlayingItemId"
        WHERE 
            jf_playback_activity."ActivityDateInserted" BETWEEN CURRENT_DATE - MAKE_INTERVAL(days => days) and NOW()
        GROUP BY 
            jf_playback_activity."NowPlayingItemId", latest_activity_date.latest_date
    ) t
    JOIN jf_library_items i 
        ON t."NowPlayingItemId" = i."Id" 
        AND i."Type" = itemType
    ORDER BY 
        t.unique_viewers DESC, t.latest_activity_date DESC;
END;
$BODY$;

ALTER FUNCTION public.fs_most_popular_items(integer, text)
    OWNER TO postgres;