DROP MATERIALIZED VIEW IF EXISTS dm.course_completion_rate;
CREATE MATERIALIZED VIEW dm.course_completion_rate
DISTRIBUTED BY (user_id)
AS
with activity_users as (
select
	e.user_id as user_id,
	e.course_id as course_id,
	COUNT(flv.viewed_at) as lessons_viewed
from
	core.enrollments e
left join core.dim_lesson dl on e.course_id = dl.course_id
left join core.fact_lesson_views flv on e.user_id = flv.user_id and e.course_id = flv.course_id and dl.lesson_id = flv.lesson_id
group by
	e.user_id,
	e.course_id),
course2 as (	
	select
		course_id,
		COUNT(*) as lessons_in_course
	from core.dim_lesson
	group by 
		course_id)
select
	au.user_id as user_id,
	du."name" as user_name,
	au.course_id as course_id,
	dc.title as course_title,
	c2.lessons_in_course as lessons_in_course,
	au.lessons_viewed as lessons_viewed,
	ROUND(au.lessons_viewed * 1.0 / c2.lessons_in_course , 2) as completion_rate
from
	activity_users au
left join core.dim_user du on au.user_id = du.user_id
left join core.dim_course dc on au.course_id = dc.course_id
left join course2 c2 on au.course_id = c2.course_id
order by
	au.user_id,
	au.course_id;