append subquery based on case- postgresql - postgresql

Question

My table is crash
id
jurisdiction
drugs_inv
alcohol_inv
dr_sex
severity_id
1
NT
true
false
Male
3
2
NSW
false
false
Male
3
3
WA
true
true
Female
3
4
WA
true
true
Male
4
I want to have a subquery based on t_factors array
if it has 1 then filter where alcohol_inv = true
if it has 2 then filter where drugs_inv = true
if both 1 and 2 then use both above conditions
something like may be append a subquery...within the query in the following spaces..
[subqry for alcohol_inv = true]
[subqry for drugs_inv = true]
how to go about it?
My query:
WITH myvars(t_state,
t_factors,
) AS(values(
'WA',
'{1,2}', --factors
))
SELECT
dr_sex,
COUNT(*) as all_crashes,
COUNT(t1.id) filter (WHERE severity_id >= 3) as fsi_crashes,
COUNT(t1.id) filter (WHERE severity_id = 3) as si_crashes,
COUNT(t1.id) filter (WHERE severity_id = 4) as fatal_crashes
FROM
crash t1
,myvars
WHERE
(jurisdiction = t_state OR t_state is null)
AND (( CASE
WHEN 1 = ANY (t_factors) THEN '[subqry for alcohol_inv = true]'
WHEN 2 = ANY (t_factors) THEN '[subqry for drugs_inv = true]'
END) factor
OR
t_factors is null)
AND severity_id > 1
AND dr_sex = ANY( '{Male, Female}'::text[] )
GROUP BY dr_sex

Answer 1

Since alcohol_inv is boolean then [subqry for alcohol_inv = true] is simply alcohol_inv. Maybe this query will do the job then
WITH myvars(t_state, t_factors) AS
(
values ('WA', '{1,2}'::integer[])
)
SELECT
dr_sex,
COUNT(*) as all_crashes,
COUNT(t1.id) filter (WHERE severity_id >= 3) as fsi_crashes,
COUNT(t1.id) filter (WHERE severity_id = 3) as si_crashes,
COUNT(t1.id) filter (WHERE severity_id = 4) as fatal_crashes
FROM
crash t1, myvars
WHERE
(jurisdiction = t_state OR t_state is null)
AND
(
CASE WHEN 1 = ANY(t_factors) THEN alcohol_inv
WHEN 2 = ANY(t_factors) THEN drugs_inv END
OR t_factors is null
)
AND severity_id > 1
AND dr_sex in ('Male', 'Female')
GROUP BY dr_sex;