Join two datasets with key duplicates one by one - clickhouse

Question

I need to join two datasets from e.g. left and right source to match values by some keys. Datasets can contain duplicates:
┌─key─┬─value──┬─source──┐
│ 1 │ val1 │ left │
│ 1 │ val1 │ left │ << duplicate from left source
│ 1 │ val1 │ left │ << another duplicate from left source
│ 1 │ val1 │ right │
│ 1 │ val1 │ right │ << duplicate from right source
│ 2 │ val2 │ left │
│ 2 │ val3 │ right │
└─────┴────────┴─-----───┘
I cant use full join, it gives cartesian products of all duplicates.
I am trying to use group by instead:
select
`key`,
anyIf(value, source = 'left') as left_value,
anyIf(value, source = 'right') as right_value
from test_raw
group by key;
It works good, but is there any way to match left and right duplicates?
Expected result:
┌─key─┬─left_value─┬─right_value─┐
│ 1 │ val1 │ val1 │
│ 1 │ val1 │ val1 │
│ 1 │ val1 │ │
│ 2 │ val2 │ val3 │
└─────┴────────────┴─────────────┘
Scripts to reproduce:
create table test_raw
(`key` Int64,`value` String,`source` String)
ENGINE = Memory;
insert into test_raw (`key`,`value`,`source`)
values
(1, 'val1', 'left'),
(1, 'val1', 'left'),
(1, 'val1', 'left'),
(1, 'val1', 'right'),
(1, 'val1', 'right'),
(2, 'val2', 'left'),
(2, 'val3', 'right');
select
`key`,
anyIf(value, source = 'left') as left_value,
anyIf(value, source = 'right') as right_value
from test_raw
group by key;

Answer 1

SELECT
key,
left_value,
right_value
FROM
(
SELECT
key,
arraySort(groupArrayIf(value, source = 'left')) AS l,
arraySort(groupArrayIf(value, source = 'right')) AS r,
arrayMap(i -> (l[i + 1], r[i + 1]), range(greatest(length(l), length(r)))) AS t
FROM test_raw
GROUP BY key
)
ARRAY JOIN
t.1 AS left_value,
t.2 AS right_value
ORDER BY key ASC
┌─key─┬─left_value─┬─right_value─┐
│ 1 │ val1 │ val1 │
│ 1 │ val1 │ val1 │
│ 1 │ val1 │ │
│ 1 │ val1 │ │
│ 2 │ val2 │ val3 │
└─────┴────────────┴─────────────┘