Loading a polymorphic model recursive with conditions - mysql

Question

I try to eager load a polymorphic model with some conditions that's connected to two other models and having some problems.
My models:
class One extends Model {
public function twos() {
return $this->hasMany(Two::class);
}
public function threes() {
return $this->morphMany(Three::class, 'threeable');
}
}
class Two extends Model {
public function one() {
return $this->belongsTo(One::class);
}
public function threes() {
return $this->morphMany(Three::class, 'threeable');
}
}
class Three extends Model {
public function threeable() {
return $this->morphTo();
}
}
So far everythings is everything great: I've a lot of One items that have a lot of Two relations and both have even more Three relations (on its own).
Now I try to get the latest Three from Two, where it also can come from a One relation (highest threes.updated_at from either A or B).
The threes table looks something like this
| id | threeable_id | threeable_type | updated_at |
|---|---|---|---|
| 1 | 1 | A | 1 |
| 2 | 1 | A | 2 |
| 3 | 1 | B | 3 |
| 4 | 1 | B | 4 |
| 5 | 2 | A | 2 |
| 6 | 2 | A | 4 |
| 7 | 2 | B | 1 |
| 8 | 2 | B | 3 |
I want threes.id = 4 for B::find(1)->withC() and threes.id = 6 for B::find(2)->withC().
For performance reasons I want to load it in one query (I'm loading multiple Two and want the related Three and don't want to fire an own query for that). So I tried to put it in a scope (in class Two). Joining on the Three table and doing some max on the updated_at in a sub query ... It was a total mess and didn't worked that well
It didn't really feel the "Laravel-way" neither :(
Thanks for any help
EDIT
Maybe as an addition here's the pure SQL
SELECT twos.id, threes.id
FROM
(SELECT
twos.id twoId, MAX(th.updated_at) threeMaxUA
FROM
twos
LEFT JOIN (SELECT
th.*
FROM
(SELECT
threeable_id, threeable_type, MAX(updated_at) AS updated_at
FROM
threes
WHERE
deleted_at IS NULL
GROUP BY threeable_id , threeable_type) thmax
LEFT JOIN
threes pr ON (th.threeable_id = thmax.threeable_id
AND th.updated_at = thmax.updated_at
AND th.threeable_type = thmax.threeable_type)
GROUP BY th.threeable_id , th.threeable_type) th
ON
(
(th.threeable_id = twos.id AND th.threeable_type = 'App\\Two')
OR
(th.threeable_id = twos.product_id AND th.threeable_type = 'App\\One')
)
GROUP BY twos.id
) twthmax
LEFT JOIN twos ON twos.id = twthmax.twoId
LEFT JOIN threes ON (
twthmax.threeMaxUA = threes.updated_at
AND
(
(threes.threeable_id = twos.id AND threes.threeable_type = 'App\\Two')
OR
(threes.threeable_id = twos.product_id AND threes.threeable_type = 'App\\One')
)
)