<?php

namespace App\Services;

use App\Models\Student;
use App\Models\User;
use Illuminate\Database\Eloquent\Collection;

class StudentService
{
    public function getAll(User $user): Collection
    {
        $unitId = $this->resolveUnitId($user);

        return Student::where('unit_id', $unitId)
            ->orderBy('created_at', 'desc')
            ->get();
    }

    public function findById(int $id): ?Student
    {
        return Student::find($id);
    }

    public function create(User $user, array $data): Student
    {
        $unitId = $this->resolveUnitId($user);

        return Student::create(array_merge($data, ['unit_id' => $unitId]));
    }

    public function update(int $id, array $data): ?Student
    {
        $model = $this->findById($id);

        if (!$model) {
            return null;
        }

        $model->update($data);
        return $model->fresh();
    }

    public function delete(int $id): bool
    {
        $model = $this->findById($id);

        if (!$model) {
            return false;
        }

        return $model->delete();
    }

    private function resolveUnitId(User $user): int
    {
        $unit = $user->units()->first();
        abort_if(!$unit, 403, 'Usuário sem unidade associada.');
        return $unit->id;
    }
}