'required|exists:students,id', 'protocol' => 'sometimes|nullable|string|max:255', 'signature_date' => 'sometimes|nullable|date_format:Y-m-d', 'end_date' => 'sometimes|nullable|date_format:Y-m-d', 'class_package_unit_id' => 'sometimes|nullable|exists:class_package_units,id', 'class_quantity' => 'sometimes|nullable|integer|min:1', 'weekday' => 'sometimes|nullable|integer|min:0|max:6', 'start_time' => 'sometimes|nullable|date_format:H:i', 'end_time' => 'sometimes|nullable|date_format:H:i', 'second_weekday' => 'sometimes|nullable|integer|min:0|max:6', 'second_start_time' => 'sometimes|nullable|date_format:H:i', 'second_end_time' => 'sometimes|nullable|date_format:H:i', 'due_date' => 'sometimes|nullable|date_format:Y-m-d', 'tax_register' => 'sometimes|nullable|numeric|min:0', 'down_payment' => 'sometimes|nullable|numeric|min:0', 'installments' => 'sometimes|nullable|integer|min:1|max:12', 'early_payment_discount' => 'sometimes|nullable|numeric|min:0|max:100', 'material_value' => 'sometimes|nullable|numeric|min:0', 'material_installments' => 'sometimes|nullable|integer|min:1|max:12', 'interest_rate' => 'sometimes|nullable|numeric|min:0', 'payment_method' => 'sometimes|nullable|string|in:pix,credit_card,debit_card', 'fine_cancelled' => 'sometimes|nullable|numeric|min:0|max:100', ]; } }