How to programmatically set a customizable option to product on submitting form in magento 2?

Question

I've already seen this post, but cannot use it : How to create order programmatically in Magento 2?

I would like to be able to programmatically add products to cart, and I need to set 'Customizable Options' that are textfields and datefield.

I'm lost into the Magento 2 core code, and keep getting errors.

The main one actually is : "Please specify product's required option(s)."

I tried using 'Magento\Catalog\Model\Product\Option', but I cannot build my options array properly.

Here is my actual code :

<?php

namespace Company\Module\Controller\Post;

use Magento\Framework\App\Action\Action;
use Magento\Catalog\Api\ProductRepositoryInterface;

class Checkout extends Action {

protected $_cart;

public function __construct(
    \Magento\Framework\App\Action\Context $context,
    \Magento\Checkout\Model\Cart $cart
/* ... here some stuff ... */


    $this->_cart = $cart;       
    parent::__construct($context);
}

public function execute()
{

    try {
        $_product = $this->_productRepository->getById(1);
        //$_product = $this->_productRepository->get('sku1');

        $params = array();
        $params['qty'] = 1;

        $this->_cart->addProduct($_product,$params);
        $this->_cart->save();
        $this->_redirect("checkout/cart/add/form_key/", $params);


    } catch (\Magento\Framework\Exception\LocalizedException $e) {
        $this->messageManager->addException($e, __('%1', $e->getMessage()));
    } catch (\Exception $e) {
        $this->messageManager->addException($e, __('error.'));
    }
}
}

This function is executed on a form submit

Answer 1

Solution (if we know option id) :

        $param = array(
            'product' => $_product->getId(),
            'qty' => 1,
            'options' => array(
                0 => 'ABC',
                1 => 'DEF'
            )
        );

EDIT 1 : To be able to get the options id :

private function getOptionIdByTitle($title, $_product){
    $result = 0;
    foreach ($_product->getOptions() as $option) {
        if($title == $option->getTitle())
            $result = $option->getId();
    }
    return $result;
}


[...]

$myOptionId = $this->getOptionIdByTitle('my_option', $_product);

[...]
$params = array(
   'product' => $_product->getId(),
   'qty' => 1,
   'price' => $_product->getPrice(),
   'options' => array(
     $myOptionId => 'ABC'
   )
);

EDIT 2 :

Due to this issue : "Unable to set different custom option labels for multiple store views" : https://github.com/magento/magento2/issues/5885

It seems very complicated to manage/retrieve options ids for multiple products... Retrieving by title is a bad idea as it is supposed to change depending on store views...