<?php
include('include/headscript.php');
header('Content-Type: application/json; charset=utf-8');

try {
    $idmatrice = (int)($_POST['idmatrice'] ?? 0);
    $raw = $_POST['idmescole'] ?? '[]';
    $idmescole = json_decode($raw, true);

    if ($idmatrice <= 0) {
        echo json_encode(['success' => false, 'message' => 'Invalid idmatrice']);
        exit;
    }
    if (!is_array($idmescole)) $idmescole = [];

    // normalizza a int e rimuovi duplicati
    $idmescole = array_values(array_unique(array_filter(array_map('intval', $idmescole), fn($v) => $v > 0)));

    $db = DBHandlerSelect::getInstance();
    $pdo = $db->getConnection();

    $pdo->beginTransaction();

    // rimuovi vecchie associazioni
    $stmt = $pdo->prepare("DELETE FROM matrici_mescole WHERE idmatrice = ?");
    $stmt->execute([$idmatrice]);

    // inserisci nuove
    if (!empty($idmescole)) {
        $stmt = $pdo->prepare("INSERT INTO matrici_mescole (idmatrice, idmescola) VALUES (?, ?)");
        foreach ($idmescole as $idmescola) {
            $stmt->execute([$idmatrice, $idmescola]);
        }
    }

    $pdo->commit();

    echo json_encode(['success' => true, 'message' => 'Associazioni aggiornate']);
} catch (Throwable $e) {
    if (isset($pdo) && $pdo->inTransaction()) $pdo->rollBack();
    echo json_encode(['success' => false, 'message' => 'Server error']);
}