<?php
$signingSecret = 'Jat10jhjLZzTLWlKaQCm6grtRqcxdc4F';

$payload = file_get_contents('php://input');
$signature = $_SERVER['HTTP_SIGNATURE'] ?? '';

$computed = hash_hmac('sha256', $payload, $signingSecret);
$match = hash_equals($computed, $signature);

error_log('[DEBUG] Signature reçue    : ' . $signature);
error_log('[DEBUG] Signature calculée : ' . $computed);
error_log('[DEBUG] Correspondance     : ' . ($match ? 'OUI' : 'NON'));
error_log('[DEBUG] Payload (100 premiers caractères) : ' . substr($payload, 0, 100));

http_response_code(200);
echo 'OK';