From a2ab3da89e96ad55a02fd95a7b1f1a9b24e6b30e Mon Sep 17 00:00:00 2001
From: Thomas de Roo <2+thomas@noreply.localhost>
Date: Mon, 15 Jun 2026 12:06:16 +0200
Subject: [PATCH] Update includes/functions.php

---
 includes/functions.php | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/includes/functions.php b/includes/functions.php
index d7ee59f..3ed1a4a 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -68,3 +68,17 @@ function listPath(
     . slug($list)
     . '.json';
 }
+
+function calculateNextInterval(array $word, bool $correct): int
+{
+    $correctCount = $word['correct'] ?? 0;
+
+    if (!$correct) {
+        return 1;
+    }
+
+    // gecontroleerde groei (SM-lite)
+    $interval = 1 + ($correctCount * 2);
+
+    return min(30, $interval);
+}
\ No newline at end of file