Harden published curriculum and student flows

2026-09-30 08:22:17 +03:00
parent e8163fe265
commit ce7b0fcf14
53 changed files with 4723 additions and 3317 deletions
@@ -0,0 +1,38 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Services;
+
+/** Structural coverage gate. Content accuracy still requires academic review. */
+final class VideoCoverageValidator
+{
+    public static function valid(array $coverage, int $durationSeconds, string $videoSha256): bool
+    {
+        if ($durationSeconds <= 0 || $durationSeconds > 4 * 60 * 60 ||
+            !preg_match('/^[0-9a-f]{64}$/i', $videoSha256) ||
+            !hash_equals(strtolower($videoSha256), strtolower((string)($coverage['video_sha256'] ?? ''))) ||
+            ($coverage['truncated'] ?? true) !== false ||
+            !empty($coverage['gaps']) ||
+            !is_array($coverage['segments'] ?? null) || $coverage['segments'] === []) {
+            return false;
+        }
+        $lastEnd = 0.0;
+        foreach ($coverage['segments'] as $segment) {
+            if (!is_array($segment) ||
+                !is_numeric($segment['start_seconds'] ?? null) ||
+                !is_numeric($segment['end_seconds'] ?? null) ||
+                !is_string($segment['transcript_ref'] ?? null) || trim($segment['transcript_ref']) === '' ||
+                !is_string($segment['visual_ref'] ?? null) || trim($segment['visual_ref']) === '') {
+                return false;
+            }
+            $start = (float)$segment['start_seconds'];
+            $end = (float)$segment['end_seconds'];
+            if (!is_finite($start) || !is_finite($end) ||
+                abs($start - $lastEnd) > 0.5 || $end <= $start || $end > $durationSeconds + 0.5) {
+                return false;
+            }
+            $lastEnd = $end;
+        }
+        return abs($lastEnd - $durationSeconds) <= 0.5;
+    }
+}