自动查重

application/common/TurnitinService.php

@@ -291,25 +291,90 @@ class TurnitinService
      *
      * 返回 viewer_url（数小时有效）
      *
-     * @param array $viewer 可选 viewer 设置 e.g. ['viewer_default_permission_set' => 'INSTRUCTOR']
+     * TCA 要求 default_mode 为小写（如 match_overview）；save_changes 等 LTI 字段会导致 400。
+     * Crossref 通道常用 ADMINISTRATOR/USER，非 INSTRUCTOR。可在 .env 配置：
+     *   turnitin.viewer_permission_set=ADMINISTRATOR
+     *
+     * @param array $viewer 可选，覆盖默认 viewer 请求体字段
      */
     public function getViewerUrl($submissionId, $viewer = [])
     {
-        $body = array_merge([
-            'viewer_default_permission_set' => 'INSTRUCTOR',
-            'similarity' => [
-                'default_mode' => 'MATCH_OVERVIEW',
-                'view_settings' => ['save_changes' => true],
-                'modes' => ['match_overview' => true, 'all_sources' => true],
-            ],
-            'locale' => 'en-US',
-        ], $viewer);
+        $submissionId = trim((string) $submissionId);
+        if ($submissionId === '') {
+            throw new Exception('submissionId required for viewer-url');
+        }
 
-        return $this->request(
-            'POST',
-            '/submissions/' . urlencode($submissionId) . '/viewer-url',
-            $body
-        );
+        $path = '/submissions/' . rawurlencode($submissionId) . '/viewer-url';
+        $lastError = null;
+
+        foreach ($this->buildViewerUrlBodies($viewer) as $body) {
+            try {
+                return $this->request('POST', $path, $body);
+            } catch (Exception $e) {
+                $lastError = $e;
+                if (strpos($e->getMessage(), 'HTTP 400') === false) {
+                    throw $e;
+                }
+            }
+        }
+
+        throw $lastError ?: new Exception('viewer-url failed');
+    }
+
+    /**
+     * 按优先级生成若干合法请求体（前者失败且为 400 时尝试后者）。
+     *
+     * @return array<int,array>
+     */
+    private function buildViewerUrlBodies(array $viewerOverrides)
+    {
+        if (!empty($viewerOverrides)) {
+            return [$viewerOverrides];
+        }
+
+        $locale = trim((string) Env::get('turnitin.viewer_locale', 'en-US')) ?: 'en-US';
+        $configured = trim((string) Env::get('turnitin.viewer_permission_set', ''));
+        $permissionSets = $configured !== ''
+            ? array_map('trim', explode(',', $configured))
+            : $this->defaultViewerPermissionSets();
+
+        $bodies = [];
+        foreach ($permissionSets as $perm) {
+            if ($perm === '') {
+                continue;
+            }
+            $bodies[] = [
+                'viewer_default_permission_set' => $perm,
+                'locale'                        => $locale,
+                'similarity'                    => [
+                    'default_mode' => 'match_overview',
+                    'modes'        => [
+                        'match_overview' => true,
+                        'all_sources'    => true,
+                    ],
+                ],
+            ];
+            // 最简请求体（部分 Crossref 租户只接受 permission + locale）
+            $bodies[] = [
+                'viewer_default_permission_set' => $perm,
+                'locale'                        => $locale,
+            ];
+        }
+
+        return $bodies;
+    }
+
+    /**
+     * Crossref Similarity Check 通常不用 INSTRUCTOR；按常见可用角色排序尝试。
+     *
+     * @return array<int,string>
+     */
+    private function defaultViewerPermissionSets()
+    {
+        if (stripos($this->baseUrl, 'crossref') !== false) {
+            return ['ADMINISTRATOR', 'USER', 'EDITOR', 'INSTRUCTOR'];
+        }
+        return ['INSTRUCTOR', 'ADMINISTRATOR', 'USER'];
     }
 
     /**