fix: guard ppt audit file integrity and disable preview on corrupted files

routes/admin_observability_routes.py

@@ -1847,6 +1847,7 @@ def ppt_audit_file(filename: str):
     action = (request.args.get('action', 'view') or 'view').strip().lower()
     try:
         import os
+        import zipfile
         from utils.security import safe_join
 
         reports_dir = os.environ.get('REPORTS_DIR', '/app/data/reports')
@@ -1858,6 +1859,17 @@ def ppt_audit_file(filename: str):
         if safe_path.suffix.lower() != '.pptx':
             return '不支援的檔案格式', 400
 
+        if action == 'view':
+            try:
+                with zipfile.ZipFile(safe_path, 'r') as zf:
+                    bad = zf.testzip()
+                    if bad is not None:
+                        return f'PPT 檔案損毀，無法預覽（損毀區段：{bad}）', 409
+            except zipfile.BadZipFile:
+                return 'PPT 檔案損毀，無法預覽（非有效 zip）', 409
+            except Exception as e:
+                return f'預覽檢查失敗：{type(e).__name__}', 409
+
         return send_file(
             str(safe_path),
             mimetype='application/vnd.openxmlformats-officedocument.presentationml.presentation',
@@ -2171,6 +2183,7 @@ def budget_update(budget_id: int):
 def ppt_audit_history():
     """掃 reports/ 目錄列指定月份 daily 報表 + 從 ppt_audit_results 讀審核歷史（Phase 38）"""
     import os
+    import zipfile
     reports_dir = os.environ.get('REPORTS_DIR', '/app/data/reports')
     files = []
     audit_records = []
@@ -2231,6 +2244,16 @@ def ppt_audit_history():
     next_month_label = f"{next_year:04d}-{next_month:02d}"
     show_next_month = (next_year < now.year) or (next_year == now.year and next_month <= now.month)
 
+    def _inspect_ppt_file(file_path: str):
+        try:
+            with zipfile.ZipFile(file_path, 'r') as zf:
+                bad = zf.testzip()
+            return (bad is None, None if bad is None else f'壓縮檔異常：{bad}')
+        except zipfile.BadZipFile:
+            return False, 'PPTX 檔案損毀（非有效 zip）'
+        except Exception as e:
+            return False, f'檢查失敗：{str(e)[:60]}'
+
     try:
         if not os.path.isdir(reports_dir):
             error = f'{reports_dir} 目錄不存在'
@@ -2248,6 +2271,7 @@ def ppt_audit_history():
                 try:
                     mtime = os.path.getmtime(full)
                     if month_start_ts <= mtime < month_end_ts:
+                        is_valid, check_msg = _inspect_ppt_file(full)
                         files_by_name[f] = {
                             'source': 'filesystem',
                             'name': f,
@@ -2256,6 +2280,8 @@ def ppt_audit_history():
                             'mtime_ts': mtime,
                             'file_exists': True,
                             'file_path': full,
+                            'is_valid_ppt': is_valid,
+                            'file_error': check_msg,
                         }
                 except OSError:
                     continue
@@ -2294,6 +2320,10 @@ def ppt_audit_history():
                             continue
                         candidate_path = os.path.join(reports_dir, name)
                         exists = os.path.isfile(candidate_path)
+                        is_valid = False
+                        check_msg = '檔案未落盤'
+                        if exists:
+                            is_valid, check_msg = _inspect_ppt_file(candidate_path)
                         files_by_name[name] = {
                             'source': 'database',
                             'name': name,
@@ -2303,6 +2333,8 @@ def ppt_audit_history():
                             'file_exists': exists,
                             'file_path': candidate_path if exists else file_path,
                             'report_type': rpt_type,
+                            'is_valid_ppt': is_valid,
+                            'file_error': None if exists else check_msg,
                         }
                 finally:
                     session.close()

templates/admin/ppt_audit_history.html

@@ -286,19 +286,42 @@
                 <td><small>{{ f.mtime }}</small></td>
                 <td>
                   {% if f.source == 'database' %}
-                    <span class="text-muted">{% if f.file_exists %}資料庫快取 + 檔案可存取{% else %}資料庫快取（檔案未落盤）{% endif %}</span>
+                    {% if f.file_exists %}
+                    {% if f.is_valid_ppt %}
+                    <span class="text-success">資料庫快取 + 檔案可預覽</span>
+                    {% else %}
+                    <span class="status-bad">資料庫快取 + 檔案損毀，建議重跑</span>
+                    {% endif %}
+                    {% else %}
+                    <span class="text-muted">資料庫快取（檔案未落盤）</span>
+                    {% endif %}
                   {% elif f.source == 'both' %}
+                    {% if f.is_valid_ppt %}
                     <span class="text-success">檔案 + 資料庫</span>
+                    {% else %}
+                    <span class="status-bad">檔案 + 資料庫，檔案損毀</span>
+                    {% endif %}
                   {% else %}
-                    <span class="text-muted">22:00 掃描落盤</span>
+                    {% if f.is_valid_ppt %}
+                    <span class="text-success">22:00 掃描落盤，可預覽</span>
+                    {% else %}
+                    <span class="status-bad">22:00 掃描落盤，檔案損毀</span>
+                    {% endif %}
+                  {% endif %}
+                  {% if f.file_error %}
+                  <div><small class="text-muted">{{ f.file_error }}</small></div>
                   {% endif %}
                 </td>
                 <td>
                   <div class="ppt-file-actions">
                     {% if f.file_exists %}
+                    {% if f.is_valid_ppt %}
                     <a class="btn btn-outline-primary btn-sm" href="{{ url_for('admin_observability.ppt_audit_file', filename=f.name) }}" target="_blank" rel="noopener">
                       <i class="fas fa-file-powerpoint me-1"></i>開啟
                     </a>
+                    {% else %}
+                    <span class="small status-bad">檔案不可預覽</span>
+                    {% endif %}
                     <a class="btn btn-outline-secondary btn-sm" href="{{ url_for('admin_observability.ppt_audit_file', filename=f.name, action='download') }}">
                       <i class="fas fa-download me-1"></i>下載
                     </a>