From b18df2f20638a566e87087d481163ad49b2842bf Mon Sep 17 00:00:00 2001
From: Lars Gebhardt-Kusche <lars@kusche.berlin>
Date: Sun, 7 Dec 2025 01:20:22 +0100
Subject: [PATCH] up

---
 public/assets/js/ui-list.js | 26 ++++++++++++--
 src/ApiKernel.php           | 72 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 94 insertions(+), 4 deletions(-)

diff --git a/public/assets/js/ui-list.js b/public/assets/js/ui-list.js
index f76c06e..1a9b529 100644
--- a/public/assets/js/ui-list.js
+++ b/public/assets/js/ui-list.js
@@ -1,5 +1,19 @@
 import { apiList, apiGet, apiDelete, apiUpdate, toast } from './api.js';
 
+function formatUsage(usage){
+  if (!usage || !usage.total) return '';
+  const parts=[];
+  if (usage.templates) parts.push(`${usage.templates} Template${usage.templates!==1?'s':''}`);
+  if (usage.sections) parts.push(`${usage.sections} Section${usage.sections!==1?'s':''}`);
+  if (usage.blocks) parts.push(`${usage.blocks} Block${usage.blocks!==1?'s':''}`);
+  if (usage.snippets) parts.push(`${usage.snippets} Snippet${usage.snippets!==1?'s':''}`);
+  if (!parts.length) return '';
+  return `<div class="mt-3 text-sm text-rose-600">
+    Dieses Element wird aktuell verwendet in: <strong>${parts.join(', ')}</strong>.<br>
+    Das Löschen entfernt diese Referenzen.
+  </div>`;
+}
+
 function esc(s=''){
   return String(s)
     .replace(/&/g,'&amp;')
@@ -145,10 +159,16 @@ export async function loadList(resource){
   let pending=null;
   delCancel && (delCancel.onclick=()=>{pending=null;delDlg.close();});
 
-  list.querySelectorAll('[data-del]').forEach(b=>b.addEventListener('click',()=>{
+  list.querySelectorAll('[data-del]').forEach(b=>b.addEventListener('click', async ()=>{
     const [res,id]=b.dataset.del.split(':'); const nm=b.dataset.name||'';
-    pending={res,id,nm};
-    delText && (delText.innerHTML=`Soll <strong>${nm || '(ohne Name)'} #${id}</strong> aus <strong>${res}</strong> wirklich gelöscht werden?<br><span class="text-rose-600">Achtung:</span> Kinder-Elemente werden <em>nicht</em> automatisch mit gelöscht.`);
+    let usage = null;
+    try {
+      const detail = await apiGet(res, id);
+      usage = detail?.usage || null;
+    } catch {}
+    pending={res,id,nm,usage};
+    const usageWarn = formatUsage(usage);
+    delText && (delText.innerHTML=`Soll <strong>${nm || '(ohne Name)'} #${id}</strong> aus <strong>${res}</strong> wirklich gelöscht werden?<br><span class="text-rose-600">Achtung:</span> Kinder-Elemente werden <em>nicht</em> automatisch mit gelöscht.${usageWarn}`);
     delDlg.showModal();
   }));
 
diff --git a/src/ApiKernel.php b/src/ApiKernel.php
index b080128..3e2d198 100644
--- a/src/ApiKernel.php
+++ b/src/ApiKernel.php
@@ -392,6 +392,8 @@ class ApiKernel
             $gjsComponents = $this->parseHtmlToGjsComponents($topHtml);
         }
 
+        $usage = $this->calculateUsage($kind, (int)$rowOut['id'], $auth);
+
         $this->respond([
             'ok' => true,
             'kind' => $kind,
@@ -400,7 +402,8 @@ class ApiKernel
             'data' => $rowOut,
             'html' => $topHtml,
             'content' => $topContent, 
-            'gjs_components' => $gjsComponents
+            'gjs_components' => $gjsComponents,
+            'usage' => $usage,
         ]);
     }
     
@@ -680,3 +683,70 @@ class ApiKernel
         }
     }
 }
+    private function lookupTableName(string $key, string $default): string
+    {
+        $tables = $this->conf['tables'] ?? [];
+        if (!empty($tables[$key])) return $tables[$key];
+        $prefix = $this->conf['projectdb']['prefix'] ?? null;
+        if ($prefix && strpos($default, 'emailtemplate_') === 0) {
+            return $prefix . substr($default, strlen('emailtemplate_'));
+        }
+        return $default;
+    }
+
+    private function countRefsInTable(string $table, string $where, array $params, array $auth): int
+    {
+        try {
+            [$tw, $tp] = $this->tenantWhere($auth);
+            $sql = "SELECT COUNT(*) AS c FROM `$table` WHERE $where" . $tw;
+            $stmt = $this->pdo->prepare($sql);
+            foreach ($params as $k => $v) $stmt->bindValue($k, $v);
+            foreach ($tp as $k => $v) $stmt->bindValue($k, $v);
+            $stmt->execute();
+            $row = $stmt->fetch();
+            return (int)($row['c'] ?? 0);
+        } catch (Throwable $e) {
+            return 0;
+        }
+    }
+
+    private function calculateUsage(string $kind, int $id, array $auth): array
+    {
+        if ($id <= 0) return ['total' => 0];
+
+        $summary = [];
+        $templateItemsTable = $this->lookupTableName('template_items', 'emailtemplate_template_items');
+        $sectionItemsTable  = $this->lookupTableName('section_items',  'emailtemplate_section_items');
+
+        if ($kind === 'sections') {
+            $summary['templates'] = $this->countRefsInTable(
+                $templateItemsTable,
+                "`ref_type` = :rt AND `ref_id` = :rid",
+                [':rt' => 'section', ':rid' => $id],
+                $auth
+            );
+        } elseif ($kind === 'blocks') {
+            $summary['templates'] = $this->countRefsInTable(
+                $templateItemsTable,
+                "`ref_type` = :rt AND `ref_id` = :rid",
+                [':rt' => 'block', ':rid' => $id],
+                $auth
+            );
+            $summary['sections'] = $this->countRefsInTable(
+                $sectionItemsTable,
+                "`ref_id` = :rid",
+                [':rid' => $id],
+                $auth
+            );
+            $summary['snippets'] = $this->countRefsInTable(
+                $this->tableMap['snippets'],
+                "`block_id` = :rid",
+                [':rid' => $id],
+                $auth
+            );
+        }
+
+        $summary = array_filter($summary, fn($v) => (int)$v > 0);
+        $summary['total'] = array_sum($summary);
+        return $summary;
+    }