frontend/src/admin/EmailTemplateEditor.tsx

@@ -8,6 +8,10 @@ import Col from 'antd/es/col';
 import Alert from 'antd/es/alert';
 import Typography from 'antd/es/typography';
 import message from 'antd/es/message';
+import MDEditor from '@uiw/react-md-editor';
+import '@uiw/react-md-editor/markdown-editor.css';
+import '@uiw/react-markdown-preview/markdown.css';
+import { useThemeMode } from '../theme/ThemeContext';
 import {
   EmailTemplate,
   saveEmailTemplate,
@@ -27,6 +31,7 @@ type Props = Readonly<{
 const PREVIEW_DEBOUNCE_MS = 400;
 
 export default function EmailTemplateEditor({ template, onChanged }: Props) {
+  const { mode } = useThemeMode();
   // Falls back to the default so the editor starts from the real copy rather
   // than an empty box. `subject`/`body` being null means "never customised",
   // which is why the badge on the tab can say so.
@@ -111,13 +116,28 @@ export default function EmailTemplateEditor({ template, onChanged }: Props) {
           placeholder="Subject"
           style={{ marginBottom: 8 }}
         />
-        <Input.TextArea
-          aria-label={`${template.label} body`}
+        {/* The same editor the item description uses, so an admin who has
+            learned one toolbar has learned both. data-color-mode is what makes
+            it follow the admin's dark mode, exactly as on the item form.
+
+            preview="edit" rather than the item form's "live": MDEditor's own
+            preview would render the markdown with a different renderer, showing
+            a literal {{resetUrl}} and no consent footer. The pane on the right
+            is the server's rendering of the actual email, and two previews
+            disagreeing about the thing being edited is worse than one. */}
+        <div data-color-mode={mode} style={{ marginBottom: 12 }}>
+          <MDEditor
             value={body}
-          onChange={(e) => setBody(e.target.value)}
-          autoSize={{ minRows: 10, maxRows: 24 }}
-          style={{ fontFamily: 'monospace', marginBottom: 12 }}
+            onChange={(val) => setBody(val || '')}
+            height={320}
+            preview="edit"
+            // Input.TextArea carried this attribute itself. MDEditor owns the
+            // textarea, so the label has to be passed through — without it every
+            // email template test loses its handle on the field, and a screen
+            // reader loses the only thing naming it.
+            textareaProps={{ 'aria-label': `${template.label} body` }}
           />
+        </div>
 
         <Space>
           <Button type="primary" loading={saving} onClick={handleSave}>