fix: handle email templates schema variations in production

- Update migration to detect and handle both old and new email template schemas
- Fix migration to insert into correct columns based on existing schema
- Update adminEmail routes to handle both schema formats gracefully
- Add proper fallbacks for German language columns

This ensures the application works whether the language migration has been
applied or not, preventing null constraint violations.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/migrations/020_ensure_default_email_templates.js

@@ -3,11 +3,20 @@ exports.up = async function(knex) {
   const templates = await knex('email_templates').select('template_key');
   const existingKeys = templates.map(t => t.template_key);
   
+  // Check which columns exist in the table
+  const hasSubjectEn = await knex.schema.hasColumn('email_templates', 'subject_en');
+  const hasSubject = await knex.schema.hasColumn('email_templates', 'subject');
+  
+  // Determine which columns to use based on schema
+  const subjectCol = hasSubjectEn ? 'subject_en' : 'subject';
+  const bodyHtmlCol = hasSubjectEn ? 'body_html_en' : 'body_html';
+  const bodyTextCol = hasSubjectEn ? 'body_text_en' : 'body_text';
+  
   const defaultTemplates = [
     {
       template_key: 'gallery_created',
-      subject: 'Your Photo Gallery is Ready!',
-      body_html: `<h2>Gallery Created Successfully</h2>
+      [subjectCol]: 'Your Photo Gallery is Ready!',
+      [bodyHtmlCol]: `<h2>Gallery Created Successfully</h2>
 <p>Dear {{host_name}},</p>
 <p>Your photo gallery "{{event_name}}" has been created successfully!</p>
 <p><strong>Gallery Details:</strong></p>
@@ -18,39 +27,39 @@ exports.up = async function(knex) {
   <li>Expires: {{expiry_date}}</li>
 </ul>
 <p>Share this link and password with your guests to allow them to view and download photos.</p>`,
-      body_text: 'Gallery Created Successfully\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has been created successfully!',
+      [bodyTextCol]: 'Gallery Created Successfully\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has been created successfully!',
       variables: JSON.stringify(['host_name', 'event_name', 'event_date', 'gallery_link', 'gallery_password', 'expiry_date'])
     },
     {
       template_key: 'expiration_warning',
-      subject: 'Your Photo Gallery Expires Soon',
-      body_html: `<h2>Gallery Expiring Soon</h2>
+      [subjectCol]: 'Your Photo Gallery Expires Soon',
+      [bodyHtmlCol]: `<h2>Gallery Expiring Soon</h2>
 <p>Dear {{host_name}},</p>
 <p>Your photo gallery "{{event_name}}" will expire in {{days_remaining}} days.</p>
 <p>After expiration, the gallery will be archived and no longer accessible to guests.</p>
 <p><a href="{{gallery_link}}">Visit Gallery</a></p>`,
-      body_text: 'Gallery Expiring Soon\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" will expire in {{days_remaining}} days.',
+      [bodyTextCol]: 'Gallery Expiring Soon\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" will expire in {{days_remaining}} days.',
       variables: JSON.stringify(['host_name', 'event_name', 'days_remaining', 'gallery_link'])
     },
     {
       template_key: 'gallery_expired',
-      subject: 'Your Photo Gallery Has Expired',
-      body_html: `<h2>Gallery Expired</h2>
+      [subjectCol]: 'Your Photo Gallery Has Expired',
+      [bodyHtmlCol]: `<h2>Gallery Expired</h2>
 <p>Dear {{host_name}},</p>
 <p>Your photo gallery "{{event_name}}" has expired and been archived.</p>
 <p>The photos are safely stored in our archive system. If you need access to the archived photos, please contact support.</p>`,
-      body_text: 'Gallery Expired\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has expired and been archived.',
+      [bodyTextCol]: 'Gallery Expired\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has expired and been archived.',
       variables: JSON.stringify(['host_name', 'event_name'])
     },
     {
       template_key: 'archive_complete',
-      subject: 'Gallery Archive Complete',
-      body_html: `<h2>Archive Complete</h2>
+      [subjectCol]: 'Gallery Archive Complete',
+      [bodyHtmlCol]: `<h2>Archive Complete</h2>
 <p>Dear {{host_name}},</p>
 <p>Your photo gallery "{{event_name}}" has been successfully archived.</p>
 <p>Archive size: {{archive_size}}</p>
 <p>The archive is stored securely and can be retrieved if needed.</p>`,
-      body_text: 'Archive Complete\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has been successfully archived.',
+      [bodyTextCol]: 'Archive Complete\n\nDear {{host_name}},\n\nYour photo gallery "{{event_name}}" has been successfully archived.',
       variables: JSON.stringify(['host_name', 'event_name', 'archive_size'])
     }
   ];
@@ -58,6 +67,20 @@ exports.up = async function(knex) {
   // Insert missing templates
   for (const template of defaultTemplates) {
     if (!existingKeys.includes(template.template_key)) {
+      // If we have language columns, also set German versions with same content
+      if (hasSubjectEn) {
+        template.subject_de = template[subjectCol];
+        template.body_html_de = template[bodyHtmlCol];
+        template.body_text_de = template[bodyTextCol];
+        
+        // Also ensure we have the basic columns if they exist
+        if (hasSubject) {
+          template.subject = template[subjectCol];
+          template.body_html = template[bodyHtmlCol];
+          template.body_text = template[bodyTextCol];
+        }
+      }
+      
       await knex('email_templates').insert(template);
     }
   }

backend/src/routes/adminEmail.js

@@ -193,20 +193,34 @@ router.get('/templates/:key', adminAuth, async (req, res) => {
       return res.status(404).json({ error: 'Template not found' });
     }
 
-    res.json({
+    // Handle both old and new schema formats
+    const response = {
       id: template.id,
       template_key: template.template_key,
-      // English versions
-      subject_en: template.subject_en || template.subject,
-      body_html_en: template.body_html_en || template.body_html,
-      body_text_en: template.body_text_en || template.body_text,
-      // German versions
-      subject_de: template.subject_de || template.subject_en || template.subject,
-      body_html_de: template.body_html_de || template.body_html_en || template.body_html,
-      body_text_de: template.body_text_de || template.body_text_en || template.body_text,
       variables: template.variables ? JSON.parse(template.variables) : [],
       updated_at: template.updated_at
-    });
+    };
+    
+    // Check which columns exist and use them appropriately
+    if (template.subject_en !== undefined) {
+      // New schema with language columns
+      response.subject_en = template.subject_en;
+      response.body_html_en = template.body_html_en;
+      response.body_text_en = template.body_text_en;
+      response.subject_de = template.subject_de;
+      response.body_html_de = template.body_html_de;
+      response.body_text_de = template.body_text_de;
+    } else {
+      // Old schema - use basic columns for both languages
+      response.subject_en = template.subject;
+      response.body_html_en = template.body_html;
+      response.body_text_en = template.body_text;
+      response.subject_de = template.subject;
+      response.body_html_de = template.body_html;
+      response.body_text_de = template.body_text;
+    }
+    
+    res.json(response);
   } catch (error) {
     console.error('Email template fetch error:', error);
     res.status(500).json({ error: 'Failed to fetch email template' });
@@ -237,13 +251,39 @@ router.put('/templates/:key', [
       updated_at: new Date()
     };
 
-    // Only update provided fields
-    if (subject_en !== undefined) updateData.subject_en = subject_en;
-    if (subject_de !== undefined) updateData.subject_de = subject_de;
-    if (body_html_en !== undefined) updateData.body_html_en = body_html_en;
-    if (body_html_de !== undefined) updateData.body_html_de = body_html_de;
-    if (body_text_en !== undefined) updateData.body_text_en = body_text_en || '';
-    if (body_text_de !== undefined) updateData.body_text_de = body_text_de || '';
+    // Check which columns exist in the database
+    const template = await db('email_templates')
+      .where('template_key', req.params.key)
+      .first();
+      
+    if (!template) {
+      return res.status(404).json({ error: 'Template not found' });
+    }
+
+    // Determine schema type and update accordingly
+    if (template.subject_en !== undefined) {
+      // New schema with language columns
+      if (subject_en !== undefined) updateData.subject_en = subject_en;
+      if (subject_de !== undefined) updateData.subject_de = subject_de;
+      if (body_html_en !== undefined) updateData.body_html_en = body_html_en;
+      if (body_html_de !== undefined) updateData.body_html_de = body_html_de;
+      if (body_text_en !== undefined) updateData.body_text_en = body_text_en || '';
+      if (body_text_de !== undefined) updateData.body_text_de = body_text_de || '';
+      
+      // Also update basic columns if they exist
+      if (template.subject !== undefined) {
+        updateData.subject = subject_en || updateData.subject_en;
+        updateData.body_html = body_html_en || updateData.body_html_en;
+        updateData.body_text = body_text_en || updateData.body_text_en || '';
+      }
+    } else {
+      // Old schema - only update basic columns
+      if (subject_en !== undefined) {
+        updateData.subject = subject_en;
+        updateData.body_html = body_html_en;
+        updateData.body_text = body_text_en || '';
+      }
+    }
 
     const updated = await db('email_templates')
       .where('template_key', req.params.key)