feat: add Telegram album purchase bot

app/api/purchases/[id]/approve/route.ts

@@ -1,5 +1,6 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { getDatabase } from '@/lib/db';
+import { purchaseDb } from '@/lib/db';
+import { notifyCustomerOfDecision } from '@/lib/telegram';
 
 export async function PATCH(
   request: NextRequest,
@@ -16,25 +17,32 @@ export async function PATCH(
       );
     }
 
-    const db = getDatabase();
-
-    // Update purchase status to approved
-    const result = db.prepare(`
-      UPDATE purchases
-      SET approvalStatus = 'approved'
-      WHERE id = ?
-    `).run(purchaseId);
-
-    if (result.changes === 0) {
+    const existing = purchaseDb.getById(purchaseId);
+    if (!existing) {
       return NextResponse.json(
         { error: 'Purchase not found' },
         { status: 404 }
       );
     }
+    if (existing.approvalStatus !== 'pending') {
+      return NextResponse.json(
+        { error: `Purchase is already ${existing.approvalStatus}` },
+        { status: 409 }
+      );
+    }
+
+    const purchase = purchaseDb.setStatus(purchaseId, 'approved');
+    if (!purchase) {
+      return NextResponse.json({ error: 'Purchase was reviewed concurrently' }, { status: 409 });
+    }
+    void notifyCustomerOfDecision(purchase).catch((error) => {
+      console.error('Failed to notify Telegram customer:', error);
+    });
 
     return NextResponse.json({
       success: true,
-      message: 'Purchase approved successfully'
+      message: 'Purchase approved successfully',
+      purchase,
     });
   } catch (error: any) {
     console.error('Error approving purchase:', error);