refactor: extract business logic from routes into reusable service modules

server/src/routes/categories.ts

@@ -1,55 +1,34 @@
 import express, { Request, Response } from 'express';
-import { db } from '../db/database';
 import { authenticate, adminOnly } from '../middleware/auth';
 import { AuthRequest } from '../types';
+import * as categoryService from '../services/categoryService';
 
 const router = express.Router();
 
 router.get('/', authenticate, (_req: Request, res: Response) => {
-  const categories = db.prepare(
-    'SELECT * FROM categories ORDER BY name ASC'
-  ).all();
-  res.json({ categories });
+  res.json({ categories: categoryService.listCategories() });
 });
 
 router.post('/', authenticate, adminOnly, (req: Request, res: Response) => {
   const authReq = req as AuthRequest;
   const { name, color, icon } = req.body;
-
   if (!name) return res.status(400).json({ error: 'Category name is required' });
-
-  const result = db.prepare(
-    'INSERT INTO categories (name, color, icon, user_id) VALUES (?, ?, ?, ?)'
-  ).run(name, color || '#6366f1', icon || '\uD83D\uDCCD', authReq.user.id);
-
-  const category = db.prepare('SELECT * FROM categories WHERE id = ?').get(result.lastInsertRowid);
+  const category = categoryService.createCategory(authReq.user.id, name, color, icon);
   res.status(201).json({ category });
 });
 
 router.put('/:id', authenticate, adminOnly, (req: Request, res: Response) => {
   const { name, color, icon } = req.body;
-  const category = db.prepare('SELECT * FROM categories WHERE id = ?').get(req.params.id);
-
-  if (!category) return res.status(404).json({ error: 'Category not found' });
-
-  db.prepare(`
-    UPDATE categories SET
-      name = COALESCE(?, name),
-      color = COALESCE(?, color),
-      icon = COALESCE(?, icon)
-    WHERE id = ?
-  `).run(name || null, color || null, icon || null, req.params.id);
-
-  const updated = db.prepare('SELECT * FROM categories WHERE id = ?').get(req.params.id);
-  res.json({ category: updated });
+  if (!categoryService.getCategoryById(req.params.id))
+    return res.status(404).json({ error: 'Category not found' });
+  const category = categoryService.updateCategory(req.params.id, name, color, icon);
+  res.json({ category });
 });
 
 router.delete('/:id', authenticate, adminOnly, (req: Request, res: Response) => {
-  const category = db.prepare('SELECT * FROM categories WHERE id = ?').get(req.params.id);
-
-  if (!category) return res.status(404).json({ error: 'Category not found' });
-
-  db.prepare('DELETE FROM categories WHERE id = ?').run(req.params.id);
+  if (!categoryService.getCategoryById(req.params.id))
+    return res.status(404).json({ error: 'Category not found' });
+  categoryService.deleteCategory(req.params.id);
   res.json({ success: true });
 });