feat: Implement deals repository and routes for fetching best watched item prices

- Added a new DealsRepository class to interact with the database for fetching the best sale prices of watched items.
- Created a new route `/api/users/deals/best-watched-prices` to handle requests for the best prices of items the authenticated user is watching.
- Enhanced logging in the FlyerDataTransformer and FlyerProcessingService for better traceability.
- Updated tests to ensure proper logging and functionality in the FlyerProcessingService.
- Refactored logger client to support structured logging for better consistency across the application.

src/routes/budget.routes.ts

@@ -4,8 +4,7 @@ import { z } from 'zod';
 import passport from './passport.routes';
 import { budgetRepo } from '../services/db/index.db';
 import { logger } from '../services/logger.server';
-import { UserProfile } from '../types';
-import { ForeignKeyConstraintError } from '../services/db/errors.db';
+import type { UserProfile } from '../types';
 import { validateRequest } from '../middleware/validation.middleware';
 
 const router = express.Router();
@@ -49,10 +48,10 @@ router.use(passport.authenticate('jwt', { session: false }));
 router.get('/', async (req, res, next: NextFunction) => {
   const user = req.user as UserProfile;
   try {
-    const budgets = await budgetRepo.getBudgetsForUser(user.user_id);
+    const budgets = await budgetRepo.getBudgetsForUser(user.user_id, req.log);
     res.json(budgets);
   } catch (error) {
-    logger.error('Error fetching budgets:', { error, userId: user.user_id });
+    req.log.error({ err: error, userId: user.user_id }, 'Error fetching budgets');
     next(error);
   }
 });
@@ -63,10 +62,10 @@ router.get('/', async (req, res, next: NextFunction) => {
 router.post('/', validateRequest(createBudgetSchema), async (req, res, next: NextFunction) => {
   const user = req.user as UserProfile;
   try {
-    const newBudget = await budgetRepo.createBudget(user.user_id, req.body);
+    const newBudget = await budgetRepo.createBudget(user.user_id, req.body, req.log);
     res.status(201).json(newBudget);
   } catch (error: unknown) {
-    logger.error('Error creating budget:', { error, userId: user.user_id, body: req.body });
+    req.log.error({ err: error, userId: user.user_id, body: req.body }, 'Error creating budget');
     next(error);
   }
 });
@@ -78,10 +77,10 @@ router.put('/:id', validateRequest(updateBudgetSchema), async (req, res, next: N
   const user = req.user as UserProfile;
   const budgetId = req.params.id as unknown as number;
   try {
-    const updatedBudget = await budgetRepo.updateBudget(budgetId, user.user_id, req.body);
+    const updatedBudget = await budgetRepo.updateBudget(budgetId, user.user_id, req.body, req.log);
     res.json(updatedBudget);
   } catch (error: unknown) {
-    logger.error('Error updating budget:', { error, userId: user.user_id, budgetId });
+    req.log.error({ err: error, userId: user.user_id, budgetId }, 'Error updating budget');
     next(error);
   }
 });
@@ -93,10 +92,10 @@ router.delete('/:id', validateRequest(budgetIdParamSchema), async (req, res, nex
   const user = req.user as UserProfile;
   const budgetId = req.params.id as unknown as number;
   try {
-    await budgetRepo.deleteBudget(budgetId, user.user_id);
+    await budgetRepo.deleteBudget(budgetId, user.user_id, req.log);
     res.status(204).send(); // No Content
   } catch (error: unknown) {
-    logger.error('Error deleting budget:', { error, userId: user.user_id, budgetId });
+    req.log.error({ err: error, userId: user.user_id, budgetId }, 'Error deleting budget');
     next(error);
   }
 });
@@ -110,10 +109,10 @@ router.get('/spending-analysis', validateRequest(spendingAnalysisSchema), async
   const { startDate, endDate } = req.query;
 
   try {
-    const spendingData = await budgetRepo.getSpendingByCategory(user.user_id, startDate as string, endDate as string);
+    const spendingData = await budgetRepo.getSpendingByCategory(user.user_id, startDate as string, endDate as string, req.log);
     res.json(spendingData);
   } catch (error) {
-    logger.error('Error fetching spending analysis:', { error, userId: user.user_id, startDate, endDate });
+    req.log.error({ err: error, userId: user.user_id, startDate, endDate }, 'Error fetching spending analysis');
     next(error);
   }
 });

src/routes/deals.routes.ts

@@ -0,0 +1,34 @@
+// src/routes/deals.routes.ts
+import express, { type Request, type Response, type NextFunction } from 'express';
+import passport from './passport.routes';
+import { dealsRepo } from '../services/db/deals.db';
+import type { UserProfile } from '../types';
+
+const router = express.Router();
+
+// --- Middleware for all deal routes ---
+
+// Per ADR-002, all routes in this file require an authenticated user.
+// We apply the standard passport JWT middleware at the router level.
+router.use(passport.authenticate('jwt', { session: false }));
+
+/**
+ * @route GET /api/users/deals/best-watched-prices
+ * @description Fetches the best current sale price for each of the authenticated user's watched items.
+ * @access Private
+ */
+router.get('/best-watched-prices', async (req: Request, res: Response, next: NextFunction) => {
+  const user = req.user as UserProfile;
+  try {
+    // The controller logic is simple enough to be handled directly in the route,
+    // consistent with other simple GET routes in the project.
+    const deals = await dealsRepo.findBestPricesForWatchedItems(user.user_id);
+    req.log.info({ dealCount: deals.length, userId: user.user_id }, 'Successfully fetched best watched item deals.');
+    res.status(200).json(deals);
+  } catch (error) {
+    req.log.error({ err: error, userId: user.user_id }, 'Error fetching best watched item deals.');
+    next(error); // Pass errors to the global error handler
+  }
+});
+
+export default router;