feat(cache): implement a simple caching mechanism with TTL and prefix invalidation

refactor(expenses): integrate caching for periodic expenses and related operations
refactor(quotes): add caching for quotes retrieval and history endpoints

apps/backend/src/modules/expenses/expenses.service.ts

@@ -1,5 +1,6 @@
 import { z } from "zod";
 import { prisma } from "../../lib/prisma";
+import { cache } from "../../lib/cache";
 import { PaymentStatus } from "../../generated/prisma/client";
 
 export const createPeriodicExpenseSchema = z.object({
@@ -37,28 +38,38 @@ export function getCurrentYearMonthUTC(): { year: number; month: number } {
 }
 
 export async function listPeriodicExpenses() {
-  return prisma.periodicExpense.findMany({
+  const cached = cache.get("expenses:periodic");
+  if (cached) return cached;
+
+  const data = await prisma.periodicExpense.findMany({
     where: { isDeleted: false },
     orderBy: { description: "asc" },
   });
+  cache.set("expenses:periodic", data);
+  return data;
 }
 
 export async function createPeriodicExpense(data: z.infer<typeof createPeriodicExpenseSchema>) {
   const result = await prisma.periodicExpense.create({ data });
   const { year, month } = getCurrentYearMonthUTC();
   const currentMonthApplicable = data.periods.includes(month);
+  cache.invalidateByPrefix("expenses:");
   return { ...result, currentMonthApplicable };
 }
 
 export async function updatePeriodicExpense(id: number, data: z.infer<typeof updatePeriodicExpenseSchema>) {
-  return prisma.periodicExpense.update({ where: { id }, data });
+  const result = await prisma.periodicExpense.update({ where: { id }, data });
+  cache.invalidateByPrefix("expenses:");
+  return result;
 }
 
 export async function softDeletePeriodicExpense(id: number) {
-  return prisma.periodicExpense.update({
+  const result = await prisma.periodicExpense.update({
     where: { id },
     data: { isDeleted: true },
   });
+  cache.invalidateByPrefix("expenses:");
+  return result;
 }
 
 export async function generateMonthlyExpense(id: number) {
@@ -71,7 +82,7 @@ export async function generateMonthlyExpense(id: number) {
   if (existing) return existing;
 
   const dueDate = buildDueDate(year, month, periodic.defaultDueDay);
-  return prisma.expense.create({
+  const result = await prisma.expense.create({
     data: {
       description: periodic.description,
       periodicExpenseId: id,
@@ -82,6 +93,8 @@ export async function generateMonthlyExpense(id: number) {
       status: PaymentStatus.PENDING,
     },
   });
+  cache.invalidateByPrefix("expenses:");
+  return result;
 }
 
 export async function listExpenses(params: {
@@ -92,6 +105,11 @@ export async function listExpenses(params: {
   search?: string;
 }) {
   const { status, page = 1, pageSize = 10, periodicExpenseId, search } = params;
+
+  const cacheKey = `expenses:list:${status ?? "all"}:${page}:${pageSize}:${periodicExpenseId ?? "none"}:${search ?? ""}`;
+  const cached = cache.get(cacheKey);
+  if (cached) return cached;
+
   const where: Record<string, unknown> = {};
   if (status === "PENDING" || status === "PAYED") {
     where.status = status;
@@ -112,14 +130,16 @@ export async function listExpenses(params: {
     }),
     prisma.expense.count({ where }),
   ]);
-  return { data, total, page, pageSize };
+  const result = { data, total, page, pageSize };
+  cache.set(cacheKey, result);
+  return result;
 }
 
 export async function createNonPeriodicExpense(data: z.infer<typeof createNonPeriodicExpenseSchema>) {
   const dueDate = new Date(data.dueDate);
   const year = dueDate.getUTCFullYear();
   const month = dueDate.getUTCMonth() + 1;
-  return prisma.expense.create({
+  const result = await prisma.expense.create({
     data: {
       description: data.description,
       amount: data.amount,
@@ -131,11 +151,13 @@ export async function createNonPeriodicExpense(data: z.infer<typeof createNonPer
       status: PaymentStatus.PAYED,
     },
   });
+  cache.invalidateByPrefix("expenses:");
+  return result;
 }
 
 export async function payExpense(id: number, data: z.infer<typeof payExpenseSchema>) {
   const paymentDate = data.paymentDate ? new Date(data.paymentDate) : new Date();
-  return prisma.expense.update({
+  const result = await prisma.expense.update({
     where: { id },
     data: {
       status: PaymentStatus.PAYED,
@@ -143,36 +165,55 @@ export async function payExpense(id: number, data: z.infer<typeof payExpenseSche
       paymentDate,
     },
   });
+  cache.invalidateByPrefix("expenses:");
+  return result;
 }
 
 export async function getMonthlyPayedTotal(year: number, month: number) {
+  const cacheKey = `expenses:monthly-total:${year}:${month}`;
+  const cached = cache.get(cacheKey);
+  if (cached) return cached;
+
   const result = await prisma.$queryRaw<Array<{ total: string | null }>>`
     SELECT CAST(SUM("amountPayed") AS NUMERIC) as total
     FROM expenses
     WHERE year = ${year} AND month = ${month} AND status = ${PaymentStatus.PAYED}::"PaymentStatus"
   `;
-  return { total: Number(result[0]?.total ?? 0) };
+  const data = { total: Number(result[0]?.total ?? 0) };
+  cache.set(cacheKey, data);
+  return data;
 }
 
 export async function getMonthlyTotals(year: number, month: number) {
+  const cacheKey = `expenses:totals:${year}:${month}`;
+  const cached = cache.get(cacheKey);
+  if (cached) return cached;
+
   const result = await prisma.$queryRaw<Array<{ payed: string | null; pending: string | null }>>`
     SELECT
       (SELECT CAST(SUM("amountPayed") AS NUMERIC) FROM expenses WHERE year = ${year} AND month = ${month} AND status = ${PaymentStatus.PAYED}::"PaymentStatus") as payed,
       (SELECT CAST(SUM(amount) AS NUMERIC) FROM expenses WHERE year = ${year} AND month = ${month} AND status = ${PaymentStatus.PENDING}::"PaymentStatus") as pending
   `;
-  return {
+  const data = {
     payed: Number(result[0]?.payed ?? 0),
     pending: Number(result[0]?.pending ?? 0),
   };
+  cache.set(cacheKey, data);
+  return data;
 }
 
 export async function getTotalPending() {
+  const cached = cache.get("expenses:pending-total");
+  if (cached) return cached;
+
   const result = await prisma.$queryRaw<Array<{ total: string | null }>>`
     SELECT CAST(SUM(amount) AS NUMERIC) as total
     FROM expenses
     WHERE status = ${PaymentStatus.PENDING}::"PaymentStatus"
   `;
-  return { total: Number(result[0]?.total ?? 0) };
+  const data = { total: Number(result[0]?.total ?? 0) };
+  cache.set("expenses:pending-total", data);
+  return data;
 }
 
 export async function generateExpensesForCurrentMonth() {
@@ -205,5 +246,6 @@ export async function generateExpensesForCurrentMonth() {
     });
     results.push({ id: periodic.id, status: "created" });
   }
+  cache.invalidateByPrefix("expenses:");
   return results;
 }