feat(expenses): add monthly totals and pagination support for expenses

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

@@ -84,16 +84,27 @@ export async function generateMonthlyExpense(id: number) {
   });
 }
 
-export async function listExpenses(status?: string) {
+export async function listExpenses(params: {
+  status?: string;
+  page?: number;
+  pageSize?: number;
+}) {
+  const { status, page = 1, pageSize = 10 } = params;
   const where: Record<string, unknown> = {};
   if (status === "PENDING" || status === "PAYED") {
     where.status = status;
   }
-  return prisma.expense.findMany({
-    where,
-    include: { periodicExpense: true },
-    orderBy: { dueDate: "asc" },
-  });
+  const [data, total] = await Promise.all([
+    prisma.expense.findMany({
+      where,
+      include: { periodicExpense: true },
+      orderBy: { dueDate: "desc" },
+      skip: (page - 1) * pageSize,
+      take: pageSize,
+    }),
+    prisma.expense.count({ where }),
+  ]);
+  return { data, total, page, pageSize };
 }
 
 export async function createNonPeriodicExpense(data: z.infer<typeof createNonPeriodicExpenseSchema>) {
@@ -126,6 +137,32 @@ export async function payExpense(id: number, data: z.infer<typeof payExpenseSche
   });
 }
 
+export async function getMonthlyPayedTotal(year: number, month: number) {
+  const expenses = await prisma.expense.findMany({
+    where: { year, month, status: PaymentStatus.PAYED },
+    select: { amountPayed: true },
+  });
+  const total = expenses.reduce((sum, e) => sum + Number(e.amountPayed ?? 0), 0);
+  return { total };
+}
+
+export async function getMonthlyTotals(year: number, month: number) {
+  const [payed, pending] = await Promise.all([
+    prisma.expense.findMany({
+      where: { year, month, status: PaymentStatus.PAYED },
+      select: { amountPayed: true },
+    }),
+    prisma.expense.findMany({
+      where: { year, month, status: PaymentStatus.PENDING },
+      select: { amount: true },
+    }),
+  ]);
+  return {
+    payed: payed.reduce((sum, e) => sum + Number(e.amountPayed ?? 0), 0),
+    pending: pending.reduce((sum, e) => sum + Number(e.amount), 0),
+  };
+}
+
 export async function generateExpensesForCurrentMonth() {
   const { year, month } = getCurrentYearMonthUTC();