From 55a01c57388d068be60293cd1af5dc63dc4d5f1f Mon Sep 17 00:00:00 2001
From: Ho Ngoc Hai <hongochai10@icloud.com>
Date: Fri, 10 Apr 2026 23:33:31 +0700
Subject: [PATCH] feat(web): centralise Vietnamese price formatting across all
 pages
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Create a single `currency.ts` utility with `formatPrice`, `formatVND`,
`formatPricePerM2`, and `parseVND` to replace 9+ duplicated inline
formatters. This fixes inconsistent decimal handling (1.5M was truncated
to "1 triệu") and standardises price/m² display. Integrated across
property cards, listing detail, dashboard, analytics, payments, pricing,
and admin moderation pages with 19 new unit tests.

Co-Authored-By: Paperclip <noreply@paperclip.ing>
---
 .../(admin)/admin/moderation/page.tsx         |  19 +--
 apps/web/app/[locale]/(admin)/admin/page.tsx  |   7 +-
 .../[locale]/(dashboard)/analytics/page.tsx   |  31 ++---
 .../[locale]/(dashboard)/dashboard/page.tsx   |  23 +---
 .../(dashboard)/dashboard/payments/page.tsx   |  16 +--
 .../[locale]/(dashboard)/listings/page.tsx    |   9 +-
 .../[locale]/(public)/listings/[id]/page.tsx  |  10 +-
 .../app/[locale]/(public)/pricing/page.tsx    |  11 +-
 .../listings/listing-detail-client.tsx        |  10 +-
 apps/web/components/search/property-card.tsx  |  10 +-
 apps/web/lib/__tests__/currency.spec.ts       | 125 ++++++++++++++++++
 apps/web/lib/currency.ts                      | 121 +++++++++++++++++
 12 files changed, 285 insertions(+), 107 deletions(-)
 create mode 100644 apps/web/lib/__tests__/currency.spec.ts
 create mode 100644 apps/web/lib/currency.ts

diff --git a/apps/web/app/[locale]/(admin)/admin/moderation/page.tsx b/apps/web/app/[locale]/(admin)/admin/moderation/page.tsx
index 9848c78..81dbda2 100644
--- a/apps/web/app/[locale]/(admin)/admin/moderation/page.tsx
+++ b/apps/web/app/[locale]/(admin)/admin/moderation/page.tsx
@@ -24,16 +24,7 @@ import {
 import { Input } from '@/components/ui/input';
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table';
 import { adminApi, type ModerationQueueItem, type PaginatedResult } from '@/lib/admin-api';
-
-function formatPrice(price: number): string {
-  if (price >= 1_000_000_000) {
-    return `${(price / 1_000_000_000).toFixed(1)} tỷ`;
-  }
-  if (price >= 1_000_000) {
-    return `${(price / 1_000_000).toFixed(0)} triệu`;
-  }
-  return price.toLocaleString('vi-VN');
-}
+import { formatPrice } from '@/lib/currency';
 
 function moderationScoreBadge(score: number | null) {
   if (score === null) return <Badge variant="secondary">N/A</Badge>;
@@ -159,14 +150,14 @@ export default function AdminModerationPage() {
         </div>
       )}
 
-      <div className="flex items-center justify-between">
+      <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
         <div>
-          <h1 className="text-2xl font-bold tracking-tight">Kiểm duyệt tin đăng</h1>
+          <h1 className="text-xl font-bold tracking-tight sm:text-2xl">Kiểm duyệt tin đăng</h1>
           <p className="text-sm text-muted-foreground">
             Duyệt hoặc từ chối các tin đăng chờ phê duyệt
           </p>
         </div>
-        <div className="flex gap-2">
+        <div className="flex flex-wrap gap-2">
           {selected.size > 0 && (
             <>
               <Button
@@ -224,6 +215,7 @@ export default function AdminModerationPage() {
                         checked={selected.size === result.data.length && result.data.length > 0}
                         onChange={toggleSelectAll}
                         className="rounded border-input"
+                        aria-label="Chọn tất cả tin đăng"
                       />
                     </TableHead>
                     <TableHead>Tiêu đề</TableHead>
@@ -244,6 +236,7 @@ export default function AdminModerationPage() {
                           checked={selected.has(item.listingId)}
                           onChange={() => toggleSelect(item.listingId)}
                           className="rounded border-input"
+                          aria-label={`Chọn tin: ${item.propertyTitle}`}
                         />
                       </TableCell>
                       <TableCell>
diff --git a/apps/web/app/[locale]/(admin)/admin/page.tsx b/apps/web/app/[locale]/(admin)/admin/page.tsx
index 1f769d4..b75d9e4 100644
--- a/apps/web/app/[locale]/(admin)/admin/page.tsx
+++ b/apps/web/app/[locale]/(admin)/admin/page.tsx
@@ -16,6 +16,7 @@ import { useEffect, useState, useCallback } from 'react';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { adminApi, type DashboardStats, type RevenueStatsItem } from '@/lib/admin-api';
+import { formatVND } from '@/lib/currency';
 
 interface StatCardProps {
   title: string;
@@ -72,7 +73,7 @@ function RevenueChart({ data }: { data: RevenueStatsItem[] }) {
             <div className="flex items-center justify-between text-sm">
               <span className="text-muted-foreground">{item.period}</span>
               <span className="font-medium">
-                {item.totalRevenue.toLocaleString('vi-VN')} VND
+                {formatVND(item.totalRevenue)}
               </span>
             </div>
             <div className="h-2 w-full rounded-full bg-muted">
@@ -82,8 +83,8 @@ function RevenueChart({ data }: { data: RevenueStatsItem[] }) {
               />
             </div>
             <div className="flex gap-3 text-xs text-muted-foreground">
-              <span>Subscription: {item.subscriptionRevenue.toLocaleString('vi-VN')}</span>
-              <span>Listing fee: {item.listingFeeRevenue.toLocaleString('vi-VN')}</span>
+              <span>Subscription: {formatVND(item.subscriptionRevenue)}</span>
+              <span>Listing fee: {formatVND(item.listingFeeRevenue)}</span>
               <span>{item.transactionCount} GD</span>
             </div>
           </div>
diff --git a/apps/web/app/[locale]/(dashboard)/analytics/page.tsx b/apps/web/app/[locale]/(dashboard)/analytics/page.tsx
index de888cd..952c4aa 100644
--- a/apps/web/app/[locale]/(dashboard)/analytics/page.tsx
+++ b/apps/web/app/[locale]/(dashboard)/analytics/page.tsx
@@ -5,6 +5,7 @@ import { useEffect, useState } from 'react';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { Tabs, TabsList, TabsTrigger, TabsContent } from '@/components/ui/tabs';
+import { formatPrice, formatPricePerM2 } from '@/lib/currency';
 import {
   useMarketReport,
   useHeatmap,
@@ -36,18 +37,6 @@ const CITIES = ['Ho Chi Minh', 'Ha Noi', 'Da Nang'];
 const CURRENT_PERIOD = '2026-Q1';
 const TREND_PERIODS = ['2025-Q1', '2025-Q2', '2025-Q3', '2025-Q4', '2026-Q1'];
 
-function formatPrice(priceStr: string): string {
-  const num = Number(priceStr);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} tỷ`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} triệu`;
-  return num.toLocaleString('vi-VN');
-}
-
-function formatPriceM2(price: number): string {
-  if (price >= 1_000_000) return `${(price / 1_000_000).toFixed(1)} tr/m²`;
-  return `${price.toLocaleString('vi-VN')} đ/m²`;
-}
-
 function YoYBadge({ value }: { value: number | null }) {
   if (value === null) return <span className="text-xs text-muted-foreground">N/A</span>;
   const isPositive = value >= 0;
@@ -124,7 +113,7 @@ export default function AnalyticsPage() {
     <div className="space-y-8">
       <div className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
         <div>
-          <h1 className="text-3xl font-bold">Phân tích thị trường</h1>
+          <h1 className="text-2xl font-bold sm:text-3xl">Phân tích thị trường</h1>
           <p className="mt-2 text-muted-foreground">
             Báo cáo thị trường bất động sản - {period}
           </p>
@@ -159,7 +148,7 @@ export default function AnalyticsPage() {
           <CardHeader className="pb-2">
             <CardDescription>Giá TB/m²</CardDescription>
             <CardTitle className="text-2xl">
-              {loading ? '...' : formatPriceM2(avgPriceM2)}
+              {loading ? '...' : formatPricePerM2(avgPriceM2)}
             </CardTitle>
           </CardHeader>
         </Card>
@@ -183,11 +172,11 @@ export default function AnalyticsPage() {
 
       {/* Tabs */}
       <Tabs value={tab} onValueChange={setTab}>
-        <TabsList>
-          <TabsTrigger value="overview">Tổng quan</TabsTrigger>
-          <TabsTrigger value="trends">Xu hướng giá</TabsTrigger>
-          <TabsTrigger value="districts">Chi tiết quận</TabsTrigger>
-          <TabsTrigger value="performance">Hiệu suất</TabsTrigger>
+        <TabsList className="w-full justify-start overflow-x-auto">
+          <TabsTrigger value="overview" className="min-w-fit">Tổng quan</TabsTrigger>
+          <TabsTrigger value="trends" className="min-w-fit">Xu hướng giá</TabsTrigger>
+          <TabsTrigger value="districts" className="min-w-fit">Chi tiết quận</TabsTrigger>
+          <TabsTrigger value="performance" className="min-w-fit">Hiệu suất</TabsTrigger>
         </TabsList>
 
         {/* Overview Tab */}
@@ -336,7 +325,7 @@ export default function AnalyticsPage() {
                               {formatPrice(stat.medianPrice)}
                             </td>
                             <td className="py-2 pr-4 text-right">
-                              {formatPriceM2(stat.avgPriceM2)}
+                              {formatPricePerM2(stat.avgPriceM2)}
                             </td>
                             <td className="py-2 pr-4 text-right">{stat.totalListings}</td>
                             <td className="py-2 pr-4 text-right">
@@ -384,7 +373,7 @@ export default function AnalyticsPage() {
                             </div>
                             <div className="flex justify-between">
                               <span className="text-muted-foreground">Giá/m²</span>
-                              <span>{formatPriceM2(district.avgPriceM2)}</span>
+                              <span>{formatPricePerM2(district.avgPriceM2)}</span>
                             </div>
                             <div className="flex justify-between">
                               <span className="text-muted-foreground">Tin đăng</span>
diff --git a/apps/web/app/[locale]/(dashboard)/dashboard/page.tsx b/apps/web/app/[locale]/(dashboard)/dashboard/page.tsx
index 53b6bb0..a31b46f 100644
--- a/apps/web/app/[locale]/(dashboard)/dashboard/page.tsx
+++ b/apps/web/app/[locale]/(dashboard)/dashboard/page.tsx
@@ -6,6 +6,7 @@ import Link from 'next/link';
 import { ListingStatusBadge } from '@/components/listings/listing-status-badge';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
+import { formatPrice, formatPricePerM2 } from '@/lib/currency';
 import { useMarketReport, useHeatmap } from '@/lib/hooks/use-analytics';
 import { useListingsSearch } from '@/lib/hooks/use-listings';
 
@@ -17,18 +18,6 @@ const DistrictBarChart = dynamic(
 const CITY = 'Ho Chi Minh';
 const PERIOD = '2026-Q1';
 
-function formatPrice(priceStr: string): string {
-  const num = Number(priceStr);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} tỷ`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} triệu`;
-  return num.toLocaleString('vi-VN');
-}
-
-function formatPriceM2(price: number): string {
-  if (price >= 1_000_000) return `${(price / 1_000_000).toFixed(1)} tr/m²`;
-  return `${price.toLocaleString('vi-VN')} đ/m²`;
-}
-
 interface StatCardProps {
   title: string;
   value: string;
@@ -105,9 +94,9 @@ export default function DashboardPage() {
 
   return (
     <div className="space-y-8">
-      <div className="flex items-center justify-between">
+      <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
         <div>
-          <h1 className="text-3xl font-bold">Bảng điều khiển</h1>
+          <h1 className="text-2xl font-bold sm:text-3xl">Bảng điều khiển</h1>
           <p className="mt-2 text-muted-foreground">
             Tổng quan thị trường và tin đăng của bạn
           </p>
@@ -136,7 +125,7 @@ export default function DashboardPage() {
         />
         <StatCard
           title="Giá TB thị trường"
-          value={loading ? '...' : formatPriceM2(avgPriceM2)}
+          value={loading ? '...' : formatPricePerM2(avgPriceM2)}
           trend={avgYoy}
           description="YoY"
         />
@@ -186,7 +175,7 @@ export default function DashboardPage() {
             <div className="flex items-center justify-between">
               <span className="text-sm text-muted-foreground">Giá TB/m²</span>
               <span className="font-semibold">
-                {loading ? '...' : formatPriceM2(avgPriceM2)}
+                {loading ? '...' : formatPricePerM2(avgPriceM2)}
               </span>
             </div>
             <div className="flex items-center justify-between">
@@ -214,7 +203,7 @@ export default function DashboardPage() {
 
       {/* Recent listings */}
       <Card>
-        <CardHeader className="flex flex-row items-center justify-between">
+        <CardHeader className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
           <div>
             <CardTitle className="text-lg">Tin đăng gần đây</CardTitle>
             <CardDescription>Danh sách tin đăng mới nhất của bạn</CardDescription>
diff --git a/apps/web/app/[locale]/(dashboard)/dashboard/payments/page.tsx b/apps/web/app/[locale]/(dashboard)/dashboard/payments/page.tsx
index e15e938..3a5c4c9 100644
--- a/apps/web/app/[locale]/(dashboard)/dashboard/payments/page.tsx
+++ b/apps/web/app/[locale]/(dashboard)/dashboard/payments/page.tsx
@@ -13,15 +13,9 @@ import {
   TableHeader,
   TableRow,
 } from '@/components/ui/table';
+import { formatVND } from '@/lib/currency';
 import { useTransactions } from '@/lib/hooks/use-payments';
 
-function formatVND(amount: string | number): string {
-  const num = typeof amount === 'string' ? Number(amount) : amount;
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} tỷ đ`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} triệu đ`;
-  return num.toLocaleString('vi-VN') + ' đ';
-}
-
 const STATUS_LABELS: Record<string, { label: string; variant: 'default' | 'secondary' | 'destructive' | 'outline' }> = {
   PENDING: { label: 'Chờ xử lý', variant: 'secondary' },
   PROCESSING: { label: 'Đang xử lý', variant: 'secondary' },
@@ -66,14 +60,14 @@ export default function PaymentsPage() {
   return (
     <div className="space-y-6">
       <div>
-        <h1 className="text-3xl font-bold">Thanh toán</h1>
+        <h1 className="text-2xl font-bold sm:text-3xl">Thanh toán</h1>
         <p className="mt-2 text-muted-foreground">
           Lịch sử giao dịch và quản lý thanh toán
         </p>
       </div>
 
       {/* Summary cards */}
-      <div className="grid gap-4 sm:grid-cols-3">
+      <div className="grid grid-cols-2 gap-4 sm:grid-cols-3">
         <Card>
           <CardHeader className="pb-2">
             <CardDescription>Tổng giao dịch</CardDescription>
@@ -104,12 +98,12 @@ export default function PaymentsPage() {
 
       {/* Transactions table */}
       <Card>
-        <CardHeader className="flex flex-row items-center justify-between">
+        <CardHeader className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
           <div>
             <CardTitle className="text-lg">Lịch sử giao dịch</CardTitle>
             <CardDescription>Tất cả giao dịch thanh toán của bạn</CardDescription>
           </div>
-          <div className="w-40">
+          <div className="w-full sm:w-40">
             <Select
               value={statusFilter}
               onChange={(e) => {
diff --git a/apps/web/app/[locale]/(dashboard)/listings/page.tsx b/apps/web/app/[locale]/(dashboard)/listings/page.tsx
index bcec7c5..ccd3bf2 100644
--- a/apps/web/app/[locale]/(dashboard)/listings/page.tsx
+++ b/apps/web/app/[locale]/(dashboard)/listings/page.tsx
@@ -8,15 +8,10 @@ import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { Select } from '@/components/ui/select';
+import { formatPrice } from '@/lib/currency';
 import { useListingsSearch } from '@/lib/hooks/use-listings';
 import type { ListingDetail as _ListingDetail } from '@/lib/listings-api';
 import { PROPERTY_TYPES, TRANSACTION_TYPES, LISTING_STATUSES } from '@/lib/validations/listings';
-function formatPrice(priceVND: string): string {
-  const num = Number(priceVND);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} tỷ`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} triệu`;
-  return num.toLocaleString('vi-VN');
-}
 
 function formatDate(dateStr: string | null): string {
   if (!dateStr) return 'N/A';
@@ -75,7 +70,7 @@ export default function ListingsPage() {
       </div>
 
       {/* Stats */}
-      <div className="grid gap-3 sm:grid-cols-4">
+      <div className="grid grid-cols-2 gap-3 sm:grid-cols-4">
         <Card>
           <CardHeader className="pb-2">
             <CardDescription>Tổng tin đăng</CardDescription>
diff --git a/apps/web/app/[locale]/(public)/listings/[id]/page.tsx b/apps/web/app/[locale]/(public)/listings/[id]/page.tsx
index 759a8dd..6dc64ae 100644
--- a/apps/web/app/[locale]/(public)/listings/[id]/page.tsx
+++ b/apps/web/app/[locale]/(public)/listings/[id]/page.tsx
@@ -6,6 +6,7 @@ import {
   generateBreadcrumbJsonLd,
   generateListingJsonLd,
 } from '@/components/seo/json-ld';
+import { formatPrice } from '@/lib/currency';
 import { fetchListingById } from '@/lib/listings-server';
 import { PROPERTY_TYPES, TRANSACTION_TYPES } from '@/lib/validations/listings';
 
@@ -20,13 +21,6 @@ function getLabel(list: readonly { value: string; label: string }[], value: stri
   return list.find((item) => item.value === value)?.label ?? value;
 }
 
-function formatPriceShort(priceVND: string): string {
-  const num = Number(priceVND);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} t\u1ef7`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} tri\u1ec7u`;
-  return num.toLocaleString('vi-VN');
-}
-
 // ---------------------------------------------------------------------------
 // Metadata (runs server-side, provides <title>, <meta>, OG, canonical)
 // ---------------------------------------------------------------------------
@@ -44,7 +38,7 @@ export async function generateMetadata({ params }: PageProps): Promise<Metadata>
   const { property } = listing;
   const propertyTypeLabel = getLabel(PROPERTY_TYPES, property.propertyType);
   const transactionLabel = getLabel(TRANSACTION_TYPES, listing.transactionType);
-  const priceStr = formatPriceShort(listing.priceVND);
+  const priceStr = formatPrice(listing.priceVND);
   const fullAddress = [property.address, property.ward, property.district, property.city]
     .filter(Boolean)
     .join(', ');
diff --git a/apps/web/app/[locale]/(public)/pricing/page.tsx b/apps/web/app/[locale]/(public)/pricing/page.tsx
index c8c35fd..66ffa85 100644
--- a/apps/web/app/[locale]/(public)/pricing/page.tsx
+++ b/apps/web/app/[locale]/(public)/pricing/page.tsx
@@ -13,6 +13,7 @@ import {
   CardTitle,
 } from '@/components/ui/card';
 import { Link } from '@/i18n/navigation';
+import { formatVND } from '@/lib/currency';
 import { usePlans } from '@/lib/hooks/use-subscription';
 import type { PlanDto } from '@/lib/subscription-api';
 import { cn } from '@/lib/utils';
@@ -134,16 +135,6 @@ const FALLBACK_PLANS: PlanDto[] = [
 // Helpers
 // ---------------------------------------------------------------------------
 
-function formatVND(amount: string | number): string {
-  const num = typeof amount === 'string' ? Number(amount) : amount;
-  if (num === 0) return 'Miễn phí';
-  if (num >= 1_000_000) {
-    const millions = num / 1_000_000;
-    return `${millions % 1 === 0 ? millions.toFixed(0) : millions.toFixed(1)} triệu đ`;
-  }
-  return num.toLocaleString('vi-VN') + ' đ';
-}
-
 // Feature labels mapped for the comparison table
 const FEATURE_LABELS: Record<string, string> = {
   maxListings: 'Tin đăng',
diff --git a/apps/web/components/listings/listing-detail-client.tsx b/apps/web/components/listings/listing-detail-client.tsx
index 7f7b8cc..07ea425 100644
--- a/apps/web/components/listings/listing-detail-client.tsx
+++ b/apps/web/components/listings/listing-detail-client.tsx
@@ -8,6 +8,7 @@ import { Badge } from '@/components/ui/badge';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { AiEstimateButton } from '@/components/valuation/ai-estimate-button';
+import { formatPrice, formatPricePerM2 } from '@/lib/currency';
 import type { ListingDetail } from '@/lib/listings-api';
 import { PROPERTY_TYPES, DIRECTIONS, TRANSACTION_TYPES } from '@/lib/validations/listings';
 
@@ -23,13 +24,6 @@ const ListingMap = dynamic(
   },
 );
 
-function formatPrice(priceVND: string): string {
-  const num = Number(priceVND);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} t\u1ef7`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} tri\u1ec7u`;
-  return num.toLocaleString('vi-VN');
-}
-
 function getLabel(list: readonly { value: string; label: string }[], value: string | null) {
   if (!value) return null;
   return list.find((item) => item.value === value)?.label ?? value;
@@ -79,7 +73,7 @@ export function ListingDetailClient({ listing }: ListingDetailClientProps) {
           <p className="text-2xl font-bold text-primary md:text-3xl">{formatPrice(listing.priceVND)} VND</p>
           {listing.pricePerM2 != null && (
             <p className="text-sm text-muted-foreground">
-              ~{listing.pricePerM2.toLocaleString('vi-VN')} VND/m²
+              ~{formatPricePerM2(listing.pricePerM2)}
             </p>
           )}
           {listing.rentPriceMonthly && (
diff --git a/apps/web/components/search/property-card.tsx b/apps/web/components/search/property-card.tsx
index 79cd0ef..c873830 100644
--- a/apps/web/components/search/property-card.tsx
+++ b/apps/web/components/search/property-card.tsx
@@ -1,18 +1,10 @@
-'use client';
-
 import Image from 'next/image';
 import Link from 'next/link';
 import { Badge } from '@/components/ui/badge';
 import { Card, CardContent } from '@/components/ui/card';
+import { formatPrice } from '@/lib/currency';
 import type { ListingDetail } from '@/lib/listings-api';
 
-function formatPrice(priceVND: string): string {
-  const num = Number(priceVND);
-  if (num >= 1_000_000_000) return `${(num / 1_000_000_000).toFixed(1)} tỷ`;
-  if (num >= 1_000_000) return `${(num / 1_000_000).toFixed(0)} triệu`;
-  return num.toLocaleString('vi-VN');
-}
-
 const PROPERTY_TYPE_LABELS: Record<string, string> = {
   APARTMENT: 'Căn hộ',
   HOUSE: 'Nhà riêng',
diff --git a/apps/web/lib/__tests__/currency.spec.ts b/apps/web/lib/__tests__/currency.spec.ts
new file mode 100644
index 0000000..d1568c1
--- /dev/null
+++ b/apps/web/lib/__tests__/currency.spec.ts
@@ -0,0 +1,125 @@
+import { describe, it, expect } from 'vitest';
+import {
+  formatPrice,
+  formatVND,
+  formatPricePerM2,
+  parseVND,
+} from '../currency';
+
+// ---------------------------------------------------------------------------
+// formatPrice — compact notation without currency suffix
+// ---------------------------------------------------------------------------
+
+describe('formatPrice', () => {
+  it('formats billions as "X ty"', () => {
+    expect(formatPrice(1_000_000_000)).toBe('1 t\u1ef7');
+    expect(formatPrice(1_500_000_000)).toBe('1.5 t\u1ef7');
+    expect(formatPrice(3_500_000_000)).toBe('3.5 t\u1ef7');
+    expect(formatPrice(10_000_000_000)).toBe('10 t\u1ef7');
+  });
+
+  it('formats millions as "X trieu"', () => {
+    expect(formatPrice(1_000_000)).toBe('1 tri\u1ec7u');
+    expect(formatPrice(1_500_000)).toBe('1.5 tri\u1ec7u');
+    expect(formatPrice(150_000_000)).toBe('150 tri\u1ec7u');
+    expect(formatPrice(800_000_000)).toBe('800 tri\u1ec7u');
+    expect(formatPrice(999_000_000)).toBe('999 tri\u1ec7u');
+  });
+
+  it('formats values below 1 million with locale separator', () => {
+    expect(formatPrice(500_000)).toMatch(/500/);
+    expect(formatPrice(1_000)).toMatch(/1/);
+    expect(formatPrice(0)).toBe('0');
+  });
+
+  it('accepts string inputs', () => {
+    expect(formatPrice('3500000000')).toBe('3.5 t\u1ef7');
+    expect(formatPrice('150000000')).toBe('150 tri\u1ec7u');
+  });
+
+  it('handles edge cases gracefully', () => {
+    expect(formatPrice(-1)).toBe('0');
+    expect(formatPrice(NaN)).toBe('0');
+    expect(formatPrice(Infinity)).toBe('0');
+    expect(formatPrice('')).toBe('0');
+  });
+
+  it('strips trailing .0', () => {
+    expect(formatPrice(2_000_000_000)).toBe('2 t\u1ef7');
+    expect(formatPrice(5_000_000)).toBe('5 tri\u1ec7u');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// formatVND — with currency suffix "d"
+// ---------------------------------------------------------------------------
+
+describe('formatVND', () => {
+  it('returns "Mien phi" for zero', () => {
+    expect(formatVND(0)).toBe('Mi\u1ec5n ph\u00ed');
+  });
+
+  it('formats billions with suffix', () => {
+    expect(formatVND(1_500_000_000)).toBe('1.5 t\u1ef7 \u0111');
+  });
+
+  it('formats millions with suffix', () => {
+    expect(formatVND(5_000_000)).toBe('5 tri\u1ec7u \u0111');
+    expect(formatVND(4_990_000)).toBe('5 tri\u1ec7u \u0111');
+  });
+
+  it('formats values below 1 million with suffix', () => {
+    expect(formatVND(500_000)).toMatch(/\u0111$/);
+  });
+
+  it('accepts string input', () => {
+    expect(formatVND('1500000000')).toBe('1.5 t\u1ef7 \u0111');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// formatPricePerM2 — price per square metre
+// ---------------------------------------------------------------------------
+
+describe('formatPricePerM2', () => {
+  it('formats millions as "X tr/m\u00b2"', () => {
+    expect(formatPricePerM2(50_500_000)).toBe('50.5 tr/m\u00b2');
+    expect(formatPricePerM2(1_000_000)).toBe('1 tr/m\u00b2');
+  });
+
+  it('formats billions as "X ty/m\u00b2"', () => {
+    expect(formatPricePerM2(1_500_000_000)).toBe('1.5 t\u1ef7/m\u00b2');
+  });
+
+  it('formats values below 1 million with "/m\u00b2" suffix', () => {
+    expect(formatPricePerM2(500_000)).toMatch(/m\u00b2$/);
+  });
+
+  it('accepts string input', () => {
+    expect(formatPricePerM2('50500000')).toBe('50.5 tr/m\u00b2');
+  });
+
+  it('handles edge cases', () => {
+    expect(formatPricePerM2(0)).toBe('0 \u0111/m\u00b2');
+    expect(formatPricePerM2(-1)).toBe('0 \u0111/m\u00b2');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// parseVND — reverse parse
+// ---------------------------------------------------------------------------
+
+describe('parseVND', () => {
+  it('parses formatted number back', () => {
+    expect(parseVND('500.000')).toBe(500000);
+  });
+
+  it('returns null for empty / non-numeric input', () => {
+    expect(parseVND('')).toBeNull();
+    expect(parseVND('abc')).toBeNull();
+  });
+
+  it('strips non-digit characters', () => {
+    expect(parseVND('1.500.000 \u0111')).toBe(1500000);
+  });
+});
diff --git a/apps/web/lib/currency.ts b/apps/web/lib/currency.ts
new file mode 100644
index 0000000..32af250
--- /dev/null
+++ b/apps/web/lib/currency.ts
@@ -0,0 +1,121 @@
+/**
+ * Vietnamese currency formatting utilities.
+ *
+ * Centralised formatter for all price displays across the platform.
+ * Converts raw VND numbers into human-readable Vietnamese format:
+ *   3,500,000,000 -> "3.5 ty"
+ *   150,000,000   -> "150 trieu"
+ *   800,000       -> "800.000"
+ */
+
+// ---------------------------------------------------------------------------
+// Core formatter
+// ---------------------------------------------------------------------------
+
+/**
+ * Format a VND amount into compact Vietnamese notation.
+ *
+ * @example
+ * formatPrice(3_500_000_000) // "3.5 ty"
+ * formatPrice(150_000_000)   // "150 trieu"
+ * formatPrice(1_500_000)     // "1.5 trieu"
+ * formatPrice(800_000)       // "800.000"
+ * formatPrice("3500000000")  // "3.5 ty" (string input accepted)
+ */
+export function formatPrice(amount: string | number): string {
+  const num = typeof amount === 'string' ? Number(amount) : amount;
+  if (!Number.isFinite(num) || num < 0) return '0';
+
+  if (num >= 1_000_000_000) {
+    const billions = num / 1_000_000_000;
+    return `${stripTrailingZero(billions.toFixed(1))} t\u1ef7`;
+  }
+
+  if (num >= 1_000_000) {
+    const millions = num / 1_000_000;
+    return `${stripTrailingZero(millions.toFixed(1))} tri\u1ec7u`;
+  }
+
+  return num.toLocaleString('vi-VN');
+}
+
+// ---------------------------------------------------------------------------
+// Variant: with currency suffix
+// ---------------------------------------------------------------------------
+
+/**
+ * Format a VND amount with a " \u0111" currency suffix.
+ * Returns "Mi\u1ec5n ph\u00ed" for zero amounts.
+ *
+ * @example
+ * formatVND(4_990_000) // "4.99 trieu d"
+ * formatVND(0)         // "Mien phi"
+ */
+export function formatVND(amount: string | number): string {
+  const num = typeof amount === 'string' ? Number(amount) : amount;
+  if (!Number.isFinite(num) || num < 0) return '0 \u0111';
+  if (num === 0) return 'Mi\u1ec5n ph\u00ed';
+
+  if (num >= 1_000_000_000) {
+    const billions = num / 1_000_000_000;
+    return `${stripTrailingZero(billions.toFixed(1))} t\u1ef7 \u0111`;
+  }
+
+  if (num >= 1_000_000) {
+    const millions = num / 1_000_000;
+    return `${stripTrailingZero(millions.toFixed(1))} tri\u1ec7u \u0111`;
+  }
+
+  return num.toLocaleString('vi-VN') + ' \u0111';
+}
+
+// ---------------------------------------------------------------------------
+// Variant: price per square metre
+// ---------------------------------------------------------------------------
+
+/**
+ * Format a VND/m\u00b2 value.
+ *
+ * @example
+ * formatPricePerM2(50_500_000)  // "50.5 tr/m\u00b2"
+ * formatPricePerM2(500_000)     // "500.000 \u0111/m\u00b2"
+ */
+export function formatPricePerM2(price: string | number): string {
+  const num = typeof price === 'string' ? Number(price) : price;
+  if (!Number.isFinite(num) || num < 0) return '0 \u0111/m\u00b2';
+
+  if (num >= 1_000_000_000) {
+    const billions = num / 1_000_000_000;
+    return `${stripTrailingZero(billions.toFixed(1))} t\u1ef7/m\u00b2`;
+  }
+
+  if (num >= 1_000_000) {
+    const millions = num / 1_000_000;
+    return `${stripTrailingZero(millions.toFixed(1))} tr/m\u00b2`;
+  }
+
+  return `${num.toLocaleString('vi-VN')} \u0111/m\u00b2`;
+}
+
+// ---------------------------------------------------------------------------
+// Parser (reverse direction)
+// ---------------------------------------------------------------------------
+
+/**
+ * Parse a formatted Vietnamese price string back into a number.
+ * Returns `null` if the input cannot be parsed.
+ */
+export function parseVND(formatted: string): number | null {
+  const cleaned = formatted.replace(/[^\d]/g, '');
+  if (cleaned === '') return null;
+  return Number(cleaned);
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/** Remove a trailing ".0" so "3.0 ty" becomes "3 ty". */
+function stripTrailingZero(str: string): string {
+  return str.replace(/\.0$/, '');
+}