Adding login admin, fix ipv6 Vienamese version, add env example

app/api/auth/login/route.ts

@@ -0,0 +1,48 @@
+import { NextResponse } from "next/server";
+import dbConnect from "@/lib/mongodb";
+import User from "@/models/User";
+import crypto from "crypto";
+
+function hashPassword(password: string) {
+  return crypto.createHash("sha256").update(password).digest("hex");
+}
+
+export async function POST(request: Request) {
+  try {
+    await dbConnect();
+    const { email, password } = await request.json();
+
+    // Tìm user và chuẩn hóa email về chữ thường
+    const user = await User.findOne({ email: email.toLowerCase().trim() });
+
+    if (!user) {
+      console.log(`Login failed: User not found -> ${email}`);
+      return NextResponse.json({ error: "Invalid email or password" }, { status: 401 });
+    }
+
+    const inputHash = hashPassword(password);
+    
+    // Kiểm tra mật khẩu (hỗ trợ cả mật khẩu chưa hash nếu lỡ có dữ liệu cũ - nhưng ưu tiên hash)
+    const isMatch = user.password === inputHash || user.password === password;
+
+    if (!isMatch) {
+      console.log(`Login failed: Password mismatch for -> ${email}`);
+      return NextResponse.json({ error: "Invalid email or password" }, { status: 401 });
+    }
+
+    const response = NextResponse.json({ success: true });
+    
+    response.cookies.set("admin_session", "true", {
+      httpOnly: true,
+      secure: process.env.NODE_ENV === "production",
+      sameSite: "lax",
+      path: "/",
+      maxAge: 60 * 60 * 24, 
+    });
+
+    return response;
+  } catch (error) {
+    console.error("Login error:", error);
+    return NextResponse.json({ error: "Internal server error" }, { status: 500 });
+  }
+}