refactor for redundant code

frontend/src/App.jsx

@@ -4,6 +4,7 @@ import {
   Routes,
   Route,
   Navigate,
+  useLocation,
 } from "react-router-dom";
 import Navbar from "./components/Navbar";
 import Home from "./pages/Home";
@@ -12,14 +13,10 @@ import Selling from "./pages/Selling";
 import Transactions from "./pages/Transactions";
 import Favorites from "./pages/Favorites";
 import ProductDetail from "./pages/ProductDetail";
-import SearchPage from "./pages/SearchPage"; // Make sure to import the SearchPage
-import Dashboard from "./pages/Dashboard";
-import UserDashboard from "./pages/UserDashboard";
-import ProductDashboard from "./pages/ProductDashboard";
+import SearchPage from "./pages/SearchPage";
+import Dashboard from "./pages/Dashboard"; // The single consolidated dashboard component
 import DashboardNav from "./components/DashboardNav";
-import CategoryDashboard from "./pages/CategoryDashboard";
 import { verifyIsAdmin } from "./api/admin";
-import TransactionDashboard from "./pages/TransactionDashboard";
 
 function App() {
   // Authentication state - initialize from localStorage if available
@@ -42,6 +39,18 @@ function App() {
     useState(false);
   const [recommendations, setRecommendations] = useState([]);
 
+  // Admin state
+  const [isAdmin, setIsAdmin] = useState(false);
+  const [showAdminDashboard, setShowAdminDashboard] = useState(false);
+
+  // Check URL to determine if we're in admin mode
+  useEffect(() => {
+    // If URL contains /admin, set showAdminDashboard to true
+    if (window.location.pathname.includes("/admin")) {
+      setShowAdminDashboard(true);
+    }
+  }, []);
+
   // New verification states
   const [verificationStep, setVerificationStep] = useState("initial"); // 'initial', 'code-sent', 'verifying'
   const [tempUserData, setTempUserData] = useState(null);
@@ -127,9 +136,6 @@ function App() {
     }
   };
 
-  const [isAdmin, setIsAdmin] = useState(false);
-  const [showAdminDashboard, setShowAdminDashboard] = useState(false);
-
   useEffect(() => {
     const userInfo = sessionStorage.getItem("user")
       ? JSON.parse(sessionStorage.getItem("user"))
@@ -142,9 +148,14 @@ function App() {
 
   const handleShowAdminDashboard = () => {
     setShowAdminDashboard(true);
+    // Update URL without reloading page
+    window.history.pushState({}, "", "/admin");
   };
+
   const handleCloseAdminDashboard = () => {
     setShowAdminDashboard(false);
+    // Update URL without reloading page
+    window.history.pushState({}, "", "/");
   };
 
   // Send verification code
@@ -436,6 +447,7 @@ function App() {
     setVerificationStep("initial");
     setTempUserData(null);
     setRecommendations([]);
+    setShowAdminDashboard(false);
 
     // Clear localStorage
     sessionStorage.removeItem("user");
@@ -774,126 +786,119 @@ function App() {
     return children;
   };
 
-  // If user is admin, show admin naviagtion
-  if (showAdminDashboard) {
-    return (
-      <Router>
+  return (
+    <Router>
+      {/* If admin dashboard should be shown */}
+      {showAdminDashboard ? (
         <div className="flex">
           <DashboardNav handleCloseAdminDashboard={handleCloseAdminDashboard} />
           <Routes>
-            {/* Admin routes */}
-            <Route path="/admin" element={<Dashboard />} />
-            <Route path="/admin/user" element={<UserDashboard />} />
-            <Route path="/admin/product" element={<ProductDashboard />} />
-            <Route path="/admin/category" element={<CategoryDashboard />} />
-            <Route
-              path="/admin/transaction"
-              element={<TransactionDashboard />}
-            />
-            <Route path="*" element={<Dashboard />} />
+            {/* Single admin route for consolidated dashboard */}
+            <Route path="/admin/*" element={<Dashboard />} />
+            {/* Any other path in admin mode should go to dashboard */}
+            <Route path="*" element={<Navigate to="/admin" />} />
           </Routes>
         </div>
-      </Router>
-    );
-  }
+      ) : (
+        /* Normal user interface */
+        <div className="min-h-screen bg-gray-50">
+          {/* Show loading overlay when generating recommendations */}
+          {isGeneratingRecommendations && <LoadingOverlay />}
 
-  return (
-    <Router>
-      <div className="min-h-screen bg-gray-50">
-        {/* Show loading overlay when generating recommendations */}
-        {isGeneratingRecommendations && <LoadingOverlay />}
-
-        {/* Only show navbar when authenticated */}
-        {isAuthenticated && (
-          <Navbar
-            isAdmin={isAdmin}
-            onLogout={handleLogout}
-            userName={user?.name}
-            handleShowAdminDashboard={handleShowAdminDashboard}
-          />
-        )}
-        <Routes>
-          {/* Public routes */}
-          <Route
-            path="/login"
-            element={isAuthenticated ? <Navigate to="/" /> : <LoginComponent />}
-          />
-          {/* Protected routes */}
-          <Route
-            path="/"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <Home recommendations={recommendations} />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/product/:id"
-            element={
-              <ProtectedRoute>
-                <ProductDetail />
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/search"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <SearchPage />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/settings"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <Settings />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/selling"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <Selling />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/transactions"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <Transactions />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          <Route
-            path="/favorites"
-            element={
-              <ProtectedRoute>
-                <div className="container mx-auto px-4 py-6">
-                  <Favorites />
-                </div>
-              </ProtectedRoute>
-            }
-          />
-          {/* Redirect to login for any unmatched routes */}
-          <Route
-            path="*"
-            element={<Navigate to={isAuthenticated ? "/" : "/login"} />}
-          />
-        </Routes>
-      </div>
+          {/* Only show navbar when authenticated */}
+          {isAuthenticated && (
+            <Navbar
+              isAdmin={isAdmin}
+              onLogout={handleLogout}
+              userName={user?.name}
+              handleShowAdminDashboard={handleShowAdminDashboard}
+            />
+          )}
+          <Routes>
+            {/* Public routes */}
+            <Route
+              path="/login"
+              element={
+                isAuthenticated ? <Navigate to="/" /> : <LoginComponent />
+              }
+            />
+            {/* Protected routes */}
+            <Route
+              path="/"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <Home recommendations={recommendations} />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/product/:id"
+              element={
+                <ProtectedRoute>
+                  <ProductDetail />
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/search"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <SearchPage />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/settings"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <Settings />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/selling"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <Selling />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/transactions"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <Transactions />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            <Route
+              path="/favorites"
+              element={
+                <ProtectedRoute>
+                  <div className="container mx-auto px-4 py-6">
+                    <Favorites />
+                  </div>
+                </ProtectedRoute>
+              }
+            />
+            {/* Redirect to login for any unmatched routes */}
+            <Route
+              path="*"
+              element={<Navigate to={isAuthenticated ? "/" : "/login"} />}
+            />
+          </Routes>
+        </div>
+      )}
     </Router>
   );
 }

frontend/src/api/admin.js

@@ -1,77 +1,20 @@
-import client from "./client";
+// api.js
 
+import axios from "axios";
+
+const client = axios.create({
+  baseURL: "http://localhost:3030/api",
+});
+
+// Users
 export const getUsers = async (page, limit = 10) => {
   try {
     const { data } = await client.get(
-      `/user/getUserWithPagination?page=${page}&limit=${limit}`
+      `/user/getUserWithPagination?page=${page}&limit=${limit}`,
     );
     return { users: data.users, total: data.total };
   } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const getProducts = async (page, limit = 10) => {
-  try {
-    const { data } = await client.get(
-      `/product/getProductWithPagination?limit=${limit}&page=${page}`
-    );
-
-    return { products: data.products, total: data.totalProd };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const getCategories = async (page, limit = 10) => {
-  try {
-    const { data } = await client.get(
-      `/category/getCategories?page=${page}&limit=${limit}`
-    );
-    return { data: data.data, total: data.total };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const getTransactions = async (page, limit = 10) => {
-  try {
-    const { data } = await client.get(
-      `/transaction/getTransactions?limit=${limit}&page=${page}`
-    );
-    return { transactions: data.data, total: data.total };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const addCategory = async (name) => {
-  try {
-    const { data } = await client.post(`/category/addCategory`, { name: name });
-    return { message: data.message };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const removeCategory = async (id) => {
-  try {
-    const { data } = await client.delete(`/category/${id}`);
-    return { message: data.message };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
+    return handleError(error);
   }
 };
 
@@ -80,20 +23,7 @@ export const removeUser = async (id) => {
     const { data } = await client.post(`/user/delete`, { userId: id });
     return { message: data.message };
   } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
-  }
-};
-
-export const removeProduct = async (id) => {
-  try {
-    const { data } = await client.delete(`/product/${id}`);
-    return { message: data.message };
-  } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
+    return handleError(error);
   }
 };
 
@@ -102,9 +32,70 @@ export const verifyIsAdmin = async (id) => {
     const { data } = await client.get(`/user/isAdmin/${id}`);
     return { isAdmin: data.isAdmin };
   } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
+    return handleError(error);
+  }
+};
+
+// Products
+export const getProducts = async (page, limit = 10) => {
+  try {
+    const { data } = await client.get(
+      `/product/getProductWithPagination?limit=${limit}&page=${page}`,
+    );
+    return { products: data.products, total: data.totalProd };
+  } catch (error) {
+    return handleError(error);
+  }
+};
+
+export const removeProduct = async (id) => {
+  try {
+    const { data } = await client.delete(`/product/any/${id}`);
+    return { message: data.message };
+  } catch (error) {
+    return handleError(error);
+  }
+};
+
+// Categories
+export const getCategories = async (page, limit = 10) => {
+  try {
+    const { data } = await client.get(
+      `/category/getCategories?page=${page}&limit=${limit}`,
+    );
+    return { data: data.data, total: data.total };
+  } catch (error) {
+    return handleError(error);
+  }
+};
+
+export const addCategory = async (name) => {
+  try {
+    const { data } = await client.post(`/category/addCategory`, { name });
+    return { message: data.message };
+  } catch (error) {
+    return handleError(error);
+  }
+};
+
+export const removeCategory = async (id) => {
+  try {
+    const { data } = await client.delete(`/category/${id}`);
+    return { message: data.message };
+  } catch (error) {
+    return handleError(error);
+  }
+};
+
+// Transactions
+export const getTransactions = async (page, limit = 10) => {
+  try {
+    const { data } = await client.get(
+      `/transaction/getTransactions?limit=${limit}&page=${page}`,
+    );
+    return { transactions: data.data, total: data.total };
+  } catch (error) {
+    return handleError(error);
   }
 };
 
@@ -113,8 +104,16 @@ export const removeTransaction = async (id) => {
     const { data } = await client.delete(`/transaction/${id}`);
     return { message: data.message };
   } catch (error) {
-    const { response } = error;
-    if (response?.data) return response.data;
-    return { error: error.message || error };
+    return handleError(error);
   }
 };
+
+// Shared Error Handler
+const handleError = (error) => {
+  const { response } = error;
+  if (response?.data) return response.data;
+  return { error: error.message || error };
+};
+
+// Optional: export client if you want to use it elsewhere
+export default client;

frontend/src/api/client.js

@@ -1,3 +0,0 @@
-import axios from "axios";
-const client = axios.create({ baseURL: "http://localhost:3030/api" });
-export default client;

frontend/src/components/DashboardNav.jsx

@@ -1,98 +1,15 @@
-import { Link, NavLink } from "react-router-dom";
-import { FaUserTag } from "react-icons/fa";
-import { FaBoxArchive } from "react-icons/fa6";
-import { MdOutlineCategory } from "react-icons/md";
 import { FaArrowLeft } from "react-icons/fa";
-import { FaMoneyBillTransfer } from "react-icons/fa6";
 
 export default function DashboardNav({ handleCloseAdminDashboard }) {
-  const handleClick = () => {
-    handleCloseAdminDashboard();
-  };
-
   return (
-    <div>
-      <div className="w-3xs h-screen bg-green-700 border border-green-700">
-        <ul>
-          <li>
-            <div className="flex-shrink-0 p-6 bg-green-200">
-              <Link to="/admin" className="flex items-center">
-                <img
-                  src="/icon/icon-512.png"
-                  alt="Campus Plug"
-                  className="h-8 px-2 "
-                />
-                <span className="hidden md:block text-green-700 font-bold text-2xl">
-                  Campus Plug
-                </span>
-              </Link>
-            </div>
-          </li>
-          <li className="w-fit pl-10">
-            <NavLink
-              to="/admin/user"
-              className={({ isActive }) =>
-                (isActive
-                  ? " text-green-400"
-                  : "text-white transition-all hover:text-green-200") +
-                " flex items-center px-5 text-lg pt-5 "
-              }
-            >
-              <FaUserTag />
-              <span className="pl-3">Users</span>
-            </NavLink>
-          </li>
-          <li className="w-fit pl-10">
-            <NavLink
-              to="/admin/product"
-              className={({ isActive }) =>
-                (isActive
-                  ? "text-green-400"
-                  : "text-white transition-all hover:text-green-200") +
-                " flex items-center px-5 text-lg pt-5"
-              }
-            >
-              <FaBoxArchive />
-              <span className="pl-3">Products</span>
-            </NavLink>
-          </li>
-          <li className="w-fit pl-10">
-            <NavLink
-              to="/admin/category"
-              className={({ isActive }) =>
-                (isActive
-                  ? "text-green-400"
-                  : "text-white transition-all hover:text-green-200") +
-                " flex items-center px-5 text-lg pt-5"
-              }
-            >
-              <MdOutlineCategory />
-              <span className="pl-3">Categories</span>
-            </NavLink>
-          </li>
-          <li className="w-fit pl-10">
-            <NavLink
-              to="/admin/transaction"
-              className={({ isActive }) =>
-                (isActive
-                  ? "text-green-400"
-                  : "text-white transition-all hover:text-green-200") +
-                " flex items-center px-5 text-lg pt-5"
-              }
-            >
-              <FaMoneyBillTransfer />
-              <span className="pl-3">Transaction</span>
-            </NavLink>
-          </li>
-        </ul>
-        <div
-          onClick={handleClick}
-          className=" text-center my-8 underline text-white underline-offset-4 flex justify-center items-center hover:cursor-pointer h-fit w-fit mx-auto hover:text-green-200 transition"
-        >
-          <FaArrowLeft className="text-sm mx-2 mt-1" />
-          <span>Go back to user page</span>
-        </div>
-      </div>
+    <div className="w-48 min-w-[12rem] bg-gray-100 text-emerald-600 flex flex-col p-4 shadow-md">
+      <button
+        onClick={handleCloseAdminDashboard}
+        className="flex items-center gap-2 text-sm font-medium hover:text-emerald-700 underline underline-offset-4 transition"
+      >
+        <FaArrowLeft className="text-xs mt-[1px]" />
+        Back to User Page
+      </button>
     </div>
   );
 }

frontend/src/pages/CategoryDashboard.jsx

@@ -1,105 +0,0 @@
-import { useEffect, useState } from "react";
-import { getCategories, removeCategory } from "../api/admin";
-import { MdDelete } from "react-icons/md";
-import Pagination from "../components/Pagination";
-import { IoAddCircleSharp } from "react-icons/io5";
-import CategoryForm from "../components/CategoryForm";
-
-export default function CategoryDashboard() {
-  const [categories, setCategories] = useState([]);
-  const [total, setTotal] = useState(0);
-  const [currentPage, setCurrentPage] = useState(1);
-
-  let pageLimit = 10;
-
-  const [visible, setVisible] = useState(false);
-
-  const onChangePage = (page, limit = 10) => {
-    setCurrentPage(page);
-    fetchCategory(page, limit);
-  };
-
-  const fetchCategory = (page = 1, limit = 10) => {
-    getCategories(page, limit).then(({ data, total }) => {
-      setCategories(data);
-      setTotal(total);
-    });
-  };
-
-  const notiChange = () => {
-    fetchCategory(currentPage);
-  };
-
-  const handleToggleForm = () => {
-    setVisible((curr) => !curr);
-  };
-
-  const handleRemove = (id) => {
-    removeCategory(id)
-      .then(() => {
-        fetchCategory(currentPage);
-      })
-      .catch((err) => {
-        console.log(err);
-      });
-  };
-
-  //Get user when initialize the component
-  useEffect(fetchCategory, []);
-
-  return (
-    <div className="pt-10 p-20 w-full">
-      <h1 className="text-4xl pb-3 font-bold text-green-800 underline">
-        CATEGORIES
-      </h1>
-      <button
-        onClick={handleToggleForm}
-        className="flex justify-end items-center bg-blue-500 rounded-md px-2 text-white text-sm p-1 mb-1 ml-auto hover:cursor-pointer hover:bg-blue-600 transtion"
-      >
-        <span className="pr-1 text-xs">Add</span>
-        <IoAddCircleSharp />
-      </button>
-      <CategoryForm onAddCategory={notiChange} visible={visible} />
-      {categories.length > 0 ? (
-        <>
-          <table className="table-fixed w-full text-center border border-green-600">
-            <thead className="bg-green-600 h-10">
-              <tr>
-                <th>CategoryID</th>
-                <th>Name</th>
-                <th>Action</th>
-              </tr>
-            </thead>
-            <tbody>
-              {categories.map((category) => (
-                <tr
-                  key={category.UserID}
-                  className="border border-green-600 h-10"
-                >
-                  <td>{category.CategoryID}</td>
-                  <td>{category.Name}</td>
-                  <td className="flex justify-center pt-2">
-                    <MdDelete
-                      onClick={() => {
-                        handleRemove(category.CategoryID);
-                      }}
-                      className="hover:text-red-600 cursor-pointer transition-all text-xl"
-                    />
-                  </td>
-                </tr>
-              ))}
-            </tbody>
-          </table>
-          <Pagination
-            pageNum={Math.ceil(total / pageLimit)}
-            onChange={onChangePage}
-          />
-        </>
-      ) : (
-        <p className="text-red-700 text-xl bg-red-200 px-3 rounded-md py-1 w-fit">
-          No category exists!
-        </p>
-      )}
-    </div>
-  );
-}

frontend/src/pages/Dashboard.jsx

@@ -1,7 +1,362 @@
-export default function Dashboard() {
+import { useEffect, useState, useCallback } from "react";
+import {
+  getUsers,
+  removeUser,
+  getTransactions,
+  removeTransaction,
+  getProducts,
+  removeProduct,
+  getCategories,
+  removeCategory,
+} from "../api/admin";
+import { MdDelete } from "react-icons/md";
+import { IoAddCircleSharp } from "react-icons/io5";
+import { FaHome } from "react-icons/fa";
+import Pagination from "../components/Pagination";
+import CategoryForm from "../components/CategoryForm";
+import DashboardNav from "../components/DashboardNav";
+import { useNavigate } from "react-router-dom";
+
+// Spinner Component
+const Spinner = () => (
+  <div className="flex justify-center items-center h-40 w-full">
+    <div className="w-12 h-12 border-4 border-green-500 border-dashed rounded-full animate-spin"></div>
+  </div>
+);
+
+// Empty State Component
+const EmptyState = () => (
+  <div className="flex flex-col items-center justify-center bg-gray-50 py-10 rounded-lg w-full">
+    <svg
+      className="w-16 h-16 text-gray-400"
+      fill="none"
+      stroke="currentColor"
+      viewBox="0 0 24 24"
+      xmlns="http://www.w3.org/2000/svg"
+    >
+      <path
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        strokeWidth="2"
+        d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"
+      ></path>
+    </svg>
+    <p className="mt-4 text-lg font-medium text-gray-600">No data found</p>
+    <p className="mt-1 text-sm text-gray-500">
+      No records are currently available.
+    </p>
+  </div>
+);
+
+// Generic Dashboard Component
+const Dashboard = ({
+  fetchDataFn,
+  deleteFn,
+  columns,
+  idKey,
+  refreshKey = 0,
+  headerAction = null,
+}) => {
+  const navigate = useNavigate();
+  const [items, setItems] = useState([]);
+  const [total, setTotal] = useState(0);
+  const [currentPage, setCurrentPage] = useState(1);
+  const [loading, setLoading] = useState(true);
+  const pageLimit = 10;
+
+  const fetchItems = useCallback(
+    (page = 1, limit = 10) => {
+      setLoading(true);
+      fetchDataFn(page, limit)
+        .then((res) => {
+          const data =
+            res.users || res.products || res.transactions || res.data || [];
+          setItems(data);
+          setTotal(res.total);
+        })
+        .catch((error) => {
+          console.error("Error fetching data:", error);
+          setItems([]);
+          setTotal(0);
+        })
+        .finally(() => setLoading(false));
+    },
+    [fetchDataFn],
+  );
+
+  const handleRemove = (id) => {
+    if (window.confirm("Are you sure you want to delete this item?")) {
+      setLoading(true);
+      deleteFn(id)
+        .then(() => fetchItems(currentPage))
+        .catch((error) => {
+          console.error("Error removing item:", error);
+          setLoading(false);
+        });
+    }
+  };
+
+  useEffect(() => {
+    fetchItems(currentPage);
+  }, [fetchItems, currentPage, refreshKey]);
+
+  const onChangePage = (page) => {
+    setCurrentPage(page);
+  };
+
+  if (loading) return <Spinner />;
+
   return (
-    <div className="text-3xl font-bold p-3 text-green-800">
-      Welcome to admin dashboard
+    <div className="w-full mt-6">
+      <div className="flex flex-col md:flex-row justify-between items-center mb-4 w-full">
+        <h2 className="text-xl font-semibold text-gray-700 mb-2 md:mb-0">
+          Total: <span className="text-green-600">{total}</span>
+        </h2>
+        {headerAction && <div>{headerAction}</div>}
+      </div>
+
+      {items.length > 0 ? (
+        <div className="w-full overflow-x-auto bg-white rounded-lg shadow">
+          <table className="min-w-full divide-y divide-gray-200 table-fixed">
+            <thead className="bg-green-600">
+              <tr>
+                {columns.map((col) => (
+                  <th
+                    key={col.label}
+                    scope="col"
+                    className="px-6 py-3 text-left text-xs font-medium text-white uppercase tracking-wider"
+                  >
+                    {col.label}
+                  </th>
+                ))}
+                <th
+                  scope="col"
+                  className="px-6 py-3 text-center text-xs font-medium text-white uppercase tracking-wider w-20"
+                >
+                  Action
+                </th>
+              </tr>
+            </thead>
+            <tbody className="bg-white divide-y divide-gray-200">
+              {items.map((item) => (
+                <tr
+                  key={item[idKey]}
+                  className="hover:bg-gray-50 transition-colors"
+                >
+                  {columns.map((col) => (
+                    <td
+                      key={`${item[idKey]}-${col.key}`}
+                      className="px-6 py-4 whitespace-nowrap text-sm text-gray-700 overflow-hidden text-ellipsis"
+                    >
+                      {item[col.key] || "—"}
+                    </td>
+                  ))}
+                  <td className="px-6 py-4 whitespace-nowrap text-center text-sm font-medium">
+                    <button
+                      onClick={() => handleRemove(item[idKey])}
+                      className="text-red-500 hover:text-red-700 transition-colors"
+                      title="Delete"
+                    >
+                      <MdDelete size={20} />
+                    </button>
+                  </td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        </div>
+      ) : (
+        <EmptyState />
+      )}
+
+      {total > pageLimit && (
+        <div className="mt-4 w-full">
+          <Pagination
+            pageNum={Math.ceil(total / pageLimit)}
+            onChange={onChangePage}
+          />
+        </div>
+      )}
+    </div>
+  );
+};
+
+// Main Admin Tabs
+export default function AdminDashboardTabs() {
+  const [activeTab, setActiveTab] = useState(0);
+  const [tabData, setTabData] = useState({
+    users: { loaded: false, data: null },
+    products: { loaded: false, data: null },
+    transactions: { loaded: false, data: null },
+    categories: { loaded: false, data: null },
+  });
+
+  const [visible, setVisible] = useState(false);
+  const [categoryRefreshKey, setCategoryRefreshKey] = useState(0);
+  const toggleForm = () => setVisible((v) => !v);
+
+  // Preload all tab data
+  useEffect(() => {
+    const tabKeys = ["users", "products", "transactions", "categories"];
+    const loadTabData = async (index) => {
+      if (index === tabKeys.length) return;
+
+      setTabData((prev) => ({
+        ...prev,
+        [tabKeys[index]]: { ...prev[tabKeys[index]], loaded: true },
+      }));
+
+      // Load next tab after a short delay
+      setTimeout(() => loadTabData(index + 1), 100);
+    };
+
+    loadTabData(0);
+  }, []);
+
+  const tabs = [
+    {
+      title: "Users",
+      icon: "👥",
+      key: "users",
+      component: () => (
+        <Dashboard
+          fetchDataFn={getUsers}
+          deleteFn={removeUser}
+          idKey="UserID"
+          columns={[
+            { label: "ID", key: "UserID" },
+            { label: "UCID", key: "UCID" },
+            { label: "Name", key: "Name" },
+            { label: "Email", key: "Email" },
+            { label: "Phone", key: "Phone" },
+            { label: "Address", key: "Address" },
+          ]}
+        />
+      ),
+    },
+    {
+      title: "Products",
+      icon: "📦",
+      key: "products",
+      component: () => (
+        <Dashboard
+          fetchDataFn={getProducts}
+          deleteFn={removeProduct}
+          idKey="ProductID"
+          columns={[
+            { label: "ID", key: "ProductID" },
+            { label: "Name", key: "ProductName" },
+            { label: "Price", key: "Price" },
+            { label: "Category", key: "Category" },
+            { label: "Seller", key: "SellerName" },
+          ]}
+        />
+      ),
+    },
+    {
+      title: "Transactions",
+      icon: "💰",
+      key: "transactions",
+      component: () => (
+        <Dashboard
+          fetchDataFn={getTransactions}
+          deleteFn={removeTransaction}
+          idKey="TransactionID"
+          columns={[
+            { label: "ID", key: "TransactionID" },
+            { label: "User", key: "UserName" },
+            { label: "Product", key: "ProductName" },
+            { label: "Date", key: "Date" },
+            { label: "Status", key: "PaymentStatus" },
+          ]}
+        />
+      ),
+    },
+    {
+      title: "Categories",
+      icon: "🏷️",
+      key: "categories",
+      component: () => (
+        <>
+          <Dashboard
+            fetchDataFn={getCategories}
+            deleteFn={removeCategory}
+            idKey="CategoryID"
+            columns={[
+              { label: "ID", key: "CategoryID" },
+              { label: "Name", key: "Name" },
+            ]}
+            refreshKey={categoryRefreshKey}
+            headerAction={
+              <button
+                onClick={toggleForm}
+                className="flex items-center bg-green-500 rounded-md px-4 py-2 text-white text-sm hover:bg-green-600 transition-colors font-medium shadow"
+              >
+                <IoAddCircleSharp className="mr-1" size={18} />
+                Add Category
+              </button>
+            }
+          />
+          <CategoryForm
+            visible={visible}
+            onAddCategory={() => {
+              setCategoryRefreshKey((prev) => prev + 1);
+              toggleForm();
+            }}
+          />
+        </>
+      ),
+    },
+  ];
+
+  return (
+    <div className="w-full min-h-screen bg-gray-50">
+      <div className="w-full px-4 py-8">
+        <div className="mb-8 flex justify-between items-center w-full">
+          <h1 className="text-2xl md:text-3xl font-bold text-gray-800">
+            Admin Dashboard
+          </h1>
+        </div>
+
+        {/* Mobile Tabs */}
+        <div className="md:hidden w-full mb-4">
+          <select
+            className="w-full rounded-md border-gray-300 shadow-sm focus:border-green-500 focus:ring focus:ring-green-500 focus:ring-opacity-50 p-2"
+            value={activeTab}
+            onChange={(e) => setActiveTab(parseInt(e.target.value))}
+          >
+            {tabs.map((tab, index) => (
+              <option key={tab.key} value={index}>
+                {tab.icon} {tab.title}
+              </option>
+            ))}
+          </select>
+        </div>
+
+        {/* Desktop Tabs */}
+        <div className="hidden md:flex space-x-1 border-b border-gray-200 w-full overflow-x-auto">
+          {tabs.map((tab, index) => (
+            <button
+              key={tab.key}
+              className={`px-6 py-3 font-medium text-sm rounded-t-lg transition-colors ${
+                index === activeTab
+                  ? "text-green-700 bg-white border-l border-t border-r border-gray-200 border-b-0"
+                  : "text-gray-600 hover:text-green-700 bg-gray-50"
+              }`}
+              onClick={() => setActiveTab(index)}
+            >
+              <span className="inline-block mr-2">{tab.icon}</span>
+              {tab.title}
+            </button>
+          ))}
+        </div>
+
+        <div className="bg-white p-4 md:p-6 rounded-lg shadow-sm border border-gray-200 mt-4 w-full">
+          <div className="w-full">
+            {tabData[tabs[activeTab].key].loaded && tabs[activeTab].component()}
+          </div>
+        </div>
+      </div>
     </div>
   );
 }

frontend/src/pages/ProductDashboard.jsx

@@ -1,91 +0,0 @@
-import { useEffect, useState } from "react";
-import { getProducts, removeProduct } from "../api/admin";
-import { MdDelete } from "react-icons/md";
-import Pagination from "../components/Pagination";
-
-export default function ProductDashboard() {
-  const [products, setProducts] = useState([]);
-  const [total, setTotal] = useState(0);
-  const [currentPage, setCurrentPage] = useState(1);
-
-  let pageLimit = 10;
-
-  const onChangePage = (page, limit = 10) => {
-    setCurrentPage(page);
-    fetchProducts(page, limit);
-  };
-
-  const fetchProducts = (page = 1, limit = 10) => {
-    getProducts(page, limit).then(({ products, total }) => {
-      setTotal(total);
-      setProducts(products);
-    });
-  };
-
-  const handleRemoveProduct = (id) => {
-    removeProduct(id)
-      .then((res) => {
-        fetchProducts(currentPage);
-      })
-      .catch((err) => {
-        console.log(err);
-      });
-  };
-
-  //Get user when initialize the component
-  useEffect(fetchProducts, []);
-
-  return (
-    <div className="pt-10 p-20">
-      <h1 className="text-4xl pb-3 font-bold text-green-800 underline">
-        PRODUCTS
-      </h1>
-      {products.length > 0 ? (
-        <>
-          <table className="table-fixed w-full text-center border border-green-600">
-            <thead className="bg-green-600 h-10">
-              <tr>
-                <th>ProductID</th>
-                <th>Name</th>
-                <th>Price</th>
-                <th>Category</th>
-                <th>Seller</th>
-                <th>Action</th>
-              </tr>
-            </thead>
-            <tbody>
-              {products.map((product) => (
-                <tr
-                  key={product.ProductID}
-                  className="border border-green-600 h-10"
-                >
-                  <td>{product.ProductID}</td>
-                  <td>{product.ProductName}</td>
-                  <td>{product.Price}</td>
-                  <td>{product.Category ? product.Category : "N/A"}</td>
-                  <td>{product.SellerName ? product.SellerName : "N/A"}</td>
-                  <td className="flex justify-center pt-2">
-                    <MdDelete
-                      onClick={() => {
-                        handleRemoveProduct(product.ProductID);
-                      }}
-                      className="hover:text-red-600 cursor-pointer transition-all text-xl"
-                    />
-                  </td>
-                </tr>
-              ))}
-            </tbody>
-          </table>
-          <Pagination
-            onChange={onChangePage}
-            pageNum={Math.ceil(total / pageLimit)}
-          />
-        </>
-      ) : (
-        <p className="text-red-700 text-xl bg-red-200 px-3 rounded-md py-1 w-fit">
-          No product exists!
-        </p>
-      )}
-    </div>
-  );
-}

frontend/src/pages/TransactionDashboard.jsx

@@ -1,91 +0,0 @@
-import { useEffect, useState } from "react";
-import { getTransactions, removeTransaction } from "../api/admin";
-import { MdDelete } from "react-icons/md";
-import Pagination from "../components/Pagination";
-
-export default function TransactionDashboard() {
-  const [transactions, setTransactions] = useState([]);
-  const [total, setTotal] = useState(0);
-  const [currentPage, setCurrentPage] = useState(1);
-
-  let pageLimit = 10;
-
-  const onChangePage = (page, limit = 10) => {
-    setCurrentPage(page);
-    fetchTransactions(page, limit);
-  };
-
-  const fetchTransactions = (page = 1, limit = 10) => {
-    getTransactions(page, limit).then(({ transactions, total }) => {
-      setTotal(total);
-      setTransactions(transactions);
-    });
-  };
-
-  const handleRemoveTransaction = (id) => {
-    removeTransaction(id)
-      .then(() => {
-        fetchTransactions(currentPage);
-      })
-      .catch((err) => {
-        console.log(err);
-      });
-  };
-
-  //Get user when initialize the component
-  useEffect(fetchTransactions, []);
-
-  return (
-    <div className="pt-10 p-20">
-      <h1 className="text-4xl pb-3 font-bold text-green-800 underline">
-        TRANSACTIONS
-      </h1>
-      {transactions.length > 0 ? (
-        <>
-          <table className="table-fixed w-full text-center border border-green-600">
-            <thead className="bg-green-600 h-10">
-              <tr>
-                <th>TransactionID</th>
-                <th>User</th>
-                <th>Product</th>
-                <th>Date</th>
-                <th>Status</th>
-                <th>Action</th>
-              </tr>
-            </thead>
-            <tbody>
-              {transactions.map((t) => (
-                <tr
-                  key={t.TransactionID}
-                  className="border border-green-600 h-10"
-                >
-                  <td>{t.TransactionID}</td>
-                  <td>{t.UserName ? t.UserName : "N/A"}</td>
-                  <td>{t.ProductName ? t.ProductName : "N/A"}</td>
-                  <td>{t.Date}</td>
-                  <td>{t.PaymentStatus}</td>
-                  <td className="flex justify-center pt-2">
-                    <MdDelete
-                      onClick={() => {
-                        handleRemoveTransaction(t.TransactionID);
-                      }}
-                      className="hover:text-red-600 cursor-pointer transition-all text-xl"
-                    />
-                  </td>
-                </tr>
-              ))}
-            </tbody>
-          </table>
-          <Pagination
-            onChange={onChangePage}
-            pageNum={Math.ceil(total / pageLimit)}
-          />
-        </>
-      ) : (
-        <p className="text-red-700 text-xl bg-red-200 px-3 rounded-md py-1 w-fit">
-          No transaction exists!
-        </p>
-      )}
-    </div>
-  );
-}

frontend/src/pages/UserDashboard.jsx

@@ -1,91 +0,0 @@
-import { useEffect, useState } from "react";
-import { getUsers, removeUser } from "../api/admin";
-import { MdDelete } from "react-icons/md";
-import Pagination from "../components/Pagination";
-
-export default function UserDashboard() {
-  const [users, setUsers] = useState([]);
-  const [total, setTotal] = useState(0);
-  const [currentPage, setCurrentPage] = useState(1);
-
-  let pageLimit = 10;
-
-  const onChangePage = (page, limit = 10) => {
-    setCurrentPage(page);
-    fetchUsers(page, limit);
-  };
-
-  const fetchUsers = (page = 1, limit = 10) => {
-    getUsers(page, limit).then(({ users, total }) => {
-      setUsers(users);
-      setTotal(total);
-    });
-  };
-
-  const handleRemoveUser = (id) => {
-    removeUser(id)
-      .then((res) => {
-        fetchUsers(currentPage);
-      })
-      .catch((err) => {
-        console.log(err);
-      });
-  };
-
-  //Get user when initialize the component
-  useEffect(fetchUsers, []);
-
-  return (
-    <div className="pt-10 p-20">
-      <h1 className="text-4xl pb-3 font-bold text-green-800 underline">
-        USERS
-      </h1>
-      {users.length > 0 ? (
-        <>
-          {" "}
-          <table className="table-fixed w-full text-center border border-green-600">
-            <thead className="bg-green-600 h-10">
-              <tr>
-                <th>UserID</th>
-                <th>UCID</th>
-                <th>Name</th>
-                <th>Email</th>
-                <th>Phone</th>
-                <th>Address</th>
-                <th>Action</th>
-              </tr>
-            </thead>
-            <tbody>
-              {users.map((user) => (
-                <tr key={user.UserID} className="border border-green-600 h-10">
-                  <td>{user.UserID}</td>
-                  <td>{user.UCID}</td>
-                  <td>{user.Name}</td>
-                  <td>{user.Email}</td>
-                  <td>{user.Phone}</td>
-                  <td>{user.Address}</td>
-                  <td className="flex justify-center pt-2">
-                    <MdDelete
-                      onClick={() => {
-                        handleRemoveUser(user.UserID);
-                      }}
-                      className="hover:text-red-600 cursor-pointer transition-all text-xl"
-                    />
-                  </td>
-                </tr>
-              ))}
-            </tbody>
-          </table>
-          <Pagination
-            pageNum={Math.ceil(total / pageLimit)}
-            onChange={onChangePage}
-          />
-        </>
-      ) : (
-        <p className="text-red-700 text-xl bg-red-200 px-3 rounded-md py-1">
-          No user exists!
-        </p>
-      )}
-    </div>
-  );
-}

frontend/src/schema.sql

@@ -0,0 +1,124 @@
+-- MySql Version 9.2.0
+CREATE DATABASE Marketplace;
+
+USE Marketplace;
+
+-- User Entity
+CREATE TABLE User (
+    UserID INT AUTO_INCREMENT PRIMARY KEY,
+    Name VARCHAR(100) NOT NULL,
+    Email VARCHAR(100) UNIQUE NOT NULL,
+    UCID VARCHAR(20) UNIQUE NOT NULL,
+    Password VARCHAR(255) NOT NULL,
+    Phone VARCHAR(20),
+    Address VARCHAR(255)
+);
+
+CREATE TABLE UserRole (
+    UserID INT,
+    Client BOOLEAN DEFAULT True,
+    Admin BOOLEAN DEFAULT FALSE,
+    PRIMARY KEY (UserID),
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE
+);
+
+-- Category Entity (must be created before Product or else error)
+CREATE TABLE Category (
+    CategoryID INT AUTO_INCREMENT PRIMARY KEY,
+    Name VARCHAR(255) NOT NULL
+);
+
+-- Product Entity
+CREATE TABLE Product (
+    ProductID INT AUTO_INCREMENT PRIMARY KEY,
+    Name VARCHAR(255) NOT NULL,
+    Price DECIMAL(10, 2) NOT NULL,
+    StockQuantity INT,
+    UserID INT,
+    Description TEXT,
+    CategoryID INT NOT NULL,
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (CategoryID) REFERENCES Category (CategoryID) ON DELETE SET NULL
+);
+
+-- Fixed Image_URL table
+CREATE TABLE Image_URL (
+    URL VARCHAR(255),
+    ProductID INT,
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE
+);
+
+-- Fixed Review Entity (Many-to-One with User, Many-to-One with Product)
+CREATE TABLE Review (
+    ReviewID INT AUTO_INCREMENT PRIMARY KEY,
+    UserID INT,
+    ProductID INT,
+    Comment TEXT,
+    Rating INT CHECK (
+        Rating >= 1
+        AND Rating <= 5
+    ),
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE
+);
+
+-- Transaction Entity (Many-to-One with User, Many-to-One with Product)
+CREATE TABLE Transaction (
+    TransactionID INT PRIMARY KEY,
+    UserID INT,
+    ProductID INT,
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP,
+    PaymentStatus VARCHAR(50),
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE 
+);
+
+-- Recommendation Entity (Many-to-One with User, Many-to-One with Product)
+CREATE TABLE Recommendation (
+    RecommendationID_PK INT AUTO_INCREMENT PRIMARY KEY,
+    UserID INT,
+    RecommendedProductID INT,
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (RecommendedProductID) REFERENCES Product (ProductID) ON DELETE CASCADE
+);
+
+-- History Entity (Many-to-One with User, Many-to-One with Product)
+CREATE TABLE History (
+    HistoryID INT AUTO_INCREMENT PRIMARY KEY,
+    UserID INT,
+    ProductID INT,
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE
+);
+
+-- Favorites Entity (Many-to-One with User, Many-to-One with Product)
+CREATE TABLE Favorites (
+    FavoriteID INT AUTO_INCREMENT PRIMARY KEY,
+    UserID INT,
+    ProductID INT,
+    FOREIGN KEY (UserID) REFERENCES User (UserID) ON DELETE CASCADE,
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE,
+    UNIQUE (UserID, ProductID)
+);
+
+-- Product-Category Junction Table (Many-to-Many)
+CREATE TABLE Product_Category (
+    ProductID INT,
+    CategoryID INT,
+    PRIMARY KEY (ProductID, CategoryID),
+    FOREIGN KEY (ProductID) REFERENCES Product (ProductID) ON DELETE CASCADE,
+    FOREIGN KEY (CategoryID) REFERENCES Category (CategoryID) ON DELETE CASCADE
+);
+
+-- Login Authentication table
+CREATE TABLE AuthVerification (
+    UserID INT AUTO_INCREMENT PRIMARY KEY,
+    Email VARCHAR(100) UNIQUE NOT NULL,
+    VerificationCode VARCHAR(6) NOT NULL,
+    Authenticated BOOLEAN DEFAULT FALSE,
+    Date DATETIME DEFAULT CURRENT_TIMESTAMP
+);