thực hiện phân quyền admin giáo viên và học sinh xong

frontend/src/app/admin/page.tsx

@@ -0,0 +1,338 @@
+"use client";
+
+import { useCallback, useEffect, useState } from "react";
+import { useRouter } from "next/navigation";
+import { api } from "@/lib/api";
+import type { User, UserRole, UserStatus } from "@/types";
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+const STATUS_LABELS: Record<UserStatus, string> = {
+  pending: "Chờ duyệt",
+  approved: "Đã duyệt",
+  rejected: "Từ chối",
+};
+
+const ROLE_LABELS: Record<UserRole, string> = {
+  admin: "Admin",
+  teacher: "Giáo viên",
+  student: "Học viên",
+};
+
+const STATUS_COLORS: Record<UserStatus, string> = {
+  pending: "bg-yellow-100 text-yellow-800",
+  approved: "bg-green-100 text-green-800",
+  rejected: "bg-red-100 text-red-800",
+};
+
+const ROLE_COLORS: Record<UserRole, string> = {
+  admin: "bg-purple-100 text-purple-800",
+  teacher: "bg-blue-100 text-blue-800",
+  student: "bg-gray-100 text-gray-700",
+};
+
+// ── Page ──────────────────────────────────────────────────────────────────────
+
+export default function AdminPage() {
+  const router = useRouter();
+  const [me, setMe] = useState<User | null>(null);
+  const [users, setUsers] = useState<User[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState("");
+  const [busy, setBusy] = useState<number | null>(null); // userId being mutated
+  const [filterStatus, setFilterStatus] = useState<UserStatus | "all">("all");
+  const [filterRole, setFilterRole] = useState<UserRole | "all">("all");
+  const [search, setSearch] = useState("");
+
+  // ── Auth guard: admin only ─────────────────────────────────────────────────
+  useEffect(() => {
+    async function init() {
+      try {
+        const me = await api.me();
+        if (me.role !== "admin") { router.replace("/dashboard"); return; }
+        setMe(me);
+        const list = await api.adminListUsers();
+        setUsers(list);
+      } catch {
+        router.replace("/login");
+      } finally {
+        setLoading(false);
+      }
+    }
+    init();
+  }, [router]);
+
+  // ── Mutate helpers ─────────────────────────────────────────────────────────
+  const updateUser = useCallback((updated: User) => {
+    setUsers(prev => prev.map(u => u.id === updated.id ? updated : u));
+  }, []);
+
+  const handleStatusChange = useCallback(async (userId: number, status: UserStatus) => {
+    setBusy(userId);
+    try {
+      const updated = await api.adminUpdateStatus(userId, status);
+      updateUser(updated);
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : "Failed to update status.");
+    } finally {
+      setBusy(null);
+    }
+  }, [updateUser]);
+
+  const handleRoleChange = useCallback(async (userId: number, role: UserRole) => {
+    setBusy(userId);
+    try {
+      const updated = await api.adminUpdateRole(userId, role);
+      updateUser(updated);
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : "Failed to update role.");
+    } finally {
+      setBusy(null);
+    }
+  }, [updateUser]);
+
+  const handleDelete = useCallback(async (userId: number, username: string) => {
+    if (!confirm(`Xoá tài khoản "${username}" và toàn bộ dữ liệu? Không thể hoàn tác.`)) return;
+    setBusy(userId);
+    try {
+      await api.adminDeleteUser(userId);
+      setUsers(prev => prev.filter(u => u.id !== userId));
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : "Failed to delete user.");
+    } finally {
+      setBusy(null);
+    }
+  }, []);
+
+  // ── Filtered list ──────────────────────────────────────────────────────────
+  const filtered = users.filter(u => {
+    if (filterStatus !== "all" && u.status !== filterStatus) return false;
+    if (filterRole !== "all" && u.role !== filterRole) return false;
+    if (search) {
+      const q = search.toLowerCase();
+      if (!u.username.toLowerCase().includes(q) && !u.email.toLowerCase().includes(q)) return false;
+    }
+    return true;
+  });
+
+  const pendingCount = users.filter(u => u.status === "pending").length;
+
+  // ── Loading ────────────────────────────────────────────────────────────────
+  if (loading) {
+    return (
+      <div className="min-h-screen flex items-center justify-center">
+        <svg className="animate-spin h-8 w-8 text-blue-500" viewBox="0 0 24 24" fill="none">
+          <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v4a4 4 0 00-4 4H4z" />
+        </svg>
+      </div>
+    );
+  }
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      {/* ── Navbar ──────────────────────────────────────────────────────────── */}
+      <header className="bg-white border-b shadow-sm sticky top-0 z-10">
+        <div className="max-w-7xl mx-auto px-4 py-3 flex items-center justify-between">
+          <div className="flex items-center gap-3">
+            <button
+              onClick={() => router.push("/dashboard")}
+              className="text-gray-400 hover:text-blue-600 transition"
+              title="Về Dashboard"
+            >
+              <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 19l-7-7 7-7" />
+              </svg>
+            </button>
+            <span className="font-bold text-lg text-blue-600">PDF LMS</span>
+            <span className="text-xs bg-purple-100 text-purple-700 font-semibold px-2 py-0.5 rounded-full">
+              Admin
+            </span>
+          </div>
+          <div className="flex items-center gap-3">
+            <span className="text-sm text-gray-500 hidden sm:block">{me?.username}</span>
+            <button
+              onClick={async () => { await api.logout(); router.replace("/login"); }}
+              className="text-sm text-gray-500 hover:text-red-600 transition"
+            >
+              Đăng xuất
+            </button>
+          </div>
+        </div>
+      </header>
+
+      <main className="max-w-7xl mx-auto px-4 py-8">
+        {/* ── Page title + stats ─────────────────────────────────────────────── */}
+        <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4 mb-8">
+          <div>
+            <h1 className="text-2xl font-bold text-gray-900">Quản lý người dùng</h1>
+            <p className="text-sm text-gray-500 mt-0.5">{users.length} tài khoản tổng cộng</p>
+          </div>
+          {pendingCount > 0 && (
+            <div
+              className="flex items-center gap-2 bg-yellow-50 border border-yellow-200 text-yellow-800 px-4 py-2 rounded-lg text-sm font-medium cursor-pointer hover:bg-yellow-100 transition"
+              onClick={() => setFilterStatus("pending")}
+            >
+              <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2}
+                  d="M12 9v2m0 4h.01M10.29 3.86L1.82 18a2 2 0 001.71 3h16.94a2 2 0 001.71-3L13.71 3.86a2 2 0 00-3.42 0z" />
+              </svg>
+              {pendingCount} tài khoản chờ duyệt
+            </div>
+          )}
+        </div>
+
+        {/* ── Error banner ──────────────────────────────────────────────────── */}
+        {error && (
+          <div className="mb-4 bg-red-50 border border-red-200 text-red-700 text-sm px-4 py-3 rounded-lg flex items-center justify-between">
+            {error}
+            <button onClick={() => setError("")} className="ml-3 text-red-400 hover:text-red-600">✕</button>
+          </div>
+        )}
+
+        {/* ── Filters ───────────────────────────────────────────────────────── */}
+        <div className="bg-white border border-gray-200 rounded-xl p-4 mb-4 flex flex-col sm:flex-row gap-3">
+          <input
+            type="text"
+            placeholder="Tìm theo username / email…"
+            value={search}
+            onChange={e => setSearch(e.target.value)}
+            className="flex-1 text-sm border border-gray-300 rounded-lg px-3 py-2 focus:outline-none focus:border-blue-500"
+          />
+          <select
+            value={filterStatus}
+            onChange={e => setFilterStatus(e.target.value as UserStatus | "all")}
+            className="text-sm border border-gray-300 rounded-lg px-3 py-2 focus:outline-none focus:border-blue-500"
+          >
+            <option value="all">Tất cả trạng thái</option>
+            <option value="pending">Chờ duyệt</option>
+            <option value="approved">Đã duyệt</option>
+            <option value="rejected">Từ chối</option>
+          </select>
+          <select
+            value={filterRole}
+            onChange={e => setFilterRole(e.target.value as UserRole | "all")}
+            className="text-sm border border-gray-300 rounded-lg px-3 py-2 focus:outline-none focus:border-blue-500"
+          >
+            <option value="all">Tất cả vai trò</option>
+            <option value="admin">Admin</option>
+            <option value="teacher">Giáo viên</option>
+            <option value="student">Học viên</option>
+          </select>
+          {(filterStatus !== "all" || filterRole !== "all" || search) && (
+            <button
+              onClick={() => { setFilterStatus("all"); setFilterRole("all"); setSearch(""); }}
+              className="text-sm text-gray-500 hover:text-red-600 transition px-2"
+            >
+              Xoá lọc
+            </button>
+          )}
+        </div>
+
+        {/* ── Table ────────────────────────────────────────────────────────── */}
+        <div className="bg-white border border-gray-200 rounded-xl overflow-hidden shadow-sm">
+          {filtered.length === 0 ? (
+            <div className="text-center text-gray-400 text-sm py-16">Không tìm thấy tài khoản nào.</div>
+          ) : (
+            <div className="overflow-x-auto">
+              <table className="w-full text-sm">
+                <thead>
+                  <tr className="bg-gray-50 border-b border-gray-200 text-left text-xs font-semibold text-gray-500 uppercase tracking-wider">
+                    <th className="px-4 py-3">ID</th>
+                    <th className="px-4 py-3">Người dùng</th>
+                    <th className="px-4 py-3">Vai trò</th>
+                    <th className="px-4 py-3">Trạng thái</th>
+                    <th className="px-4 py-3">Ngày đăng ký</th>
+                    <th className="px-4 py-3 text-right">Hành động</th>
+                  </tr>
+                </thead>
+                <tbody className="divide-y divide-gray-100">
+                  {filtered.map(u => {
+                    const isSelf = u.id === me?.id;
+                    const isLoading = busy === u.id;
+                    return (
+                      <tr key={u.id} className="hover:bg-gray-50 transition">
+                        {/* ID */}
+                        <td className="px-4 py-3 text-gray-400 tabular-nums">{u.id}</td>
+
+                        {/* User info */}
+                        <td className="px-4 py-3">
+                          <div className="font-medium text-gray-900">{u.username}</div>
+                          <div className="text-xs text-gray-400">{u.email}</div>
+                        </td>
+
+                        {/* Role selector */}
+                        <td className="px-4 py-3">
+                          {isSelf ? (
+                            <span className={`text-xs font-semibold px-2 py-0.5 rounded-full ${ROLE_COLORS[u.role]}`}>
+                              {ROLE_LABELS[u.role]}
+                            </span>
+                          ) : (
+                            <select
+                              value={u.role}
+                              disabled={isLoading}
+                              onChange={e => handleRoleChange(u.id, e.target.value as UserRole)}
+                              className={`text-xs border rounded-lg px-2 py-1 focus:outline-none focus:border-blue-500 disabled:opacity-50 ${ROLE_COLORS[u.role]} border-transparent`}
+                            >
+                              <option value="student">Học viên</option>
+                              <option value="teacher">Giáo viên</option>
+                              <option value="admin">Admin</option>
+                            </select>
+                          )}
+                        </td>
+
+                        {/* Status selector */}
+                        <td className="px-4 py-3">
+                          {isSelf ? (
+                            <span className={`text-xs font-semibold px-2 py-0.5 rounded-full ${STATUS_COLORS[u.status]}`}>
+                              {STATUS_LABELS[u.status]}
+                            </span>
+                          ) : (
+                            <select
+                              value={u.status}
+                              disabled={isLoading}
+                              onChange={e => handleStatusChange(u.id, e.target.value as UserStatus)}
+                              className={`text-xs border rounded-lg px-2 py-1 focus:outline-none focus:border-blue-500 disabled:opacity-50 ${STATUS_COLORS[u.status]} border-transparent`}
+                            >
+                              <option value="pending">Chờ duyệt</option>
+                              <option value="approved">Duyệt</option>
+                              <option value="rejected">Từ chối</option>
+                            </select>
+                          )}
+                        </td>
+
+                        {/* Created at */}
+                        <td className="px-4 py-3 text-gray-400 tabular-nums whitespace-nowrap">
+                          {new Date(u.created_at).toLocaleDateString("vi-VN")}
+                        </td>
+
+                        {/* Actions */}
+                        <td className="px-4 py-3 text-right">
+                          {isLoading ? (
+                            <svg className="animate-spin h-4 w-4 text-blue-500 ml-auto" viewBox="0 0 24 24" fill="none">
+                              <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+                              <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v4a4 4 0 00-4 4H4z" />
+                            </svg>
+                          ) : isSelf ? (
+                            <span className="text-xs text-gray-300">—</span>
+                          ) : (
+                            <button
+                              onClick={() => handleDelete(u.id, u.username)}
+                              className="text-xs text-red-400 hover:text-red-600 hover:bg-red-50 px-2 py-1 rounded transition"
+                            >
+                              Xoá
+                            </button>
+                          )}
+                        </td>
+                      </tr>
+                    );
+                  })}
+                </tbody>
+              </table>
+            </div>
+          )}
+        </div>
+      </main>
+    </div>
+  );
+}

frontend/src/app/dashboard/page.tsx

@@ -71,6 +71,14 @@ export default function DashboardPage() {
           <span className="font-bold text-lg text-blue-600">PDF LMS</span>
           <div className="flex items-center gap-3">
             <span className="text-sm text-gray-500 hidden sm:block">{user?.username}</span>
+            {user?.role === "admin" && (
+              <button
+                onClick={() => router.push("/admin")}
+                className="text-xs bg-purple-100 text-purple-700 font-semibold px-2.5 py-1 rounded-full hover:bg-purple-200 transition"
+              >
+                Quản trị
+              </button>
+            )}
             <button
               onClick={handleLogout}
               className="text-sm text-gray-500 hover:text-red-600 transition"

frontend/src/components/WorkbookViewer.tsx

@@ -142,6 +142,8 @@ export default function WorkbookViewer({ pdfId }: Props) {
   const currentPageRef = useRef(1);  // mutable copy for collab callbacks
   const skipRemoteRef = useRef(false); // prevent echo-back when applying remote events
   const currentUserIdRef = useRef<number | null>(null); // populated from api.me(); used to identify own vs remote objects
+  const [userRole, setUserRole] = useState<"admin" | "teacher" | "student">("student");
+  const userRoleRef = useRef<"admin" | "teacher" | "student">("student");
   // Buffer for remote events that arrive while renderPageWithAnnotations is in progress
   const renderingRef = useRef(false);
   const pendingRemoteEvents = useRef<RemoteEvent[]>([]);
@@ -225,6 +227,8 @@ export default function WorkbookViewer({ pdfId }: Props) {
   useEffect(() => {
     api.me().then((u) => {
       currentUserIdRef.current = u.id;
+      setUserRole(u.role);
+      userRoleRef.current = u.role;
       // Assign deterministic color from preset palette based on user id
       const assigned = userIdToPresetColor(u.id);
       setPenColor(assigned);
@@ -299,11 +303,12 @@ export default function WorkbookViewer({ pdfId }: Props) {
       skipRemoteRef.current = true;
       skipObjectTracking.current = true;
       fabric.util.enlivenObjects([objJson], (objects: any[]) => {
+        const canInteract = userRoleRef.current !== "student";
         objects.forEach((obj: any) => {
           obj.collab_id = objJson.collab_id;
           obj._isRemote = true;  // don't save other users' live strokes under our account
-          obj.selectable = false;
-          obj.evented = false;
+          obj.selectable = canInteract;
+          obj.evented = canInteract;
           fc.add(obj);
         });
         fc.renderAll();
@@ -481,12 +486,13 @@ export default function WorkbookViewer({ pdfId }: Props) {
               // Mark objects from other users as remote — prevents saving them under current user
               const uid = currentUserIdRef.current;
               if (uid !== null) {
+                const canInteract = userRoleRef.current !== "student";
                 // eslint-disable-next-line @typescript-eslint/no-explicit-any
                 fc.getObjects().forEach((obj: any) => {
                   if (obj._owner_id != null && obj._owner_id !== uid) {
                     obj._isRemote = true;
-                    obj.selectable = false;
-                    obj.evented = false;
+                    obj.selectable = canInteract;
+                    obj.evented = canInteract;
                   }
                 });
               }
@@ -512,11 +518,12 @@ export default function WorkbookViewer({ pdfId }: Props) {
             skipRemoteRef.current = true;
             skipObjectTracking.current = true;
             fabric.util.enlivenObjects([objJson], (objects: any[]) => {
+              const canInteract = userRoleRef.current !== "student";
               objects.forEach((obj: any) => {
                 obj.collab_id = objJson.collab_id;
                 obj._isRemote = true;
-                obj.selectable = false;
-                obj.evented = false;
+                obj.selectable = canInteract;
+                obj.evented = canInteract;
                 fc.add(obj);
               });
               fc.renderAll();
@@ -618,12 +625,13 @@ export default function WorkbookViewer({ pdfId }: Props) {
             // Mark objects from other users as remote
             const uid = currentUserIdRef.current;
             if (uid !== null) {
+              const canInteract = userRoleRef.current !== "student";
               // eslint-disable-next-line @typescript-eslint/no-explicit-any
               fc.getObjects().forEach((obj: any) => {
                 if (obj._owner_id != null && obj._owner_id !== uid) {
                   obj._isRemote = true;
-                  obj.selectable = false;
-                  obj.evented = false;
+                  obj.selectable = canInteract;
+                  obj.evented = canInteract;
                 }
               });
             }
@@ -899,9 +907,15 @@ export default function WorkbookViewer({ pdfId }: Props) {
         // eslint-disable-next-line @typescript-eslint/no-explicit-any
         fc.on("mouse:down", (options: any) => {
           if (!options.target) return;
-          const collab_id = options.target.collab_id as string | undefined;
-          fc.remove(options.target);
-          addedObjects.current = addedObjects.current.filter(o => o !== options.target);
+          const obj = options.target as any;
+          const ownerId: number | undefined = obj._owner_id;
+          const uid = currentUserIdRef.current;
+          const role = userRoleRef.current;
+          // Students can only erase their own annotations
+          if (role === "student" && (obj._isRemote || (ownerId != null && ownerId !== uid))) return;
+          const collab_id = obj.collab_id as string | undefined;
+          fc.remove(obj);
+          addedObjects.current = addedObjects.current.filter(o => o !== obj);
           fc.renderAll();
           if (collab_id) collabSendRef.current?.objectRemove(collab_id, currentPageRef.current);
         });
@@ -947,8 +961,14 @@ export default function WorkbookViewer({ pdfId }: Props) {
           fc.isDrawingMode = false; fc.selection = false;
           fc.on("mouse:down", (options: any) => {
             if (!options.target) return;
-            const collab_id = options.target.collab_id as string | undefined;
-            fc.remove(options.target); fc.renderAll();
+            const obj = options.target as any;
+            const ownerId: number | undefined = obj._owner_id;
+            const uid = currentUserIdRef.current;
+            const role = userRoleRef.current;
+            // Students can only erase their own annotations
+            if (role === "student" && (obj._isRemote || (ownerId != null && ownerId !== uid))) return;
+            const collab_id = obj.collab_id as string | undefined;
+            fc.remove(obj); fc.renderAll();
             if (collab_id) collabSendRef.current?.objectRemove(collab_id, currentPageRef.current);
           }); break;
       }
@@ -1031,13 +1051,33 @@ export default function WorkbookViewer({ pdfId }: Props) {
   const handleClear = useCallback(() => {
     const fc = fabricRef.current;
     if (!fc) return;
-    if (!confirm("Clear all annotations on this page?")) return;
-    fc.clear();
-    addedObjects.current = [];
-    fc.renderAll();
-    collabSendRef.current?.clear(currentPageRef.current);
-    // Push empty canvas to Redis so other users see the clear immediately on next load
-    syncTempCanvasRef.current(currentPageRef.current);
+
+    const role = userRoleRef.current;
+    const uid = currentUserIdRef.current;
+
+    if (role === "student") {
+      // Students: only remove their own objects, leave others untouched
+      if (!confirm("Xoá annotation của bạn trên trang này?")) return;
+      const toRemove = fc.getObjects().filter((o: any) => !o._isRemote && (o._owner_id == null || o._owner_id === uid));
+      toRemove.forEach((o: any) => {
+        fc.remove(o);
+        // Broadcast removal so teacher canvas updates in real time
+        const collab_id = o.collab_id as string | undefined;
+        if (collab_id) collabSendRef.current?.objectRemove(collab_id, currentPageRef.current);
+      });
+      addedObjects.current = addedObjects.current.filter(o => toRemove.indexOf(o) === -1);
+      fc.renderAll();
+      // Sync own cleared state to Redis
+      syncTempCanvasRef.current(currentPageRef.current);
+    } else {
+      // Teacher / Admin: clear everything
+      if (!confirm("Xoá tất cả annotation trên trang này?")) return;
+      fc.clear();
+      addedObjects.current = [];
+      fc.renderAll();
+      collabSendRef.current?.clear(currentPageRef.current);
+      syncTempCanvasRef.current(currentPageRef.current);
+    }
   }, []);
 
   // ─────────────────────────────────────────────────────────────────────────
@@ -1317,16 +1357,50 @@ export default function WorkbookViewer({ pdfId }: Props) {
               <span className={`w-1.5 h-1.5 rounded-full flex-shrink-0 ${collabConnected ? "bg-green-500" : "bg-gray-300"}`} />
               {collabUsers.length > 0 && (
                 <div className="flex -space-x-1">
-                  {collabUsers.slice(0, 5).map(u => (
-                    <span
-                      key={u.user_id}
-                      title={u.username}
-                      style={{ background: u.color }}
-                      className="w-5 h-5 rounded-full border-2 border-white flex items-center justify-center text-[9px] text-white font-bold uppercase"
-                    >
-                      {u.username[0]}
-                    </span>
-                  ))}
+                  {collabUsers.slice(0, 5).map(u => {
+                    const isSelf = u.user_id === currentUserIdRef.current;
+                    const canClear = !isSelf && (userRole === "admin" || userRole === "teacher");
+                    return (
+                      <div key={u.user_id} className="relative group">
+                        <span
+                          title={u.username}
+                          style={{ background: u.color }}
+                          className="w-5 h-5 rounded-full border-2 border-white flex items-center justify-center text-[9px] text-white font-bold uppercase select-none"
+                        >
+                          {u.username[0]}
+                        </span>
+                        {canClear && (
+                          <button
+                            onClick={async () => {
+                              if (!confirm(`Xoá annotation của "${u.username}" trên trang ${currentPageRef.current}?`)) return;
+                              try {
+                                await api.clearUserAnnotation(pdfId, currentPageRef.current, u.user_id);
+                                // Remove their objects from canvas
+                                const removeFromCanvas = (fc: any) => {
+                                  const toRemove = fc.getObjects().filter((o: any) => o._owner_id === u.user_id);
+                                  toRemove.forEach((o: any) => fc.remove(o));
+                                  if (toRemove.length) fc.renderAll();
+                                };
+                                if (scrollModeRef.current === "continuous") {
+                                  pageFabricRefs.current.forEach(fc => { if (fc) removeFromCanvas(fc); });
+                                } else if (fabricRef.current) {
+                                  removeFromCanvas(fabricRef.current);
+                                }
+                                localAnnotations.current = {};
+                              } catch (e: unknown) {
+                                alert(e instanceof Error ? e.message : "Xoá thất bại.");
+                              }
+                            }}
+                            title={`Xoá annotation của ${u.username} trang này`}
+                            className="absolute -top-1.5 -right-1.5 w-3.5 h-3.5 rounded-full bg-red-500 text-white hidden group-hover:flex items-center justify-center shadow z-10"
+                            style={{ fontSize: 8 }}
+                          >
+                            ✕
+                          </button>
+                        )}
+                      </div>
+                    );
+                  })}
                   {collabUsers.length > 5 && (
                     <span className="w-5 h-5 rounded-full border-2 border-white bg-gray-400 flex items-center justify-center text-[9px] text-white font-bold">
                       +{collabUsers.length - 5}

frontend/src/lib/api.ts

@@ -52,4 +52,24 @@ export const api = {
       method: "PUT",
       body: JSON.stringify(body),
     }),
+  deleteAnnotation: (annotationId: number) =>
+    request<void>(`/api/annotations/${annotationId}`, { method: "DELETE" }),
+  clearUserAnnotation: (pdfId: number, page: number, userId: number) =>
+    request<void>(`/api/annotations/${pdfId}/${page}/user/${userId}`, { method: "DELETE" }),
+
+  // Admin
+  adminListUsers: () =>
+    request<import("@/types").User[]>("/api/admin/users"),
+  adminUpdateStatus: (userId: number, status: import("@/types").UserStatus) =>
+    request<import("@/types").User>(`/api/admin/users/${userId}/status`, {
+      method: "PATCH",
+      body: JSON.stringify({ status }),
+    }),
+  adminUpdateRole: (userId: number, role: import("@/types").UserRole) =>
+    request<import("@/types").User>(`/api/admin/users/${userId}/role`, {
+      method: "PATCH",
+      body: JSON.stringify({ role }),
+    }),
+  adminDeleteUser: (userId: number) =>
+    request<void>(`/api/admin/users/${userId}`, { method: "DELETE" }),
 };

frontend/src/types/index.ts

@@ -1,7 +1,12 @@
+export type UserRole = "admin" | "teacher" | "student";
+export type UserStatus = "pending" | "approved" | "rejected";
+
 export interface User {
   id: number;
   username: string;
   email: string;
+  role: UserRole;
+  status: UserStatus;
   created_at: string;
 }