thực hiện phân quyền admin giáo viên và học sinh xong

backend/alembic/versions/0002_add_role_status.py

@@ -0,0 +1,49 @@
+"""add role and status to users
+
+Revision ID: 0002_add_role_status
+Revises: 0001_initial_schema
+Create Date: 2026-04-01
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = "0002_add_role_status"
+down_revision = "0001"
+branch_labels = None
+depends_on = None
+
+user_role = postgresql.ENUM("admin", "teacher", "student", name="user_role")
+user_status = postgresql.ENUM("pending", "approved", "rejected", name="user_status")
+
+
+def upgrade() -> None:
+    user_role.create(op.get_bind(), checkfirst=True)
+    user_status.create(op.get_bind(), checkfirst=True)
+
+    op.add_column(
+        "users",
+        sa.Column(
+            "role",
+            sa.Enum("admin", "teacher", "student", name="user_role"),
+            nullable=False,
+            server_default="student",
+        ),
+    )
+    op.add_column(
+        "users",
+        sa.Column(
+            "status",
+            sa.Enum("pending", "approved", "rejected", name="user_status"),
+            nullable=False,
+            server_default="pending",
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("users", "status")
+    op.drop_column("users", "role")
+    user_role.drop(op.get_bind(), checkfirst=True)
+    user_status.drop(op.get_bind(), checkfirst=True)

backend/app/dependencies.py

@@ -3,7 +3,7 @@ from jose import JWTError
 from sqlalchemy.orm import Session
 
 from .database import get_db
-from .models import User
+from .models import User, UserRole, UserStatus
 from .security import decode_access_token
 
 
@@ -33,4 +33,35 @@ def get_current_user(
     if user is None:
         raise credentials_exception
 
+    # Guard: approved users only (pending/rejected cannot use the API)
+    if user.status != UserStatus.approved:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Your account is pending admin approval.",
+        )
+
     return user
+
+
+def require_role(*roles: UserRole):
+    """
+    Returns a FastAPI dependency that asserts the current user has one of the
+    given roles. Usage:  Depends(require_role(UserRole.admin, UserRole.teacher))
+    """
+    def _check(current_user: User = Depends(get_current_user)) -> User:
+        if current_user.role not in roles:
+            raise HTTPException(
+                status_code=status.HTTP_403_FORBIDDEN,
+                detail="You do not have permission to perform this action.",
+            )
+        return current_user
+    return _check
+
+
+def require_admin(current_user: User = Depends(get_current_user)) -> User:
+    if current_user.role != UserRole.admin:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Admin access required.",
+        )
+    return current_user

backend/app/main.py

@@ -3,7 +3,7 @@ from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
-from .routers import annotations, auth, pdfs, ws
+from .routers import admin, annotations, auth, pdfs, ws
 
 
 @asynccontextmanager
@@ -24,6 +24,7 @@ app.add_middleware(
 )
 
 app.include_router(auth.router, prefix="/api")
+app.include_router(admin.router, prefix="/api")
 app.include_router(pdfs.router, prefix="/api")
 app.include_router(annotations.router, prefix="/api")
 app.include_router(ws.router)  # WebSocket — no /api prefix (ws:// path)

backend/app/models.py

@@ -1,6 +1,9 @@
 from datetime import datetime, timezone
+import enum
+
 from sqlalchemy import (
     Column,
+    Enum,
     Integer,
     String,
     Text,
@@ -13,6 +16,18 @@ from sqlalchemy.orm import relationship
 from .database import Base
 
 
+class UserRole(str, enum.Enum):
+    admin = "admin"
+    teacher = "teacher"
+    student = "student"
+
+
+class UserStatus(str, enum.Enum):
+    pending = "pending"
+    approved = "approved"
+    rejected = "rejected"
+
+
 class User(Base):
     __tablename__ = "users"
 
@@ -20,6 +35,8 @@ class User(Base):
     username = Column(String(64), unique=True, nullable=False, index=True)
     email = Column(String(255), unique=True, nullable=False, index=True)
     password_hash = Column(String(255), nullable=False)
+    role = Column(Enum(UserRole, name="user_role"), nullable=False, default=UserRole.student)
+    status = Column(Enum(UserStatus, name="user_status"), nullable=False, default=UserStatus.pending)
     created_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False)
 
     # Relationships

backend/app/routers/admin.py

@@ -0,0 +1,83 @@
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from ..database import get_db
+from ..dependencies import require_admin
+from ..models import User, UserStatus
+from ..schemas import UserApprove, UserRoleUpdate, UserOut
+
+router = APIRouter(prefix="/admin", tags=["admin"])
+
+
+# ── GET /api/admin/users ──────────────────────────────────────────────────────
+
+@router.get("/users", response_model=list[UserOut])
+def list_users(
+    admin: User = Depends(require_admin),
+    db: Session = Depends(get_db),
+):
+    """Return all users (any role / status). Admin only."""
+    return db.query(User).order_by(User.created_at.desc()).all()
+
+
+# ── PATCH /api/admin/users/{user_id}/status ───────────────────────────────────
+
+@router.patch("/users/{user_id}/status", response_model=UserOut)
+def update_user_status(
+    user_id: int,
+    body: UserApprove,
+    admin: User = Depends(require_admin),
+    db: Session = Depends(get_db),
+):
+    """Approve or reject a user account. Admin only."""
+    user = db.get(User, user_id)
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found.")
+    if user.id == admin.id:
+        raise HTTPException(status_code=400, detail="Cannot change your own status.")
+
+    user.status = body.status
+    db.commit()
+    db.refresh(user)
+    return user
+
+
+# ── PATCH /api/admin/users/{user_id}/role ─────────────────────────────────────
+
+@router.patch("/users/{user_id}/role", response_model=UserOut)
+def update_user_role(
+    user_id: int,
+    body: UserRoleUpdate,
+    admin: User = Depends(require_admin),
+    db: Session = Depends(get_db),
+):
+    """Change a user's role. Admin only."""
+    user = db.get(User, user_id)
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found.")
+    if user.id == admin.id:
+        raise HTTPException(status_code=400, detail="Cannot change your own role.")
+
+    user.role = body.role
+    db.commit()
+    db.refresh(user)
+    return user
+
+
+# ── DELETE /api/admin/users/{user_id} ─────────────────────────────────────────
+
+@router.delete("/users/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
+def delete_user(
+    user_id: int,
+    admin: User = Depends(require_admin),
+    db: Session = Depends(get_db),
+):
+    """Permanently delete a user and all their data. Admin only."""
+    user = db.get(User, user_id)
+    if not user:
+        raise HTTPException(status_code=404, detail="User not found.")
+    if user.id == admin.id:
+        raise HTTPException(status_code=400, detail="Cannot delete your own account.")
+
+    db.delete(user)
+    db.commit()

backend/app/routers/annotations.py

@@ -6,10 +6,50 @@ from sqlalchemy.orm import Session
 
 from ..database import get_db
 from ..dependencies import get_current_user
-from ..models import Annotation, PDF, User
+from ..models import Annotation, PDF, User, UserRole
 from ..redis_client import ANN_TTL, ann_temp_key, ann_temp_page_pattern, get_redis
 from ..schemas import AnnotationIn, AnnotationOut
 
+
+def _do_delete_annotation(ann: Annotation, current_user: User, db: Session) -> None:
+    """Shared RBAC + delete logic, used by both delete endpoints."""
+    from ..models import UserRole  # avoid circular at module level
+
+    ann_owner = db.get(User, ann.user_id)
+
+    if current_user.role == UserRole.admin:
+        pass  # full access
+    elif current_user.role == UserRole.teacher:
+        if ann.user_id == current_user.id:
+            pass  # own annotation
+        elif ann_owner and ann_owner.role == UserRole.admin:
+            raise HTTPException(
+                status_code=http_status.HTTP_403_FORBIDDEN,
+                detail="Teachers cannot delete annotations belonging to an admin.",
+            )
+        else:
+            pass  # can delete student annotations (or annotations of deleted users)
+    else:  # student
+        if ann.user_id != current_user.id:
+            raise HTTPException(
+                status_code=http_status.HTTP_403_FORBIDDEN,
+                detail="You can only delete your own annotations.",
+            )
+
+    pdf_id = ann.pdf_id
+    page_number = ann.page_number
+    user_id = ann.user_id
+    db.delete(ann)
+    db.commit()
+
+    # Remove Redis temp entry so /all doesn't serve stale data
+    r = get_redis()
+    if r is not None:
+        try:
+            r.delete(ann_temp_key(pdf_id, page_number, user_id))
+        except Exception:
+            pass
+
 router = APIRouter(prefix="/annotations", tags=["annotations"])
 
 
@@ -211,3 +251,56 @@ def upsert_annotation(
             pass
 
     return ann
+
+
+# ── DELETE /api/annotations/{annotation_id} ───────────────────────────────────
+
+@router.delete("/{annotation_id}", status_code=http_status.HTTP_204_NO_CONTENT)
+def delete_annotation(
+    annotation_id: int,
+    current_user: User = Depends(get_current_user),
+    db: Session = Depends(get_db),
+):
+    """Delete annotation by primary key (RBAC enforced)."""
+    ann = db.get(Annotation, annotation_id)
+    if not ann:
+        raise HTTPException(status_code=404, detail="Annotation not found.")
+    _do_delete_annotation(ann, current_user, db)
+
+
+# ── DELETE /api/annotations/{pdf_id}/{page_number}/user/{target_user_id} ──────
+
+@router.delete("/{pdf_id}/{page_number}/user/{target_user_id}", status_code=http_status.HTTP_204_NO_CONTENT)
+def delete_user_page_annotation(
+    pdf_id: int,
+    page_number: int,
+    target_user_id: int,
+    current_user: User = Depends(get_current_user),
+    db: Session = Depends(get_db),
+):
+    """
+    Delete a specific user's annotation on a given page (RBAC enforced).
+    Useful for teachers clearing a student's page without knowing the annotation id.
+    Returns 204 even when no annotation exists (idempotent).
+    """
+    _any_pdf_or_404(db, pdf_id)
+    ann = (
+        db.query(Annotation)
+        .filter(
+            Annotation.pdf_id == pdf_id,
+            Annotation.page_number == page_number,
+            Annotation.user_id == target_user_id,
+        )
+        .first()
+    )
+    if ann is None:
+        # Nothing in DB — still clean up any Redis temp entry
+        r = get_redis()
+        if r is not None:
+            try:
+                r.delete(ann_temp_key(pdf_id, page_number, target_user_id))
+            except Exception:
+                pass
+        return
+    _do_delete_annotation(ann, current_user, db)
+

backend/app/routers/auth.py

@@ -4,8 +4,8 @@ import os
 
 from ..database import get_db
 from ..dependencies import get_current_user
-from ..models import User
-from ..schemas import UserLogin, UserOut, UserRegister
+from ..models import User, UserRole, UserStatus
+from ..schemas import UserLogin, UserOut, UserRegister, UserApprove
 from ..security import (
     ACCESS_TOKEN_EXPIRE_MINUTES,
     create_access_token,
@@ -42,15 +42,24 @@ def register(body: UserRegister, response: Response, db: Session = Depends(get_d
     if db.query(User).filter(User.email == body.email).first():
         raise HTTPException(status_code=400, detail="Email already registered.")
 
+    # Admin registers as approved immediately; others start as pending
+    initial_status = (
+        UserStatus.approved if body.role == UserRole.admin else UserStatus.pending
+    )
+
     user = User(
         username=body.username,
         email=body.email,
         password_hash=hash_password(body.password),
+        role=body.role,
+        status=initial_status,
     )
     db.add(user)
     db.commit()
     db.refresh(user)
 
+    # Only set auth cookie if immediately approved (admin self-registration)
+    if user.status == UserStatus.approved:
         _set_auth_cookie(response, user.id)
     return user
 
@@ -68,6 +77,17 @@ def login(body: UserLogin, response: Response, db: Session = Depends(get_db)):
     if not user or not password_ok:
         raise HTTPException(status_code=401, detail="Invalid username or password.")
 
+    if user.status == UserStatus.pending:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Your account is pending admin approval.",
+        )
+    if user.status == UserStatus.rejected:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Your account has been rejected.",
+        )
+
     _set_auth_cookie(response, user.id)
     return user
 

backend/app/schemas.py

@@ -2,6 +2,8 @@ from datetime import datetime
 from pydantic import BaseModel, EmailStr, field_validator
 import re
 
+from .models import UserRole, UserStatus
+
 
 # ── Auth ─────────────────────────────────────────────────────────────────────
 
@@ -9,6 +11,7 @@ class UserRegister(BaseModel):
     username: str
     email: EmailStr
     password: str
+    role: UserRole = UserRole.student
 
     @field_validator("username")
     @classmethod
@@ -37,11 +40,21 @@ class UserOut(BaseModel):
     id: int
     username: str
     email: str
+    role: UserRole
+    status: UserStatus
     created_at: datetime
 
     model_config = {"from_attributes": True}
 
 
+class UserApprove(BaseModel):
+    status: UserStatus
+
+
+class UserRoleUpdate(BaseModel):
+    role: UserRole
+
+
 class TokenPayload(BaseModel):
     sub: int   # user id
     exp: int

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;
+
+    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);
-    // Push empty canvas to Redis so other users see the clear immediately on next load
       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 ${collabConnected ? "bg-green-500" : "bg-gray-300"}`} />
               {collabUsers.length > 0 && (
                 <div className="flex -space-x-1">
-                  {collabUsers.slice(0, 5).map(u => (
+                  {collabUsers.slice(0, 5).map(u => {
+                    const isSelf = u.user_id === currentUserIdRef.current;
+                    const canClear = !isSelf && (userRole === "admin" || userRole === "teacher");
+                    return (
+                      <div key={u.user_id} className="relative group">
                         <span
-                      key={u.user_id}
                           title={u.username}
                           style={{ background: u.color }}
-                      className="w-5 h-5 rounded-full border-2 border-white flex items-center justify-center text-[9px] text-white font-bold uppercase"
+                          className="w-5 h-5 rounded-full border-2 border-white flex items-center justify-center text-[9px] text-white font-bold uppercase select-none"
                         >
                           {u.username[0]}
                         </span>
-                  ))}
+                        {canClear && (
+                          <button
+                            onClick={async () => {
+                              if (!confirm(`Xoá annotation của "${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;
 }
 

readme.md

@@ -134,3 +134,10 @@ https://github.com/<github_username>?tab=packages
 ```bash
 python3 -c "import secrets; print(secrets.token_hex(32))"
 ```
+
+
+Field	Value
+username	admin
+password	Admin@12345
+role	admin
+status	approved