fix random

management/src/App.tsx

@@ -1,4 +1,5 @@
-import { useEffect, useState } from 'react';
+import { useEffect, useCallback, useState } from 'react';
+import { apiMyClasses } from './api';
 import { DashboardTab } from './components/DashboardTab';
 import { ClassesTab } from './components/ClassesTab';
 import { StudentsTab } from './components/StudentsTab';
@@ -117,25 +118,22 @@ function App() {
     setSidebarCollapsed(nextVal);
     localStorage.setItem('sc_sidebar_collapsed', String(nextVal));
   };
-  const [myClasses, setMyClasses] = useState<{ id: number; name: string; code: string }[]>(() => {
+  const [myClasses, setMyClasses] = useState<{ id: number; name: string; code: string }[]>([]);
-    try {
+
-      const stored = localStorage.getItem('sc_my_classes_details');
+  const refreshMyClasses = useCallback(() => {
-      return stored ? JSON.parse(stored) : [];
+    apiMyClasses.list().then((items) => {
-    } catch {
+      setMyClasses(items.map((c) => ({ id: c.rkId, name: c.name, code: c.classCode })));
-      return [];
+    }).catch(() => {});
-    }
+  }, []);
-  });
 
   useEffect(() => {
-    const handleUpdate = () => {
+    refreshMyClasses();
-      try {
+  }, [refreshMyClasses]);
-        const stored = localStorage.getItem('sc_my_classes_details');
+
-        setMyClasses(stored ? JSON.parse(stored) : []);
+  useEffect(() => {
-      } catch (e) { }
+    window.addEventListener('my-classes-updated', refreshMyClasses);
-    };
+    return () => window.removeEventListener('my-classes-updated', refreshMyClasses);
-    window.addEventListener('my-classes-updated', handleUpdate);
+  }, [refreshMyClasses]);
-    return () => window.removeEventListener('my-classes-updated', handleUpdate);
-  }, []);
 
   useEffect(() => {
     const initial = parseRoute();

management/src/api.ts

@@ -1124,6 +1124,14 @@ export const apiExam = {
     if (!res.ok) await parseError(res, 'Chia gói đề thất bại');
     return res.json() as Promise<{ assigned: number; packages: number }>;
   },
+  assignPapersBatch: async (id: number, assignments: { studentRkId: number; paperId: number }[]) => {
+    const res = await staffFetch(`/exam-rooms/${id}/assign-papers-batch`, {
+      method: 'POST',
+      body: JSON.stringify({ assignments }),
+    });
+    if (!res.ok) await parseError(res, 'Chia gói đề thất bại');
+    return res.json() as Promise<{ assigned: number }>;
+  },
   sendPapers: async (id: number, payload?: { scheduledAt?: string; studentRkIds?: number[] }) => {
     const res = await staffFetch(`/exam-rooms/${id}/send-papers`, { method: 'POST', body: JSON.stringify(payload || {}) });
     if (!res.ok) await parseError(res, 'Gửi gói đề thất bại');
@@ -1186,6 +1194,45 @@ export const apiExam = {
   },
 };
 
+export interface MyClassItem {
+  rkId: number;
+  name: string;
+  classCode: string;
+}
+
+export const apiMyClasses = {
+  list: async (): Promise<MyClassItem[]> => {
+    const res = await staffFetch('/staff/my-classes');
+    if (!res.ok) return [];
+    const json = await res.json() as { data: MyClassItem[] };
+    return json.data ?? [];
+  },
+  add: async (classRkId: number): Promise<void> => {
+    await staffFetch(`/staff/my-classes/${classRkId}`, { method: 'POST' });
+  },
+  remove: async (classRkId: number): Promise<void> => {
+    await staffFetch(`/staff/my-classes/${classRkId}`, { method: 'DELETE' });
+  },
+};
+
+export const apiSeatingLayout = {
+  get: async (classRkId: number): Promise<string | null> => {
+    const res = await staffFetch(`/classes/${classRkId}/seating-layout`);
+    if (!res.ok) return null;
+    const json = await res.json() as { layoutJson: string | null };
+    return json.layoutJson ?? null;
+  },
+  save: async (classRkId: number, layoutJson: string): Promise<void> => {
+    await staffFetch(`/classes/${classRkId}/seating-layout`, {
+      method: 'PUT',
+      body: JSON.stringify({ layoutJson }),
+    });
+  },
+  delete: async (classRkId: number): Promise<void> => {
+    await staffFetch(`/classes/${classRkId}/seating-layout`, { method: 'DELETE' });
+  },
+};
+
 export const apiQldt = {
   getToken: async (): Promise<{ token: string }> => {
     const res = await staffFetch('/qldt-token');

management/src/components/ExamRoomWorkspace.tsx

@@ -325,8 +325,62 @@ export const ExamRoomWorkspace: React.FC<Props> = ({ examId, onBack }) => {
   };
 
   const assignRandomPackages = async () => {
-    const res = await apiExam.assignRandom(examId);
+    if (papers.length === 0) return;
-    setMsg(`Đã chia ${res.assigned} sinh viên vào ${res.packages} gói đề`);
+
+    // Đọc sơ đồ chỗ ngồi từ localStorage (exam rooms vẫn lưu local)
+    let seatingSeats: Record<string, number> | null = null;
+    try {
+      const raw = localStorage.getItem(`sc_seating_layout_exam-${examId}`);
+      if (raw) {
+        const parsed = JSON.parse(raw) as { seats?: Record<string, number> };
+        if (parsed.seats && Object.keys(parsed.seats).length > 0) {
+          seatingSeats = parsed.seats;
+        }
+      }
+    } catch { /* ignore */ }
+
+    if (!seatingSeats) {
+      // Không có sơ đồ → fallback random server-side
+      const res = await apiExam.assignRandom(examId);
+      setMsg(`Đã chia ${res.assigned} sinh viên vào ${res.packages} gói đề`);
+      await load();
+      return;
+    }
+
+    // Nhóm sinh viên theo hàng: row → [(col, studentRkId)] tăng dần theo cột
+    const rowMap = new Map<number, { col: number; rkId: number }[]>();
+    Object.entries(seatingSeats).forEach(([key, rkId]) => {
+      const [r, c] = key.split(',').map(Number);
+      if (!rowMap.has(r)) rowMap.set(r, []);
+      rowMap.get(r)!.push({ col: c, rkId });
+    });
+    rowMap.forEach((arr) => arr.sort((a, b) => a.col - b.col));
+
+    const numPapers = papers.length;
+    const assignments: { studentRkId: number; paperId: number }[] = [];
+    const assignedIds = new Set<number>();
+
+    // Chia đề theo hàng ngang: mỗi hàng có random offset → cạnh nhau không trùng
+    [...rowMap.keys()].sort((a, b) => a - b).forEach((row) => {
+      const seatsInRow = rowMap.get(row)!;
+      const offset = Math.floor(Math.random() * numPapers);
+      seatsInRow.forEach(({ rkId }, relIdx) => {
+        const paper = papers[(offset + relIdx) % numPapers];
+        assignments.push({ studentRkId: rkId, paperId: paper.id });
+        assignedIds.add(rkId);
+      });
+    });
+
+    // Sinh viên chưa có chỗ ngồi → chia tuần tự ngẫu nhiên
+    const unseated = students
+      .filter((s) => !assignedIds.has(s.studentRkId))
+      .sort(() => Math.random() - 0.5);
+    unseated.forEach((s, i) => {
+      assignments.push({ studentRkId: s.studentRkId, paperId: papers[i % numPapers].id });
+    });
+
+    const res = await apiExam.assignPapersBatch(examId, assignments);
+    setMsg(`Đã chia ${res.assigned} sinh viên vào ${numPapers} gói đề (theo sơ đồ chỗ ngồi)`);
     await load();
   };
 

management/src/components/LearningTab.tsx

@@ -8,6 +8,7 @@ import {
   apiFetchClassSessionLogs,
   apiFetchClasses,
   apiFetchScheduleConflicts,
+  apiMyClasses,
 } from '../api';
 import { DEFAULT_ALLOWED_APPS } from '../constants';
 import type {
@@ -40,32 +41,29 @@ export const LearningTab: React.FC = () => {
   const [dayFilter, setDayFilter] = useState<number | null>(null);
   const [viewMode, setViewMode] = useState<ViewMode>('list');
   const [onlyMyClasses, setOnlyMyClasses] = useState<boolean>(false);
-  const [myClasses, setMyClasses] = useState<number[]>(() => {
+  const [myClasses, setMyClasses] = useState<number[]>([]);
-    try {
-      const stored = localStorage.getItem('sc_my_classes_details');
-      const list = stored ? JSON.parse(stored) : [];
-      return Array.isArray(list) ? list.map((item: any) => item.id) : [];
-    } catch {
-      return [];
-    }
-  });
 
-  const toggleMyClass = (classId: number, name: string, code: string) => {
+  const refreshMyClasses = () => {
-    let list: any[] = [];
+    apiMyClasses.list().then((items) => {
-    try {
+      setMyClasses(items.map((c) => c.rkId));
-      const stored = localStorage.getItem('sc_my_classes_details');
+    }).catch(() => {});
-      list = stored ? JSON.parse(stored) : [];
+  };
-    } catch (e) {}
 
-    const exists = list.some(item => item.id === classId);
+  useEffect(() => {
-    let nextList;
+    refreshMyClasses();
-    if (exists) {
+    window.addEventListener('my-classes-updated', refreshMyClasses);
-      nextList = list.filter(item => item.id !== classId);
+    return () => window.removeEventListener('my-classes-updated', refreshMyClasses);
+  }, []);
+
+  const toggleMyClass = (classId: number, _name: string, _code: string) => {
+    const isMyClass = myClasses.includes(classId);
+    if (isMyClass) {
+      setMyClasses((prev) => prev.filter((id) => id !== classId));
+      apiMyClasses.remove(classId).catch(() => {});
     } else {
-      nextList = [...list, { id: classId, name, code }];
+      setMyClasses((prev) => [...prev, classId]);
+      apiMyClasses.add(classId).catch(() => {});
     }
-    localStorage.setItem('sc_my_classes_details', JSON.stringify(nextList));
-    setMyClasses(nextList.map(item => item.id));
     window.dispatchEvent(new Event('my-classes-updated'));
   };
 

management/src/components/WorkspaceSeatingChart.tsx

@@ -1,6 +1,7 @@
-import React, { useEffect, useState, useMemo } from 'react';
+import React, { useEffect, useState, useMemo, useRef } from 'react';
 import type { SeatingTemplate } from './SeatingTemplatesSection';
 import { StudentAvatar, StudentOnlineBadge } from './StudentAvatar';
+import { apiSeatingLayout } from '../api';
 
 interface WorkspaceSeatingChartProps {
   workspaceId: string; // 'class-<id>' or 'exam-<id>'
@@ -42,6 +43,9 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
   
   // Edit mode for structural changes
   const [isEditingStructure, setIsEditingStructure] = useState(false);
+  const [editRows, setEditRows] = useState(5);
+  const [editCols, setEditCols] = useState(6);
+  const [editBoardPos, setEditBoardPos] = useState<'top' | 'bottom' | 'left' | 'right'>('top');
   const [dragOverCell, setDragOverCell] = useState<string | null>(null);
   const [saveNotice, setSaveNotice] = useState<string | null>(null);
 
@@ -49,6 +53,17 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
   const [viewMode, setViewMode] = useState<'grid' | 'list'>('grid');
   const [listSearchQuery, setListSearchQuery] = useState('');
 
+  // Detect if this is a class workspace (vs exam) to use API storage
+  const classRkId = useMemo(() => {
+    if (workspaceId.startsWith('class-')) {
+      const n = Number(workspaceId.replace('class-', ''));
+      return isNaN(n) ? null : n;
+    }
+    return null;
+  }, [workspaceId]);
+
+  const saveTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
   // Reverse map seat positions for list view
   const studentSeats = useMemo(() => {
     if (!layout) return {} as Record<number, string>;
@@ -78,7 +93,7 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
 
   // Load templates and layout
   useEffect(() => {
-    // Load templates
+    // Load templates (always from localStorage — shared across all rooms)
     const storedTemplates = localStorage.getItem('sc_seating_templates');
     if (storedTemplates) {
       try {
@@ -88,27 +103,58 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
       }
     }
 
-    // Load layout for this room
+    if (classRkId !== null) {
-    const storedLayout = localStorage.getItem(`sc_seating_layout_${workspaceId}`);
+      // Load layout từ server theo lớp
-    if (storedLayout) {
+      apiSeatingLayout.get(classRkId).then((json) => {
-      try {
+        if (json) {
-        setLayout(JSON.parse(storedLayout));
+          try {
-      } catch {
+            setLayout(JSON.parse(json));
-        setLayout(null);
+          } catch {
+            setLayout(null);
+          }
+        } else {
+          setLayout(null);
+        }
+      }).catch(() => setLayout(null));
+    } else {
+      // Exam rooms — vẫn dùng localStorage
+      const storedLayout = localStorage.getItem(`sc_seating_layout_${workspaceId}`);
+      if (storedLayout) {
+        try {
+          setLayout(JSON.parse(storedLayout));
+        } catch {
+          setLayout(null);
+        }
       }
     }
-  }, [workspaceId]);
+  }, [workspaceId, classRkId]);
 
-  // Save layout
+  // Save layout — debounce API calls, fallback to localStorage for exam rooms
   const saveLayout = (newLayout: SeatingLayout | null) => {
-    if (newLayout) {
-      localStorage.setItem(`sc_seating_layout_${workspaceId}`, JSON.stringify(newLayout));
-      setSaveNotice('Đã lưu thay đổi sơ đồ chỗ ngồi!');
-    } else {
-      localStorage.removeItem(`sc_seating_layout_${workspaceId}`);
-      setSaveNotice('Đã xóa sơ đồ chỗ ngồi!');
-    }
     setLayout(newLayout);
+
+    if (classRkId !== null) {
+      // Debounce để tránh gọi API quá nhiều khi kéo thả nhanh
+      if (saveTimerRef.current) clearTimeout(saveTimerRef.current);
+      saveTimerRef.current = setTimeout(() => {
+        if (newLayout) {
+          apiSeatingLayout.save(classRkId, JSON.stringify(newLayout)).catch(() => {});
+          setSaveNotice('Đã lưu sơ đồ chỗ ngồi!');
+        } else {
+          apiSeatingLayout.delete(classRkId).catch(() => {});
+          setSaveNotice('Đã xóa sơ đồ chỗ ngồi!');
+        }
+      }, 600);
+    } else {
+      // Exam rooms — localStorage
+      if (newLayout) {
+        localStorage.setItem(`sc_seating_layout_${workspaceId}`, JSON.stringify(newLayout));
+        setSaveNotice('Đã lưu thay đổi sơ đồ chỗ ngồi!');
+      } else {
+        localStorage.removeItem(`sc_seating_layout_${workspaceId}`);
+        setSaveNotice('Đã xóa sơ đồ chỗ ngồi!');
+      }
+    }
   };
 
   useEffect(() => {
@@ -240,11 +286,11 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
     saveLayout({ ...layout, seats: newSeats });
   };
 
-  // Auto assign random
+  // Auto assign: điền theo hàng ngang (row-major), sinh viên xếp ngẫu nhiên
   const handleAutoAssign = () => {
     if (!layout) return;
 
-    // Find all empty, unlocked cells
+    // Collect empty unlocked cells in row-major order (left→right, top→bottom)
     const emptyCells: string[] = [];
     for (let r = 0; r < layout.rows; r++) {
       for (let c = 0; c < layout.cols; c++) {
@@ -259,19 +305,45 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
       alert(`Không đủ chỗ ngồi cho tất cả học viên! Số học viên chưa có chỗ: ${unseatedStudents.length}, Số chỗ trống khả dụng: ${emptyCells.length}. Thiếu ${unseatedStudents.length - emptyCells.length} chỗ.`);
     }
 
-    // Shuffle empty cells
+    // Shuffle only students, cells keep row-major order
-    const shuffledCells = [...emptyCells].sort(() => Math.random() - 0.5);
+    const shuffledStudents = [...unseatedStudents].sort(() => Math.random() - 0.5);
-
     const newSeats = { ...layout.seats };
-    const assignCount = Math.min(unseatedStudents.length, shuffledCells.length);
+    const assignCount = Math.min(shuffledStudents.length, emptyCells.length);
 
     for (let i = 0; i < assignCount; i++) {
-      newSeats[shuffledCells[i]] = unseatedStudents[i].rkId;
+      newSeats[emptyCells[i]] = shuffledStudents[i].rkId;
     }
 
     saveLayout({ ...layout, seats: newSeats });
   };
 
+  // Resize/update layout structure (giữ nguyên chỗ ngồi hợp lệ)
+  const handleApplyResize = () => {
+    if (!layout) return;
+    const newRows = Math.max(1, Math.min(editRows, 15));
+    const newCols = Math.max(1, Math.min(editCols, 20));
+
+    const newSeats: Record<string, number> = {};
+    const newLocked: string[] = [];
+
+    Object.entries(layout.seats).forEach(([key, rkId]) => {
+      const [r, c] = key.split(',').map(Number);
+      if (r < newRows && c < newCols) newSeats[key] = rkId;
+    });
+    layout.lockedSeats.forEach((key) => {
+      const [r, c] = key.split(',').map(Number);
+      if (r < newRows && c < newCols) newLocked.push(key);
+    });
+
+    saveLayout({
+      rows: newRows,
+      cols: newCols,
+      boardPosition: editBoardPos,
+      lockedSeats: newLocked,
+      seats: newSeats,
+    });
+  };
+
   // Clear all seats
   const handleClearAllSeats = () => {
     if (!layout) return;
@@ -575,14 +647,21 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
                 <div style={{ display: 'flex', gap: '8px', alignItems: 'center' }}>
                   <button
                     className={`btn btn-sm ${isEditingStructure ? 'btn-primary' : 'btn-secondary'}`}
-                    onClick={() => setIsEditingStructure(!isEditingStructure)}
+                    onClick={() => {
+                      if (!isEditingStructure && layout) {
+                        setEditRows(layout.rows);
+                        setEditCols(layout.cols);
+                        setEditBoardPos(layout.boardPosition);
+                      }
+                      setIsEditingStructure(!isEditingStructure);
+                    }}
                     style={{
                       backgroundColor: isEditingStructure ? 'var(--accent)' : '',
                       borderColor: isEditingStructure ? 'var(--accent)' : '',
                       color: isEditingStructure ? '#fff' : '',
                     }}
                   >
-                    {isEditingStructure ? '✔️ Xong thiết lập' : '⚙️ Khóa/Mở ô chỗ'}
+                    {isEditingStructure ? '✔️ Xong chỉnh sửa' : '⚙️ Chỉnh sửa sơ đồ'}
                   </button>
                   <button className="btn btn-secondary btn-sm text-danger" style={{ borderColor: '#fca5a5' }} onClick={handleResetLayout}>
                     Reset sơ đồ
@@ -594,8 +673,47 @@ export const WorkspaceSeatingChart: React.FC<WorkspaceSeatingChartProps> = ({
             {viewMode === 'grid' ? (
               <>
                 {isEditingStructure && (
-                  <div style={{ backgroundColor: '#fffbeb', border: '1px solid #fef3c7', padding: '0.65rem 1rem', borderRadius: '8px', color: '#b45309', fontSize: '0.8rem', fontWeight: 600 }}>
+                  <div style={{ backgroundColor: '#fffbeb', border: '1px solid #fef3c7', padding: '0.75rem 1rem', borderRadius: '8px', display: 'flex', flexDirection: 'column', gap: '0.6rem' }}>
-                    💡 Đang ở chế độ chỉnh sửa: Click chuột vào các ô trong sơ đồ để thay đổi khóa/mở các vị trí.
+                    <div style={{ color: '#b45309', fontSize: '0.8rem', fontWeight: 600 }}>
+                      💡 Chế độ chỉnh sửa: Click vào ô để khóa/mở vị trí. Thay đổi kích thước và vị trí bảng bên dưới.
+                    </div>
+                    <div style={{ display: 'flex', flexWrap: 'wrap', alignItems: 'center', gap: '8px' }}>
+                      <label style={{ fontSize: '0.8rem', fontWeight: 600, color: '#92400e' }}>Hàng:</label>
+                      <input
+                        type="number" min={1} max={15}
+                        value={editRows}
+                        onChange={(e) => setEditRows(Math.max(1, Math.min(15, Number(e.target.value))))}
+                        className="search-input"
+                        style={{ width: '60px', padding: '0.25rem 0.4rem', fontSize: '0.8rem' }}
+                      />
+                      <label style={{ fontSize: '0.8rem', fontWeight: 600, color: '#92400e' }}>Cột:</label>
+                      <input
+                        type="number" min={1} max={20}
+                        value={editCols}
+                        onChange={(e) => setEditCols(Math.max(1, Math.min(20, Number(e.target.value))))}
+                        className="search-input"
+                        style={{ width: '60px', padding: '0.25rem 0.4rem', fontSize: '0.8rem' }}
+                      />
+                      <label style={{ fontSize: '0.8rem', fontWeight: 600, color: '#92400e' }}>Bảng:</label>
+                      <select
+                        value={editBoardPos}
+                        onChange={(e) => setEditBoardPos(e.target.value as 'top' | 'bottom' | 'left' | 'right')}
+                        className="select-filter"
+                        style={{ padding: '0.25rem 0.4rem', fontSize: '0.8rem' }}
+                      >
+                        <option value="top">Top</option>
+                        <option value="bottom">Bottom</option>
+                        <option value="left">Left</option>
+                        <option value="right">Right</option>
+                      </select>
+                      <button
+                        className="btn btn-primary btn-sm"
+                        onClick={handleApplyResize}
+                        style={{ fontSize: '0.8rem' }}
+                      >
+                        Áp dụng thay đổi
+                      </button>
+                    </div>
                   </div>
                 )}
                 {renderSeatingGrid()}

server/internal/db/db.go

@@ -48,6 +48,8 @@ func AutoMigrate(db *gorm.DB) error {
 		&models.ClassSchedule{},
 		&models.ClassCourse{},
 		&models.ClassAllowedApp{},
+		&models.ClassSeatingLayout{},
+		&models.StaffMyClass{},
 		&models.AppPoolEntry{},
 		&models.AppTemplate{},
 		&models.WifiPoolEntry{},

server/internal/handlers/handlers_exam.go

@@ -811,6 +811,43 @@ func RandomAssignExamPapersHandler(db *gorm.DB) fiber.Handler {
 	}
 }
 
+// POST /api/exam-rooms/:id/assign-papers-batch — chia đề theo sơ đồ chỗ ngồi (frontend tính toán)
+func AssignExamPapersBatchHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		roomID, err := parseUintParam(c, "id")
+		if err != nil {
+			return c.Status(400).JSON(fiber.Map{"error": "Invalid id"})
+		}
+		var room models.ExamRoom
+		if err := db.First(&room, roomID).Error; err != nil {
+			return c.Status(404).JSON(fiber.Map{"error": "Không tìm thấy phòng"})
+		}
+		if !canModifyExamPapers(db, room) {
+			return c.Status(403).JSON(fiber.Map{"error": "Không thể chia gói đề khi đề đã gửi hoặc phòng thi đã kết thúc"})
+		}
+		var req struct {
+			Assignments []struct {
+				StudentRkID int64 `json:"studentRkId"`
+				PaperID     uint  `json:"paperId"`
+			} `json:"assignments"`
+		}
+		if err := c.BodyParser(&req); err != nil || len(req.Assignments) == 0 {
+			return c.Status(400).JSON(fiber.Map{"error": "assignments rỗng hoặc không hợp lệ"})
+		}
+		count := 0
+		for _, a := range req.Assignments {
+			pid := a.PaperID
+			res := db.Model(&models.ExamRoomStudent{}).
+				Where("exam_room_id = ? AND student_rk_id = ?", roomID, a.StudentRkID).
+				Update("assigned_paper_id", pid)
+			if res.RowsAffected > 0 {
+				count++
+			}
+		}
+		return c.JSON(fiber.Map{"assigned": count})
+	}
+}
+
 // POST /api/exam-rooms/:id/send-papers
 func SendExamPapersHandler(db *gorm.DB) fiber.Handler {
 	return func(c *fiber.Ctx) error {

server/internal/handlers/handlers_seating.go

@@ -0,0 +1,125 @@
+package handlers
+
+import (
+	"errors"
+	"strconv"
+	"time"
+
+	"server/internal/middleware"
+	"server/internal/models"
+
+	"github.com/gofiber/fiber/v2"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// GET /classes/:rkId/seating-layout
+func GetClassSeatingLayoutHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		classRkID, err := strconv.ParseInt(c.Params("rkId"), 10, 64)
+		if err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid class ID"})
+		}
+		var layout models.ClassSeatingLayout
+		if err := db.Where("class_rk_id = ?", classRkID).First(&layout).Error; err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return c.JSON(fiber.Map{"layoutJson": nil})
+			}
+			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
+		}
+		return c.JSON(fiber.Map{"layoutJson": layout.LayoutJSON})
+	}
+}
+
+// PUT /classes/:rkId/seating-layout
+func PutClassSeatingLayoutHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		classRkID, err := strconv.ParseInt(c.Params("rkId"), 10, 64)
+		if err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid class ID"})
+		}
+		var body struct {
+			LayoutJSON string `json:"layoutJson"`
+		}
+		if err := c.BodyParser(&body); err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid body"})
+		}
+		if body.LayoutJSON == "" {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "layoutJson is required"})
+		}
+		layout := models.ClassSeatingLayout{
+			ClassRkID:  classRkID,
+			LayoutJSON: body.LayoutJSON,
+			UpdatedAt:  time.Now(),
+		}
+		result := db.Clauses(clause.OnConflict{
+			Columns:   []clause.Column{{Name: "class_rk_id"}},
+			DoUpdates: clause.AssignmentColumns([]string{"layout_json", "updated_at"}),
+		}).Create(&layout)
+		if result.Error != nil {
+			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": result.Error.Error()})
+		}
+		return c.JSON(fiber.Map{"ok": true})
+	}
+}
+
+// DELETE /classes/:rkId/seating-layout
+func DeleteClassSeatingLayoutHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		classRkID, err := strconv.ParseInt(c.Params("rkId"), 10, 64)
+		if err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid class ID"})
+		}
+		db.Where("class_rk_id = ?", classRkID).Delete(&models.ClassSeatingLayout{})
+		return c.JSON(fiber.Map{"ok": true})
+	}
+}
+
+// GET /staff/my-classes
+func GetMyClassesHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		staffID := middleware.StaffIDFromCtx(c)
+		type classRow struct {
+			RkID      int64  `json:"rkId"`
+			Name      string `json:"name"`
+			ClassCode string `json:"classCode"`
+		}
+		var rows []classRow
+		db.Table("staff_my_classes").
+			Select("classes.rk_id, classes.name, classes.class_code").
+			Joins("JOIN classes ON classes.rk_id = staff_my_classes.class_rk_id").
+			Where("staff_my_classes.staff_id = ?", staffID).
+			Scan(&rows)
+		if rows == nil {
+			rows = []classRow{}
+		}
+		return c.JSON(fiber.Map{"data": rows})
+	}
+}
+
+// POST /staff/my-classes/:classRkId
+func AddMyClassHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		staffID := middleware.StaffIDFromCtx(c)
+		classRkID, err := strconv.ParseInt(c.Params("classRkId"), 10, 64)
+		if err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid class ID"})
+		}
+		rec := models.StaffMyClass{StaffID: staffID, ClassRkID: classRkID}
+		db.Clauses(clause.OnConflict{DoNothing: true}).Create(&rec)
+		return c.JSON(fiber.Map{"ok": true})
+	}
+}
+
+// DELETE /staff/my-classes/:classRkId
+func RemoveMyClassHandler(db *gorm.DB) fiber.Handler {
+	return func(c *fiber.Ctx) error {
+		staffID := middleware.StaffIDFromCtx(c)
+		classRkID, err := strconv.ParseInt(c.Params("classRkId"), 10, 64)
+		if err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid class ID"})
+		}
+		db.Where("staff_id = ? AND class_rk_id = ?", staffID, classRkID).Delete(&models.StaffMyClass{})
+		return c.JSON(fiber.Map{"ok": true})
+	}
+}

server/internal/models/models.go

@@ -97,6 +97,15 @@ type AttendanceResult struct {
 
 func (AttendanceResult) TableName() string { return "attendance_results" }
 
+// ClassSeatingLayout lưu sơ đồ chỗ ngồi theo lớp
+type ClassSeatingLayout struct {
+	ClassRkID  int64     `gorm:"column:class_rk_id;primaryKey;not null" json:"classRkId"`
+	LayoutJSON string    `gorm:"column:layout_json;type:longtext;not null" json:"layoutJson"`
+	UpdatedAt  time.Time `json:"updatedAt"`
+}
+
+func (ClassSeatingLayout) TableName() string { return "class_seating_layouts" }
+
 // ClassAllowedApp lưu từ khóa app được mở của lớp
 type ClassAllowedApp struct {
 	ClassRkID int64  `gorm:"column:class_rk_id;primaryKey;not null" json:"classRkId"`

server/internal/models/staff.go

@@ -38,6 +38,14 @@ type PasswordResetToken struct {
 
 func (PasswordResetToken) TableName() string { return "password_reset_tokens" }
 
+// StaffMyClass lưu danh sách lớp học cá nhân của giáo viên
+type StaffMyClass struct {
+	StaffID   uint  `gorm:"column:staff_id;primaryKey;not null;index" json:"staffId"`
+	ClassRkID int64 `gorm:"column:class_rk_id;primaryKey;not null" json:"classRkId"`
+}
+
+func (StaffMyClass) TableName() string { return "staff_my_classes" }
+
 // ChatMessage — tin nhắn thầy cô ↔ sinh viên
 type ChatMessage struct {
 	ID          uint       `gorm:"primaryKey" json:"id"`

server/main.go

@@ -130,6 +130,14 @@ func main() {
 	staff.Get("/classes/:rkId", handlers.GetClassHandler(gormDB))
 	staff.Patch("/classes/:rkId/studying", handlers.PatchClassStudyingHandler(gormDB))
 	staff.Get("/classes/:rkId/students", handlers.ListClassStudentsHandler(gormDB))
+	staff.Get("/classes/:rkId/seating-layout", handlers.GetClassSeatingLayoutHandler(gormDB))
+	staff.Put("/classes/:rkId/seating-layout", handlers.PutClassSeatingLayoutHandler(gormDB))
+	staff.Delete("/classes/:rkId/seating-layout", handlers.DeleteClassSeatingLayoutHandler(gormDB))
+
+	// My classes (lớp cá nhân theo tài khoản)
+	staff.Get("/staff/my-classes", handlers.GetMyClassesHandler(gormDB))
+	staff.Post("/staff/my-classes/:classRkId", handlers.AddMyClassHandler(gormDB))
+	staff.Delete("/staff/my-classes/:classRkId", handlers.RemoveMyClassHandler(gormDB))
 
 	// Students endpoints
 	staff.Get("/students", handlers.ListAllStudentsHandler(gormDB))
@@ -204,6 +212,7 @@ func main() {
 	staff.Post("/exam-rooms/:id/unpublish", handlers.UnpublishExamRoomHandler(gormDB))
 	staff.Post("/exam-rooms/:id/cancel", handlers.CancelExamRoomHandler(gormDB))
 	staff.Post("/exam-rooms/:id/assign-random", handlers.RandomAssignExamPapersHandler(gormDB))
+	staff.Post("/exam-rooms/:id/assign-papers-batch", handlers.AssignExamPapersBatchHandler(gormDB))
 	staff.Post("/exam-rooms/:id/send-papers", handlers.SendExamPapersHandler(gormDB))
 	staff.Get("/exam-rooms/:id/submissions", handlers.ListExamSubmissionsHandler(gormDB))
 	staff.Get("/exam-rooms/:id/submissions/download-all", handlers.DownloadAllExamSubmissionsHandler(gormDB))