feat: data export — CSV export for tasks, users, activities

- Backend: GET /api/export/{tasks,users,activities}?month=YYYY-MM
- Frontend: Export panel on Reports page (CEO/CTO/Manager only)
- API: apiExportCsv helper for browser download

server/index.js

@@ -3,6 +3,7 @@ import cors from 'cors';
 import { initDB } from './db.js';
 import authRoutes from './routes/auth.js';
 import taskRoutes from './routes/tasks.js';
+import exportRoutes from './routes/export.js';
 
 const app = express();
 const PORT = process.env.PORT || 3001;
@@ -13,6 +14,7 @@ app.use(express.json());
 // Routes
 app.use('/api/auth', authRoutes);
 app.use('/api/tasks', taskRoutes);
+app.use('/api/export', exportRoutes);
 
 // Health check
 app.get('/api/health', (_req, res) => {

server/routes/export.js

@@ -0,0 +1,131 @@
+import { Router } from 'express';
+import pool from '../db.js';
+
+const router = Router();
+
+// Helper: escape CSV field
+function csvEscape(val) {
+    if (val == null) return '';
+    const str = String(val);
+    if (str.includes(',') || str.includes('"') || str.includes('\n')) {
+        return `"${str.replace(/"/g, '""')}"`;
+    }
+    return str;
+}
+
+// Helper: convert rows to CSV string
+function toCsv(headers, rows) {
+    const headerLine = headers.map(csvEscape).join(',');
+    const dataLines = rows.map(row => headers.map(h => csvEscape(row[h])).join(','));
+    return [headerLine, ...dataLines].join('\n');
+}
+
+// Helper: build month filter clause for a date column
+function monthFilter(column, month) {
+    if (!month || !/^\d{4}-\d{2}$/.test(month)) return { clause: '', params: [] };
+    const [year, mon] = month.split('-');
+    const start = `${year}-${mon}-01`;
+    // Last day of month
+    const nextMonth = parseInt(mon) === 12 ? `${parseInt(year) + 1}-01-01` : `${year}-${String(parseInt(mon) + 1).padStart(2, '0')}-01`;
+    return { clause: ` AND ${column} >= ? AND ${column} < ?`, params: [start, nextMonth] };
+}
+
+// GET /api/export/tasks?month=YYYY-MM
+router.get('/tasks', async (req, res) => {
+    try {
+        const { month } = req.query;
+        const mf = monthFilter('t.due_date', month);
+
+        const [rows] = await pool.query(`
+            SELECT t.id, t.title, t.description, t.status, t.priority,
+                   t.due_date, t.created_at,
+                   a.name AS assignee_name, a.email AS assignee_email,
+                   r.name AS reporter_name,
+                   GROUP_CONCAT(tt.tag SEPARATOR '; ') AS tags
+            FROM tasks t
+            LEFT JOIN users a ON t.assignee_id = a.id
+            LEFT JOIN users r ON t.reporter_id = r.id
+            LEFT JOIN task_tags tt ON tt.task_id = t.id
+            WHERE 1=1 ${mf.clause}
+            GROUP BY t.id
+            ORDER BY t.created_at DESC
+        `, mf.params);
+
+        const csv = toCsv(
+            ['id', 'title', 'description', 'status', 'priority', 'due_date', 'created_at', 'assignee_name', 'assignee_email', 'reporter_name', 'tags'],
+            rows
+        );
+
+        const filename = month ? `tasks_${month}.csv` : 'tasks_all.csv';
+        res.setHeader('Content-Type', 'text/csv');
+        res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
+        res.send(csv);
+    } catch (err) {
+        console.error('Export tasks error:', err);
+        res.status(500).json({ error: 'Export failed' });
+    }
+});
+
+// GET /api/export/users?month=YYYY-MM
+router.get('/users', async (req, res) => {
+    try {
+        const { month } = req.query;
+        const mf = monthFilter('t.due_date', month);
+
+        const [rows] = await pool.query(`
+            SELECT u.id, u.name, u.email, u.role, u.dept,
+                   COUNT(t.id) AS total_tasks,
+                   SUM(CASE WHEN t.status = 'done' THEN 1 ELSE 0 END) AS completed_tasks,
+                   SUM(CASE WHEN t.status != 'done' AND t.due_date < CURDATE() THEN 1 ELSE 0 END) AS overdue_tasks
+            FROM users u
+            LEFT JOIN tasks t ON t.assignee_id = u.id ${mf.clause ? 'AND' + mf.clause.replace(' AND', '') : ''}
+            GROUP BY u.id
+            ORDER BY u.name
+        `, mf.params);
+
+        const csv = toCsv(
+            ['id', 'name', 'email', 'role', 'dept', 'total_tasks', 'completed_tasks', 'overdue_tasks'],
+            rows
+        );
+
+        const filename = month ? `users_${month}.csv` : 'users_all.csv';
+        res.setHeader('Content-Type', 'text/csv');
+        res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
+        res.send(csv);
+    } catch (err) {
+        console.error('Export users error:', err);
+        res.status(500).json({ error: 'Export failed' });
+    }
+});
+
+// GET /api/export/activities?month=YYYY-MM
+router.get('/activities', async (req, res) => {
+    try {
+        const { month } = req.query;
+        const mf = monthFilter('a.timestamp', month);
+
+        const [rows] = await pool.query(`
+            SELECT a.id, a.text AS activity, a.timestamp,
+                   t.title AS task_title, t.status AS task_status
+            FROM activities a
+            LEFT JOIN tasks t ON a.task_id = t.id
+            WHERE 1=1 ${mf.clause}
+            ORDER BY a.timestamp DESC
+        `, mf.params);
+
+        const csv = toCsv(
+            ['id', 'activity', 'timestamp', 'task_title', 'task_status'],
+            rows
+        );
+
+        const filename = month ? `activities_${month}.csv` : 'activities_all.csv';
+        res.setHeader('Content-Type', 'text/csv');
+        res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
+        res.send(csv);
+    } catch (err) {
+        console.error('Export activities error:', err);
+        res.status(500).json({ error: 'Export failed' });
+    }
+});
+
+export default router;

src/App.tsx

@@ -240,7 +240,7 @@ export default function App() {
               filterUser={null} searchQuery={searchQuery} onToggleDone={handleToggleDone} users={users} />
           )}
           {displayPage === 'teamtasks' && <TeamTasksPage tasks={tasks} currentUser={currentUser} users={users} />}
-          {displayPage === 'reports' && <ReportsPage tasks={tasks} users={users} />}
+          {displayPage === 'reports' && <ReportsPage tasks={tasks} users={users} currentUser={currentUser} />}
           {displayPage === 'members' && <MembersPage tasks={tasks} users={users} currentUser={currentUser} onAddUser={handleAddUser} onDeleteUser={handleDeleteUser} />}
         </div>
       </div>

src/Reports.tsx

@@ -1,5 +1,7 @@
+import { useState } from 'react';
 import type { Task, User } from './data';
 import { STATUS_COLORS, PRIORITY_COLORS } from './data';
+import { apiExportCsv } from './api';
 import { BarChart, Bar, PieChart, Pie, Cell, LineChart, Line, XAxis, YAxis, Tooltip, ResponsiveContainer, Legend } from 'recharts';
 
 const tooltipStyle = {
@@ -8,7 +10,12 @@ const tooltipStyle = {
     labelStyle: { color: '#94a3b8' },
 };
 
-export function ReportsPage({ tasks, users }: { tasks: Task[]; users: User[] }) {
+export function ReportsPage({ tasks, users, currentUser }: { tasks: Task[]; users: User[]; currentUser: User }) {
+    const [exportType, setExportType] = useState<'tasks' | 'users' | 'activities'>('tasks');
+    const [exportMonth, setExportMonth] = useState('');
+    const [exporting, setExporting] = useState(false);
+
+    const canExport = ['ceo', 'cto', 'manager'].includes(currentUser.role);
     const total = tasks.length;
     const completed = tasks.filter(t => t.status === 'done').length;
     const overdue = tasks.filter(t => new Date(t.dueDate + 'T00:00:00') < new Date() && t.status !== 'done').length;
@@ -113,6 +120,44 @@ export function ReportsPage({ tasks, users }: { tasks: Task[]; users: User[] })
                     </ResponsiveContainer>
                 </div>
             </div>
+
+            {canExport && (
+                <div className="chart-card" style={{ marginTop: 24 }}>
+                    <div className="chart-card-title" style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+                        <span>📥</span> Export Data
+                    </div>
+                    <div style={{ display: 'flex', gap: 12, alignItems: 'flex-end', flexWrap: 'wrap' }}>
+                        <div className="modal-field" style={{ margin: 0 }}>
+                            <label style={{ fontSize: 11, color: '#94a3b8', display: 'block', marginBottom: 4 }}>Dataset</label>
+                            <select className="modal-input" style={{ width: 160 }} value={exportType} onChange={e => setExportType(e.target.value as 'tasks' | 'users' | 'activities')}>
+                                <option value="tasks">Tasks</option>
+                                <option value="users">Users & Workload</option>
+                                <option value="activities">Activity Log</option>
+                            </select>
+                        </div>
+                        <div className="modal-field" style={{ margin: 0 }}>
+                            <label style={{ fontSize: 11, color: '#94a3b8', display: 'block', marginBottom: 4 }}>Month (optional)</label>
+                            <input className="modal-input" type="month" style={{ width: 160 }} value={exportMonth} onChange={e => setExportMonth(e.target.value)} />
+                        </div>
+                        <button
+                            className="btn-primary"
+                            disabled={exporting}
+                            onClick={async () => {
+                                setExporting(true);
+                                try {
+                                    await apiExportCsv(exportType, exportMonth || undefined);
+                                } catch (err) {
+                                    console.error('Export failed:', err);
+                                } finally {
+                                    setExporting(false);
+                                }
+                            }}
+                        >
+                            {exporting ? 'Exporting...' : '⬇ Download CSV'}
+                        </button>
+                    </div>
+                </div>
+            )}
         </div>
     );
 }

src/api.ts

@@ -48,6 +48,21 @@ export async function apiDeleteUser(id: string) {
     });
 }
 
+export async function apiExportCsv(type: 'tasks' | 'users' | 'activities', month?: string) {
+    const params = month ? `?month=${month}` : '';
+    const res = await fetch(`${API_BASE}/export/${type}${params}`);
+    if (!res.ok) throw new Error('Export failed');
+    const blob = await res.blob();
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = month ? `${type}_${month}.csv` : `${type}_all.csv`;
+    document.body.appendChild(a);
+    a.click();
+    document.body.removeChild(a);
+    URL.revokeObjectURL(url);
+}
+
 // Tasks
 export async function apiFetchTasks() {
     return request('/tasks');