// --- Time Tracker Backend Server (Updated) ---

require('dotenv').config();
const express = require('express');
const sqlite3 = require('sqlite3');
const { open } = require('sqlite');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const cors = require('cors');
const path = require('path');

const PORT = process.env.PORT || 3000;
const JWT_SECRET = process.env.JWT_SECRET || 'default_secret_key';
const ADMIN_USERNAME = process.env.ADMIN_USERNAME || 'admin';
const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD || 'adminpassword';

const app = express();
app.use(cors());
app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

let db;

async function startServer() {
  try {
    const dbPath = path.resolve(__dirname, 'data', 'timetracker.db');
    db = await open({ filename: dbPath, driver: sqlite3.Database });
    console.log("Connected to the SQLite database.");
    await initializeDatabase();
    setupRoutes();
    app.listen(PORT, () => console.log(`Server running on http://localhost:${PORT}`));
  } catch (err) {
    console.error("FATAL: Could not start server.", err);
    process.exit(1);
  }
}

async function initializeDatabase() {
  console.log("Initializing database schema...");
  await db.exec(`CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    username TEXT UNIQUE NOT NULL,
    password TEXT NOT NULL,
    role TEXT NOT NULL DEFAULT 'employee'
  )`);
  await db.exec(`CREATE TABLE IF NOT EXISTS time_entries (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    user_id INTEGER NOT NULL,
    username TEXT,
    punch_in_time DATETIME NOT NULL,
    punch_out_time DATETIME,
    status TEXT NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
  )`);
  await db.exec(`CREATE TABLE IF NOT EXISTS archived_time_entries (
    id INTEGER PRIMARY KEY,
    user_id INTEGER NOT NULL,
    username TEXT,
    punch_in_time DATETIME NOT NULL,
    punch_out_time DATETIME,
    status TEXT NOT NULL,
    archived_at DATETIME NOT NULL
  )`);
  await db.exec(`CREATE TABLE IF NOT EXISTS time_off_requests (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    user_id INTEGER NOT NULL,
    username TEXT,
    start_date TEXT NOT NULL,
    end_date TEXT NOT NULL,
    reason TEXT,
    status TEXT NOT NULL DEFAULT 'pending',
    FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
  )`);
  const adminUser = await db.get('SELECT * FROM users WHERE username = ?', [ADMIN_USERNAME]);
  if (!adminUser) {
    const hashedPassword = await bcrypt.hash(ADMIN_PASSWORD, 10);
    await db.run('INSERT INTO users (username, password, role) VALUES (?, ?, ?)', [ADMIN_USERNAME, hashedPassword, 'admin']);
    console.log("Primary admin user created.");
  }
  console.log("Database initialization complete.");
}

function setupRoutes() {
  const authenticateToken = (req, res, next) => {
    const token = req.headers['authorization']?.split(' ')[1];
    if (!token) return res.status(401).json({ message: "Authentication required. No token provided." });
    jwt.verify(token, JWT_SECRET, (err, user) => {
      if (err) return res.status(403).json({ message: "Access denied. Invalid or expired token." });
      req.user = user;
      next();
    });
  };

  const requireRole = (role) => (req, res, next) => {
    if (req.user && req.user.role === role) next();
    else res.status(403).json({ message: "Access denied." });
  };

  // --- Auth ---
  app.post('/api/login', async (req, res) => {
    try {
      const { username, password } = req.body;
      const user = await db.get('SELECT * FROM users WHERE username = ?', [username]);
      if (!user) return res.status(404).json({ message: "User not found." });
      const isMatch = await bcrypt.compare(password, user.password);
      if (!isMatch) return res.status(401).json({ message: "Invalid credentials." });
      const tokenPayload = { id: user.id, username: user.username, role: user.role };
      const token = jwt.sign(tokenPayload, JWT_SECRET, { expiresIn: '8h' });
      res.json({ token, user: tokenPayload });
    } catch {
      res.status(500).json({ message: "Server error during login." });
    }
  });

  // --- Punch ---
  app.post('/api/punch', authenticateToken, async (req, res) => {
    try {
      const { id, username } = req.user;
      const openPunch = await db.get(`SELECT * FROM time_entries WHERE user_id = ? AND status = 'in' ORDER BY punch_in_time DESC LIMIT 1`, [id]);
      const now = new Date().toISOString();

      if (openPunch) {
        await db.run(`UPDATE time_entries SET punch_out_time = ?, status = 'out' WHERE id = ?`, [now, openPunch.id]);
        res.json({ message: "Punched out." });
      } else {
        await db.run(`INSERT INTO time_entries (user_id, username, punch_in_time, status) VALUES (?, ?, ?, 'in')`, [id, username, now]);
        res.json({ message: "Punched in." });
      }
    } catch {
      res.status(500).json({ message: "Server error during punch." });
    }
  });

  app.get('/api/status', authenticateToken, async (req, res) => {
    try {
      const rows = await db.all(`SELECT * FROM time_entries WHERE user_id = ? ORDER BY punch_in_time DESC`, [req.user.id]);
      res.json(rows);
    } catch {
      res.status(500).json({ message: "Server error fetching status." });
    }
  });

  // --- User ---
  app.post('/api/user/change-password', authenticateToken, async (req, res) => {
    try {
      const { currentPassword, newPassword } = req.body;
      const user = await db.get('SELECT * FROM users WHERE id = ?', [req.user.id]);
      if (!user) return res.status(404).json({ message: "User not found." });
      const isMatch = await bcrypt.compare(currentPassword, user.password);
      if (!isMatch) return res.status(401).json({ message: "Incorrect current password." });
      const hashed = await bcrypt.hash(newPassword, 10);
      await db.run('UPDATE users SET password = ? WHERE id = ?', [hashed, req.user.id]);
      res.json({ message: "Password updated successfully." });
    } catch {
      res.status(500).json({ message: "Error changing password." });
    }
  });

  app.post('/api/user/request-time-off', authenticateToken, async (req, res) => {
    try {
      const { startDate, endDate, reason } = req.body;
      const { id, username } = req.user;
      await db.run(`INSERT INTO time_off_requests (user_id, username, start_date, end_date, reason) VALUES (?, ?, ?, ?, ?)`, [id, username, startDate, endDate, reason]);
      res.status(201).json({ message: "Time off request submitted." });
    } catch {
      res.status(500).json({ message: "Failed to submit request." });
    }
  });

  app.get('/api/user/time-off-requests', authenticateToken, async (req, res) => {
    try {
      const rows = await db.all("SELECT * FROM time_off_requests WHERE user_id = ? ORDER BY start_date DESC", [req.user.id]);
      res.json(rows);
    } catch {
      res.status(500).json({ message: "Failed to fetch requests." });
    }
  });

  // --- Admin Tools ---
  app.post('/api/admin/force-clock-out', authenticateToken, requireRole('admin'), async (req, res) => {
    try {
      const { userId } = req.body;
      const punch = await db.get(`SELECT * FROM time_entries WHERE user_id = ? AND status = 'in' ORDER BY punch_in_time DESC LIMIT 1`, [userId]);
      if (!punch) return res.status(404).json({ message: "No active punch-in found." });
      await db.run(`UPDATE time_entries SET punch_out_time = ?, status = 'out' WHERE id = ?`, [new Date().toISOString(), punch.id]);
      res.json({ message: "User has been clocked out." });
    } catch {
      res.status(500).json({ message: "Server error forcing clock out." });
    }
  });

  app.post('/api/cleanup/malformed-entries', authenticateToken, requireRole('admin'), async (req, res) => {
    try {
      const result = await db.run(`
        UPDATE time_entries
        SET status = 'out'
        WHERE status = 'in' AND punch_out_time IS NOT NULL
      `);
      res.json({ message: `Corrected ${result.changes} malformed entries.` });
    } catch (err) {
      console.error("Error during cleanup:", err);
      res.status(500).json({ message: "Server error during cleanup." });
    }
  });
  app.get('/api/admin/logs', authenticateToken, requireRole('admin'), async (req, res) => {
    try {
        const rows = await db.all("SELECT * FROM time_entries ORDER BY punch_in_time DESC");
        res.json(rows);
    } catch {
        res.status(500).json({ message: "Server error fetching logs." });
    }
});

// THIS IS THE NEW/FIXED ROUTE
app.put('/api/admin/logs/:id', authenticateToken, requireRole('admin'), async (req, res) => {
    try {
        const { id } = req.params;
        const { punch_in_time, punch_out_time } = req.body;

        // **THE FIX IS HERE**
        // Determine the correct status based on the punch_out_time.
        const status = punch_out_time ? 'out' : 'in';

        await db.run(
            `UPDATE time_entries 
             SET punch_in_time = ?, punch_out_time = ?, status = ?
             WHERE id = ?`,
            [punch_in_time, punch_out_time, status, id]
        );
        res.json({ message: 'Entry updated successfully.' });
    } catch (err) {
        console.error("Error updating log:", err);
        res.status(500).json({ message: 'Failed to update entry.' });
    }
});
  // Other admin routes (logs, users, roles, etc.) stay the same...
}

startServer();