/***********************************************************************************************************************************************************************
 * File Name: users.controller.js  (staff)
 * Type of Program: Controller
 * Description: Staff-level user management.
 *              Staff can VIEW any client/staff user and perform limited actions.
 *              Staff CANNOT modify admin accounts or assign/revoke admin roles.
 *
 *              Endpoints (require authenticate → requireStaff()):
 *              GET  /api/staff/users             → paginated user list (non-admins)
 *              GET  /api/staff/users/:id         → view any non-admin user
 *              PUT  /api/staff/users/:id/status  → activate / deactivate user
 *              GET  /api/staff/users/:id/sessions → view user sessions
 *
 * Author: rgrgogu
 * Date Created: Oct. 6, 2025
 ***********************************************************************************************************************************************************************/
const { Op }           = require('sequelize');
const mdl_Users        = require('../../models/users/users.mdl');
const mdl_UserSessions = require('../../models/users/user_sessions.mdl');
const logActivity      = require('../../utils/logActivity.util');
const R                = require('../../utils/response.util');

const EXCLUDED = ['password', 'otp_code', 'otp_expires_at'];

// ─── GET paginated list (no admins) ────────────────────────────────────────────
exports.getUsers = async (req, res) => {
  try {
    const page  = Math.max(1, parseInt(req.query.page)  || 1);
    const limit = Math.min(100, parseInt(req.query.limit) || 20);
    const offset = (page - 1) * limit;

    const { count, rows } = await mdl_Users.findAndCountAll({
      where:      { acc_type: { [Op.ne]: 'admin' } },
      attributes: { exclude: EXCLUDED },
      limit,
      offset,
      order:      [['createdAt', 'DESC']],
    });

    return R.success(res, 'Users retrieved.', {
      total: count,
      page,
      totalPages: Math.ceil(count / limit),
      users: rows,
    });
  } catch (err) {
    console.error('[STAFF] getUsers error:', err);
    return R.error(res, 'Could not retrieve users.', 500);
  }
};

// ─── GET single non-admin user ─────────────────────────────────────────────────
exports.getUser = async (req, res) => {
  try {
    const user = await mdl_Users.findOne({
      where:      { user_id: req.params.id, acc_type: { [Op.ne]: 'admin' } },
      attributes: { exclude: EXCLUDED },
    });
    if (!user) return R.error(res, 'User not found.', 404);
    return R.success(res, 'User retrieved.', user);
  } catch (err) {
    return R.error(res, 'Could not retrieve user.', 500);
  }
};

// ─── PUT activate / deactivate ─────────────────────────────────────────────────
exports.setUserStatus = async (req, res) => {
  try {
    const { is_active } = req.body;
    if (typeof is_active !== 'boolean')
      return R.error(res, 'is_active must be a boolean.', 400);

    const user = await mdl_Users.findOne({
      where: { user_id: req.params.id, acc_type: { [Op.ne]: 'admin' } },
    });
    if (!user) return R.error(res, 'User not found or operation not permitted.', 404);

    await user.update({ is_active });

    logActivity(req.user.user_id, 'set_user_status', {
      entityType: 'user',
      entityId:   Number(req.params.id),
      metadata:   { is_active },
    });

    return R.success(res, `User ${is_active ? 'activated' : 'deactivated'}.`);
  } catch (err) {
    return R.error(res, 'Could not update user status.', 500);
  }
};

// ─── GET user sessions ─────────────────────────────────────────────────────────
exports.getUserSessions = async (req, res) => {
  try {
    const user = await mdl_Users.findOne({
      where: { user_id: req.params.id, acc_type: { [Op.ne]: 'admin' } },
    });
    if (!user) return R.error(res, 'User not found.', 404);

    const sessions = await mdl_UserSessions.findAll({
      where:      { user_id: req.params.id },
      attributes: { exclude: ['refresh_token_hash'] },
      order:      [['createdAt', 'DESC']],
    });
    return R.success(res, 'Sessions retrieved.', sessions);
  } catch (err) {
    return R.error(res, 'Could not retrieve sessions.', 500);
  }
};

// ─── Staff profile (re-use client controller) ──────────────────────────────────
// Staff also manage their own profile through the same client endpoints.
// No additional staff-specific profile endpoints needed.