const db = require('../db');

/**
 * Middleware to check if a module is active.
 * @param {string} moduleCode - Code of the module to check (e.g., 'monitoring', 'asset', 'production')
 */
const requireModule = (moduleCode) => {
    return async (req, res, next) => {
        try {
            const [rows] = await db.query(
                'SELECT is_active, expiry_date FROM system_modules WHERE code = ?',
                [moduleCode]
            );

            if (rows.length === 0 || !rows[0].is_active) {
                return res.status(403).json({
                    error: 'Module Not Active',
                    message: `The '${moduleCode}' module is not active. Please activate a license first.`
                });
            }

            const moduleData = rows[0];
            if (moduleData.expiry_date) {
                const now = new Date();
                const expiry = new Date(moduleData.expiry_date);
                if (now > expiry) {
                    return res.status(403).json({
                        error: 'License Expired',
                        message: `The license for '${moduleCode}' has expired on ${moduleData.expiry_date}.`
                    });
                }
            }

            next();
        } catch (err) {
            console.error('[License Check Error]', err);
            res.status(500).json({ error: 'Internal Server Error' });
        }
    };
};

module.exports = { requireModule };