const morgan = require('morgan');
const requestIp = require('request-ip');
const config = require('./config');
const logger = require('./logger');

// Custom tokens
morgan.token('clientIp', (req) => {
    const ip = requestIp.getClientIp(req);
    // Anonymize IP in production for GDPR compliance
    return config.env === 'production' && ip 
        ? ip.replace(/\.\d+$/, '.XXX') 
        : ip || 'unknown';
});

morgan.token('error', (req, res) => res.locals.error?.message || '');

// Formats
const getFormat = (isError = false) => {
    const base = `${config.env === 'development' ? ':date[iso] ' : ''}:clientIp - :method :url :status`;
    return isError 
        ? `${base} - :response-time ms - error: :error - referrer: :referrer`
        : `${base} - :response-time ms`;
};

// Success handler (2xx, 3xx responses)
const successHandler = morgan(getFormat(), {
    skip: (req, res) => res.statusCode >= 400,
    stream: { 
        write: (msg) => logger.info(msg.trim()) 
    }
});

// Error handler (4xx, 5xx responses)
const errorHandler = morgan(getFormat(true), {
    skip: (req, res) => res.statusCode < 400,
    stream: { 
        write: (msg) => {
            const status = msg.match(/:status (\d+)/)?.[1] || 500;
            status >= 500 ? logger.error(msg.trim()) : logger.warn(msg.trim());
        } 
    }
});

module.exports = { successHandler, errorHandler };