// /middlewares/activityLogger.js
'use strict';

const activityLogService = require('../components/activityLogs/activityLogService');
const logger = require('../utils/logger');

const SKIP_PREFIXES = [
  '/api/health',
  '/api/activity-logs'
];

const MUTATING_METHODS = new Set(['POST', 'PUT', 'PATCH', 'DELETE']);

const resolveResource = (path = '') => {
  const clean = path.split('?')[0].replace(/^\/api\//, '');
  const [resource] = clean.split('/').filter(Boolean);
  return resource || 'unknown';
};

const resolveResourceId = (req) => {
  if (req.params?.id) return String(req.params.id);
  if (req.params?.userId) return String(req.params.userId);
  if (req.body?._id) return String(req.body._id);
  if (req.body?.id) return String(req.body.id);
  return null;
};

const resolveAction = (method, path = '') => {
  const p = path.toLowerCase();

  if (p.includes('/auth/login')) return 'login';
  if (p.includes('/auth/logout')) return 'logout';
  if (p.includes('/auth/refresh')) return 'other';
  if (p.includes('reset-password')) return 'update';
  if (p.includes('enroll') || p.includes('register')) return 'enroll';
  if (p.includes('attendance')) return 'attendance';
  if (p.includes('upload')) return 'upload';
  if (p.includes('retry')) return 'retry';

  switch (method) {
    case 'POST':
      return 'create';
    case 'PUT':
    case 'PATCH':
      return 'update';
    case 'DELETE':
      return 'delete';
    default:
      return 'other';
  }
};

const shouldSkip = (req) => {
  if (!MUTATING_METHODS.has(req.method)) return true;

  const path = req.originalUrl || req.url || '';
  if (SKIP_PREFIXES.some((prefix) => path.startsWith(prefix))) return true;
  if (path.includes('/auth/refresh')) return true;

  return false;
};

const activityLogger = (req, res, next) => {
  if (shouldSkip(req)) {
    return next();
  }

  res.on('finish', () => {
    // Only persist completed mutating requests (success or business failure)
    if (res.statusCode < 200 || res.statusCode >= 600) return;

    const path = (req.originalUrl || req.url || '').split('?')[0];
    const action = resolveAction(req.method, path);
    const actor = req.user || null;

    const payload = {
      actor: actor?._id || null,
      actorUsername: actor?.username || req.body?.username || null,
      actorName: actor
        ? `${actor.name || ''}`.trim() || actor.username
        : req.body?.username || null,
      action,
      resource: resolveResource(path),
      resourceId: resolveResourceId(req),
      method: req.method,
      path,
      statusCode: res.statusCode,
      ip: req.ip || req.headers['x-forwarded-for'] || req.connection?.remoteAddress || null,
      userAgent: req.headers['user-agent'] || null,
      metadata: {
        params: activityLogService.sanitizeValue(req.params || {}),
        query: activityLogService.sanitizeValue(req.query || {}),
        body: activityLogService.sanitizeValue(req.body || {})
      }
    };

    activityLogService.createActivityLog(payload).catch((err) => {
      logger.error(`[ActivityLog] Failed to write log: ${err.message}`);
    });
  });

  next();
};

module.exports = activityLogger;