hrms-api-kpi/src/middlewares/logs.ts

import { NextFunction, Request, Response } from "express";
import { Client } from "@elastic/elasticsearch";
import permission from "../interfaces/permission";

if (!process.env.ELASTICSEARCH_INDEX) {
  throw new Error("Require ELASTICSEARCH_INDEX to store log.");
}

const ELASTICSEARCH_INDEX = process.env.ELASTICSEARCH_INDEX;

const LOG_LEVEL_MAP: Record<string, number> = {
  debug: 4,
  info: 3,
  warning: 2,
  error: 1,
  none: 0,
};

const elasticsearch = new Client({
  node: `${process.env.ELASTICSEARCH_PROTOCOL}://${process.env.ELASTICSEARCH_HOST}:${process.env.ELASTICSEARCH_PORT}`,
});

async function logMiddleware(req: Request, res: Response, next: NextFunction) {
  if (!req.url.startsWith("/api/")) return next();

  let data: any;

  const originalJson = res.json;

  res.json = function (v: any) {
    data = v;
    return originalJson.call(this, v);
  };

  const timestamp = new Date().toISOString();
  const start = performance.now();

  req.app.locals.logData = {};

  res.on("finish", async () => {
    if (!req.url.startsWith("/api/")) return;

    const level = LOG_LEVEL_MAP[process.env.LOG_LEVEL ?? "debug"] || 4;

    if (level === 1 && res.statusCode < 500) return;
    if (level === 2 && res.statusCode < 400) return;
    if (level === 3 && res.statusCode < 200) return;
    let token: any; 
    token = req.headers['authorization']
    
    const rootId = await new permission().checkOrg(token,req.app.locals.logData.userId);
    
    const obj = {
      logType: res.statusCode >= 500 ? "error" : res.statusCode >= 400 ? "warning" : "info",
      ip: req.ip,
      rootId: rootId?rootId.orgRootId:null,
      systemName: "KPI",
      startTimeStamp: timestamp,
      endTimeStamp: new Date().toISOString(),
      processTime: performance.now() - start,
      host: req.hostname,
      method: req.method,
      endpoint: req.url,
      responseCode: String(res.statusCode === 304 ? 200 : res.statusCode),
      responseDescription: data?.message,
      input: (level === 4 && JSON.stringify(req.body, null, 2)) || undefined,
      output: (level === 4 && JSON.stringify(data, null, 2)) || undefined,
      ...req.app.locals.logData,
    };

    elasticsearch.index({
      index: ELASTICSEARCH_INDEX,
      document: obj,
    });
  });

  return next();
}

export default logMiddleware;