logger.js

import path from "path";
import winston from "winston";

const initializeLogger = () => {
  winston.exceptions.handle = () => {};

  // Set default NYPL agreed upon log levels
  const nyplLogLevels = {
    emergency: 0,
    alert: 1,
    critical: 2,
    error: 3,
    warning: 4,
    notice: 5,
    info: 6,
    debug: 7,
  };

  const getLogLevelCode = (levelString) => {
    switch (levelString) {
      case "emergency":
        return 0;
      case "alert":
        return 1;
      case "critical":
        return 2;
      case "error":
        return 3;
      case "warning":
        return 4;
      case "notice":
        return 5;
      case "info":
        return 6;
      case "debug":
        return 7;
      default:
        return "n/a";
    }
  };

  const { combine, timestamp, printf } = winston.format;

  const formatter = printf((info) => {
    const timestamp = new Date().toISOString();
    const logObject = {
      timestamp,
      pid: process.pid,
      level: info.level,
      levelCode: getLogLevelCode(info.level),
      message: info.message,
    };
    return JSON.stringify(logObject);
  });

  const transports = [
    new winston.transports.Console(),
    new winston.transports.File({
      filename: path.resolve(process.cwd(), "log", "dc.log"),
      // Log format space limited
      format: combine(winston.format.uncolorize(), formatter),
      maxsize: 5242880,
      maxFiles: 5,
    }),
  ];

  return winston.createLogger({
    levels: nyplLogLevels,
    level: process.env.LOG_LEVEL || "info",
    format: combine(
      timestamp({
        format: "YYYY-MM-DD hh:mm:ss.SSS A",
      }),
      formatter
    ),
    transports,
  });
};

const isRunningOnVercel = process.env.VERCEL === "1";

const logger = isRunningOnVercel ? console : initializeLogger();

export default logger;