OmniRoute/src/shared/utils/logger.ts

/**
 * Structured Logger — Pino-based logger for OmniRoute
 *
 * Usage:
 *   import { logger } from "@/shared/utils/logger";
 *   const log = logger.child({ module: "proxy" });
 *   log.info({ model: "gpt-4o" }, "Request received");
 *   log.error({ err }, "Connection failed");
 *
 * In development, output is pretty-printed via pino-pretty.
 * In production, output is structured JSON for log aggregation.
 */
import pino from "pino";

const isDev = process.env.NODE_ENV !== "production";

const baseConfig = {
  level: process.env.LOG_LEVEL || (isDev ? "debug" : "info"),
  base: { service: "omniroute" },
  timestamp: pino.stdTimeFunctions.isoTime,
  formatters: {
    level(label) {
      return { level: label };
    },
  },
};

// In development, use pino-pretty for human-readable output
const devTransport = isDev
  ? {
      transport: {
        target: "pino-pretty",
        options: {
          colorize: true,
          translateTime: "HH:MM:ss.l",
          ignore: "pid,hostname,service",
          messageFormat: "[{module}] {msg}",
        },
      },
    }
  : {};

export const logger = pino({ ...baseConfig, ...devTransport });

/**
 * Create a child logger with a module tag.
 * @param {string} module - Module name for log context (e.g., "proxy", "db", "sse")
 * @returns {pino.Logger}
 */
export function createLogger(module) {
  return logger.child({ module });
}

export default logger;