import * as log from "@thi.ng/rstream-logger";

const logger = new log.Logger("main");
// or with min level
const logger = new log.Logger("main", log.Level.DEBUG);

// add console output w/ string formatter (a transducer)
logger.subscribe(log.writeConsole(), log.formatString());

// add file output w/ JSON output & post-filtering (only WARN or ERROR levels)
import * as tx from "@thi.ng/transducers";
logger.subscribe(
    log.writeFile("main.log"),
    // compose filter + formatter transducers
    tx.comp(log.minLevel(log.Level.WARN), log.formatJSON())
);

logger.debug("hello world");

// only shown in console:
// [DEBUG] [main] 2018-01-20T09:04:05.198Z hello world

logger.warn("eek"); // shown in console & appended to file

// console:
// [WARN] [main] 2018-01-20T09:04:16.913Z eek

// file:
// {"level":"WARN","id":"main","time":"2018-01-23T09:05:55.647Z","body":["eek"]}

// each logger instance is a rstream StreamMerge instance
// allowing to form logger hierarchies

const mod1 = new log.Logger("module-1", log.Level.INFO);
// pipe mod1 into main logger
logger.add(mod1);

import { postWorker } from "@thi.ng/rstream";
// additionally send messages from this logger to worker
mod1.subscribe(postWorker("log-worker.js"));

mod1.info("hi from sub-module");

// only shown in console:
// [INFO] [module-1] 2018-01-20T09:05:21.198Z hi from sub-module