import jsLogger from 'js-logger'
import { version } from '../package.json'
/**
* @module Logger
* @description Manages all log messages from SDK modules, you can use this logger to add your custom
* messages and set your custom log handlers to forward all messages to your own monitoring
* system.
*
* By default all loggers are set in level OFF (Logger.OFF), and there are available
* the following log levels.
*
* This module is based on [js-logger](https://github.com/jonnyreeves/js-logger) you can refer
* to its documentation or following our examples.
* @example
* // Log a message
* Logger.info('This is an info log', 445566)
* // [Global] 2021-04-05T15:58:44.893Z - This is an info log 445566
* @example
* // Create a named logger
* const myLogger = Logger.get('CustomLogger')
* myLogger.setLevel(Logger.WARN)
* myLogger.warn('This is a warning log')
* // [CustomLogger] 2021-04-05T15:59:53.377Z - This is a warning log
* @example
* // Profiling
* // Start timing something
* Logger.time('Timer name')
*
* // ... some time passes ...
*
* // Stop timing something.
* Logger.timeEnd('Timer name')
* // Timer name: 35282.997802734375 ms
*/
jsLogger.useDefaults({ defaultLevel: jsLogger.TRACE })
const formatter = (messages, context) => {
messages.unshift(`[${context.name || 'Global'}] ${new Date().toISOString()} - ${context.level.name} -`)
}
const enabledFor = (level, loggerName) => {
if (loggerName) {
return level.value >= namedLoggerLevels[loggerName].value
}
return level.value >= loggerLevel.value
}
const historyHandler = (messages, context) => {
messages = Array.prototype.slice.call(messages)
messages = messages.map((m) => typeof m === 'object' ? JSON.stringify(m) : m)
formatter(messages, context)
if (maxLogHistorySize !== 0) {
history.push(messages.join(' '))
if (history.length >= maxLogHistorySize) {
history = history.slice(-maxLogHistorySize)
}
} else {
history = []
}
}
const consoleHandler = jsLogger.createDefaultHandler({ formatter })
jsLogger.setHandler((messages, context) => {
historyHandler(messages, context)
if (enabledFor(context.level, context.name)) {
consoleHandler(messages, context)
}
for (const { handler, level } of customHandlers) {
if (context.level.value >= level.value) {
handler(messages, context)
}
}
})
const DEFAULT_LOG_HISTORY_SIZE = 10000
let maxLogHistorySize = DEFAULT_LOG_HISTORY_SIZE
let history = []
let loggerLevel = jsLogger.OFF
const namedLoggerLevels = {}
const customHandlers = []
/**
* @typedef {Object} LogLevel
* @global
* @property {Number} value - The numerical representation of the level.
* @property {String} name - Human readable name of the log level.
*/
/** @constant {LogLevel} TRACE - Logger.TRACE */
/** @constant {LogLevel} DEBUG - Logger.DEBUG */
/** @constant {LogLevel} INFO - Logger.INFO */
/** @constant {LogLevel} TIME - Logger.TIME */
/** @constant {LogLevel} WARN - Logger.WARN */
/** @constant {LogLevel} ERROR - Logger.ERROR */
/** @constant {LogLevel} OFF - Logger.OFF */
const Logger = {
...jsLogger,
enabledFor,
/**
* @function
* @name getHistory
* @description Get all logs generated during a session.
* All logs are recollected besides the log level selected by the user.
* @returns {Array<String>} All logs recollected from level TRACE.
* @example Logger.getHistory()
* // Outupt
* // [
* // "[Director] 2021-04-05T14:09:26.625Z - Getting publisher connection data for stream name: 1xxx2",
* // "[Director] 2021-04-05T14:09:27.064Z - Getting publisher response",
* // "[Publish] 2021-04-05T14:09:27.066Z - Broadcasting"
* // ]
*/
getHistory: () => history,
/**
* @function
* @name getHistoryMaxSize
* @description Get the maximum count of logs preserved during a session.
* @example Logger.getHistoryMaxSize()
*/
getHistoryMaxSize: () => maxLogHistorySize,
/**
* @function
* @name setHistoryMaxSize
* @description Set the maximum count of logs to preserve during a session.
* By default it is set to 10000.
* @param {Number} maxSize - Max size of log history. Set 0 to disable history or -1 to unlimited log history.
* @example Logger.setHistoryMaxSize(100)
*/
setHistoryMaxSize: maxSize => { maxLogHistorySize = maxSize },
/**
* @function
* @name setLevel
* @description Set log level to all loggers.
* @param {LogLevel} level - New log level to be set.
* @example
* // Global Level
* Logger.setLevel(Logger.DEBUG)
*
* // Module Level
* Logger.get('Publish').setLevel(Logger.DEBUG)
*/
setLevel: level => {
loggerLevel = level
for (const key in namedLoggerLevels) {
namedLoggerLevels[key] = level
}
},
/**
* @function
* @name getLevel
* @description Get global current logger level.
* Also you can get the level of any particular logger.
* @returns {LogLevel}
* @example
* // Global Level
* Logger.getLevel()
* // Output
* // {value: 2, name: 'DEBUG'}
*
* // Module Level
* Logger.get('Publish').getLevel()
* // Output
* // {value: 5, name: 'WARN'}
*/
getLevel: () => loggerLevel,
/**
* @function
* @name get
* @description Gets or creates a named logger. Named loggers are used to group log messages
* that refers to a common context.
* @param {String} name
* @returns {Object} Logger object with same properties and functions as Logger except
* history and handlers related functions.
* @example
* const myLogger = Logger.get('MyLogger')
* // Set logger level
* myLogger.setLevel(Logger.DEBUG)
*
* myLogger.debug('This is a debug log')
* myLogger.info('This is a info log')
* myLogger.warn('This is a warning log')
*
* // Get logger level
* myLogger.getLevel()
* // {value: 3, name: 'INFO'}
*/
get: name => {
if (!namedLoggerLevels[name]) {
namedLoggerLevels[name] = loggerLevel
}
const logger = jsLogger.get(name)
logger.setLevel = (level) => { namedLoggerLevels[name] = level }
logger.getLevel = () => namedLoggerLevels[name]
return logger
},
/**
* Callback which handles log messages.
*
* @callback loggerHandler
* @global
* @param {any[]} messages - Arguments object with the supplied log messages.
* @param {Object} context
* @param {LogLevel} context.level - The currrent log level.
* @param {String?} context.name - The optional current logger name.
*/
/**
* @function
* @name setHandler
* @description Add your custom log handler to Logger at the specified level.
* @param {loggerHandler} handler - Your custom log handler function.
* @param {LogLevel} level - Log level to filter messages.
* @example
* const myHandler = (messages, context) => {
* // You can filter by logger
* if (context.name === 'Publish') {
* sendToMyLogger(messages[0])
* }
*
* // You can filter by logger level
* if (context.level.value >= Logger.INFO.value) {
* sendToMyLogger(messages[0])
* }
* }
*
* Logger.setHandler(myHandler, Logger.INFO)
*/
setHandler: (handler, level) => { customHandlers.push({ handler, level }) },
VERSION: version
}
export default Logger