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wiki/backend/core/logger.ts

93 lines
2.7 KiB

import chalk from 'chalk'
import EventEmitter from 'node:events'
export type LogLevel = 'error' | 'warn' | 'info' | 'debug'
export type IgnoredLogLevel = 'verbose' | 'silly'
export type LogFn = (...args: unknown[]) => void
/**
* Formatted lines kept in memory, replayed to an admin terminal the moment it connects
* (`controllers/terminal.ts`). Enough to see how the instance got to where it is, not a log file.
*/
const BACKLOG_SIZE = 100
const LEVELS: LogLevel[] = ['error', 'warn', 'info', 'debug']
const LEVELSIGNORED: IgnoredLogLevel[] = ['verbose', 'silly']
const LEVELCOLORS: Record<LogLevel, 'red' | 'yellow' | 'green' | 'cyan'> = {
error: 'red',
warn: 'yellow',
info: 'green',
debug: 'cyan'
}
class Logger extends EventEmitter {
// -> Assigned dynamically in init(). `declare` keeps these type-only so that no class field is
// emitted, leaving the runtime shape of the instance untouched.
declare ws: EventEmitter
declare backlog: () => string[]
declare error: LogFn
declare warn: LogFn
declare info: LogFn
declare debug: LogFn
declare verbose: LogFn
declare silly: LogFn
}
export default {
loggers: {},
init(): Logger {
const primaryLogger = new Logger()
let ignoreNextLevels = false
const backlog: string[] = []
primaryLogger.ws = new EventEmitter()
// -> One listener per connected admin terminal, so the default cap of 10 is a leak warning rather
// than a limit worth respecting
primaryLogger.ws.setMaxListeners(0)
primaryLogger.backlog = () => [...backlog]
LEVELS.forEach((lvl) => {
primaryLogger[lvl] = (...args: unknown[]) => {
primaryLogger.emit(lvl, ...args)
}
if (!ignoreNextLevels) {
primaryLogger.on(lvl, (msg: unknown) => {
let formatted = ''
if (WIKI.config.logFormat === 'json') {
formatted = JSON.stringify({
timestamp: new Date().toISOString(),
instance: WIKI.INSTANCE_ID,
level: lvl,
message: msg
})
} else {
if (msg instanceof Error) {
msg = msg.stack
}
formatted = `${new Date().toISOString()} ${chalk.dim('[' + WIKI.INSTANCE_ID + ']')} ${chalk[LEVELCOLORS[lvl]].bold(lvl)}: ${msg}`
}
console.log(formatted)
backlog.push(formatted)
if (backlog.length > BACKLOG_SIZE) {
backlog.shift()
}
primaryLogger.ws.emit('log', formatted)
})
}
if (lvl === WIKI.config.logLevel) {
ignoreNextLevels = true
}
})
LEVELSIGNORED.forEach((lvl) => {
primaryLogger[lvl] = () => {}
})
return primaryLogger
}
}