+ console.log('Opening %s.', file)
+
+ const stream = createReadStream(file)
+
+ const rl = createInterface({
+ input: stream
+ })
+
+ rl.on('line', line => {
+ try {
+ const log = JSON.parse(line)
+ if (options.tags && !containsTags(log.tags, options.tags)) {
+ return
+ }
+
+ if (options.notTags && containsTags(log.tags, options.notTags)) {
+ return
+ }
+
+ // Don't know why but loggerFormat does not remove splat key
+ Object.assign(log, { splat: undefined })
+
+ logLevels[log.level](log)
+ } catch (err) {
+ console.error('Cannot parse line.', inspect(line))
+ throw err
+ }
+ })
+
+ stream.once('close', () => res())
+ }
+ })
+}
+
+// Thanks: https://stackoverflow.com/a/37014317
+async function getNewestFile (files: string[], basePath: string) {
+ const sorted = await mtimeSortFilesDesc(files, basePath)
+
+ return (sorted.length > 0) ? sorted[0].file : ''
+}
+
+async function getFiles () {
+ if (options.files) return options.files
+
+ const logFiles = await readdir(CONFIG.STORAGE.LOG_DIR)
+
+ const filename = await getNewestFile(logFiles, CONFIG.STORAGE.LOG_DIR)
+ return [ join(CONFIG.STORAGE.LOG_DIR, filename) ]
+}
+
+function toTimeFormat (time: string) {
+ const timestamp = Date.parse(time)
+
+ if (isNaN(timestamp) === true) return 'Unknown date'
+
+ const d = new Date(timestamp)
+ return d.toLocaleString() + `.${d.getMilliseconds()}`
+}
+
+function containsTags (loggerTags: string[], optionsTags: string[]) {
+ if (!loggerTags) return false
+
+ for (const lt of loggerTags) {
+ for (const ot of optionsTags) {
+ if (lt === ot) return true
+ }
+ }
+
+ return false
+}