Implement logger (boundlessfi#186)

* Create logger.types.ts

* Create logger.ts

Author: Michaelkingsdev

lib/logger.ts

@@ -0,0 +1,59 @@
+import type { ILogger, LoggerData } from './types/logger.types'
+
+type LogLevel = LoggerData['LogLevel']
+type LogData = LoggerData['LogData']
+
+export class Logger implements ILogger {
+	private minLevel: LogLevel = 'info'
+
+	setMinLevel(level: LogLevel) {
+		this.minLevel = level
+	}
+
+	private shouldLog(level: LogLevel): boolean {
+		const levels: LogLevel[] = ['error', 'warn', 'info']
+		return levels.indexOf(level) <= levels.indexOf(this.minLevel)
+	}
+
+	private log(level: LogLevel, data: LogData) {
+		if (!this.shouldLog(level)) return
+
+		const timestamp = new Date().toISOString()
+		const logMethod = console[level] as (
+			message: string,
+			...optionalParams: unknown[]
+		) => void
+		const prefix = `[${level.toUpperCase()}] ${timestamp}:`
+
+		try {
+			const { eventType, ...rest } = data
+			const logData = {
+				eventType,
+				timestamp,
+				...rest,
+			}
+			const jsonData = JSON.stringify(logData, null, 2)
+			logMethod(prefix, eventType, '\n', jsonData)
+		} catch (error) {
+			console.error(`Error stringifying log data: ${error}`)
+			logMethod(
+				prefix,
+				data.eventType,
+				'\n',
+				'Error: Unable to stringify log data',
+			)
+		}
+	}
+
+	error(data: LogData) {
+		this.log('error', data)
+	}
+
+	warn(data: LogData) {
+		this.log('warn', data)
+	}
+
+	info(data: LogData) {
+		this.log('info', data)
+	}
+}

types/logger.types.ts

@@ -0,0 +1,15 @@
+export interface LoggerData {
+	LogLevel: 'error' | 'warn' | 'info'
+
+	LogData: {
+		eventType: string
+		[key: string]: unknown
+	}
+}
+
+export interface ILogger {
+	setMinLevel: (level: LoggerData['LogLevel']) => void
+	error: (data: LoggerData['LogData']) => void
+	warn: (data: LoggerData['LogData']) => void
+	info: (data: LoggerData['LogData']) => void
+}