Add skeleton for file event handling

plugin/src/logger.ts

@@ -0,0 +1,68 @@
+enum LogLevel {
+	INFO,
+	WARNING,
+	ERROR,
+}
+
+class LogLine {
+	constructor(public level: LogLevel, public message: string) {}
+
+	public toString(): string {
+		return `${this.formatLevel()}: ${this.message}`;
+	}
+
+	private formatLevel(): string {
+		switch (this.level) {
+			case LogLevel.INFO:
+				return "INFO";
+			case LogLevel.WARNING:
+				return "WARNING";
+			case LogLevel.ERROR:
+				return "ERROR";
+			default:
+				return "UNKNOWN";
+		}
+	}
+}
+
+export class Logger {
+	private static readonly MAX_MESSAGES = 1000;
+
+	private static instance: Logger;
+	private messages: LogLine[] = [];
+
+	private constructor() {}
+
+	static getInstance(): Logger {
+		if (!Logger.instance) {
+			Logger.instance = new Logger();
+		}
+		return Logger.instance;
+	}
+
+	public info(message: string): void {
+		this.pushMessage(message, LogLevel.INFO);
+		console.log(message);
+	}
+
+	public warn(message: string): void {
+		this.pushMessage(message, LogLevel.WARNING);
+		console.warn(message);
+	}
+
+	public error(message: string): void {
+		this.pushMessage(message, LogLevel.ERROR);
+		console.error(message);
+	}
+
+	public getMessages(): LogLine[] {
+		return this.messages;
+	}
+
+	private pushMessage(message: string, level: LogLevel): void {
+		this.messages.push(new LogLine(level, message));
+		if (this.messages.length > Logger.MAX_MESSAGES) {
+			this.messages.shift();
+		}
+	}
+}