MCP Color Server

/** * Structured logging utility for the MCP Color Server */ import { LogEntry } from '../types/index'; export class Logger { private static instance: Logger; private logLevel: 'debug' | 'info' | 'warn' | 'error' = 'warn'; private constructor() {} public static getInstance(): Logger { if (!Logger.instance) { Logger.instance = new Logger(); } return Logger.instance; } public setLogLevel(level: 'debug' | 'info' | 'warn' | 'error'): void { this.logLevel = level; } private shouldLog(level: 'debug' | 'info' | 'warn' | 'error'): boolean { const levels = ['debug', 'info', 'warn', 'error']; return levels.indexOf(level) >= levels.indexOf(this.logLevel); } private createLogEntry( level: 'debug' | 'info' | 'warn' | 'error', message: string, options?: { tool?: string; executionTime?: number; error?: Error; } ): LogEntry { const entry: LogEntry = { level, message, timestamp: new Date().toISOString(), }; if (options?.tool !== undefined) { entry.tool = options.tool; } if (options?.executionTime !== undefined) { entry.executionTime = options.executionTime; } if (options?.error !== undefined) { entry.error = options.error; } return entry; } private formatLogEntry(entry: LogEntry): string { const parts = [`[${entry.timestamp}]`, `[${entry.level.toUpperCase()}]`]; if (entry.tool) { parts.push(`[${entry.tool}]`); } parts.push(entry.message); if (entry.executionTime !== undefined) { parts.push(`(${entry.executionTime}ms)`); } if (entry.error) { parts.push(`Error: ${entry.error.message}`); if (entry.error.stack) { parts.push(`Stack: ${entry.error.stack}`); } } return parts.join(' '); } public debug( message: string, options?: { tool?: string; executionTime?: number; [key: string]: unknown } ): void { if (!this.shouldLog('debug')) return; const entry = this.createLogEntry('debug', message, options); // eslint-disable-next-line no-console console.debug(this.formatLogEntry(entry)); } public info( message: string, options?: { tool?: string; executionTime?: number; [key: string]: unknown } ): void { if (!this.shouldLog('info')) return; const entry = this.createLogEntry('info', message, options); // eslint-disable-next-line no-console console.info(this.formatLogEntry(entry)); } public warn( message: string, options?: { tool?: string; executionTime?: number; error?: Error; [key: string]: unknown; } ): void { if (!this.shouldLog('warn')) return; const entry = this.createLogEntry('warn', message, options); // eslint-disable-next-line no-console console.warn(this.formatLogEntry(entry)); } public error( message: string, options?: { tool?: string; executionTime?: number; error?: Error } ): void { if (!this.shouldLog('error')) return; const entry = this.createLogEntry('error', message, options); // eslint-disable-next-line no-console console.error(this.formatLogEntry(entry)); } public logToolExecution( tool: string, message: string, executionTime: number, level: 'debug' | 'info' | 'warn' | 'error' = 'info' ): void { this[level](message, { tool, executionTime }); } public logError(message: string, error: Error, tool?: string): void { const options: { error: Error; tool?: string } = { error }; if (tool !== undefined) { options.tool = tool; } this.error(message, options); } } // Export singleton instance export const logger = Logger.getInstance();