import { loadEnvConfig } from '../config/env';

type LogLevel = 'debug' | 'info' | 'warn' | 'error';

interface LogContext {
  [key: string]: any;
}

/**
 * Structured logger with standard log levels
 */
class Logger {
  private logLevel: LogLevel;
  private logLevels: Record<LogLevel, number> = {
    debug: 0,
    info: 1,
    warn: 2,
    error: 3,
  };

  constructor() {
    const config = loadEnvConfig();
    this.logLevel = config.logLevel || 'info';
  }

  /**
   * Log a debug message
   * @param message Message to log
   * @param context Optional context to include
   */
  debug(message: string, context?: LogContext | unknown): void {
    this.log('debug', message, context);
  }

  /**
   * Log an info message
   * @param message Message to log
   * @param context Optional context to include
   */
  info(message: string, context?: LogContext | unknown): void {
    this.log('info', message, context);
  }

  /**
   * Log a warning message
   * @param message Message to log
   * @param context Optional context to include
   */
  warn(message: string, context?: LogContext | unknown): void {
    this.log('warn', message, context);
  }

  /**
   * Log an error message
   * @param message Message to log
   * @param context Optional context to include (error object or additional context)
   */
  error(message: string, context?: Error | LogContext | unknown): void {
    this.log('error', message, context);
  }

  /**
   * Internal log method
   * @param level Log level
   * @param message Message to log
   * @param context Optional context to include
   */
  private log(level: LogLevel, message: string, context?: LogContext | unknown): void {
    if (this.logLevels[level] < this.logLevels[this.logLevel]) {
      return;
    }

    const timestamp = new Date().toISOString();
    const logObject = {
      timestamp,
      level,
      message,
      ...(context && typeof context === 'object' && !Array.isArray(context) ? context : {})
    };
    
    // Format for structured logging (JSON)
    const formattedLog = JSON.stringify(logObject);
    
    switch (level) {
      case 'debug':
        console.debug(formattedLog);
        break;
      case 'info':
        console.info(formattedLog);
        break;
      case 'warn':
        console.warn(formattedLog);
        break;
      case 'error':
        console.error(formattedLog);
        break;
    }
  }
}

// Export a singleton instance
export const logger = new Logger();