import { ErrorInfo, ErrorCategory, ErrorHandlingStrategy, ErrorReportingConfig } from '../Types';
import { Logger } from '../Logger';

// ErrorCategory, ErrorHandlingStrategy, ErrorReportingConfig

class NetworkError extends Error {
  constructor(message: string) {
    super(message);
    this.name = 'NetworkError';
  }
}


export class ErrorHandler {
  private static instance: ErrorHandler;
  private logger: Logger;
  private strategies: Map<ErrorCategory, ErrorHandlingStrategy> = new Map();
  private reportingConfig: ErrorReportingConfig | null = null;

  private constructor() {
    this.logger = Logger.getInstance();
  }

  /**
   * Get the singleton instance of ErrorHandler
   */
  static getInstance(): ErrorHandler {
    if (!ErrorHandler.instance) {
      ErrorHandler.instance = new ErrorHandler();
    }
    return ErrorHandler.instance;
  }

  /**
   * Handle an error with optional context
   * @param error The error object
   * @param context Optional context information
   */
  handleError(error: Error, context?: string): void {
    const errorInfo: ErrorInfo = {
      code: error.name,
      message: error.message,
      stack: error.stack,
      context: context
    };

    this.logger.error(`Error occurred: ${error.message}`, context, errorInfo);

    const category = this.categorizeError(error);
    const strategy = this.strategies.get(category);
    if (strategy) {
      strategy(error, errorInfo);
    }

    this.reportError(errorInfo);
  }

  /**
   * Handle an asynchronous error
   * @param promise The promise that might throw an error
   * @param context Optional context information
   */
  async handleAsyncError<T>(promise: Promise<T>, context?: string): Promise<T> {
    try {
      return await promise;
    } catch (error) {
      this.handleError(error as Error, context);
      throw error;
    }
  }

  /**
   * Register global error handlers
   */
  registerGlobalErrorHandlers(): void {
    window.addEventListener('error', (event: ErrorEvent) => {
      this.handleError(event.error, 'Global Error');
    });

    window.addEventListener('unhandledrejection', (event: PromiseRejectionEvent) => {
      this.handleError(event.reason, 'Unhandled Promise Rejection');
    });
  }

  /**
   * Set a handling strategy for a specific error category
   * @param category The error category
   * @param strategy The handling strategy function
   */
  setStrategy(category: ErrorCategory, strategy: ErrorHandlingStrategy): void {
    this.strategies.set(category, strategy);
  }

  /**
   * Categorize an error
   * @param error The error to categorize
   */
  private categorizeError(error: Error): ErrorCategory {
    // Implement your categorization logic here
    // This is a simple example; you might want to use more sophisticated logic
    if (error instanceof TypeError) {
      return 'TYPE_ERROR';
    } else if (error instanceof ReferenceError) {
      return 'REFERENCE_ERROR';
    } else if (error instanceof NetworkError) {
      return 'NETWORK_ERROR';
    }
    return 'UNKNOWN_ERROR';
  }

  /**
   * Configure error reporting
   * @param config The error reporting configuration
   */
  configureErrorReporting(config: ErrorReportingConfig): void {
    this.reportingConfig = config;
  }

  /**
   * Report an error based on the current configuration
   * @param errorInfo The error information to report
   */
  private reportError(errorInfo: ErrorInfo): void {
    if (this.reportingConfig && this.reportingConfig.endpoint) {
      // Implement the logic to send the error to the configured endpoint
      fetch(this.reportingConfig.endpoint, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(errorInfo)
      }).catch(error => {
        this.logger.error('Failed to report error', 'ErrorReporting', error);
      });
    }
  }

  /**
   * Attempt to recover from an error
   * @param error The error to recover from
   * @returns A boolean indicating whether recovery was successful
   */
  attemptErrorRecovery(error: Error): boolean {
    // Implement your error recovery logic here
    // This is a placeholder implementation
    this.logger.info(`Attempting to recover from error: ${error.message}`, 'ErrorRecovery');
    return false;
  }
}