import { Component, ReactNode } from 'react';

interface ErrorBoundaryProps {
  children: ReactNode;
  fallback?: ReactNode;
  onError?: (error: Error, errorInfo: React.ErrorInfo) => void;
}

interface ErrorBoundaryState {
  hasError: boolean;
  error?: Error;
}

/**
 * Error Boundary component to catch React errors and prevent full app crashes.
 *
 * Usage:
 * ```tsx
 * <ErrorBoundary>
 *   <YourComponent />
 * </ErrorBoundary>
 * ```
 *
 * With custom fallback:
 * ```tsx
 * <ErrorBoundary fallback={<div>Custom error UI</div>}>
 *   <YourComponent />
 * </ErrorBoundary>
 * ```
 */
export class ErrorBoundary extends Component<ErrorBoundaryProps, ErrorBoundaryState> {
  constructor(props: ErrorBoundaryProps) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error: Error): ErrorBoundaryState {
    return { hasError: true, error };
  }

  componentDidCatch(error: Error, errorInfo: React.ErrorInfo) {
    console.error('ErrorBoundary caught an error:', error, errorInfo);
    this.props.onError?.(error, errorInfo);
  }

  handleReset = () => {
    this.setState({ hasError: false, error: undefined });
  };

  render() {
    if (this.state.hasError) {
      if (this.props.fallback) {
        return this.props.fallback;
      }

      return (
        <div className="p-24 bg-red-50 border border-red-200 rounded-12 m-20">
          <h2 className="text-lg font-semibold text-red-800 mb-8">
            Something went wrong
          </h2>
          <p className="text-sm text-red-600 mb-16">
            {this.state.error?.message || 'An unexpected error occurred'}
          </p>
          <button
            onClick={this.handleReset}
            className="px-16 py-8 bg-red-600 hover:bg-red-700 text-white rounded-8 text-sm font-medium transition-colors"
          >
            Try Again
          </button>
        </div>
      );
    }

    return this.props.children;
  }
}