import React, { ErrorInfo, ReactNode } from 'react';

interface ErrorBoundaryProps {
  children?: ReactNode;
}

interface ErrorBoundaryState {
  hasError: boolean;
  error: Error | null;
}

/**
 * Global Error Boundary to catch UI crashes and display a fallback screen.
 */
// Use React.Component explicitly to ensure proper inheritance and property access for props and state
export default class ErrorBoundary extends React.Component<ErrorBoundaryProps, ErrorBoundaryState> {
  // Explicitly define properties for TypeScript to recognize them on the class instance
  public state: ErrorBoundaryState;
  public props: ErrorBoundaryProps;

  constructor(props: ErrorBoundaryProps) {
    super(props);
    // Initialize state in constructor to follow standard React patterns and avoid property conflicts
    this.state = {
      hasError: false,
      error: null
    };
    this.props = props;
  }

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

  public componentDidCatch(error: Error, errorInfo: ErrorInfo) {
    console.error("Uncaught license-tracker error:", error, errorInfo);
  }

  public render(): ReactNode {
    // Destructuring state and props from this. Inheritance from Component ensures they exist.
    // Explicit usage of this.state and this.props helps avoid shadowing or scoping issues.
    const { hasError, error } = this.state;
    const { children } = this.props;
    
    if (hasError) {
      return (
        <div className="min-h-screen bg-slate-900 flex items-center justify-center p-4 text-gray-200">
            <div className="bg-slate-800 border border-red-500/50 p-6 rounded-lg max-w-2xl shadow-2xl w-full">
                <div className="flex items-center gap-3 mb-4">
                    <div className="bg-red-500/20 p-2 rounded-full">
                        <svg className="w-6 h-6 text-red-500" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" />
                        </svg>
                    </div>
                    <h1 className="text-2xl font-bold text-red-400">Application Failure</h1>
                </div>
                <p className="mb-4 text-gray-300">The interface encountered an unexpected error during rendering.</p>
                <div className="bg-black/40 p-4 rounded text-xs font-mono text-red-300 overflow-auto max-h-64 mb-6 border border-slate-700 whitespace-pre-wrap">
                    {error?.stack || error?.toString()}
                </div>
                <div className="flex gap-4">
                    <button 
                        onClick={() => window.location.reload()} 
                        className="flex-1 px-6 py-3 bg-cyan-600 hover:bg-cyan-500 text-white font-bold rounded-xl transition-all shadow-lg active:scale-95"
                    >
                        Reload Interface
                    </button>
                    <button 
                        onClick={() => { localStorage.clear(); window.location.reload(); }} 
                        className="px-6 py-3 bg-slate-700 hover:bg-slate-600 text-slate-300 font-bold rounded-xl transition-all"
                    >
                        Clear Cache & Reset
                    </button>
                </div>
            </div>
        </div>
      );
    }

    return children || null;
  }
}