import * as React from 'react';

interface BeforeInstallPromptEvent extends Event {
  readonly platforms: string[];
  readonly userChoice: Promise<{
    outcome: 'accepted' | 'dismissed';
    platform: string;
  }>;
  prompt(): Promise<void>;
}

export function InstallPrompt() {
  const [deferredPrompt, setDeferredPrompt] = React.useState<BeforeInstallPromptEvent | null>(null);
  const [showPrompt, setShowPrompt] = React.useState(false);
  const [isIOS, setIsIOS] = React.useState(false);
  const [isInstalled, setIsInstalled] = React.useState(false);

  React.useEffect(() => {
    // Check if already installed
    if (window.matchMedia('(display-mode: standalone)').matches) {
      setIsInstalled(true);
      return;
    }

    // Check if iOS
    const ua = window.navigator.userAgent;
    const isIOSDevice = /iPad|iPhone|iPod/.test(ua) && !(window as any).MSStream;
    setIsIOS(isIOSDevice);

    // Check if user has dismissed the prompt recently
    const dismissedAt = localStorage.getItem('pwa-prompt-dismissed');
    if (dismissedAt) {
      const dismissedTime = new Date(dismissedAt).getTime();
      const now = Date.now();
      const dayInMs = 24 * 60 * 60 * 1000;
      if (now - dismissedTime < 7 * dayInMs) {
        return;
      }
    }

    // For non-iOS devices, wait for the beforeinstallprompt event
    const handleBeforeInstallPrompt = (e: Event) => {
      e.preventDefault();
      setDeferredPrompt(e as BeforeInstallPromptEvent);
      setShowPrompt(true);
    };

    window.addEventListener('beforeinstallprompt', handleBeforeInstallPrompt);

    // For iOS, show prompt after a delay if not installed
    if (isIOSDevice && !navigator.standalone) {
      const timer = setTimeout(() => {
        setShowPrompt(true);
      }, 3000);
      return () => clearTimeout(timer);
    }

    return () => {
      window.removeEventListener('beforeinstallprompt', handleBeforeInstallPrompt);
    };
  }, []);

  const handleInstall = async () => {
    if (!deferredPrompt) return;

    deferredPrompt.prompt();
    const { outcome } = await deferredPrompt.userChoice;

    if (outcome === 'accepted') {
      setShowPrompt(false);
      setIsInstalled(true);
    }

    setDeferredPrompt(null);
  };

  const handleDismiss = () => {
    setShowPrompt(false);
    localStorage.setItem('pwa-prompt-dismissed', new Date().toISOString());
  };

  if (!showPrompt || isInstalled) {
    return null;
  }

  return (
    <div className="fixed bottom-20 left-4 right-4 z-50 md:left-auto md:right-4 md:max-w-sm animate-slide-up">
      <div className="bg-white rounded-2xl shadow-lg border border-gray-200 overflow-hidden">
        <div className="p-4">
          <div className="flex items-start space-x-3">
            {/* App Icon */}
            <div className="flex-shrink-0">
              <div className="w-12 h-12 bg-green-600 rounded-xl flex items-center justify-center">
                <svg
                  xmlns="http://www.w3.org/2000/svg"
                  className="h-7 w-7 text-white"
                  fill="none"
                  viewBox="0 0 24 24"
                  stroke="currentColor"
                >
                  <path
                    strokeLinecap="round"
                    strokeLinejoin="round"
                    strokeWidth={2}
                    d="M4 16l4.586-4.586a2 2 0 012.828 0L16 16m-2-2l1.586-1.586a2 2 0 012.828 0L20 14m-6-6h.01M6 20h12a2 2 0 002-2V6a2 2 0 00-2-2H6a2 2 0 00-2 2v12a2 2 0 002 2z"
                  />
                </svg>
              </div>
            </div>

            {/* Content */}
            <div className="flex-1 min-w-0">
              <h3 className="text-base font-semibold text-gray-900">Install LocalGreenChain</h3>
              <p className="mt-1 text-sm text-gray-500">
                {isIOS
                  ? 'Tap the share button and select "Add to Home Screen"'
                  : 'Install our app for a better experience with offline support'}
              </p>
            </div>

            {/* Close button */}
            <button
              onClick={handleDismiss}
              className="flex-shrink-0 p-1 rounded-full hover:bg-gray-100"
              aria-label="Dismiss"
            >
              <svg
                xmlns="http://www.w3.org/2000/svg"
                className="h-5 w-5 text-gray-400"
                fill="none"
                viewBox="0 0 24 24"
                stroke="currentColor"
              >
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
              </svg>
            </button>
          </div>

          {/* iOS Instructions */}
          {isIOS && (
            <div className="mt-3 flex items-center space-x-2 text-sm text-gray-600 bg-gray-50 rounded-lg p-3">
              <svg
                xmlns="http://www.w3.org/2000/svg"
                className="h-5 w-5 text-blue-500"
                fill="none"
                viewBox="0 0 24 24"
                stroke="currentColor"
              >
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M8.684 13.342C8.886 12.938 9 12.482 9 12c0-.482-.114-.938-.316-1.342m0 2.684a3 3 0 110-2.684m0 2.684l6.632 3.316m-6.632-6l6.632-3.316m0 0a3 3 0 105.367-2.684 3 3 0 00-5.367 2.684zm0 9.316a3 3 0 105.368 2.684 3 3 0 00-5.368-2.684z"
                />
              </svg>
              <span>Then tap "Add to Home Screen"</span>
            </div>
          )}

          {/* Install Button (non-iOS) */}
          {!isIOS && deferredPrompt && (
            <div className="mt-3 flex space-x-3">
              <button
                onClick={handleDismiss}
                className="flex-1 px-4 py-2 text-sm font-medium text-gray-700 bg-gray-100 rounded-lg hover:bg-gray-200"
              >
                Not now
              </button>
              <button
                onClick={handleInstall}
                className="flex-1 px-4 py-2 text-sm font-medium text-white bg-green-600 rounded-lg hover:bg-green-700"
              >
                Install
              </button>
            </div>
          )}
        </div>
      </div>
    </div>
  );
}

export default InstallPrompt;