// Utility to load Google Maps JavaScript API script dynamically
let googleMapsPromise: Promise<any> | null = null;

export function loadGoogleMapsScript(): Promise<any> {
  if (typeof window === 'undefined') return Promise.reject('SSR environment');
  if ((window as any).google?.maps) return Promise.resolve((window as any).google);

  if (!googleMapsPromise) {
    googleMapsPromise = new Promise((resolve, reject) => {
      const apiKey = process.env.NEXT_PUBLIC_GOOGLE_MAPS_API_KEY || 'AIzaSyBprvEDlcJcKRAKCkAJYXRvMXcDwx288Ws';

      const existingScript = document.getElementById('google-maps-js-script');
      if (existingScript) {
        existingScript.addEventListener('load', () => resolve((window as any).google));
        existingScript.addEventListener('error', (err) => reject(err));
        return;
      }

      const script = document.createElement('script');
      script.id = 'google-maps-js-script';
      script.src = `https://maps.googleapis.com/maps/api/js?key=${apiKey}&libraries=places,geometry`;
      script.async = true;
      script.defer = true;
      script.onload = () => resolve((window as any).google);
      script.onerror = (err) => reject(err);
      document.head.appendChild(script);
    });
  }

  return googleMapsPromise;
}

// Dark Mode Custom Map Theme for Google Maps
export const DARK_MAP_STYLES = [
  { elementType: "geometry", stylers: [{ color: "#111827" }] },
  { elementType: "labels.text.fill", stylers: [{ color: "#9ca3af" }] },
  { elementType: "labels.text.stroke", stylers: [{ color: "#111827" }] },
  {
    featureType: "administrative.country",
    elementType: "geometry.stroke",
    stylers: [{ color: "#374151" }],
  },
  {
    featureType: "administrative.province",
    elementType: "geometry.stroke",
    stylers: [{ color: "#374151" }],
  },
  {
    featureType: "landscape.man_made",
    elementType: "geometry.stroke",
    stylers: [{ color: "#1f2937" }],
  },
  {
    featureType: "landscape.natural",
    elementType: "geometry",
    stylers: [{ color: "#0f172a" }],
  },
  {
    featureType: "poi",
    elementType: "geometry",
    stylers: [{ color: "#1f2937" }],
  },
  {
    featureType: "poi",
    elementType: "labels.text.fill",
    stylers: [{ color: "#6b7280" }],
  },
  {
    featureType: "poi.park",
    elementType: "geometry.fill",
    stylers: [{ color: "#064e3b" }],
  },
  {
    featureType: "road",
    elementType: "geometry",
    stylers: [{ color: "#374151" }],
  },
  {
    featureType: "road",
    elementType: "labels.text.fill",
    stylers: [{ color: "#9ca3af" }],
  },
  {
    featureType: "road.highway",
    elementType: "geometry",
    stylers: [{ color: "#2563eb" }],
  },
  {
    featureType: "road.highway",
    elementType: "geometry.stroke",
    stylers: [{ color: "#1e40af" }],
  },
  {
    featureType: "transit",
    elementType: "labels.text.fill",
    stylers: [{ color: "#9ca3af" }],
  },
  {
    featureType: "water",
    elementType: "geometry",
    stylers: [{ color: "#030712" }],
  },
  {
    featureType: "water",
    elementType: "labels.text.fill",
    stylers: [{ color: "#3b82f6" }],
  },
];