// Geolocation utilities

export function calculateDistance(lat1: number, lng1: number, lat2: number, lng2: number): number {
  const R = 3959; // Earth's radius in miles
  const dLat = (lat2 - lat1) * Math.PI / 180;
  const dLng = (lng2 - lng1) * Math.PI / 180;
  const a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
    Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) *
    Math.sin(dLng / 2) * Math.sin(dLng / 2);
  const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
  return R * c;
}

export async function getCurrentLocation(): Promise<{ lat: number; lng: number } | null> {
  return new Promise((resolve) => {
    if (!navigator.geolocation) {
      resolve(null);
      return;
    }

    navigator.geolocation.getCurrentPosition(
      (position) => {
        resolve({
          lat: position.coords.latitude,
          lng: position.coords.longitude,
        });
      },
      () => {
        resolve(null);
      },
      { timeout: 10000 }
    );
  });
}

// San Diego ZIP code validation and coordinates
const SAN_DIEGO_ZIP_COORDINATES: Record<string, { lat: number; lng: number }> = {
  '92101': { lat: 32.7157, lng: -117.1611 }, // Downtown
  '92102': { lat: 32.7030, lng: -117.1289 }, // Logan Heights
  '92103': { lat: 32.7328, lng: -117.1461 }, // Core-Columbia
  '92104': { lat: 32.7482, lng: -117.0704 }, // College-Rolando
  '92105': { lat: 32.7089, lng: -117.1242 }, // Southeastern San Diego
  '92106': { lat: 32.7330, lng: -117.1430 }, // Point Loma
  '92107': { lat: 32.7469, lng: -117.1978 }, // Ocean Beach
  '92108': { lat: 32.7469, lng: -117.1978 }, // Mission Valley
  '92109': { lat: 32.7714, lng: -117.1789 }, // Pacific Beach
  '92110': { lat: 32.7714, lng: -117.1789 }, // Mission Bay
  '92111': { lat: 32.8328, lng: -117.2050 }, // Clairemont
  '92113': { lat: 32.6747, lng: -117.0742 }, // Southeastern San Diego
  '92114': { lat: 32.7030, lng: -117.1289 }, // Southeastern San Diego
  '92115': { lat: 32.7411, lng: -117.1045 }, // City Heights
  '92116': { lat: 32.7644, lng: -117.1164 }, // Kensington
  '92117': { lat: 32.8328, lng: -117.2050 }, // Clairemont
  '92118': { lat: 32.6144, lng: -117.0845 }, // Coronado
  '92119': { lat: 32.7482, lng: -117.0704 }, // College Area
  '92120': { lat: 32.7482, lng: -117.0704 }, // College Area
  '92121': { lat: 32.9340, lng: -117.2340 }, // Sorrento Valley
  '92122': { lat: 32.8344, lng: -117.2544 }, // La Jolla
  '92123': { lat: 32.7714, lng: -117.1789 }, // Serra Mesa
  '92124': { lat: 32.7714, lng: -117.1789 }, // Serra Mesa
  '92126': { lat: 32.9286, lng: -117.1311 }, // Carmel Mountain
  '92127': { lat: 33.0200, lng: -117.1156 }, // Rancho Bernardo
  '92128': { lat: 32.958034, lng: -117.121975 }, // Rancho Penasquitos
  '92129': { lat: 32.958034, lng: -117.121975 }, // Rancho Penasquitos
  '92130': { lat: 32.9340, lng: -117.2340 }, // Carmel Valley
  '92131': { lat: 32.9286, lng: -117.1311 }, // Carmel Mountain
  '92132': { lat: 32.8344, lng: -117.2544 }, // La Jolla
  '92133': { lat: 32.7157, lng: -117.1611 }, // Naval Base
  '92134': { lat: 32.7157, lng: -117.1611 }, // Naval Base
  '92135': { lat: 32.7157, lng: -117.1611 }, // Naval Base
  '92136': { lat: 32.7330, lng: -117.1430 }, // Point Loma
  '92137': { lat: 32.7330, lng: -117.1430 }, // Point Loma
  '92138': { lat: 32.6144, lng: -117.0845 }, // Naval Air Station
  '92139': { lat: 32.6747, lng: -117.0742 }, // Paradise Hills
  '92140': { lat: 32.6144, lng: -117.0845 }, // Coronado
  '92145': { lat: 32.7157, lng: -117.1611 }, // Naval Medical Center
  '92147': { lat: 32.7330, lng: -117.1430 }, // Point Loma
  '92154': { lat: 32.5592, lng: -117.0431 }, // San Ysidro
  '92155': { lat: 32.5592, lng: -117.0431 }, // San Ysidro
  '92173': { lat: 32.6781, lng: -117.0200 }, // Skyline Hills
};

export function isValidSanDiegoZip(zip: string): boolean {
  return zip in SAN_DIEGO_ZIP_COORDINATES;
}

export function getCoordinatesFromZip(zip: string): { lat: number; lng: number } | null {
  return SAN_DIEGO_ZIP_COORDINATES[zip] || null;
}