34 lines
1.1 KiB
TypeScript
34 lines
1.1 KiB
TypeScript
export function haversineDistance(lat1: number, lon1: number, lat2: number, lon2: number): number {
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const R = 6371e3; // Earth radius in meters
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const φ1 = (lat1 * Math.PI) / 180;
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const φ2 = (lat2 * Math.PI) / 180;
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const Δφ = ((lat2 - lat1) * Math.PI) / 180;
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const Δλ = ((lon2 - lon1) * Math.PI) / 180;
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const a =
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Math.sin(Δφ / 2) * Math.sin(Δφ / 2) +
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Math.cos(φ1) * Math.cos(φ2) * Math.sin(Δλ / 2) * Math.sin(Δλ / 2);
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const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
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return R * c; // Distance in meters
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}
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export async function reverseGeocode(lat: number, lon: number): Promise<string | undefined> {
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try {
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const response = await fetch(
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`https://nominatim.openstreetmap.org/reverse?format=json&lat=${lat}&lon=${lon}&zoom=14&addressdetails=1`,
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{
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headers: {
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'Accept-Language': 'en,fi'
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}
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}
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);
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if (!response.ok) return undefined;
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const data = await response.json();
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return data.display_name || data.name || undefined;
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} catch (error) {
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console.error('Geocoding failed:', error);
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return undefined;
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}
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}
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