Many more changes for btter experience.

frontend/src/utils/units.ts

@@ -0,0 +1,57 @@
+export type UnitPreference = 'METRIC' | 'IMPERIAL'
+
+const KM_TO_MILES = 0.621371
+const METERS_TO_FEET = 3.28084
+
+export function formatDistance(km: number, unit: UnitPreference): string {
+  if (unit === 'IMPERIAL') {
+    if (km < 0.1) {
+      const feet = km * 1000 * METERS_TO_FEET
+      return `${Math.round(feet)} ft`
+    }
+    const miles = km * KM_TO_MILES
+    return `${miles.toFixed(2)} mi`
+  }
+  if (km < 1) {
+    const meters = km * 1000
+    return `${Math.round(meters)} m`
+  }
+  return `${km.toFixed(2)} km`
+}
+
+export function formatDistanceShort(km: number, unit: UnitPreference): string {
+  if (unit === 'IMPERIAL') {
+    const miles = km * KM_TO_MILES
+    if (miles < 0.1) {
+      return `${Math.round(miles * 5280)} ft`
+    }
+    return `${miles.toFixed(1)} mi`
+  }
+  if (km < 1) {
+    return `${Math.round(km * 1000)} m`
+  }
+  return `${km.toFixed(1)} km`
+}
+
+export function formatRadius(meters: number, unit: UnitPreference): string {
+  if (unit === 'IMPERIAL') {
+    const feet = meters * METERS_TO_FEET
+    if (feet < 5280) {
+      return `${Math.round(feet)} ft`
+    }
+    const miles = feet / 5280
+    return `${miles.toFixed(1)} mi`
+  }
+  if (meters < 1000) {
+    return `${Math.round(meters)} m`
+  }
+  return `${(meters / 1000).toFixed(1)} km`
+}
+
+export function kmToMiles(km: number): number {
+  return km * KM_TO_MILES
+}
+
+export function metersToFeet(meters: number): number {
+  return meters * METERS_TO_FEET
+}