Fix unit conversions in forms

src/lib/units.ts

@@ -75,4 +75,133 @@ export const IMPERIAL_COUNTRIES = ['US', 'LR', 'MM'];
 // Detect measurement system from country code
 export function getMeasurementSystemFromCountry(countryCode: string): MeasurementSystem {
   return IMPERIAL_COUNTRIES.includes(countryCode.toUpperCase()) ? 'imperial' : 'metric';
+}
+
+// Unit type detection
+export type UnitType = 'speed' | 'distance' | 'height' | 'weight' | 'unknown';
+
+export function detectUnitType(unit: string): UnitType {
+  const normalized = unit.toLowerCase().trim();
+  
+  // Speed units
+  if (['km/h', 'kmh', 'kph', 'mph', 'm/s', 'ms'].includes(normalized)) {
+    return 'speed';
+  }
+  
+  // Distance units (meters/feet)
+  if (['m', 'meter', 'meters', 'metre', 'metres', 'ft', 'feet', 'foot'].includes(normalized)) {
+    return 'distance';
+  }
+  
+  // Height units (cm/inches)
+  if (['cm', 'centimeter', 'centimeters', 'in', 'inch', 'inches'].includes(normalized)) {
+    return 'height';
+  }
+  
+  // Weight units
+  if (['kg', 'kilogram', 'kilograms', 'lb', 'lbs', 'pound', 'pounds'].includes(normalized)) {
+    return 'weight';
+  }
+  
+  return 'unknown';
+}
+
+// Convert any value to metric based on its unit
+export function convertValueToMetric(value: number, unit: string): number {
+  const normalized = unit.toLowerCase().trim();
+  
+  // Speed conversions to km/h
+  if (normalized === 'mph') {
+    return Math.round(value / 0.621371);
+  }
+  if (['m/s', 'ms'].includes(normalized)) {
+    return Math.round(value * 3.6);
+  }
+  if (['km/h', 'kmh', 'kph'].includes(normalized)) {
+    return Math.round(value);
+  }
+  
+  // Distance conversions to meters
+  if (['ft', 'feet', 'foot'].includes(normalized)) {
+    return Math.round(value / 3.28084);
+  }
+  if (['m', 'meter', 'meters', 'metre', 'metres'].includes(normalized)) {
+    return Math.round(value);
+  }
+  
+  // Height conversions to cm
+  if (['in', 'inch', 'inches'].includes(normalized)) {
+    return Math.round(value / 0.393701);
+  }
+  if (['cm', 'centimeter', 'centimeters'].includes(normalized)) {
+    return Math.round(value);
+  }
+  
+  // Weight conversions to kg
+  if (['lb', 'lbs', 'pound', 'pounds'].includes(normalized)) {
+    return Math.round(value / 2.20462);
+  }
+  if (['kg', 'kilogram', 'kilograms'].includes(normalized)) {
+    return Math.round(value);
+  }
+  
+  // Unknown unit, return as-is
+  return value;
+}
+
+// Convert metric value to target unit
+export function convertValueFromMetric(value: number, targetUnit: string, metricUnit: string): number {
+  const normalized = targetUnit.toLowerCase().trim();
+  const metricNormalized = metricUnit.toLowerCase().trim();
+  
+  // Speed conversions from km/h
+  if (metricNormalized === 'km/h' || metricNormalized === 'kmh' || metricNormalized === 'kph') {
+    if (normalized === 'mph') {
+      return Math.round(value * 0.621371);
+    }
+    if (normalized === 'm/s' || normalized === 'ms') {
+      return Math.round(value / 3.6);
+    }
+  }
+  
+  // Distance conversions from meters
+  if (metricNormalized === 'm' || metricNormalized === 'meter' || metricNormalized === 'meters') {
+    if (['ft', 'feet', 'foot'].includes(normalized)) {
+      return Math.round(value * 3.28084);
+    }
+  }
+  
+  // Height conversions from cm
+  if (metricNormalized === 'cm' || metricNormalized === 'centimeter' || metricNormalized === 'centimeters') {
+    if (['in', 'inch', 'inches'].includes(normalized)) {
+      return Math.round(value * 0.393701);
+    }
+  }
+  
+  // Weight conversions from kg
+  if (metricNormalized === 'kg' || metricNormalized === 'kilogram' || metricNormalized === 'kilograms') {
+    if (['lb', 'lbs', 'pound', 'pounds'].includes(normalized)) {
+      return Math.round(value * 2.20462);
+    }
+  }
+  
+  return value;
+}
+
+// Get metric unit for a given unit type
+export function getMetricUnit(unit: string): string {
+  const unitType = detectUnitType(unit);
+  
+  switch (unitType) {
+    case 'speed':
+      return 'km/h';
+    case 'distance':
+      return 'm';
+    case 'height':
+      return 'cm';
+    case 'weight':
+      return 'kg';
+    default:
+      return unit;
+  }
 }