import type { Sport } from './types';

export function formatDistance(m: number | null, unit: 'metric' | 'imperial' = 'metric'): string {
  if (m == null) return '—';
  if (unit === 'imperial') {
    const miles = m / 1609.344;
    return miles >= 10 ? `${miles.toFixed(1)} mi` : `${miles.toFixed(2)} mi`;
  }
  const km = m / 1000;
  return km >= 10 ? `${km.toFixed(1)} km` : `${km.toFixed(2)} km`;
}

export function formatDuration(s: number | null): string {
  if (s == null) return '—';
  const h = Math.floor(s / 3600);
  const m = Math.floor((s % 3600) / 60);
  const sec = s % 60;
  if (h > 0) return `${h}h ${m.toString().padStart(2, '0')}m`;
  return `${m}m ${sec.toString().padStart(2, '0')}s`;
}

export function formatSpeed(kmh: number | null): string {
  if (kmh == null) return '—';
  return `${kmh.toFixed(1)} km/h`;
}

export function formatElevation(m: number | null): string {
  if (m == null) return '—';
  return `${Math.round(m)} m`;
}

export function formatDate(iso: string): string {
  return new Date(iso).toLocaleDateString('en-GB', {
    day: 'numeric', month: 'short', year: 'numeric',
  });
}

export function formatTime(iso: string): string {
  return new Date(iso).toLocaleTimeString('en-GB', {
    hour: '2-digit', minute: '2-digit',
  });
}

export function formatDateShort(iso: string): string {
  return new Date(iso).toLocaleDateString('en-GB', {
    day: 'numeric', month: 'short',
  });
}

const SPORT_ICONS: Record<Sport, string> = {
  cycling:  '🚴',
  running:  '🏃',
  hiking:   '🥾',
  walking:  '🚶',
  swimming: '🏊',
  other:    '⚡',
};

const SPORT_COLORS: Record<Sport, string> = {
  cycling:  '#00c8ff',
  running:  '#ff6b35',
  hiking:   '#4ade80',
  walking:  '#a3e635',
  swimming: '#38bdf8',
  other:    '#a78bfa',
};

export function sportIcon(sport: Sport): string {
  return SPORT_ICONS[sport] ?? '⚡';
}

export function sportColor(sport: Sport): string {
  return SPORT_COLORS[sport] ?? '#a78bfa';
}

export function sportLabel(sport: Sport, subSport?: string | null): string {
  const base = sport.charAt(0).toUpperCase() + sport.slice(1);
  if (subSport && subSport !== 'generic') {
    return `${subSport.charAt(0).toUpperCase() + subSport.slice(1)} ${base}`;
  }
  return base;
}