export const WASTE_PPM_MAX = 0.5;
export const JV_PPM_MIN = 0.5;
export const JV_PPM_MAX = 1.29;
export const PREMIUM_PPM_MIN = 2.0;

export type GradeBand = 'WASTE' | 'JV_BAND' | 'MID' | 'PREMIUM';

export function gradeBand(ppm: number): GradeBand {
  if (ppm < WASTE_PPM_MAX) return 'WASTE';
  if (ppm >= JV_PPM_MIN && ppm <= JV_PPM_MAX) return 'JV_BAND';
  if (ppm >= PREMIUM_PPM_MIN) return 'PREMIUM';
  return 'MID';
}

export function isWaste(ppm: number): boolean {
  return ppm < WASTE_PPM_MAX;
}

export function isJvAutoSwitch(ppm: number): boolean {
  return ppm >= JV_PPM_MIN && ppm <= JV_PPM_MAX;
}

export function isPremium(ppm: number): boolean {
  return ppm >= PREMIUM_PPM_MIN;
}