/**
 * The visibility score's bands, in one place. The score ring on the dashboard
 * and the week's canvas on HQ both colour a score, and a threshold copied
 * into two files is a threshold that will disagree with itself.
 */

/** One band of the 0-100 visibility score. */
export interface ScoreBand {
  /** Inclusive lower bound. */
  min: number;
  /** Range as shown in a legend. */
  range: string;
  /** What a score in this band means for the merchant. */
  label: string;
  /** Text colour for a number in this band. */
  text: string;
  /** Pill classes for a legend row. */
  pill: string;
}

/** The bands, highest first, so the first match wins. */
export const SCORE_BANDS: readonly ScoreBand[] = [
  {
    min: 75,
    range: '75+',
    label: 'You hold position against competitors',
    text: 'text-brand',
    pill: 'border border-pink-500/30 bg-pink-500/15 text-brand',
  },
  {
    min: 60,
    range: '60-74',
    label: 'AI engines start citing you regularly',
    text: 'text-emerald-600',
    pill: 'border border-emerald-500/30 bg-emerald-500/15 text-emerald-600',
  },
  {
    min: 40,
    range: '40-59',
    label: 'Inconsistent mentions',
    text: 'text-amber-600',
    pill: 'border border-amber-500/30 bg-amber-500/15 text-amber-600',
  },
  {
    min: 0,
    range: '0-39',
    label: 'AI engines rarely cite you',
    text: 'text-red-600',
    pill: 'border border-red-500/30 bg-red-500/15 text-red-600',
  },
];

/** The bands low to high, for a legend that reads upwards. */
export const SCORE_BANDS_ASCENDING: readonly ScoreBand[] = [
  ...SCORE_BANDS,
].reverse();

/**
 * The band a score falls in.
 *
 * @param score - The visibility score, 0-100.
 * @return Its band; the lowest one for anything under the first bound.
 */
export function bandForScore(score: number): ScoreBand {
  const clamped: number = Math.max(0, Math.min(100, Math.round(score)));

  return (
    SCORE_BANDS.find(band => clamped >= band.min) ??
    SCORE_BANDS[SCORE_BANDS.length - 1]
  );
}