import type {
  ScanHistoryPoint,
  WeeklyReportResponse,
} from '../../service/visibility/visibility.interface';

export interface PulseNumbers {
  score: number;
  shareOfVoice: number;
  point: ScanHistoryPoint | null;
  /** The week the numbers come from when it is not the one picked. */
  scanWeek: string | null;
}

/**
 * The headline numbers of a week. The weekly report is written a while
 * after the scan, so a week without its report (this week, most days)
 * reads the scan history instead: the latest scan when the week picked has
 * none either. Score, share of voice and the "mentioned in" footnote then
 * come from the same scan and never contradict each other.
 *
 * @param {WeeklyReportResponse | null} report  - The week's report, or null.
 * @param {ScanHistoryPoint[]}          history - The scans, oldest first.
 * @param {string}                      weekIso - The week picked.
 * @returns {PulseNumbers}
 */
export const pulseNumbers = (
  report: WeeklyReportResponse | null,
  history: ScanHistoryPoint[],
  weekIso: string
): PulseNumbers => {
  const point =
    history.find(scanPoint => scanPoint?.week_iso === weekIso) ??
    history[history.length - 1] ??
    null;
  if (report) {
    return {
      score: report.visibility_score ?? 0,
      shareOfVoice: report.share_of_voice ?? 0,
      point,
      scanWeek: null,
    };
  }
  return {
    score: point?.visibility_score ?? 0,
    shareOfVoice: point?.share_of_voice ?? 0,
    point,
    scanWeek:
      point?.week_iso && point.week_iso !== weekIso ? point.week_iso : null,
  };
};