import { useMemo } from 'react';

interface SparklineProps {
  timestamps: number[];
  periodDays: number;
}

/**
 * Mini bar-chart SVG affichant l'activité journalière sur la période.
 * Utilise les timestamps déjà en mémoire — aucune requête supplémentaire.
 */
export function Sparkline({ timestamps, periodDays }: SparklineProps) {
  const buckets = useMemo(() => {
    if (timestamps.length === 0) return [];
    const n = periodDays === 1 ? 24 : Math.min(periodDays, 30);
    const now = Date.now();
    const start = now - periodDays * 864e5;
    const step = (periodDays * 864e5) / n;
    const counts = new Array(n).fill(0);
    for (const ts of timestamps) {
      const i = Math.floor((ts - start) / step);
      if (i >= 0 && i < n) counts[i]++;
    }
    return counts;
  }, [timestamps, periodDays]);

  if (buckets.length === 0) return null;

  const n = buckets.length;
  const max = Math.max(...buckets, 1);
  const W = 100;
  const H = 32;
  const barW = W / n;
  const gap = barW * 0.18;

  return (
    <div className="space-y-1">
      <svg
        viewBox={`0 0 ${W} ${H}`}
        preserveAspectRatio="none"
        className="w-full h-8"
        aria-hidden="true"
      >
        {buckets.map((count, i) => {
          const h = Math.max(1, (count / max) * H);
          return (
            <rect
              key={i}
              x={i * barW + gap / 2}
              y={H - h}
              width={barW - gap}
              height={h}
              fill="#d4a843"
              opacity={0.25 + 0.75 * (count / max)}
              rx={0.5}
            />
          );
        })}
      </svg>
      <div className="flex justify-between text-[10px] text-[#4b5563]">
        <span>{periodDays === 1 ? '0h' : 'J-' + periodDays}</span>
        <span>{periodDays === 1 ? 'maintenant' : 'aujourd\'hui'}</span>
      </div>
    </div>
  );
}