import React from "react";
import { motion } from "framer-motion";
import { getStats, type Stats } from "../api";

const REFRESH_MS = 45_000;

export interface StatsSectionProps {
  /** Optional refetch trigger: when this value changes, stats are refetched. */
  refetchTrigger?: number;
}

function AnimatedNumber({ value }: { value: number }) {
  return (
    <motion.span
      key={value}
      initial={{ opacity: 0.6 }}
      animate={{ opacity: 1 }}
      transition={{ duration: 0.2 }}
    >
      {value.toLocaleString()}
    </motion.span>
  );
}

export function StatsSection({ refetchTrigger }: StatsSectionProps) {
  const [stats, setStats] = React.useState<Stats | null>(null);
  const [loading, setLoading] = React.useState(true);
  const [refreshing, setRefreshing] = React.useState(false);

  const load = React.useCallback(async (userRefresh = false) => {
    if (userRefresh) setRefreshing(true);
    try {
      const s = await getStats();
      setStats(s);
    } catch {
      setStats(null);
    } finally {
      setLoading(false);
      if (userRefresh) setRefreshing(false);
    }
  }, []);

  React.useEffect(() => {
    load();
    const t = setInterval(load, REFRESH_MS);
    return () => clearInterval(t);
  }, [load, refetchTrigger]);

  if (loading && !stats) {
    return (
      <div className="stats-box stats-skeleton">
        <div className="skeleton-line balance" />
        <div className="skeleton-line short" />
        <div className="skeleton-line" />
        <div className="skeleton-line" />
        <div className="skeleton-line" />
      </div>
    );
  }
  if (!stats) return <div className="stats-box"><p>Stats unavailable</p></div>;

  const n = (v: number | undefined | null) => Number(v ?? 0);
  const ts = (v: number | undefined | null) => new Date(Number(v ?? 0) * 1000).toLocaleString();
  const dailyBudget = Number(stats.dailyBudgetSats) || 1;
  const budgetUsed = n(stats.spentTodaySats);
  const budgetPct = Math.min(100, (budgetUsed / dailyBudget) * 100);

  return (
    <div className="stats-box">
      <h3>Faucet stats</h3>
      <p className="stats-balance">
        <AnimatedNumber value={n(stats.balanceSats)} /> sats
      </p>
      <p className="stats-balance-label">Pool balance</p>

      <div className="stats-progress-wrap">
        <div className="stats-progress-label">
          Daily budget: <AnimatedNumber value={budgetUsed} /> / <AnimatedNumber value={n(stats.dailyBudgetSats)} /> sats
        </div>
        <div className="stats-progress-bar">
          <div className="stats-progress-fill" style={{ width: `${budgetPct}%` }} />
        </div>
      </div>

      <div className="stats-rows">
        <div className="stats-row">
          <span>Total paid</span>
          <span><AnimatedNumber value={n(stats.totalPaidSats)} /> sats</span>
        </div>
        <div className="stats-row">
          <span>Total claims</span>
          <span><AnimatedNumber value={n(stats.totalClaims)} /></span>
        </div>
        <div className="stats-row">
          <span>Claims (24h)</span>
          <span><AnimatedNumber value={n(stats.claimsLast24h)} /></span>
        </div>
      </div>

      {stats.recentPayouts?.length > 0 && (
        <>
          <h3 className="stats-recent-title">Recent payouts</h3>
          <ul className="stats-recent-list">
            {stats.recentPayouts.slice(0, 10).map((p, i) => (
              <li key={i}>
                {p.pubkey_prefix ?? "…"} — {n(p.payout_sats).toLocaleString()} sats — {ts(p.claimed_at)}
              </li>
            ))}
          </ul>
        </>
      )}
      <button
        type="button"
        className={`entropy-btn stats-refresh ${refreshing ? "stats-refresh--spinning" : ""}`}
        onClick={() => load(true)}
        disabled={refreshing}
      >
        <span className="stats-refresh-icon" aria-hidden>↻</span>
        Refresh
      </button>
    </div>
  );
}