'use client';

import { useEffect, useState } from 'react';
import { getHeadshotUrl, PLAYER_SILHOUETTE } from '@/lib/playerHeadshot';
import { getVisibleCount, getHiddenCount, type Tier } from '@/lib/tierGate';

/**
 * HotListPanel (Session 23).
 *
 * Rolling recent-window leaders — ranked by who's TRENDING, not who has
 * the biggest raw number. A 20-PPG player erupting for 28/31/25 is hot;
 * a 30-PPG star who dropped 28 is not. Free users see the top 3.
 *
 * Self-hides when empty so the landing page never renders a dead box.
 */

interface HotPlayer {
  rank: number;
  name: string;
  playerId: string | number | null;
  team: string | null;
  stat: string;
  recentAvg: number;
  statLine: string;
  trendDescription: string;
}

export interface HotListPanelProps {
  sport: string;
  tier?: Tier;
  stat?: string;
  limit?: number;
}

export default function HotListPanel({ sport, tier = 'free', stat = 'all', limit }: HotListPanelProps) {
  const [players, setPlayers] = useState<HotPlayer[] | null>(null);

  useEffect(() => {
    let cancelled = false;
    async function load() {
      try {
        const res = await fetch(`/api/hotlist/${sport}?stat=${encodeURIComponent(stat)}`);
        if (!res.ok) { if (!cancelled) setPlayers([]); return; }
        const data = await res.json();
        if (!cancelled) setPlayers(Array.isArray(data?.players) ? data.players : []);
      } catch {
        if (!cancelled) setPlayers([]);
      }
    }
    load();
    return () => { cancelled = true; };
  }, [sport, stat]);

  if (!players || players.length === 0) return null;

  const tierCount = getVisibleCount(tier, players.length);
  const cap = limit && limit > 0 ? Math.min(limit, tierCount) : tierCount;
  const visible = players.slice(0, cap);
  const hidden = limit ? players.length - visible.length : getHiddenCount(tier, players.length);

  return (
    <section className="hot-list-panel" style={{ margin: '16px 0' }}>
      <h3 style={panelHeading}>📈 HOT RIGHT NOW</h3>
      <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
        {visible.map((p) => (
          <div key={`${p.name}-${p.stat}`} style={rowStyle}>
            <span style={rankStyle}>#{p.rank}</span>
            <img
              src={getHeadshotUrl({ sport, playerId: p.playerId })}
              alt={p.name}
              width={36}
              height={36}
              style={avatarStyle}
              onError={(e) => { (e.target as HTMLImageElement).src = PLAYER_SILHOUETTE; }}
            />
            <div style={{ flex: 1, minWidth: 0 }}>
              <div style={playerName}>{p.name}{p.team ? ` · ${p.team}` : ''}</div>
              <div style={statLineStyle}>{p.statLine}</div>
            </div>
            <span style={trendStyle}>{p.trendDescription}</span>
          </div>
        ))}
      </div>
      {hidden > 0 && (
        <a href="/pricing" style={upsellStyle}>
          {hidden} more — upgrade to see the full board →
        </a>
      )}
    </section>
  );
}

const panelHeading: React.CSSProperties = {
  fontSize: 12, letterSpacing: '0.12em', textTransform: 'uppercase',
  color: 'var(--text-tertiary, #6A6A78)', margin: '0 0 10px',
};
const rowStyle: React.CSSProperties = {
  display: 'flex', alignItems: 'center', gap: 10,
  padding: '8px 10px', borderRadius: 10,
  background: 'var(--surface, #12121A)', border: '1px solid var(--border, #2A2A36)',
};
const rankStyle: React.CSSProperties = {
  flex: '0 0 auto', fontSize: 13, fontWeight: 800, width: 28,
  color: 'var(--text-tertiary, #6A6A78)',
};
const avatarStyle: React.CSSProperties = {
  borderRadius: '50%', objectFit: 'cover', background: '#1A1A24', flex: '0 0 auto',
};
const playerName: React.CSSProperties = {
  fontSize: 14, fontWeight: 700, color: 'var(--text-primary, #F0F0F4)',
  whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
};
const statLineStyle: React.CSSProperties = {
  fontSize: 12, color: 'var(--text-secondary, #9A9AA8)',
};
const trendStyle: React.CSSProperties = {
  flex: '0 0 auto', fontSize: 11, fontWeight: 700, padding: '3px 8px',
  borderRadius: 6, background: 'rgba(46,160,67,0.15)', color: '#3FB950',
};
const upsellStyle: React.CSSProperties = {
  display: 'inline-block', marginTop: 10, fontSize: 12, fontWeight: 600,
  color: 'var(--accent, #E94B3C)', textDecoration: 'none',
};