import { useState, useEffect } from 'react';
import { Trophy, Medal, Clock, TrendingUp } from 'lucide-react';
import { useGameStore } from '@/store';
import { formatMoney, formatNumber } from '@ai-tycoon/shared';
import { api, getAuthToken } from '@/lib/api';

interface LeaderboardEntry {
  companyName: string;
  score: number;
  era: string;
  tickCount: number;
}

const CATEGORIES = [
  { id: 'revenue', label: 'Highest Revenue', icon: TrendingUp },
  { id: 'fastest-agi', label: 'Fastest to AGI', icon: Clock },
  { id: 'capability', label: 'Best Model', icon: Trophy },
] as const;

export function LeaderboardPage() {
  const [category, setCategory] = useState('revenue');
  const [entries, setEntries] = useState<LeaderboardEntry[]>([]);
  const [loading, setLoading] = useState(false);
  const [submitted, setSubmitted] = useState(false);
  const companyName = useGameStore((s) => s.meta.companyName);
  const totalRevenue = useGameStore((s) => s.economy.totalRevenue);
  const era = useGameStore((s) => s.meta.currentEra);
  const tickCount = useGameStore((s) => s.meta.tickCount);
  const bestModel = useGameStore((s) =>
    s.models.trainedModels.reduce((best, m) => Math.max(best, m.benchmarkScore), 0),
  );

  useEffect(() => {
    setLoading(true);
    api.leaderboard.get(category)
      .then(data => setEntries(data.entries))
      .catch(() => setEntries([]))
      .finally(() => setLoading(false));
  }, [category]);

  const handleSubmit = async () => {
    if (!getAuthToken()) return;
    const scoreMap: Record<string, number> = {
      revenue: Math.floor(totalRevenue),
      'fastest-agi': era === 'agi' ? tickCount : 0,
      capability: Math.floor(bestModel * 10),
    };
    const score = scoreMap[category];
    if (score <= 0) return;
    try {
      await api.leaderboard.submit({ companyName, category, score, era, tickCount });
      setSubmitted(true);
      const data = await api.leaderboard.get(category);
      setEntries(data.entries);
    } catch { /* ignore */ }
  };

  return (
    <div className="space-y-6">
      <h2 className="text-2xl font-bold">Leaderboard</h2>

      <div className="flex gap-2">
        {CATEGORIES.map(cat => (
          <button
            key={cat.id}
            onClick={() => { setCategory(cat.id); setSubmitted(false); }}
            className={`flex items-center gap-2 px-4 py-2 rounded-lg text-sm border transition-colors ${
              category === cat.id
                ? 'bg-accent/20 border-accent text-accent-light'
                : 'bg-surface-900 border-surface-700 text-surface-300 hover:border-surface-500'
            }`}
          >
            <cat.icon size={14} />
            {cat.label}
          </button>
        ))}
      </div>

      {getAuthToken() && !submitted && (
        <button
          onClick={handleSubmit}
          className="bg-accent hover:bg-accent-dark text-white px-4 py-2 rounded-lg text-sm font-medium"
        >
          Submit My Score
        </button>
      )}
      {submitted && <p className="text-sm text-success">Score submitted!</p>}

      <div className="bg-surface-900 border border-surface-700 rounded-xl overflow-hidden">
        {loading ? (
          <div className="p-8 text-center text-surface-500">Loading...</div>
        ) : entries.length === 0 ? (
          <div className="p-8 text-center text-surface-500">
            <Trophy size={48} className="mx-auto mb-4 opacity-50" />
            <p>No entries yet. Be the first!</p>
          </div>
        ) : (
          <table className="w-full text-sm">
            <thead>
              <tr className="border-b border-surface-700 text-surface-400 text-xs uppercase">
                <th className="p-3 text-left w-12">#</th>
                <th className="p-3 text-left">Company</th>
                <th className="p-3 text-right">Score</th>
                <th className="p-3 text-right">Era</th>
              </tr>
            </thead>
            <tbody>
              {entries.map((entry, i) => (
                <tr key={i} className="border-b border-surface-800 hover:bg-surface-800/50">
                  <td className="p-3">
                    {i < 3 ? <Medal size={16} className={i === 0 ? 'text-yellow-400' : i === 1 ? 'text-gray-400' : 'text-orange-400'} /> : i + 1}
                  </td>
                  <td className="p-3 font-medium">{entry.companyName}</td>
                  <td className="p-3 text-right font-mono">{formatNumber(entry.score)}</td>
                  <td className="p-3 text-right text-surface-400 capitalize">{entry.era}</td>
                </tr>
              ))}
            </tbody>
          </table>
        )}
      </div>
    </div>
  );
}