frontend/src/pages/PineScriptLab.tsx

import { useState, useEffect } from 'react';
import { pinescriptAPI } from '../api/client';
import { formatCurrency, detectCurrencyFromTicker } from '../utils/currencyUtils';
import TickerSearch from '../components/TickerSearch';

/* ── SVG Icons ─────────────────────────────────────────────────────────── */
const CodeIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="18" height="18"><path fillRule="evenodd" d="M12.316 3.051a1 1 0 01.633 1.265l-4 12a1 1 0 11-1.898-.632l4-12a1 1 0 011.265-.633zM5.707 6.293a1 1 0 010 1.414L3.414 10l2.293 2.293a1 1 0 11-1.414 1.414l-3-3a1 1 0 010-1.414l3-3a1 1 0 011.414 0zm8.586 0a1 1 0 011.414 0l3 3a1 1 0 010 1.414l-3 3a1 1 0 11-1.414-1.414L16.586 10l-2.293-2.293a1 1 0 010-1.414z" clipRule="evenodd" /></svg>;
const TemplateIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="18" height="18"><path d="M3 4a1 1 0 011-1h12a1 1 0 011 1v2a1 1 0 01-1 1H4a1 1 0 01-1-1V4zM3 10a1 1 0 011-1h6a1 1 0 011 1v6a1 1 0 01-1 1H4a1 1 0 01-1-1v-6zM14 9a1 1 0 00-1 1v6a1 1 0 001 1h2a1 1 0 001-1v-6a1 1 0 00-1-1h-2z" /></svg>;
const PlayIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="16" height="16"><path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM9.555 7.168A1 1 0 008 8v4a1 1 0 001.555.832l3-2a1 1 0 000-1.664l-3-2z" clipRule="evenodd" /></svg>;
const CopyIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="14" height="14"><path d="M8 2a1 1 0 000 2h2a1 1 0 100-2H8z" /><path d="M3 5a2 2 0 012-2 3 3 0 003 3h2a3 3 0 003-3 2 2 0 012 2v6h-4.586l1.293-1.293a1 1 0 00-1.414-1.414l-3 3a1 1 0 000 1.414l3 3a1 1 0 001.414-1.414L10.414 13H15v3a2 2 0 01-2 2H5a2 2 0 01-2-2V5z" /></svg>;
const DownloadIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="14" height="14"><path fillRule="evenodd" d="M3 17a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zm3.293-7.707a1 1 0 011.414 0L9 10.586V3a1 1 0 112 0v7.586l1.293-1.293a1 1 0 111.414 1.414l-3 3a1 1 0 01-1.414 0l-3-3a1 1 0 010-1.414z" clipRule="evenodd" /></svg>;
const CheckIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="14" height="14"><path fillRule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clipRule="evenodd" /></svg>;
const XIcon = () => <svg viewBox="0 0 20 20" fill="currentColor" width="14" height="14"><path fillRule="evenodd" d="M4.293 4.293a1 1 0 011.414 0L10 8.586l4.293-4.293a1 1 0 111.414 1.414L11.414 10l4.293 4.293a1 1 0 01-1.414 1.414L10 11.414l-4.293 4.293a1 1 0 01-1.414-1.414L8.586 10 4.293 5.707a1 1 0 010-1.414z" clipRule="evenodd" /></svg>;

const CATEGORY_COLORS: Record<string, string> = {
  'Momentum': '#3b82f6',
  'Mean Reversion': '#a855f7',
  'Volatility': '#f59e0b',
  'Trend Following': '#10b981',
  'Oscillator': '#ec4899',
  'Statistical': '#6366f1',
  'Risk-Managed': '#14b8a6',
  'Advanced': '#f97316',
  'Intraday': '#06b6d4',
  'Multi-Signal': '#8b5cf6',
  'Hedging': '#ef4444',
  'Forex': '#22d3ee',
  'Crypto': '#d97706',
  'Commodities': '#a3e635',
  'Futures': '#c084fc',
};

export default function PineScriptLab() {
  const [mode, setMode] = useState<'generate' | 'templates'>('templates');
  const [description, setDescription] = useState('');
  const [code, setCode] = useState('');
  const [templates, setTemplates] = useState<any[]>([]);
  const [backtestTicker, setBacktestTicker] = useState('');
  const [backtestPeriod, setBacktestPeriod] = useState('3y');
  const [loading, setLoading] = useState(false);
  const [generating, setGenerating] = useState(false);
  const [results, setResults] = useState<any>(null);
  const [validation, setValidation] = useState<any>(null);
  const [error, setError] = useState('');
  const [copied, setCopied] = useState(false);

  useEffect(() => {
    loadTemplates();
  }, []);

  const loadTemplates = async () => {
    try {
      const { data } = await pinescriptAPI.templates();
      setTemplates(data.templates || []);
    } catch (err) {
      console.error('Failed to load templates');
    }
  };

  const handleGenerate = async () => {
    if (!description.trim()) return;
    setGenerating(true);
    setError('');
    try {
      const { data } = await pinescriptAPI.generate({ description });
      setCode(data.code || '');
      setValidation(null);
      setResults(null);
    } catch (err: any) {
      setError(err.response?.data?.detail || 'Generation failed');
    } finally {
      setGenerating(false);
    }
  };

  const handleTemplateSelect = async (templateId: string) => {
    setGenerating(true);
    setError('');
    try {
      const { data } = await pinescriptAPI.generateFromTemplate({ template_id: templateId });
      setCode(data.code || '');
      setValidation(null);
      setResults(null);
    } catch (err: any) {
      setError(err.response?.data?.detail || 'Template load failed');
    } finally {
      setGenerating(false);
    }
  };

  const handleValidate = async () => {
    if (!code.trim()) return;
    try {
      const { data } = await pinescriptAPI.validate({ code });
      setValidation(data);
    } catch (err) {
      setError('Validation failed');
    }
  };

  const handleBacktest = async () => {
    if (!code.trim()) return;
    setLoading(true);
    setError('');
    try {
      const { data } = await pinescriptAPI.backtest({
        code, ticker: backtestTicker, period: backtestPeriod,
      });
      setResults(data);
    } catch (err: any) {
      setError(err.response?.data?.detail || 'Backtest failed');
    } finally {
      setLoading(false);
    }
  };

  const handleCopy = () => {
    navigator.clipboard.writeText(code);
    setCopied(true);
    setTimeout(() => setCopied(false), 2000);
  };

  const handleDownload = () => {
    const blob = new Blob([code], { type: 'text/plain' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'strategy.pine';
    a.click();
    URL.revokeObjectURL(url);
  };

  const metricColor = (val: number, positive: boolean = true) => {
    if (positive) return val >= 0 ? 'var(--accent-green)' : '#ef4444';
    return val >= 0 ? '#ef4444' : 'var(--accent-green)';
  };

  return (
    <div className="page-container" style={{ padding: '1.5rem 2rem' }}>
      {/* Header */}
      <div style={{ marginBottom: '1.5rem' }}>
        <h1 style={{ fontSize: '1.5rem', fontWeight: 700, margin: 0, display: 'flex', alignItems: 'center', gap: '0.5rem' }}>
          <CodeIcon /> Pine Script Lab
        </h1>
        <p style={{ color: 'var(--text-muted)', margin: '0.25rem 0 0', fontSize: '0.85rem' }}>
          Generate, validate, and backtest TradingView Pine Script v5 strategies
        </p>
      </div>

      <div style={{ display: 'grid', gap: '1rem', gridTemplateColumns: '1fr 1fr' }}>
        {/* ── Left Panel: Code Generation ────────────────────────────── */}
        <div style={{ display: 'flex', flexDirection: 'column', gap: '0.75rem' }}>
          {/* Mode Toggle */}
          <div style={{ display: 'flex', gap: '0.25rem', background: 'var(--bg-secondary)', borderRadius: '0.5rem', padding: '0.2rem' }}>
            <button
              onClick={() => setMode('templates')}
              style={{
                flex: 1, padding: '0.45rem', border: 'none', borderRadius: '0.4rem', cursor: 'pointer',
                fontSize: '0.8rem', fontWeight: 600, transition: 'all 0.2s',
                background: mode === 'templates' ? 'var(--accent-green)' : 'transparent',
                color: mode === 'templates' ? '#fff' : 'var(--text-muted)',
              }}
            >
              <TemplateIcon /> Templates
            </button>
            <button
              onClick={() => setMode('generate')}
              style={{
                flex: 1, padding: '0.45rem', border: 'none', borderRadius: '0.4rem', cursor: 'pointer',
                fontSize: '0.8rem', fontWeight: 600, transition: 'all 0.2s',
                background: mode === 'generate' ? 'var(--accent-green)' : 'transparent',
                color: mode === 'generate' ? '#fff' : 'var(--text-muted)',
              }}
            >
              AI Generate
            </button>
          </div>

          {/* Template Browser */}
          {mode === 'templates' && (
            <div style={{ display: 'grid', gap: '0.4rem', maxHeight: 220, overflow: 'auto', gridTemplateColumns: '1fr 1fr' }}>
              {templates.map((t: any) => (
                <button
                  key={t.id}
                  onClick={() => handleTemplateSelect(t.id)}
                  style={{
                    padding: '0.6rem 0.75rem', borderRadius: '0.5rem', cursor: 'pointer',
                    border: '1px solid var(--border-subtle)', background: 'var(--bg-secondary)',
                    textAlign: 'left', transition: 'all 0.15s',
                    color: 'var(--text-primary)',
                  }}
                  onMouseOver={e => (e.currentTarget.style.borderColor = 'var(--accent-green)')}
                  onMouseOut={e => (e.currentTarget.style.borderColor = 'var(--border-subtle)')}
                >
                  <div style={{ display: 'flex', alignItems: 'center', gap: '0.4rem', marginBottom: '0.2rem' }}>
                    <span style={{ fontSize: '0.8rem', fontWeight: 600 }}>{t.name}</span>
                    <span style={{
                      fontSize: '0.55rem', padding: '0.1rem 0.35rem', borderRadius: 20,
                      background: `${CATEGORY_COLORS[t.category] || '#6b7280'}22`,
                      color: CATEGORY_COLORS[t.category] || '#6b7280', fontWeight: 600,
                    }}>{t.category}</span>
                  </div>
                  <div style={{ fontSize: '0.65rem', color: 'var(--text-muted)', lineHeight: 1.3 }}>
                    {t.description.length > 80 ? t.description.slice(0, 80) + '...' : t.description}
                  </div>
                </button>
              ))}
            </div>
          )}

          {/* NL Generator */}
          {mode === 'generate' && (
            <div style={{ display: 'flex', flexDirection: 'column', gap: '0.5rem' }}>
              <textarea
                value={description}
                onChange={e => setDescription(e.target.value)}
                placeholder="Describe your strategy in natural language...&#10;e.g., 'Create a strategy that buys when RSI is below 30 and the price is above the 200-day SMA, sells when RSI goes above 70'"
                style={{
                  width: '100%', minHeight: 100, padding: '0.75rem', borderRadius: '0.5rem',
                  border: '1px solid var(--border-subtle)', background: 'var(--bg-secondary)',
                  color: 'var(--text-primary)', fontSize: '0.8rem', resize: 'vertical',
                  fontFamily: 'inherit', lineHeight: 1.5,
                }}
              />
              <button
                onClick={handleGenerate}
                disabled={generating || !description.trim()}
                style={{
                  padding: '0.55rem 1rem', borderRadius: '0.5rem', border: 'none',
                  background: 'var(--accent-green)', color: '#fff', fontWeight: 600,
                  fontSize: '0.8rem', cursor: generating ? 'wait' : 'pointer',
                  opacity: generating || !description.trim() ? 0.6 : 1,
                }}
              >
                {generating ? 'Generating...' : 'Generate Pine Script'}
              </button>
            </div>
          )}

          {/* Code Editor */}
          <div style={{ position: 'relative', flex: 1 }}>
            <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', marginBottom: '0.3rem' }}>
              <span style={{ fontSize: '0.7rem', fontWeight: 600, textTransform: 'uppercase', color: 'var(--text-muted)' }}>Pine Script v5 Code</span>
              <div style={{ display: 'flex', gap: '0.3rem' }}>
                {validation && (
                  <span style={{
                    display: 'flex', alignItems: 'center', gap: '0.2rem', fontSize: '0.65rem', fontWeight: 600,
                    color: validation.valid ? 'var(--accent-green)' : '#ef4444',
                  }}>
                    {validation.valid ? <><CheckIcon /> Valid</> : <><XIcon /> {validation.errors?.length} Error(s)</>}
                  </span>
                )}
                <button onClick={handleValidate} disabled={!code} style={{ padding: '0.2rem 0.5rem', borderRadius: '0.3rem', border: '1px solid var(--border-subtle)', background: 'transparent', color: 'var(--text-muted)', fontSize: '0.65rem', cursor: 'pointer' }}>Validate</button>
                <button onClick={handleCopy} disabled={!code} style={{ padding: '0.2rem 0.5rem', borderRadius: '0.3rem', border: '1px solid var(--border-subtle)', background: 'transparent', color: 'var(--text-muted)', fontSize: '0.65rem', cursor: 'pointer', display: 'flex', alignItems: 'center', gap: '0.2rem' }}>
                  <CopyIcon /> {copied ? 'Copied' : 'Copy'}
                </button>
                <button onClick={handleDownload} disabled={!code} style={{ padding: '0.2rem 0.5rem', borderRadius: '0.3rem', border: '1px solid var(--border-subtle)', background: 'transparent', color: 'var(--text-muted)', fontSize: '0.65rem', cursor: 'pointer', display: 'flex', alignItems: 'center', gap: '0.2rem' }}>
                  <DownloadIcon /> .pine
                </button>
              </div>
            </div>
            <textarea
              value={code}
              onChange={e => { setCode(e.target.value); setValidation(null); }}
              style={{
                width: '100%', minHeight: 280, padding: '0.75rem', borderRadius: '0.5rem',
                border: '1px solid var(--border-subtle)', background: 'var(--bg-tertiary, #0d1117)',
                color: 'var(--text-primary)', fontSize: '0.75rem', fontFamily: '"JetBrains Mono", "Fira Code", monospace',
                lineHeight: 1.6, resize: 'vertical', tabSize: 4,
              }}
              placeholder="// Your Pine Script v5 code will appear here..."
              spellCheck={false}
            />
          </div>

          {/* Validation Errors */}
          {validation && !validation.valid && (
            <div style={{ display: 'flex', flexDirection: 'column', gap: '0.25rem' }}>
              {(validation.errors || []).map((e: any, i: number) => (
                <div key={i} style={{ fontSize: '0.7rem', padding: '0.3rem 0.5rem', borderRadius: '0.3rem', background: 'rgba(239,68,68,0.1)', color: '#ef4444', border: '1px solid rgba(239,68,68,0.2)' }}>
                  {e.line > 0 && `Line ${e.line}: `}{e.message}
                </div>
              ))}
              {(validation.warnings || []).map((w: any, i: number) => (
                <div key={i} style={{ fontSize: '0.7rem', padding: '0.3rem 0.5rem', borderRadius: '0.3rem', background: 'rgba(245,158,11,0.1)', color: '#f59e0b', border: '1px solid rgba(245,158,11,0.2)' }}>
                  {w.line > 0 && `Line ${w.line}: `}{w.message}
                </div>
              ))}
            </div>
          )}
        </div>

        {/* ── Right Panel: Backtest Results ──────────────────────────── */}
        <div style={{ display: 'flex', flexDirection: 'column', gap: '0.75rem' }}>
          {/* Backtest Controls */}
          <div className="card" style={{ padding: '0.75rem 1rem' }}>
            <div style={{ display: 'flex', gap: '0.5rem', alignItems: 'center', flexWrap: 'wrap' }}>
              <TickerSearch
                value={backtestTicker}
                onChange={setBacktestTicker}
                placeholder="Backtest ticker..."
                style={{ width: 200 }}
              />
              <select value={backtestPeriod} onChange={e => setBacktestPeriod(e.target.value)} style={{
                padding: '0.45rem 0.6rem', borderRadius: '0.4rem',
                border: '1px solid var(--border-subtle)', background: 'var(--bg-secondary)',
                color: 'var(--text-primary)', fontSize: '0.8rem',
              }}>
                <option value="1y">1 Year</option>
                <option value="2y">2 Years</option>
                <option value="3y">3 Years</option>
                <option value="5y">5 Years</option>
              </select>
              <button
                onClick={handleBacktest}
                disabled={loading || !code.trim()}
                style={{
                  display: 'flex', alignItems: 'center', gap: '0.3rem',
                  padding: '0.45rem 1rem', borderRadius: '0.4rem', border: 'none',
                  background: 'var(--accent-green)', color: '#fff', fontWeight: 600,
                  fontSize: '0.8rem', cursor: loading ? 'wait' : 'pointer',
                  opacity: loading || !code.trim() ? 0.6 : 1,
                }}
              >
                <PlayIcon /> {loading ? 'Running...' : 'Run Backtest'}
              </button>
            </div>
          </div>

          {error && (
            <div style={{ padding: '0.5rem 0.75rem', borderRadius: '0.4rem', background: 'rgba(239,68,68,0.1)', color: '#ef4444', fontSize: '0.75rem', border: '1px solid rgba(239,68,68,0.2)' }}>
              {error}
            </div>
          )}

          {/* Results */}
          {results && (
            <>
              {/* Key Metrics */}
              <div style={{ display: 'grid', gap: '0.5rem', gridTemplateColumns: 'repeat(3, 1fr)' }}>
                {[
                  { label: 'Net Profit', value: `${results.net_profit_pct >= 0 ? '+' : ''}${results.net_profit_pct.toFixed(2)}%`, color: metricColor(results.net_profit_pct) },
                  { label: 'Sharpe Ratio', value: results.sharpe_ratio.toFixed(2), color: metricColor(results.sharpe_ratio) },
                  { label: 'Max Drawdown', value: `${results.max_drawdown_pct.toFixed(2)}%`, color: '#ef4444' },
                  { label: 'Win Rate', value: `${(results.win_rate * 100).toFixed(1)}%`, color: metricColor(results.win_rate - 0.5) },
                  { label: 'Profit Factor', value: results.profit_factor === Infinity ? 'N/A' : results.profit_factor.toFixed(2), color: metricColor(results.profit_factor - 1) },
                  { label: 'Total Trades', value: results.total_trades, color: 'var(--text-primary)' },
                ].map((m, i) => (
                  <div key={i} className="card" style={{ padding: '0.6rem 0.75rem', textAlign: 'center' }}>
                    <div style={{ fontSize: '0.6rem', textTransform: 'uppercase', color: 'var(--text-muted)', fontWeight: 600, letterSpacing: '0.03em' }}>{m.label}</div>
                    <div style={{ fontSize: '1.15rem', fontWeight: 700, color: m.color }}>{m.value}</div>
                  </div>
                ))}
              </div>

              {/* Secondary Metrics */}
              <div className="card" style={{ padding: '0.75rem 1rem' }}>
                <div style={{ display: 'grid', gap: '0.5rem', gridTemplateColumns: 'repeat(auto-fill, minmax(130px, 1fr))', fontSize: '0.75rem' }}>
                  <div><span style={{ color: 'var(--text-muted)' }}>Sortino: </span><strong>{results.sortino_ratio.toFixed(2)}</strong></div>
                  <div><span style={{ color: 'var(--text-muted)' }}>Ann. Return: </span><strong style={{ color: metricColor(results.annualized_return_pct) }}>{results.annualized_return_pct.toFixed(2)}%</strong></div>
                  <div><span style={{ color: 'var(--text-muted)' }}>Avg Win: </span><strong style={{ color: 'var(--accent-green)' }}>{results.avg_win_pct.toFixed(2)}%</strong></div>
                  <div><span style={{ color: 'var(--text-muted)' }}>Avg Loss: </span><strong style={{ color: '#ef4444' }}>{results.avg_loss_pct.toFixed(2)}%</strong></div>
                  <div><span style={{ color: 'var(--text-muted)' }}>Final Equity: </span><strong>{formatCurrency(results.final_equity, detectCurrencyFromTicker(backtestTicker))}</strong></div>
                  <div><span style={{ color: 'var(--text-muted)' }}>Trading Days: </span><strong>{results.trading_days}</strong></div>
                </div>
              </div>

              {/* Equity Curve */}
              <div className="card" style={{ padding: '1rem' }}>
                <div style={{ fontSize: '0.7rem', fontWeight: 700, textTransform: 'uppercase', color: 'var(--text-muted)', marginBottom: '0.5rem' }}>
                  Equity Curve
                </div>
                {results.equity_curve && results.equity_curve.length > 0 && (
                  <svg viewBox={`0 0 ${results.equity_curve.length} 100`} style={{ width: '100%', height: 120 }} preserveAspectRatio="none">
                    {(() => {
                      const eqData = results.equity_curve;
                      const minEq = Math.min(...eqData.map((d: any) => d.equity));
                      const maxEq = Math.max(...eqData.map((d: any) => d.equity));
                      const range = maxEq - minEq || 1;
                      const points = eqData.map((d: any, i: number) =>
                        `${i},${100 - ((d.equity - minEq) / range) * 90 - 5}`
                      ).join(' ');
                      const fillPoints = `0,100 ${points} ${eqData.length - 1},100`;
                      const isProfit = eqData[eqData.length - 1].equity >= eqData[0].equity;
                      return (
                        <>
                          <defs>
                            <linearGradient id="eqGrad" x1="0" y1="0" x2="0" y2="1">
                              <stop offset="0%" stopColor={isProfit ? '#10b981' : '#ef4444'} stopOpacity="0.3" />
                              <stop offset="100%" stopColor={isProfit ? '#10b981' : '#ef4444'} stopOpacity="0.02" />
                            </linearGradient>
                          </defs>
                          <polygon points={fillPoints} fill="url(#eqGrad)" />
                          <polyline points={points} fill="none" stroke={isProfit ? '#10b981' : '#ef4444'} strokeWidth="1.5" />
                        </>
                      );
                    })()}
                  </svg>
                )}
              </div>

              {/* Trade Log */}
              <div className="card" style={{ padding: 0, overflow: 'hidden', maxHeight: 250, overflowY: 'auto' }}>
                <div style={{ fontSize: '0.7rem', fontWeight: 700, textTransform: 'uppercase', color: 'var(--text-muted)', padding: '0.6rem 0.75rem', background: 'var(--bg-secondary)', borderBottom: '1px solid var(--border-subtle)' }}>
                  Trade Log (Last {results.trades?.length || 0})
                </div>
                <table style={{ width: '100%', borderCollapse: 'collapse', fontSize: '0.75rem' }}>
                  <tbody>
                    {(results.trades || []).map((t: any, i: number) => (
                      <tr key={i} style={{ borderBottom: '1px solid var(--border-subtle)' }}>
                        <td style={{ padding: '0.35rem 0.75rem' }}>
                          <span style={{
                            fontSize: '0.6rem', fontWeight: 700, padding: '0.1rem 0.35rem', borderRadius: 3,
                            background: t.type === 'ENTRY' ? 'rgba(16,185,129,0.15)' : 'rgba(239,68,68,0.15)',
                            color: t.type === 'ENTRY' ? '#10b981' : '#ef4444',
                          }}>{t.type}</span>
                        </td>
                        <td style={{ padding: '0.35rem 0.5rem', color: 'var(--text-muted)' }}>{t.date}</td>
                        <td style={{ padding: '0.35rem 0.5rem' }}>{formatCurrency(t.price, detectCurrencyFromTicker(backtestTicker))}</td>
                        {t.pnl_pct !== undefined && (
                          <td style={{ padding: '0.35rem 0.5rem', fontWeight: 600, color: t.pnl_pct >= 0 ? 'var(--accent-green)' : '#ef4444' }}>
                            {t.pnl_pct >= 0 ? '+' : ''}{t.pnl_pct}%
                          </td>
                        )}
                      </tr>
                    ))}
                  </tbody>
                </table>
              </div>
            </>
          )}

          {/* Empty State */}
          {!results && (
            <div style={{ textAlign: 'center', padding: '3rem 2rem', color: 'var(--text-muted)', flex: 1, display: 'flex', flexDirection: 'column', alignItems: 'center', justifyContent: 'center' }}>
              <PlayIcon />
              <p style={{ fontSize: '0.85rem', marginTop: '0.5rem' }}>Select a template or generate code, then click Run Backtest</p>
              <p style={{ fontSize: '0.7rem' }}>Results will show equity curve, metrics, and trade log</p>
            </div>
          )}
        </div>
      </div>
    </div>
  );
}