'use client';

import React, { useState, useMemo } from 'react';
import { useSandboxStore, PortfolioHolding, Transaction } from '@/lib/store';
import { calculateEWMA, calculateKellyFraction, calculateAssetCovariance } from '@/lib/math/statistics';
import { LineChart, Line, XAxis, YAxis, CartesianGrid, Tooltip, ResponsiveContainer, Legend } from 'recharts';
import 'katex/dist/katex.min.css';
import { BlockMath, InlineMath } from 'react-katex';
import {
  TrendingUp, Wallet, ArrowDownRight, ArrowUpRight, Percent, Plus, FolderSync,
  HelpCircle, Settings, Calendar, DollarSign, Tag, Check, AlertCircle, ChevronDown, ChevronUp, Sparkles
} from 'lucide-react';

export default function SandboxDemo() {
  const {
    portfolios,
    activePortfolioId,
    ewmaLambda,
    createPortfolio,
    setActivePortfolio,
    executeTransaction,
    setEwmaLambda,
    scannerAlerts,
    posteriorProbability
  } = useSandboxStore();

  // Selected portfolio
  const activePortfolio = useMemo(() => {
    return portfolios.find(p => p.id === activePortfolioId) || portfolios[0];
  }, [portfolios, activePortfolioId]);

  const [mounted, setMounted] = useState(false);
  React.useEffect(() => {
    setMounted(true);
  }, []);

  if (!mounted) {
    return (
      <div className="bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl min-h-[400px] flex items-center justify-center">
        <div className="text-slate-400 text-sm font-mono animate-pulse">Lade Sandbox-Modul...</div>
      </div>
    );
  }

  // UI state
  const [showNewPortfolioModal, setShowNewPortfolioModal] = useState(false);
  const [newPortfolioName, setNewPortfolioName] = useState('');
  const [newStartingBalance, setNewStartingBalance] = useState(50000);
  
  const [tradeSymbol, setTradeSymbol] = useState('AAPL');
  const [tradeWknOrIsin, setTradeWknOrIsin] = useState('865985');
  const [tradeShares, setTradeShares] = useState(10);
  const [tradePrice, setTradePrice] = useState(182);
  const [tradeType, setTradeType] = useState<'BUY' | 'SELL'>('BUY');
  const [simulateFees, setSimulateFees] = useState(true);
  const [isBackfill, setIsBackfill] = useState(false);
  const [backfillDate, setBackfillDate] = useState('2026-05-20');
  const [hypothesisTag, setHypothesisTag] = useState('Fokus auf KI-Infrastruktur');
  const [orderError, setOrderError] = useState<string | null>(null);
  const [orderSuccess, setOrderSuccess] = useState(false);

  const [showMathAccordion, setShowMathAccordion] = useState(false);
  const [showMsciBenchmark, setShowMsciBenchmark] = useState(true);

  // Kelly Position Sizing states
  const [kellySource, setKellySource] = useState<'scanner' | 'crypto' | 'econometric' | 'custom'>('custom');
  const [customProb, setCustomProb] = useState<number>(0.60);
  const [oddsRatio, setOddsRatio] = useState<number>(1.5);

  // Compute Net Worth
  const netWorth = useMemo(() => {
    const assetsVal = activePortfolio.holdings.reduce((sum, h) => sum + h.shares * h.currentPrice, 0);
    return Math.round((activePortfolio.cash + assetsVal) * 100) / 100;
  }, [activePortfolio]);

  // Dynamic winning probability (p) based on selected source
  const kellyProbability = useMemo(() => {
    if (kellySource === 'scanner') {
      const alert = scannerAlerts.find(a => a.ticker.toUpperCase() === tradeSymbol.toUpperCase());
      return alert ? alert.overreactionScore / 100 : 0.52;
    }
    if (kellySource === 'crypto') {
      return posteriorProbability; // e.g. 0.72
    }
    if (kellySource === 'econometric') {
      return 0.65; // ROC target probability
    }
    return customProb;
  }, [kellySource, customProb, tradeSymbol, scannerAlerts, posteriorProbability]);

  // Check potential cluster risk for the input symbol
  const potentialClusterRisk = useMemo(() => {
    if (!tradeSymbol) return false;
    const holdingsWithWeights = activePortfolio.holdings.map(h => ({
      symbol: h.symbol,
      weight: (h.shares * h.currentPrice) / (netWorth || 1.0)
    }));
    const covResult = calculateAssetCovariance(holdingsWithWeights, tradeSymbol);
    return covResult.clusterRisk;
  }, [activePortfolio.holdings, tradeSymbol, netWorth]);

  // Compute Kelly fraction and recommended cash amount
  const kellyFraction = useMemo(() => {
    const rawKelly = calculateKellyFraction(kellyProbability, oddsRatio);
    // Cap at Half-Kelly already done in calculateKellyFraction, but we can scale by 50% if there is cluster risk
    return potentialClusterRisk ? rawKelly * 0.5 : rawKelly;
  }, [kellyProbability, oddsRatio, potentialClusterRisk]);

  const recommendedKellyCash = useMemo(() => {
    return activePortfolio.cash * kellyFraction;
  }, [activePortfolio.cash, kellyFraction]);

  // Compute returns based on active portfolio's historical value series
  const portfolioReturns = useMemo(() => {
    const vals = activePortfolio.historicalValues;
    if (vals.length < 2) return [];
    const r: number[] = [];
    for (let i = 1; i < vals.length; i++) {
      r.push((vals[i].value - vals[i - 1].value) / vals[i - 1].value);
    }
    return r;
  }, [activePortfolio.historicalValues]);

  // Calculate EWMA Volatility live
  const ewmaResult = useMemo(() => {
    return calculateEWMA(portfolioReturns, ewmaLambda);
  }, [portfolioReturns, ewmaLambda]);

  // Combine data for charting
  const chartData = useMemo(() => {
    const vals = activePortfolio.historicalValues;
    if (vals.length === 0) return [];
    
    // Normalize MSCI World index from the same starting value of the portfolio
    const baseValue = vals[0].value;
    let msciVal = baseValue;
    
    return vals.map((hv, idx) => {
      // Deterministic pseudo-random walk for MSCI World
      if (idx > 0) {
        const rand = Math.sin(idx * 57.8) * 0.45 + 0.05; // range: -0.4% to +0.5% return
        msciVal = msciVal * (1 + rand * 0.015);
      }
      
      const vol = ewmaResult.series[idx - 1] || 0;
      
      return {
        date: hv.date,
        Portfolio: hv.value,
        'MSCI World (Benchmark)': Math.round(msciVal),
        'EWMA Vol (%)': parseFloat(vol.toFixed(2)),
      };
    });
  }, [activePortfolio.historicalValues, ewmaResult]);

  // Total gain/loss
  const totalGainLoss = netWorth - activePortfolio.startingBalance;
  const totalGainLossPct = (totalGainLoss / activePortfolio.startingBalance) * 100;
  const isPositiveOverall = totalGainLoss >= 0;

  const handleCreatePortfolio = (e: React.FormEvent) => {
    e.preventDefault();
    if (!newPortfolioName.trim()) return;
    createPortfolio(newPortfolioName, newStartingBalance);
    setNewPortfolioName('');
    setShowNewPortfolioModal(false);
  };

  const handleTransactionSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    setOrderError(null);
    setOrderSuccess(false);

    if (tradeShares <= 0 || tradePrice <= 0) {
      setOrderError('Bitte geben Sie eine gültige Stückzahl und einen Kurs an.');
      return;
    }

    const ok = executeTransaction(
      activePortfolio.id,
      tradeSymbol,
      tradeWknOrIsin,
      tradeType,
      tradeShares,
      tradePrice,
      simulateFees,
      isBackfill,
      backfillDate,
      hypothesisTag
    );

    if (ok) {
      setOrderSuccess(true);
      setTimeout(() => setOrderSuccess(false), 3000);
    } else {
      setOrderError(
        tradeType === 'BUY'
          ? 'Unzureichendes Barguthaben (inklusive allfälliger Transaktionsgebühren).'
          : 'Unzureichende Anteile im Depot für den Verkauf.'
      );
    }
  };

  return (
    <div className="space-y-6">
      
      {activePortfolio.riskProfile?.status === 'RED' && (
        <div className="bg-rose-950/40 border border-rose-800/80 text-rose-400 text-xs rounded-xl p-4 flex items-center gap-3 shadow-[0_0_15px_rgba(244,63,94,0.15)] animate-pulse">
          <AlertCircle className="w-5 h-5 text-rose-400 shrink-0" />
          <div className="flex-1">
            <span className="font-bold">Kritische Klumpenrisiken (Kovarianz RED):</span> {activePortfolio.riskProfile.message}
          </div>
        </div>
      )}

      {/* SECTION 1: Portfolio Selector & Stats Bar */}
      <div className="bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl relative overflow-hidden">
        <div className="absolute top-0 right-0 w-32 h-32 bg-emerald-500/10 rounded-full blur-3xl -z-10" />
        
        <div className="flex flex-col md:flex-row justify-between items-start md:items-center gap-4 mb-6">
          <div className="space-y-1">
            <span className="text-emerald-400 text-xs font-semibold uppercase tracking-wider">Strategic Sandbox</span>
            <div className="flex items-center gap-3">
              <FolderSync className="text-emerald-400 w-6 h-6" />
              <select
                value={activePortfolioId}
                onChange={(e) => setActivePortfolio(e.target.value)}
                className="bg-slate-950 border border-slate-800 rounded-xl px-4 py-2 text-slate-100 font-sans font-semibold text-lg focus:outline-none focus:border-emerald-500 cursor-pointer"
              >
                {portfolios.map((p) => (
                  <option key={p.id} value={p.id}>
                    {p.name}
                  </option>
                ))}
              </select>
              <button
                onClick={() => setShowNewPortfolioModal(true)}
                className="p-2 rounded-xl bg-slate-800 hover:bg-slate-700 text-emerald-400 hover:text-emerald-300 transition-colors border border-slate-700"
                title="Neues Sandbox-Portfolio erstellen"
              >
                <Plus className="w-5 h-5" />
              </button>
            </div>
          </div>
          
          <div className="flex flex-wrap gap-4 w-full md:w-auto">
            {/* Net Worth Card */}
            <div className="flex-1 md:flex-initial bg-slate-950/80 border border-slate-800 rounded-xl p-3 px-5 min-w-[140px]">
              <div className="text-[10px] text-slate-400 uppercase font-semibold">Gesamtwert</div>
              <div className="font-mono text-xl font-bold text-slate-100 mt-1">
                ${netWorth.toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
              </div>
            </div>

            {/* Performance Card */}
            <div className="flex-1 md:flex-initial bg-slate-950/80 border border-slate-800 rounded-xl p-3 px-5 min-w-[140px]">
              <div className="text-[10px] text-slate-400 uppercase font-semibold">GuV (Gesamt)</div>
              <div className={`font-mono text-xl font-bold mt-1 flex items-center gap-1 ${isPositiveOverall ? 'text-emerald-400' : 'text-rose-400'}`}>
                {isPositiveOverall ? <ArrowUpRight className="w-5 h-5" /> : <ArrowDownRight className="w-5 h-5" />}
                <span>{isPositiveOverall ? '+' : ''}{totalGainLossPct.toFixed(2)}%</span>
              </div>
            </div>

            {/* Live EWMA Vol Card */}
            <div className="flex-1 md:flex-initial bg-slate-950/80 border border-slate-800 rounded-xl p-3 px-5 min-w-[140px] relative group">
              <div className="text-[10px] text-slate-400 uppercase font-semibold flex items-center gap-1">
                <span>EWMA Volatilität</span>
                <span className="cursor-help flex items-center" title="Annualisierte Schwankungsbreite basierend auf historischen Renditen.">
                  <HelpCircle className="w-3.5 h-3.5 text-slate-500 group-hover:text-emerald-400 transition-colors" />
                </span>
              </div>
              <div className="font-mono text-xl font-bold text-teal-400 mt-1">
                {ewmaResult.latest.toFixed(2)}%
              </div>
            </div>

            {/* Covariance Risk Traffic Light Card */}
            <div className="flex-1 md:flex-initial bg-slate-950/80 border border-slate-800 rounded-xl p-3 px-5 min-w-[150px] relative group">
              <div className="text-[10px] text-slate-400 uppercase font-semibold flex items-center gap-1">
                <span>Kovarianz-Ampel</span>
                <span className="cursor-help flex items-center" title="Systemische Portfolio-Klumpenrisiken basierend auf historischen Asset-Kovarianzen.">
                  <HelpCircle className="w-3.5 h-3.5 text-slate-500 group-hover:text-rose-400 transition-colors" />
                </span>
              </div>
              <div className="flex items-center gap-2 mt-1.5">
                <span className={`w-3.5 h-3.5 rounded-full ${
                  activePortfolio.riskProfile?.status === 'RED' ? 'bg-rose-500 animate-pulse shadow-[0_0_8px_#f43f5e]' :
                  activePortfolio.riskProfile?.status === 'YELLOW' ? 'bg-amber-500 shadow-[0_0_8px_#f59e0b]' :
                  'bg-emerald-500 shadow-[0_0_8px_#10b981]'
                }`} />
                <span className={`font-mono text-sm font-bold ${
                  activePortfolio.riskProfile?.status === 'RED' ? 'text-rose-400' :
                  activePortfolio.riskProfile?.status === 'YELLOW' ? 'text-amber-400' :
                  'text-emerald-400'
                }`}>
                  {activePortfolio.riskProfile?.status || 'GREEN'} RISK
                </span>
              </div>
            </div>
          </div>
        </div>

        {/* Modal for creating a new Portfolio */}
        {showNewPortfolioModal && (
          <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm p-4">
            <div className="bg-slate-900 border border-slate-800 rounded-2xl p-6 max-w-sm w-full space-y-4 shadow-2xl">
              <h3 className="text-lg font-bold text-white">Neues Sandbox-Portfolio</h3>
              <form onSubmit={handleCreatePortfolio} className="space-y-4">
                <div>
                  <label className="text-xs text-slate-400 block mb-1">Portfolio Name</label>
                  <input
                    type="text"
                    required
                    placeholder="z.B. Biotech Risk High Yield"
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2.5 text-slate-100 focus:outline-none focus:border-emerald-500"
                    value={newPortfolioName}
                    onChange={(e) => setNewPortfolioName(e.target.value)}
                  />
                </div>
                <div>
                  <label className="text-xs text-slate-400 block mb-1">Startkapital ($)</label>
                  <input
                    type="number"
                    required
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2.5 text-slate-100 focus:outline-none focus:border-emerald-500 font-mono"
                    value={newStartingBalance}
                    onChange={(e) => setNewStartingBalance(Number(e.target.value))}
                  />
                </div>
                <div className="flex gap-3 pt-2">
                  <button
                    type="button"
                    onClick={() => setShowNewPortfolioModal(false)}
                    className="flex-1 bg-slate-850 hover:bg-slate-800 text-slate-300 font-semibold py-2 rounded-lg transition-colors border border-slate-700"
                  >
                    Abbrechen
                  </button>
                  <button
                    type="submit"
                    className="flex-1 bg-gradient-to-r from-emerald-500 to-teal-500 hover:from-emerald-600 hover:to-teal-600 text-slate-950 font-bold py-2 rounded-lg transition-all shadow-lg shadow-emerald-500/20"
                  >
                    Erstellen
                  </button>
                </div>
              </form>
            </div>
          </div>
        )}

        {/* Accordion / Math Button */}
        <div className="border-t border-slate-850 pt-4 mt-4">
          <button
            onClick={() => setShowMathAccordion(!showMathAccordion)}
            className="flex items-center gap-1.5 text-xs text-slate-400 hover:text-emerald-400 transition-colors focus:outline-none"
          >
            <span>{showMathAccordion ? <ChevronUp className="w-4 h-4" /> : <ChevronDown className="w-4 h-4" />}</span>
            <span className="font-semibold uppercase tracking-wider">Mathematische Spezifikation & EWMA-Volatilitätsmodell</span>
          </button>
          
          {showMathAccordion && (
            <div className="mt-4 p-4 rounded-xl border border-slate-850 bg-slate-950/40 text-xs text-slate-300 space-y-4">
              <div>
                <h4 className="font-semibold text-emerald-400 mb-1.5">1. EWMA Volatilitätsmodell</h4>
                <p className="mb-2">
                  Die Volatilit&auml;t wird mittels des <strong>Exponentially Weighted Moving Average (EWMA)</strong>-Modells ermittelt. J&uuml;ngere Renditen erhalten hierbei ein h&ouml;heres Gewicht als weiter in der Vergangenheit liegende Renditen, gesteuert durch den Zerfallsparameter <InlineMath math="\lambda" /> (Lambda).
                </p>
                <div className="py-2 overflow-x-auto">
                  <BlockMath math="\sigma_t^2 = \lambda \sigma_{t-1}^2 + (1 - \lambda) r_{t-1}^2" />
                </div>
                <p className="mb-2">
                  Die t&auml;gliche Volatilit&auml;t <InlineMath math="\sigma_t" /> wird auf ein ganzes Jahr hochgerechnet (Annualisierung) unter der Annahme von 252 Handelstagen:
                </p>
                <div className="py-2 overflow-x-auto">
                  <BlockMath math="\sigma_{\text{ann}} = \sqrt{\sigma_t^2 \times 252}" />
                </div>
                <p className="text-slate-400">
                  RiskMetrics empfiehlt f&uuml;r t&auml;gliche Finanzdaten einen Lambda-Wert von <InlineMath math="\lambda = 0.94" />.
                </p>
              </div>

              <div className="border-t border-slate-800 pt-3">
                <h4 className="font-semibold text-emerald-400 mb-1.5">2. Kelly-Kriterium zur Positionsgrößenbestimmung</h4>
                <p className="mb-2">
                  Die Kelly-Formel bestimmt den optimalen Anteil des Kapitals (<InlineMath math="f^*" />), der in ein Geschäft investiert werden soll, um das exponentielle Wachstum des Kapitals zu maximieren:
                </p>
                <div className="py-2 overflow-x-auto">
                  <BlockMath math="f^* = \frac{p \cdot b - q}{b} = \frac{p \cdot b - (1 - p)}{b}" />
                </div>
                <p className="mb-2">
                  Um Risiken durch ungenaue Schätzungen zu verringern, wenden wir das konservative <strong>Half-Kelly</strong>-Sizing an und begrenzen das Ergebnis auf <InlineMath math="0.5 \times f^*" /> (zusätzlich begrenzt auf <InlineMath math="\ge 0" />).
                </p>
              </div>

              <div className="border-t border-slate-800 pt-3">
                <h4 className="font-semibold text-rose-400 mb-1.5">3. Covariance & Cluster Risk (Kovarianz-Ampel)</h4>
                <p className="mb-2">
                  Die Kovarianz zwischen Assets wird durch Multiplikation ihrer paarweisen Korrelation mit ihren jeweiligen Standardabweichungen (Volatilitäten) bestimmt:
                </p>
                <div className="py-2 overflow-x-auto">
                  <BlockMath math="\text{Cov}(A, B) = \text{Corr}(A, B) \times \sigma_A \times \sigma_B" />
                </div>
                <p className="text-slate-400">
                  Ein <strong>Klumpenrisiko (Risk RED)</strong> wird ausgelöst, wenn ein Asset eine Korrelation <InlineMath math="\text{Corr}(A, B) > 0.70" /> zu bestehenden Positionen aufweist und diese Positionen jeweils mehr als 15% des Portfolios ausmachen.
                </p>
              </div>
            </div>
          )}
        </div>
      </div>

      {/* SECTION 2: Chart / Analytics & Order Form */}
      <div className="grid grid-cols-1 xl:grid-cols-3 gap-8">
        
        {/* Left 2 Columns: Analytics Performance Plot */}
        <div className="xl:col-span-2 bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl space-y-6">
          <div className="flex justify-between items-center border-b border-slate-800 pb-3">
            <h3 className="text-lg font-bold text-white flex items-center gap-2">
              <TrendingUp className="text-emerald-400 w-5 h-5" /> Portfolio Wertentwicklung & Benchmark
            </h3>
            <div className="flex items-center gap-3">
              <label className="flex items-center gap-2 text-xs text-slate-400 cursor-pointer">
                <input
                  type="checkbox"
                  checked={showMsciBenchmark}
                  onChange={(e) => setShowMsciBenchmark(e.target.checked)}
                  className="rounded border-slate-800 text-emerald-500 focus:ring-0 accent-emerald-500 w-4 h-4"
                />
                <span>MSCI World (Benchmark) anzeigen</span>
              </label>
            </div>
          </div>

          <div className="h-80 w-full">
            <ResponsiveContainer width="100%" height="100%">
              <LineChart data={chartData}>
                <CartesianGrid strokeDasharray="3 3" stroke="#1e293b" />
                <XAxis dataKey="date" stroke="#64748b" fontSize={10} />
                <YAxis stroke="#64748b" fontSize={10} domain={['auto', 'auto']} tickFormatter={(v) => `$${v.toLocaleString()}`} />
                <Tooltip contentStyle={{ backgroundColor: '#0f172a', borderColor: '#334155', borderRadius: '8px' }} />
                <Legend verticalAlign="top" height={36} />
                <Line type="monotone" dataKey="Portfolio" name={activePortfolio.name} stroke="#10b981" strokeWidth={3} dot={false} activeDot={{ r: 6 }} />
                {showMsciBenchmark && (
                  <Line type="monotone" dataKey="MSCI World (Benchmark)" name="MSCI World Index (Normiert)" stroke="#3b82f6" strokeWidth={2} strokeDasharray="4 4" dot={false} />
                )}
              </LineChart>
            </ResponsiveContainer>
          </div>

          {/* EWMA parameter tuner slider */}
          <div className="p-4 rounded-xl border border-slate-850 bg-slate-950/20 flex flex-col sm:flex-row justify-between items-start sm:items-center gap-4">
            <div className="space-y-1">
              <h4 className="text-sm font-semibold text-slate-200">Parameteranpassung EWMA Lambda (&lambda;)</h4>
              <p className="text-xs text-slate-400">Zerfallsfaktor steuert die Schock-Sensitivität des Volatilitätsmodells.</p>
            </div>
            <div className="flex items-center gap-4 w-full sm:w-auto">
              <input
                type="range"
                min="0.80"
                max="0.99"
                step="0.01"
                value={ewmaLambda}
                onChange={(e) => setEwmaLambda(parseFloat(e.target.value))}
                className="w-40 accent-emerald-400 cursor-pointer"
              />
              <span className="font-mono text-emerald-400 text-sm font-bold bg-emerald-500/10 px-2 py-0.5 rounded border border-emerald-500/20">&lambda; = {ewmaLambda.toFixed(2)}</span>
            </div>
          </div>
        </div>

        {/* Right 1 Column: Advanced Order Mask */}
        <div className="bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl relative overflow-hidden flex flex-col justify-between">
          <div className="space-y-6">
            <div className="border-b border-slate-800 pb-3">
              <h3 className="text-lg font-bold text-white flex items-center gap-2">
                <Settings className="text-emerald-400 w-5 h-5" /> Order-Maske (Simuliert)
              </h3>
            </div>

            <form onSubmit={handleTransactionSubmit} className="space-y-4">
              <div className="grid grid-cols-2 gap-3">
                <div>
                  <label className="text-xs text-slate-400 block mb-1">Ticker / Symbol</label>
                  <input
                    type="text"
                    required
                    placeholder="AAPL"
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 font-mono focus:outline-none focus:border-emerald-500"
                    value={tradeSymbol}
                    onChange={(e) => setTradeSymbol(e.target.value.toUpperCase())}
                  />
                </div>
                <div>
                  <label className="text-xs text-slate-400 block mb-1">WKN / ISIN</label>
                  <input
                    type="text"
                    placeholder="865985"
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 font-mono focus:outline-none focus:border-emerald-500"
                    value={tradeWknOrIsin}
                    onChange={(e) => setTradeWknOrIsin(e.target.value)}
                  />
                </div>
                <div>
                  <label className="text-xs text-slate-400 block mb-1">Stücke</label>
                  <input
                    type="number"
                    required
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 font-mono focus:outline-none focus:border-emerald-500"
                    value={tradeShares}
                    onChange={(e) => setTradeShares(Number(e.target.value))}
                  />
                </div>
                <div>
                  <label className="text-xs text-slate-400 block mb-1">Kurs ($)</label>
                  <input
                    type="number"
                    required
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 font-mono focus:outline-none focus:border-emerald-500"
                    value={tradePrice}
                    onChange={(e) => setTradePrice(Number(e.target.value))}
                  />
                </div>
              </div>

              {/* Order direction buttons */}
              <div className="flex gap-2 p-1 rounded-xl bg-slate-950 border border-slate-800">
                <button
                  type="button"
                  onClick={() => setTradeType('BUY')}
                  className={`flex-1 py-1.5 text-xs font-bold rounded-lg transition-all ${tradeType === 'BUY' ? 'bg-emerald-500 text-slate-950 shadow-md shadow-emerald-500/10' : 'text-slate-400 hover:text-slate-200'}`}
                >
                  Kauf (Long)
                </button>
                <button
                  type="button"
                  onClick={() => setTradeType('SELL')}
                  className={`flex-1 py-1.5 text-xs font-bold rounded-lg transition-all ${tradeType === 'SELL' ? 'bg-rose-500 text-white shadow-md shadow-rose-500/10' : 'text-slate-400 hover:text-slate-200'}`}
                >
                  Verkauf (Short)
                </button>
              </div>

              {/* Kelly Sizing Risk Recommendation Widget */}
              {tradeType === 'BUY' && (
                <div className="bg-slate-950/60 border border-slate-850 rounded-xl p-3 text-[11px] space-y-2 relative overflow-hidden">
                  <div className="flex justify-between items-center">
                    <span className="text-[10px] text-slate-400 uppercase font-semibold flex items-center gap-1">
                      <Sparkles className="w-3 h-3 text-emerald-400" /> Risk-Engine Sizing
                    </span>
                    <span className="font-bold text-emerald-400 text-[10px] uppercase tracking-wider">Kelly recommendation</span>
                  </div>

                  <div className="grid grid-cols-2 gap-2">
                    <div>
                      <label className="text-[9px] text-slate-500 block mb-0.5 font-semibold uppercase">Prob Source (p)</label>
                      <select
                        value={kellySource}
                        onChange={(e) => setKellySource(e.target.value as any)}
                        className="w-full bg-slate-900 border border-slate-800 rounded px-1.5 py-1 text-[10px] text-slate-200 focus:outline-none"
                      >
                        <option value="custom">Manueller Regler</option>
                        <option value="scanner">El. 2 Scanner-Score</option>
                        <option value="crypto">El. 4 Bayes Posterior</option>
                        <option value="econometric">El. 5 ROC Breakout</option>
                      </select>
                    </div>

                    <div>
                      <label className="text-[9px] text-slate-500 block mb-0.5 font-semibold uppercase">Odds-Verhältnis (b)</label>
                      <input
                        type="number"
                        step="0.1"
                        min="0.1"
                        value={oddsRatio}
                        onChange={(e) => setOddsRatio(Number(e.target.value))}
                        className="w-full bg-slate-900 border border-slate-800 rounded px-1.5 py-1 text-[10px] text-slate-200 font-mono focus:outline-none"
                      />
                    </div>
                  </div>

                  {kellySource === 'custom' && (
                    <div className="space-y-1">
                      <div className="flex justify-between text-[9px] text-slate-500">
                        <span>Erfolgswahrscheinlichkeit:</span>
                        <span className="font-mono text-emerald-400 font-bold">{(kellyProbability * 100).toFixed(0)}%</span>
                      </div>
                      <input
                        type="range"
                        min="0.1"
                        max="0.99"
                        step="0.01"
                        value={customProb}
                        onChange={(e) => setCustomProb(Number(e.target.value))}
                        className="w-full accent-emerald-500 h-1 bg-slate-900 rounded"
                      />
                    </div>
                  )}

                  {kellySource !== 'custom' && (
                    <div className="text-[9px] text-slate-400 flex justify-between bg-slate-900/40 p-1 px-1.5 rounded border border-slate-900">
                      <span>System-Wahrscheinlichkeit:</span>
                      <span className="font-mono text-emerald-400 font-bold">{(kellyProbability * 100).toFixed(1)}%</span>
                    </div>
                  )}

                  {potentialClusterRisk && (
                    <div className="p-2 bg-rose-500/10 text-rose-400 border border-rose-500/20 text-[9px] rounded flex items-start gap-1">
                      <AlertCircle className="w-3.5 h-3.5 shrink-0 text-rose-400" />
                      <div>
                        <strong>Klumpenrisiko!</strong> Korrelation &gt; 0.70 zu bestehenden Positionen. Kelly-Empfehlung wurde um 50% halbiert.
                      </div>
                    </div>
                  )}

                  <div className="bg-slate-900/80 p-2 rounded-lg border border-slate-850 flex justify-between items-center text-xs">
                    <div>
                      <span className="block text-[9px] text-slate-500 uppercase font-semibold">Kelly-Anteil:</span>
                      <span className="font-mono font-bold text-slate-200">{(kellyFraction * 100).toFixed(1)}% des Cashs</span>
                    </div>
                    <div className="text-right">
                      <span className="block text-[9px] text-slate-500 uppercase font-semibold">Kaufvolumen:</span>
                      <span className="font-mono font-bold text-emerald-400">${Math.round(recommendedKellyCash).toLocaleString()}</span>
                    </div>
                  </div>
                </div>
              )}

              {/* Hypothesis input */}
              <div>
                <label className="text-xs text-slate-400 block mb-1 flex items-center gap-1">
                  <Tag className="w-3 h-3 text-emerald-400" />
                  <span>Hypothese / What-if Notiz</span>
                </label>
                <input
                  type="text"
                  placeholder="z.B. Ferrari E-Auto Skepsis"
                  className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 text-xs focus:outline-none focus:border-emerald-500"
                  value={hypothesisTag}
                  onChange={(e) => setHypothesisTag(e.target.value)}
                />
              </div>

              {/* Fees Toggle */}
              <div className="flex items-center justify-between border-t border-slate-850 pt-3 text-xs">
                <span className="text-slate-400 flex items-center gap-1">
                  <DollarSign className="w-3.5 h-3.5 text-slate-500" /> Ordergebühren simulieren
                </span>
                <input
                  type="checkbox"
                  checked={simulateFees}
                  onChange={(e) => setSimulateFees(e.target.checked)}
                  className="rounded border-slate-800 text-emerald-500 focus:ring-0 accent-emerald-500 w-4 h-4 cursor-pointer"
                />
              </div>

              {/* Backfill Date Picker Toggle */}
              <div className="space-y-2 border-t border-slate-850 pt-3 text-xs">
                <div className="flex items-center justify-between">
                  <span className="text-slate-400 flex items-center gap-1">
                    <Calendar className="w-3.5 h-3.5 text-slate-500" /> Historischer Backfill
                  </span>
                  <input
                    type="checkbox"
                    checked={isBackfill}
                    onChange={(e) => setIsBackfill(e.target.checked)}
                    className="rounded border-slate-800 text-emerald-500 focus:ring-0 accent-emerald-500 w-4 h-4 cursor-pointer"
                  />
                </div>
                
                {isBackfill && (
                  <input
                    type="date"
                    className="w-full bg-slate-950 border border-slate-800 rounded-lg p-2 text-slate-100 text-xs focus:outline-none focus:border-emerald-500 font-mono"
                    value={backfillDate}
                    onChange={(e) => setBackfillDate(e.target.value)}
                  />
                )}
              </div>

              {orderError && (
                <div className="p-3 rounded-lg bg-rose-500/10 text-rose-400 border border-rose-500/20 text-xs flex items-center gap-2">
                  <AlertCircle className="w-4 h-4 shrink-0" />
                  <span>{orderError}</span>
                </div>
              )}

              {orderSuccess && (
                <div className="p-3 rounded-lg bg-emerald-500/10 text-emerald-400 border border-emerald-500/20 text-xs flex items-center gap-2">
                  <Check className="w-4 h-4 shrink-0" />
                  <span>Transaktion erfolgreich gebucht!</span>
                </div>
              )}

              <button
                type="submit"
                className={`w-full font-bold py-2.5 px-4 rounded-lg transition-all active:scale-[0.98] mt-2 shadow-lg ${tradeType === 'BUY' ? 'bg-gradient-to-r from-emerald-500 to-teal-500 hover:from-emerald-600 hover:to-teal-600 text-slate-950 shadow-emerald-500/10' : 'bg-gradient-to-r from-rose-500 to-pink-500 hover:from-rose-600 hover:to-pink-600 text-white shadow-rose-500/10'}`}
              >
                Order an den Markt senden
              </button>
            </form>
          </div>
        </div>

      </div>

      {/* SECTION 3: Holdings Table & Transactions Log */}
      <div className="grid grid-cols-1 xl:grid-cols-3 gap-8">
        
        {/* Left 2 Columns: Holdings List */}
        <div className="xl:col-span-2 bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl space-y-4">
          <div className="flex justify-between items-center border-b border-slate-800 pb-3">
            <h3 className="text-lg font-bold text-white flex items-center gap-2">
              <TrendingUp className="text-emerald-400 w-5 h-5" /> Depotbestände ({activePortfolio.holdings.length})
            </h3>
            <div className="text-xs text-slate-400 flex items-center gap-4">
              <span>Barguthaben: <span className="font-mono text-emerald-400 font-bold">${activePortfolio.cash.toLocaleString()}</span></span>
            </div>
          </div>

          <div className="overflow-x-auto border border-slate-850 rounded-xl bg-slate-950/40">
            <table className="w-full border-collapse text-left text-sm">
              <thead>
                <tr className="border-b border-slate-800 text-slate-400 font-semibold bg-slate-900/40">
                  <th className="p-3">Asset</th>
                  <th className="p-3">Stücke</th>
                  <th className="p-3">Einstand</th>
                  <th className="p-3">Kurs</th>
                  <th className="p-3">Hypothese</th>
                  <th className="p-3 text-right">GuV</th>
                </tr>
              </thead>
              <tbody>
                {activePortfolio.holdings.length === 0 ? (
                  <tr>
                    <td colSpan={6} className="p-8 text-center text-slate-500">
                      Keine Bestände in diesem Sandbox-Portfolio. Nutzen Sie die Order-Maske, um Werte hinzuzufügen.
                    </td>
                  </tr>
                ) : (
                  activePortfolio.holdings.map((hold) => {
                    const profitLoss = (hold.currentPrice - hold.avgPrice) * hold.shares;
                    const isPositive = profitLoss >= 0;
                    return (
                      <tr key={hold.symbol} className="border-b border-slate-850/50 hover:bg-slate-850/20 transition-colors">
                        <td className="p-3">
                          <div className="font-bold text-teal-400 font-mono">{hold.symbol}</div>
                          {hold.wknOrIsin && <div className="text-[10px] text-slate-500 font-mono">WKN: {hold.wknOrIsin}</div>}
                        </td>
                        <td className="p-3 font-mono font-medium">{hold.shares}</td>
                        <td className="p-3 font-mono text-slate-300">${hold.avgPrice.toFixed(2)}</td>
                        <td className="p-3 font-mono text-slate-300">${hold.currentPrice.toFixed(2)}</td>
                        <td className="p-3 text-slate-400 max-w-[200px] truncate text-xs" title={hold.hypothesisTag}>
                          {hold.hypothesisTag || '-'}
                        </td>
                        <td className={`p-3 font-mono text-right flex items-center justify-end gap-1 ${isPositive ? 'text-emerald-400' : 'text-rose-400'}`}>
                          {isPositive ? <ArrowUpRight className="w-4 h-4" /> : <ArrowDownRight className="w-4 h-4" />}
                          ${Math.abs(profitLoss).toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 })}
                        </td>
                      </tr>
                    );
                  })
                )}
              </tbody>
            </table>
          </div>
        </div>

        {/* Right 1 Column: Transactions History */}
        <div className="bg-slate-900/60 backdrop-blur-md border border-slate-800 rounded-2xl p-6 text-slate-100 shadow-xl space-y-4">
          <div className="border-b border-slate-800 pb-3">
            <h3 className="text-lg font-bold text-white flex items-center gap-2">
              <Calendar className="text-emerald-400 w-5 h-5" /> Letzte Orderbuch-Einträge
            </h3>
          </div>

          <div className="max-h-60 overflow-y-auto space-y-2 pr-1">
            {activePortfolio.transactions.length === 0 ? (
              <p className="text-xs text-slate-500 text-center py-8">Bislang keine Transaktionen in diesem Portfolio.</p>
            ) : (
              activePortfolio.transactions.map((tx) => {
                const isBuy = tx.type === 'BUY';
                return (
                  <div key={tx.id} className="p-3 bg-slate-950/40 border border-slate-850 rounded-lg space-y-1.5">
                    <div className="flex justify-between items-start">
                      <div className="flex items-center gap-2">
                        <span className={`px-1.5 py-0.5 rounded text-[9px] font-bold ${isBuy ? 'bg-emerald-500/10 text-emerald-400 border border-emerald-500/20' : 'bg-rose-500/10 text-rose-400 border border-rose-500/20'}`}>
                          {isBuy ? 'KAUF' : 'VERKAUF'}
                        </span>
                        <span className="font-mono font-bold text-slate-200">{tx.symbol}</span>
                      </div>
                      <span className="text-[10px] text-slate-500 font-mono">{tx.timestamp}</span>
                    </div>

                    <div className="flex justify-between text-xs font-mono text-slate-400">
                      <span>{tx.shares} Stk @ ${tx.price.toFixed(2)}</span>
                      <span className="text-[10px] text-slate-500">Gebühr: ${tx.feeApplied.toFixed(2)}</span>
                    </div>

                    {tx.hypothesisTag && (
                      <div className="text-[10px] text-slate-500 flex items-center gap-1 border-t border-slate-900 pt-1">
                        <Tag className="w-2.5 h-2.5 text-teal-500" />
                        <span className="italic truncate max-w-[220px]">{tx.hypothesisTag}</span>
                      </div>
                    )}
                  </div>
                );
              })
            )}
          </div>
        </div>

      </div>

    </div>
  );
}