import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:finlytic_app/core/theme/app_theme.dart';
import 'package:finlytic_app/core/widgets/status_badge.dart';
import 'package:finlytic_app/core/network/api_client.dart';
import '../../../../features/trades/models/trade_model.dart';
import '../../../../features/trades/models/trade_acceptance_dto.dart';

class TradeExecutionDialog {
  static const double _defaultPositionSize = 1000.0;
  static const double _defaultLeverage = 1.0;

  static const List<String> _allowedInstruments = ['Stock', 'KnockOut', 'Option', 'CFD', 'Crypto'];

  /// Normalisiert beliebige Freitexte/Bezeichnungen auf die erlaubten Dropdown-Werte
  static String _normalizeInstrumentType(String raw) {
    final clean = raw.toLowerCase().trim();
    if (clean.contains('knock') || clean.contains('zertifikat') || clean.contains('turbo')) {
      return 'KnockOut';
    }
    if (clean.contains('option')) {
      return 'Option';
    }
    if (clean.contains('cfd')) {
      return 'CFD';
    }
    if (clean.contains('crypto') || clean.contains('krypto')) {
      return 'Crypto';
    }
    if (clean.contains('stock') || clean.contains('aktie') || clean.contains('etf')) {
      return 'Stock';
    }
    return 'KnockOut'; // Fallback
  }

  static void show(
      BuildContext context, {
        required TradeModel trade,
        required String defaultSymbol,
        bool isActive = false,
        required Function(TradeAcceptanceDto dto) onAccept,
        Function(String tradeId)? onReject,
      }) {
    final initEntry = trade.actualEntryPrice > 0 ? trade.actualEntryPrice : (trade.entryPrice > 0 ? trade.entryPrice : 100.0);
    final initPos = trade.positionSize > 0 ? trade.positionSize : _defaultPositionSize;
    final initLev = trade.leverageUsed > 0 ? trade.leverageUsed : _defaultLeverage;

    final calcQty = (initEntry > 0 && initPos > 0) ? (initPos / initEntry) : 10.0;
    final initQty = trade.quantity > 0 ? trade.quantity : calcQty;

    final actualEntryController = TextEditingController(text: initEntry.toStringAsFixed(2));
    final positionSizeController = TextEditingController(text: initPos.toStringAsFixed(2));
    final leverageController = TextEditingController(text: initLev.toStringAsFixed(1));
    final quantityController = TextEditingController(text: initQty.toStringAsFixed(4));

    final entryFeeController = TextEditingController(text: trade.entryFee.toStringAsFixed(2));
    final exitFeeController = TextEditingController(text: trade.exitFee.toStringAsFixed(2));

    final slController = TextEditingController(text: trade.stopLoss.toString());
    final tpController = TextEditingController(text: trade.takeProfit.toString());

    final derivativeIsinController = TextEditingController(text: trade.derivativeIsin);

    // Normalisierte Zuweisung verhindert den DropdownButton Assertion-Error
    String selectedInstrumentType = _normalizeInstrumentType(
      trade.instrumentType.isNotEmpty ? trade.instrumentType : 'KnockOut',
    );

    bool isFetchingDerivativePrice = false;

    void recalculateQuantity() {
      final entryStr = actualEntryController.text.replaceAll(',', '.').trim();
      final posStr = positionSizeController.text.replaceAll(',', '.').trim();

      final entry = double.tryParse(entryStr) ?? 0.0;
      final posSize = double.tryParse(posStr) ?? 0.0;
      if (entry > 0 && posSize > 0) {
        final q = posSize / entry;
        quantityController.text = q.toStringAsFixed(4);
      }
    }

    TradeAcceptanceDto buildDto() {
      final isinVal = trade.isin.isNotEmpty ? trade.isin : (trade.symbol.isNotEmpty ? trade.symbol : defaultSymbol);
      final symbolVal = trade.symbol.isNotEmpty ? trade.symbol : defaultSymbol;

      double parseNum(String text, double fallback) {
        final clean = text.replaceAll(',', '.').trim();
        return double.tryParse(clean) ?? fallback;
      }

      return TradeAcceptanceDto(
        userId: trade.userId,
        tradeId: trade.id,
        analysisId: trade.analysisId,
        isin: isinVal,
        symbol: symbolVal,
        actualEntryPrice: parseNum(actualEntryController.text, trade.actualEntryPrice > 0 ? trade.actualEntryPrice : trade.entryPrice),
        positionSize: parseNum(positionSizeController.text, trade.positionSize > 0 ? trade.positionSize : 1000.0),
        leverageUsed: parseNum(leverageController.text, trade.leverageUsed > 0 ? trade.leverageUsed : 1.0),
        entryFee: parseNum(entryFeeController.text, trade.entryFee),
        exitFee: parseNum(exitFeeController.text, trade.exitFee),
        quantity: parseNum(quantityController.text, trade.quantity),
        executionTimestamp: DateTime.now().toUtc(),
        signalType: trade.signalType,
        entryPrice: trade.entryPrice,
        stopLoss: parseNum(slController.text, trade.stopLoss),
        takeProfit: parseNum(tpController.text, trade.takeProfit),
        instrumentType: selectedInstrumentType,
        derivativeIsin: derivativeIsinController.text.trim(),
        timeframe: trade.timeframe,
        reasoning: trade.reasoning,
      );
    }

    Future<void> fetchDerivativePrice(StateSetter setModalState, String inputIsin) async {
      final cleanIsin = inputIsin.trim().toUpperCase();
      if (cleanIsin.isEmpty) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Bitte gib eine gültige Derivat/Knock-Out ISIN ein.'),
            backgroundColor: Colors.amber,
            behavior: SnackBarBehavior.floating,
          ),
        );
        return;
      }

      setModalState(() => isFetchingDerivativePrice = true);
      try {
        final apiClient = context.read<ApiClient>();
        final res = await apiClient.get('/api/v1/assets/$cleanIsin/technicals?forceRefresh=true');
        if (res.statusCode == 200 && res.data != null) {
          final Map<String, dynamic> data = res.data;
          double? fetchedPrice;
          if (data['candles'] is List && (data['candles'] as List).isNotEmpty) {
            fetchedPrice = ((data['candles'] as List).last['close'] as num?)?.toDouble();
          } else if (data['currentPrice'] != null) {
            fetchedPrice = (data['currentPrice'] as num?)?.toDouble();
          }

          if (fetchedPrice != null && fetchedPrice > 0) {
            actualEntryController.text = fetchedPrice.toStringAsFixed(2);
            recalculateQuantity();
            ScaffoldMessenger.of(context).showSnackBar(
              SnackBar(
                content: Text('Live-Kurs für Derivat $cleanIsin abgerufen: €${fetchedPrice.toStringAsFixed(2)}'),
                backgroundColor: AppTheme.primaryEmerald,
                behavior: SnackBarBehavior.floating,
              ),
            );
          } else {
            ScaffoldMessenger.of(context).showSnackBar(
              SnackBar(
                content: Text('Kein Kurs für Derivat ISIN $cleanIsin gefunden.'),
                backgroundColor: Colors.amber,
                behavior: SnackBarBehavior.floating,
              ),
            );
          }
        }
      } catch (e) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Fehler beim Abrufen des Kurses für $cleanIsin via tr_GetPrice: $e'),
            backgroundColor: AppTheme.accentRed,
            behavior: SnackBarBehavior.floating,
          ),
        );
      } finally {
        setModalState(() => isFetchingDerivativePrice = false);
      }
    }

    actualEntryController.addListener(recalculateQuantity);
    positionSizeController.addListener(recalculateQuantity);

    showDialog(
      context: context,
      builder: (dialogContext) {
        return StatefulBuilder(
          builder: (stfContext, setModalState) {
            final isKnockout = selectedInstrumentType.toLowerCase().contains('knock') ||
                selectedInstrumentType.toLowerCase().contains('zertifikat') ||
                selectedInstrumentType.toLowerCase().contains('option') ||
                selectedInstrumentType.toLowerCase().contains('cfd');

            // Absicherung gegen Assertion-Errors: Stellt sicher, dass der selektierte Wert in der Liste existiert
            final safeInstrumentValue = _allowedInstruments.contains(selectedInstrumentType)
                ? selectedInstrumentType
                : 'KnockOut';

            return AlertDialog(
              backgroundColor: AppTheme.cardSurface,
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(16),
                side: BorderSide(color: AppTheme.glassBorder),
              ),
              title: Row(
                children: [
                  Icon(isActive ? Icons.tune : Icons.edit_note_outlined, color: AppTheme.primaryEmerald, size: 22),
                  const SizedBox(width: 8),
                  Expanded(
                    child: Text(
                      isActive ? 'Einstellungen für Trade #${trade.id}' : 'Trade-Ausführung & Parameter',
                      style: const TextStyle(color: Colors.white, fontSize: 16, fontWeight: FontWeight.bold),
                    ),
                  ),
                ],
              ),
              content: SizedBox(
                width: 580,
                child: SingleChildScrollView(
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'Trade-ID: ${trade.id} | Symbol/ISIN: ${trade.symbol.isNotEmpty ? trade.symbol : defaultSymbol}',
                        style: TextStyle(color: AppTheme.textSecondary, fontSize: 12),
                      ),
                      const SizedBox(height: 12),

                      Builder(
                        builder: (context) {
                          final signal = trade.signalType.toUpperCase();
                          final isLong = signal == 'BUY' || signal == 'LONG';
                          final signalColor = isLong ? AppTheme.primaryEmerald : AppTheme.accentRed;

                          final entryZoneMin = trade.entryZoneMin;
                          final entryZoneMax = trade.entryZoneMax;
                          final entryPrice = trade.entryPrice;
                          final stopLoss = trade.stopLoss;
                          final takeProfit = trade.takeProfit;
                          final takeProfitTargets = trade.takeProfitTargets;
                          final crv = (takeProfit - entryPrice) / (entryPrice - stopLoss).abs();
                          final maxLeverage = trade.maxLeverage;

                          final reasoning = trade.reasoning;
                          final techRationale = trade.technicalRationale;
                          final fundRationale = trade.fundamentalRationale;
                          final riskWarning = trade.riskWarning;

                          return Container(
                            padding: const EdgeInsets.all(12),
                            decoration: BoxDecoration(
                              color: AppTheme.glassSurface,
                              borderRadius: BorderRadius.circular(12),
                              border: Border.all(color: AppTheme.glassBorder),
                            ),
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Row(
                                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                  children: [
                                    Row(
                                      children: [
                                        StatusBadge(label: isLong ? 'LONG / KAUFEN' : 'SHORT / VERKAUFEN', color: signalColor),
                                        const SizedBox(width: 8),
                                        if (trade.instrumentType.isNotEmpty)
                                          Container(
                                            padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                                            decoration: BoxDecoration(
                                              color: AppTheme.glassSurface,
                                              borderRadius: BorderRadius.circular(6),
                                            ),
                                            child: Text(trade.instrumentType, style: const TextStyle(color: Colors.white, fontSize: 11, fontWeight: FontWeight.bold)),
                                          ),
                                      ],
                                    ),
                                    if (trade.winRate > 0)
                                      Row(
                                        children: [
                                          Icon(Icons.bolt, size: 14, color: AppTheme.accentCyan),
                                          Text('Win-Rate: ${trade.winRate}%', style: TextStyle(color: AppTheme.accentCyan, fontWeight: FontWeight.bold, fontSize: 12)),
                                        ],
                                      ),
                                  ],
                                ),
                                const SizedBox(height: 10),

                                Row(
                                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                  children: [
                                    Text('Haltedauer: ${trade.timeframe.isNotEmpty ? trade.timeframe : '1-14 Tage'}', style: TextStyle(color: AppTheme.textMuted, fontSize: 11)),
                                    Text('Risiko: ${trade.riskTolerance}', style: TextStyle(color: AppTheme.textMuted, fontSize: 11)),
                                    if (trade.vixValue > 0)
                                      Text('VIX: ${_fmt(trade.vixValue)} (${trade.vixRegime})', style: const TextStyle(color: Colors.orangeAccent, fontSize: 11, fontWeight: FontWeight.bold)),
                                  ],
                                ),
                                const Divider(color: Colors.white12, height: 16),

                                Row(
                                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                  children: [
                                    _buildTradeStat('Einstiegszone', entryZoneMin > 0 && entryZoneMax > 0 ? '€${_fmt(entryZoneMin)} - €${_fmt(entryZoneMax)}' : '€${_fmt(entryPrice)}', Colors.white),
                                    _buildTradeStat('Stop-Loss Target', '€${_fmt(stopLoss)}', AppTheme.accentRed),
                                    _buildTradeStat('Take-Profit Target', takeProfitTargets.isNotEmpty ? takeProfitTargets.map((t) => '€${_fmt(t)}').join(' / ') : '€${_fmt(takeProfit)}', AppTheme.primaryEmerald),
                                  ],
                                ),
                                const SizedBox(height: 10),
                                Row(
                                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                  children: [
                                    if (crv > 0) _buildTradeStat('Chance-Risiko-Verh. (CRV)', '${_fmt(crv)}x', AppTheme.accentCyan),
                                    if (maxLeverage > 0) _buildTradeStat('Empf. Max Hebel', '${_fmt(maxLeverage)}x', Colors.orangeAccent),
                                    _buildTradeStat('Signal Typ', isLong ? 'LONG / BULLISH' : 'SHORT / BEARISH', signalColor),
                                  ],
                                ),

                                if (reasoning.isNotEmpty || techRationale.isNotEmpty || fundRationale.isNotEmpty || riskWarning.isNotEmpty) ...[
                                  const SizedBox(height: 10),
                                  ExpansionTile(
                                    tilePadding: EdgeInsets.zero,
                                    childrenPadding: EdgeInsets.zero,
                                    dense: true,
                                    title: Text('Ausführliche KI-Analyse & Begründung anzeigen', style: TextStyle(color: AppTheme.accentCyan, fontWeight: FontWeight.bold, fontSize: 12)),
                                    children: [
                                      if (reasoning.isNotEmpty) ...[
                                        _buildRationaleBlock('Gesamt-Strategie & KI-Entscheidung', reasoning, Colors.white70),
                                        const SizedBox(height: 6),
                                      ],
                                      if (techRationale.isNotEmpty) ...[
                                        _buildRationaleBlock('Technische Analyse', techRationale, Colors.white70),
                                        const SizedBox(height: 6),
                                      ],
                                      if (fundRationale.isNotEmpty) ...[
                                        _buildRationaleBlock('Fundamentale Analyse', fundRationale, Colors.white70),
                                        const SizedBox(height: 6),
                                      ],
                                      if (riskWarning.isNotEmpty)
                                        _buildRationaleBlock('Risikowarnung', riskWarning, AppTheme.accentRed),
                                    ],
                                  ),
                                ],
                              ],
                            ),
                          );
                        },
                      ),
                      const SizedBox(height: 16),
                      const Text('Ihre Ausführungsdaten für das Depot:', style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 14)),
                      const SizedBox(height: 10),

                      // Instrument-Type Dropdown mit abgesichertem Value
                      DropdownButtonFormField<String>(
                        value: safeInstrumentValue,
                        dropdownColor: AppTheme.cardSurface,
                        decoration: const InputDecoration(
                          labelText: 'Finanzinstrument Typ',
                          contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8),
                        ),
                        items: const [
                          DropdownMenuItem(value: 'Stock', child: Text('Aktie / ETF (Direktinvestment)', style: TextStyle(color: Colors.white, fontSize: 13))),
                          DropdownMenuItem(value: 'KnockOut', child: Text('Knock-Out Zertifikat', style: TextStyle(color: Colors.white, fontSize: 13))),
                          DropdownMenuItem(value: 'Option', child: Text('Optionsschein / Derivat', style: TextStyle(color: Colors.white, fontSize: 13))),
                          DropdownMenuItem(value: 'CFD', child: Text('CFD (Hebel-Derivat)', style: TextStyle(color: Colors.white, fontSize: 13))),
                          DropdownMenuItem(value: 'Crypto', child: Text('Krypto', style: TextStyle(color: Colors.white, fontSize: 13))),
                        ],
                        onChanged: (val) {
                          if (val != null) {
                            setModalState(() {
                              selectedInstrumentType = val;
                            });
                          }
                        },
                      ),
                      const SizedBox(height: 10),

                      if (isKnockout) ...[
                        Row(
                          crossAxisAlignment: CrossAxisAlignment.center,
                          children: [
                            Expanded(
                              child: TextField(
                                controller: derivativeIsinController,
                                decoration: const InputDecoration(
                                  labelText: 'Knock-Out / Derivat ISIN (z.B. DE000...)',
                                  hintText: 'ISIN des Hebels eingeben...',
                                  contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8),
                                ),
                              ),
                            ),
                            const SizedBox(width: 8),
                            ElevatedButton.icon(
                              onPressed: isFetchingDerivativePrice
                                  ? null
                                  : () => fetchDerivativePrice(setModalState, derivativeIsinController.text),
                              icon: isFetchingDerivativePrice
                                  ? const SizedBox(width: 14, height: 14, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.black))
                                  : const Icon(Icons.bolt, size: 16),
                              label: const Text('tr_GetPrice'),
                              style: ElevatedButton.styleFrom(
                                backgroundColor: AppTheme.accentCyan,
                                foregroundColor: Colors.black,
                                padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
                              ),
                            ),
                          ],
                        ),
                        const SizedBox(height: 10),
                      ],

                      Row(
                        children: [
                          Expanded(
                            child: TextField(
                              controller: actualEntryController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Tatsächlicher Einstiegskurs (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                          const SizedBox(width: 8),
                          Expanded(
                            child: TextField(
                              controller: positionSizeController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Investitionsvolumen (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(height: 10),

                      Row(
                        children: [
                          Expanded(
                            child: TextField(
                              controller: leverageController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Genutzter Hebel (x)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                          const SizedBox(width: 8),
                          Expanded(
                            child: TextField(
                              controller: quantityController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Stückzahl (Invest. / Einstieg)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(height: 10),

                      Row(
                        children: [
                          Expanded(
                            child: TextField(
                              controller: entryFeeController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Einstiegsgebühr (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                          const SizedBox(width: 8),
                          Expanded(
                            child: TextField(
                              controller: exitFeeController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Ausstiegsgebühr (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(height: 10),

                      Row(
                        children: [
                          Expanded(
                            child: TextField(
                              controller: slController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Stop-Loss (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                          const SizedBox(width: 8),
                          Expanded(
                            child: TextField(
                              controller: tpController,
                              keyboardType: const TextInputType.numberWithOptions(decimal: true),
                              decoration: const InputDecoration(labelText: 'Take-Profit (€)', contentPadding: EdgeInsets.symmetric(horizontal: 10, vertical: 8)),
                            ),
                          ),
                        ],
                      ),
                    ],
                  ),
                ),
              ),
              actions: [
                TextButton(
                  onPressed: () => Navigator.pop(dialogContext),
                  child: Text('Abbrechen', style: TextStyle(color: AppTheme.textMuted)),
                ),
                if (!isActive && onReject != null)
                  OutlinedButton.icon(
                    onPressed: () {
                      onReject(trade.id);
                      Navigator.pop(dialogContext);
                    },
                    icon: Icon(Icons.cancel, color: AppTheme.accentRed, size: 16),
                    label: Text('Trade Ablehnen', style: TextStyle(color: AppTheme.accentRed)),
                    style: OutlinedButton.styleFrom(
                      side: BorderSide(color: AppTheme.accentRed),
                    ),
                  ),
                if (!isActive && onReject != null) const SizedBox(width: 8),
                ElevatedButton.icon(
                  onPressed: () {
                    final dto = buildDto();
                    onAccept(dto);
                    Navigator.of(dialogContext).pop();
                  },
                  icon: Icon(isActive ? Icons.save : Icons.check_circle, size: 16),
                  label: Text(isActive ? 'Einstellungen Speichern' : 'Trade Annehmen & Ausführen'),
                  style: ElevatedButton.styleFrom(
                    backgroundColor: isActive ? AppTheme.accentCyan : AppTheme.primaryEmerald,
                    foregroundColor: Colors.black,
                  ),
                ),
              ],
            );
          },
        );
      },
    );
  }

  static String _fmt(dynamic val) {
    if (val == null) return '0.00';
    if (val is double) {
      if (val > 100) return val.toStringAsFixed(1);
      return val.toStringAsFixed(2);
    }
    return val.toString();
  }

  static Widget _buildTradeStat(String label, String value, Color color) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(label, style: const TextStyle(color: Colors.white54, fontSize: 11)),
        const SizedBox(height: 2),
        Text(value, style: TextStyle(color: color, fontWeight: FontWeight.bold, fontSize: 13)),
      ],
    );
  }

  static Widget _buildRationaleBlock(String title, String content, Color color) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 8.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(title, style: TextStyle(color: color, fontSize: 12, fontWeight: FontWeight.bold)),
          const SizedBox(height: 4),
          Text(content, style: const TextStyle(color: Colors.white70, fontSize: 12, height: 1.4)),
        ],
      ),
    );
  }
}