import 'package:flutter/material.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import 'package:provider/provider.dart';
import 'package:google_fonts/google_fonts.dart';
import '../../../core/theme/app_color_scheme.dart';
import '../../../core/theme/app_spacing.dart';
import '../../../data/models/coin.dart';
import '../../../providers/market_provider.dart';
import '../../../providers/asset_provider.dart';
import '../../shared/ui_constants.dart';
import '../../components/glass_panel.dart';
import '../../components/neon_glow.dart';

/// 交易页面 - Material Design 3 风格
class TradePage extends StatefulWidget {
  const TradePage({super.key});

  @override
  State<TradePage> createState() => _TradePageState();
}

class _TradePageState extends State<TradePage> with AutomaticKeepAliveClientMixin {
  int _tradeType = 0; // 0=买入, 1=卖出
  Coin? _selectedCoin;
  final _formKey = GlobalKey<ShadFormState>();
  final _priceController = TextEditingController();
  final _quantityController = TextEditingController();

  @override
  bool get wantKeepAlive => true;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _loadData());
  }

  void _loadData() {
    context.read<MarketProvider>().loadCoins();
  }

  @override
  void dispose() {
    _priceController.dispose();
    _quantityController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);

    return Scaffold(
      backgroundColor: AppColorScheme.darkBackground,
      body: Consumer2<MarketProvider, AssetProvider>(
        builder: (context, market, asset, _) {
          return SingleChildScrollView(
            padding: AppSpacing.pagePadding,
            child: ShadForm(
              key: _formKey,
              child: Column(
                children: [
                  _CoinSelector(
                    selectedCoin: _selectedCoin,
                    coins: market.allCoins,
                    onCoinLoaded: (coin) {
                      _selectedCoin = coin;
                      _priceController.text = coin.formattedPrice;
                    },
                  ),
                  SizedBox(height: AppSpacing.md),
                  if (_selectedCoin != null) _PriceCard(coin: _selectedCoin!),
                  SizedBox(height: AppSpacing.md),
                  _TradeForm(
                    tradeType: _tradeType,
                    selectedCoin: _selectedCoin,
                    priceController: _priceController,
                    quantityController: _quantityController,
                    tradeBalance: asset.overview?.tradeBalance,
                    onTradeTypeChanged: (type) => setState(() => _tradeType = type),
                  ),
                  SizedBox(height: AppSpacing.lg),
                  _TradeButton(
                    isBuy: _tradeType == 0,
                    coinCode: _selectedCoin?.code,
                    onPressed: () {
                      if (_formKey.currentState!.saveAndValidate()) {
                        _executeTrade();
                      }
                    },
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  void _executeTrade() {
    final price = _priceController.text;
    final quantity = _quantityController.text;
    final isBuy = _tradeType == 0;

    showShadDialog(
      context: context,
      builder: (ctx) => ShadDialog.alert(
        title: Text(isBuy ? '确认买入' : '确认卖出'),
        description: Text('${isBuy ? '买入' : '卖出'} $quantity ${_selectedCoin?.code ?? ''} @ $price USDT'),
        actions: [
          ShadButton.outline(child: const Text('取消'), onPressed: () => Navigator.of(ctx).pop()),
          ShadButton(
            child: const Text('确认'),
            onPressed: () {
              Navigator.of(ctx).pop();
              _showTradeResult();
            },
          ),
        ],
      ),
    );
  }

  void _showTradeResult() {
    final isBuy = _tradeType == 0;

    showShadDialog(
      context: context,
      builder: (ctx) => ShadDialog.alert(
        title: Row(
          children: [
            NeonIcon(
              icon: Icons.check_circle,
              color: AppColorScheme.darkPrimary,
              size: 24,
            ),
            SizedBox(width: AppSpacing.sm),
            const Text('交易成功'),
          ],
        ),
        description: Text('已${isBuy ? '买入' : '卖出'} ${_quantityController.text} ${_selectedCoin?.code ?? ''}'),
        actions: [
          ShadButton(
            child: const Text('确定'),
            onPressed: () {
              Navigator.of(ctx).pop();
              _quantityController.clear();
            },
          ),
        ],
      ),
    );
  }
}

/// 币种选择器 - Glass Panel 风格
class _CoinSelector extends StatelessWidget {
  final Coin? selectedCoin;
  final List<Coin> coins;
  final ValueChanged<Coin> onCoinLoaded;

  const _CoinSelector({
    required this.selectedCoin,
    required this.coins,
    required this.onCoinLoaded,
  });

  @override
  Widget build(BuildContext context) {
    // 自动选择第一个币种
    if (selectedCoin == null && coins.isNotEmpty) {
      WidgetsBinding.instance.addPostFrameCallback((_) => onCoinLoaded(coins.first));
    }

    return GlassCard(
      showNeonGlow: false,
      child: Row(
        children: [
          _CoinAvatar(icon: selectedCoin?.displayIcon),
          SizedBox(width: AppSpacing.sm + AppSpacing.xs),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  selectedCoin != null ? '${selectedCoin!.code}/USDT' : '选择币种',
                  style: GoogleFonts.spaceGrotesk(
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                    color: AppColorScheme.darkOnSurface,
                  ),
                ),
                SizedBox(height: AppSpacing.xs),
                Text(
                  selectedCoin?.name ?? '点击选择交易对',
                  style: TextStyle(
                    fontSize: 12,
                    color: AppColorScheme.darkOnSurfaceVariant,
                  ),
                ),
              ],
            ),
          ),
          Icon(
            LucideIcons.chevronRight,
            color: AppColorScheme.darkOnSurfaceVariant,
          ),
        ],
      ),
    );
  }
}

/// 币种头像 - 带霓虹光效
class _CoinAvatar extends StatelessWidget {
  final String? icon;

  const _CoinAvatar({this.icon});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: 44,
      height: 44,
      decoration: BoxDecoration(
        color: AppColorScheme.darkPrimary.withValues(alpha: 0.1),
        borderRadius: BorderRadius.circular(AppRadius.md),
        border: Border.all(
          color: AppColorScheme.darkPrimary.withValues(alpha: 0.2),
        ),
      ),
      child: Center(
        child: Text(
          icon ?? '?',
          style: TextStyle(
            fontSize: 20,
            color: AppColorScheme.darkPrimary,
            fontWeight: FontWeight.bold,
          ),
        ),
      ),
    );
  }
}

/// 价格卡片 - Glass Panel 风格
class _PriceCard extends StatelessWidget {
  final Coin coin;

  const _PriceCard({required this.coin});

  @override
  Widget build(BuildContext context) {
    final color = coin.isUp ? AppColorScheme.up : AppColorScheme.down;
    final bgColor = coin.isUp
        ? AppColorScheme.darkTertiary.withValues(alpha: 0.1)
        : AppColorScheme.darkError.withValues(alpha: 0.1);

    return GlassCard(
      showNeonGlow: false,
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                '最新价',
                style: TextStyle(
                  fontSize: 12,
                  color: AppColorScheme.darkOnSurfaceVariant,
                ),
              ),
              SizedBox(height: AppSpacing.xs),
              Text(
                '\$${coin.formattedPrice}',
                style: GoogleFonts.spaceGrotesk(
                  fontSize: 28,
                  fontWeight: FontWeight.bold,
                  color: AppColorScheme.darkOnSurface,
                ),
              ),
            ],
          ),
          Container(
            padding: EdgeInsets.symmetric(
              horizontal: AppSpacing.md,
              vertical: AppSpacing.sm,
            ),
            decoration: BoxDecoration(
              color: bgColor,
              borderRadius: BorderRadius.circular(AppRadius.md),
              border: Border.all(
                color: color.withValues(alpha: 0.2),
              ),
            ),
            child: Text(
              coin.formattedChange,
              style: TextStyle(
                fontSize: 16,
                color: color,
                fontWeight: FontWeight.w700,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

/// 交易表单 - Glass Panel 风格
class _TradeForm extends StatelessWidget {
  final int tradeType;
  final Coin? selectedCoin;
  final TextEditingController priceController;
  final TextEditingController quantityController;
  final String? tradeBalance;
  final ValueChanged<int> onTradeTypeChanged;

  const _TradeForm({
    required this.tradeType,
    required this.selectedCoin,
    required this.priceController,
    required this.quantityController,
    required this.tradeBalance,
    required this.onTradeTypeChanged,
  });

  @override
  Widget build(BuildContext context) {
    return GlassPanel(
      padding: EdgeInsets.all(AppSpacing.lg),
      child: Column(
        children: [
          // 买入/卖出切换
          _TradeTypeSelector(
            tradeType: tradeType,
            onChanged: onTradeTypeChanged,
          ),
          SizedBox(height: AppSpacing.lg),
          // 价格输入
          _buildInputField(
            label: '价格(USDT)',
            controller: priceController,
            placeholder: '输入价格',
            suffix: 'USDT',
          ),
          SizedBox(height: AppSpacing.md),
          // 数量输入
          _buildInputField(
            label: '数量',
            controller: quantityController,
            placeholder: '输入数量',
            suffix: selectedCoin?.code ?? '',
          ),
          SizedBox(height: AppSpacing.lg),
          // 信息行
          _InfoRow(label: '交易金额', value: '${_calculateAmount()} USDT'),
          SizedBox(height: AppSpacing.sm),
          _InfoRow(label: '可用', value: '${tradeBalance ?? '0.00'} USDT'),
        ],
      ),
    );
  }

  Widget _buildInputField({
    required String label,
    required TextEditingController controller,
    required String placeholder,
    required String suffix,
  }) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          label,
          style: TextStyle(
            fontSize: 10,
            fontWeight: FontWeight.w700,
            letterSpacing: 0.2,
            color: AppColorScheme.darkOnSurfaceVariant,
          ),
        ),
        SizedBox(height: AppSpacing.xs),
        Container(
          decoration: BoxDecoration(
            color: AppColorScheme.darkSurfaceLowest,
            borderRadius: BorderRadius.circular(AppRadius.xl),
            border: Border.all(
              color: AppColorScheme.darkOutlineVariant.withValues(alpha: 0.3),
            ),
          ),
          child: TextField(
            controller: controller,
            keyboardType: const TextInputType.numberWithOptions(decimal: true),
            style: GoogleFonts.spaceGrotesk(
              fontSize: 20,
              fontWeight: FontWeight.bold,
              color: AppColorScheme.darkOnSurface,
            ),
            decoration: InputDecoration(
              hintText: placeholder,
              hintStyle: TextStyle(
                color: AppColorScheme.darkOutlineVariant.withValues(alpha: 0.5),
              ),
              border: InputBorder.none,
              contentPadding: EdgeInsets.symmetric(
                horizontal: AppSpacing.md,
                vertical: AppSpacing.md,
              ),
              suffixIcon: Padding(
                padding: EdgeInsets.only(right: AppSpacing.sm),
                child: Text(
                  suffix,
                  style: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.bold,
                    color: AppColorScheme.darkOnSurfaceVariant,
                  ),
                ),
              ),
              suffixIconConstraints: const BoxConstraints(minWidth: 50),
            ),
          ),
        ),
      ],
    );
  }

  String _calculateAmount() {
    final price = double.tryParse(priceController.text) ?? 0;
    final quantity = double.tryParse(quantityController.text) ?? 0;
    return (price * quantity).toStringAsFixed(2);
  }
}

/// 交易类型选择器 - Material Design 3 风格
class _TradeTypeSelector extends StatelessWidget {
  final int tradeType;
  final ValueChanged<int> onChanged;

  const _TradeTypeSelector({required this.tradeType, required this.onChanged});

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.all(AppSpacing.xs),
      decoration: BoxDecoration(
        color: AppColorScheme.darkSurfaceLowest,
        borderRadius: BorderRadius.circular(AppRadius.xl),
      ),
      child: Row(
        children: [
          Expanded(
            child: _TypeButton(
              label: 'Buy',
              isSelected: tradeType == 0,
              color: AppColorScheme.up,
              onTap: () => onChanged(0),
            ),
          ),
          SizedBox(width: AppSpacing.sm),
          Expanded(
            child: _TypeButton(
              label: 'Sell',
              isSelected: tradeType == 1,
              color: AppColorScheme.down,
              onTap: () => onChanged(1),
            ),
          ),
        ],
      ),
    );
  }
}

/// 类型按钮
class _TypeButton extends StatelessWidget {
  final String label;
  final bool isSelected;
  final Color color;
  final VoidCallback onTap;

  const _TypeButton({
    required this.label,
    required this.isSelected,
    required this.color,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 200),
        padding: EdgeInsets.symmetric(vertical: AppSpacing.sm + AppSpacing.xs),
        decoration: BoxDecoration(
          color: isSelected ? color.withValues(alpha: 0.15) : Colors.transparent,
          borderRadius: BorderRadius.circular(AppRadius.md),
          border: isSelected ? null : Border.all(color: color.withValues(alpha: 0.3)),
        ),
        child: Center(
          child: Text(
            label,
            style: TextStyle(
              color: isSelected ? color : color.withValues(alpha: 0.7),
              fontWeight: FontWeight.w700,
              fontSize: 14,
              letterSpacing: 0.5,
            ),
          ),
        ),
      ),
    );
  }
}

/// 信息行
class _InfoRow extends StatelessWidget {
  final String label;
  final String value;

  const _InfoRow({required this.label, required this.value});

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(
          label,
          style: TextStyle(
            fontSize: 14,
            color: AppColorScheme.darkOnSurfaceVariant,
          ),
        ),
        Text(
          value,
          style: GoogleFonts.spaceGrotesk(
            fontSize: 14,
            fontWeight: FontWeight.w600,
            color: AppColorScheme.darkOnSurface,
          ),
        ),
      ],
    );
  }
}

/// 交易按钮 - 带霓虹光效
class _TradeButton extends StatelessWidget {
  final bool isBuy;
  final String? coinCode;
  final VoidCallback onPressed;

  const _TradeButton({
    required this.isBuy,
    required this.coinCode,
    required this.onPressed,
  });

  @override
  Widget build(BuildContext context) {
    return NeonButton(
      text: '${isBuy ? '买入' : '卖出'} ${coinCode ?? ''}',
      type: isBuy ? NeonButtonType.tertiary : NeonButtonType.error,
      icon: isBuy ? Icons.arrow_downward : Icons.arrow_upward,
      onPressed: onPressed,
      width: double.infinity,
      showGlow: true,
    );
  }
}