import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

/// 结算币种枚举
enum SettlementCurrency { bnb, og, usdt, dst }

/// 交易页面 - 显示可结算收益和交易功能
/// 支持一键结算和DST转USDT
class TradingPage extends ConsumerStatefulWidget {
  const TradingPage({super.key});

  @override
  ConsumerState<TradingPage> createState() => _TradingPageState();
}

class _TradingPageState extends ConsumerState<TradingPage> {
  // 当前选中的结算币种
  SettlementCurrency _selectedCurrency = SettlementCurrency.usdt;

  // 模拟数据
  final double _settleableAmount = 1234.56;
  final double _dstBalance = 5678.90;

  /// 选择结算币种
  void _selectCurrency(SettlementCurrency currency) {
    setState(() {
      _selectedCurrency = currency;
    });
  }

  /// 一键结算
  void _onSettlement() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('确认结算'),
        content: Text(
          '确定将 ${_formatNumber(_settleableAmount)} USDT 结算为 ${_getCurrencyName(_selectedCurrency)} 吗？',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () {
              Navigator.pop(context);
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(
                  content: Text('结算成功'),
                  backgroundColor: Color(0xFFD4AF37),
                ),
              );
            },
            child: const Text('确认'),
          ),
        ],
      ),
    );
  }

  /// 卖出DST转换为USDT
  void _onSellDst() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('卖出 DST'),
        content: Text(
          '确定将 ${_formatNumber(_dstBalance)} DST 转换为 USDT 吗？',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () {
              Navigator.pop(context);
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(
                  content: Text('转换成功'),
                  backgroundColor: Color(0xFFD4AF37),
                ),
              );
            },
            child: const Text('确认'),
          ),
        ],
      ),
    );
  }

  /// 格式化数字（添加千分位）
  String _formatNumber(double number) {
    final parts = number.toStringAsFixed(2).split('.');
    final intPart = parts[0].replaceAllMapped(
      RegExp(r'(\d{1,3})(?=(\d{3})+(?!\d))'),
      (Match m) => '${m[1]},',
    );
    return '$intPart.${parts[1]}';
  }

  /// 获取币种名称
  String _getCurrencyName(SettlementCurrency currency) {
    switch (currency) {
      case SettlementCurrency.bnb:
        return 'BNB';
      case SettlementCurrency.og:
        return 'OG';
      case SettlementCurrency.usdt:
        return 'USDT';
      case SettlementCurrency.dst:
        return 'DST';
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: Container(
        width: double.infinity,
        height: double.infinity,
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [
              Color(0xFFFFF5E6),
              Color(0xFFFFE4B5),
            ],
          ),
        ),
        child: SafeArea(
          child: SingleChildScrollView(
            child: Column(
              children: [
                // 顶部标题栏
                _buildAppBar(),
                const SizedBox(height: 16),
                // 可结算收益卡片
                _buildSettleableCard(),
                const SizedBox(height: 24),
                // 一键结算按钮
                _buildSettlementButton(),
                const SizedBox(height: 16),
                // 结算币种选择
                _buildCurrencySelector(),
                const SizedBox(height: 24),
                // 分隔线
                _buildDivider(),
                const SizedBox(height: 24),
                // 卖出DST按钮
                _buildSellDstButton(),
                const SizedBox(height: 8),
                // DST余额显示
                _buildDstBalance(),
              ],
            ),
          ),
        ),
      ),
    );
  }

  /// 构建顶部标题栏
  Widget _buildAppBar() {
    return Container(
      height: 56,
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: const Center(
        child: Text(
          '交易',
          style: TextStyle(
            fontSize: 18,
            fontFamily: 'Inter',
            fontWeight: FontWeight.w700,
            height: 1.25,
            letterSpacing: -0.27,
            color: Color(0xFF5D4037),
          ),
        ),
      ),
    );
  }

  /// 构建可结算收益卡片
  Widget _buildSettleableCard() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        width: double.infinity,
        padding: const EdgeInsets.all(24),
        decoration: BoxDecoration(
          color: const Color(0x1A8B5A2B),
          borderRadius: BorderRadius.circular(12),
        ),
        child: Column(
          children: [
            const Text(
              '可结算收益',
              style: TextStyle(
                fontSize: 14,
                fontFamily: 'Inter',
                height: 1.5,
                color: Color(0xCC8B5A2B),
              ),
            ),
            const SizedBox(height: 8),
            Text(
              '${_formatNumber(_settleableAmount)} USDT',
              style: const TextStyle(
                fontSize: 32,
                fontFamily: 'Inter',
                fontWeight: FontWeight.w700,
                height: 1.25,
                letterSpacing: -0.8,
                color: Color(0xFF5D4037),
              ),
            ),
          ],
        ),
      ),
    );
  }

  /// 构建一键结算按钮
  Widget _buildSettlementButton() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: GestureDetector(
        onTap: _onSettlement,
        child: Container(
          width: double.infinity,
          height: 56,
          decoration: BoxDecoration(
            color: const Color(0xFFD4AF37),
            borderRadius: BorderRadius.circular(12),
          ),
          child: const Center(
            child: Text(
              '一键结算',
              style: TextStyle(
                fontSize: 16,
                fontFamily: 'Inter',
                fontWeight: FontWeight.w700,
                height: 1.5,
                letterSpacing: 0.24,
                color: Colors.white,
              ),
            ),
          ),
        ),
      ),
    );
  }

  /// 构建结算币种选择器
  Widget _buildCurrencySelector() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Column(
        children: [
          const Text(
            '结算的币种',
            style: TextStyle(
              fontSize: 14,
              fontFamily: 'Inter',
              fontWeight: FontWeight.w700,
              height: 1.5,
              letterSpacing: 0.21,
              color: Color(0xCC8B5A2B),
            ),
          ),
          const SizedBox(height: 12),
          Container(
            padding: const EdgeInsets.all(6),
            decoration: BoxDecoration(
              color: const Color(0x1A8B5A2B),
              borderRadius: BorderRadius.circular(12),
            ),
            child: Row(
              children: [
                _buildCurrencyChip(SettlementCurrency.bnb, 'BNB'),
                const SizedBox(width: 8),
                _buildCurrencyChip(SettlementCurrency.og, 'OG'),
                const SizedBox(width: 8),
                _buildCurrencyChip(SettlementCurrency.usdt, 'USDT'),
                const SizedBox(width: 8),
                _buildCurrencyChip(SettlementCurrency.dst, 'DST'),
              ],
            ),
          ),
        ],
      ),
    );
  }

  /// 构建币种选择标签
  Widget _buildCurrencyChip(SettlementCurrency currency, String label) {
    final isSelected = _selectedCurrency == currency;
    return Expanded(
      child: GestureDetector(
        onTap: () => _selectCurrency(currency),
        child: Container(
          height: 40,
          decoration: BoxDecoration(
            color: isSelected ? const Color(0xFFD4AF37) : Colors.transparent,
            borderRadius: BorderRadius.circular(8),
          ),
          child: Center(
            child: Text(
              label,
              style: TextStyle(
                fontSize: 14,
                fontFamily: 'Inter',
                fontWeight: isSelected ? FontWeight.w700 : FontWeight.w600,
                height: 1.43,
                color: isSelected ? Colors.white : const Color(0xCC5D4037),
              ),
            ),
          ),
        ),
      ),
    );
  }

  /// 构建分隔线
  Widget _buildDivider() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: Container(
        height: 1,
        color: const Color(0x1A8B5A2B),
      ),
    );
  }

  /// 构建卖出DST按钮
  Widget _buildSellDstButton() {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 16),
      child: GestureDetector(
        onTap: _onSellDst,
        child: Container(
          width: double.infinity,
          height: 56,
          decoration: BoxDecoration(
            color: const Color(0x338B5A2B),
            borderRadius: BorderRadius.circular(12),
            border: Border.all(
              color: const Color(0x808B5A2B),
              width: 1,
            ),
          ),
          child: const Center(
            child: Text(
              '卖出 DST 转换为 USDT',
              style: TextStyle(
                fontSize: 16,
                fontFamily: 'Inter',
                fontWeight: FontWeight.w700,
                height: 1.5,
                letterSpacing: 0.24,
                color: Color(0xFF8B5A2B),
              ),
            ),
          ),
        ),
      ),
    );
  }

  /// 构建DST余额显示
  Widget _buildDstBalance() {
    return Text(
      'DST 余额: ${_formatNumber(_dstBalance)}',
      style: const TextStyle(
        fontSize: 14,
        fontFamily: 'Inter',
        height: 1.5,
        color: Color(0x995D4037),
      ),
    );
  }
}