import 'package:flutter/material.dart';
import '../models/record.dart';
import '../data/categories.dart';
import 'package:uuid/uuid.dart';

class RecordPage extends StatefulWidget {
  final Record? record;
  final Function(Record) onSave;  // 添加保存回调

  const RecordPage({
    Key? key,
    this.record,
    required this.onSave,
  }) : super(key: key);

  @override
  State<RecordPage> createState() => _RecordPageState();
}

class _RecordPageState extends State<RecordPage> with SingleTickerProviderStateMixin {
  late TabController _tabController;
  String? _selectedCategoryId;
  String _note = '';
  double _amount = 0.0;
  DateTime _selectedDate = DateTime.now();
  final _uuid = const Uuid();
  
  @override
  void initState() {
    super.initState();
    // 如果是编辑模式，初始化现有记录的数据
    if (widget.record != null) {
      _selectedCategoryId = widget.record!.categoryId;
      _note = widget.record!.note ?? '';
      _amount = widget.record!.amount;
      _selectedDate = widget.record!.createTime;
    }
    
    _tabController = TabController(
      length: 2,
      vsync: this,
      initialIndex: widget.record?.type == RecordType.income ? 1 : 0,
    );
    _tabController.addListener(_onTabChanged);
  }

  /// 标签切换监听
  void _onTabChanged() {
    setState(() {
      _selectedCategoryId = null;  // 切换类型时重置选中的分类
    });
  }

  /// 获取当前记录类型
  RecordType get _currentType => 
      _tabController.index == 0 ? RecordType.expense : RecordType.income;

  /// 获取当前分类列表
  List<Category> get _currentCategories => 
      _currentType == RecordType.expense ? expenseCategories : incomeCategories;

  /// 保存记录
  void _saveRecord() {
    if (_selectedCategoryId == null) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请选择分类')),
      );
      return;
    }
    if (_amount <= 0) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('请输入金额')),
      );
      return;
    }

    final record = Record(
      id: widget.record?.id ?? _uuid.v4(),
      type: _currentType,
      categoryId: _selectedCategoryId!,
      note: _note.isEmpty ? null : _note,
      amount: _amount,
      createTime: _selectedDate,
    );

    widget.onSave(record);
    Navigator.of(context).pop();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: TabBar(
          controller: _tabController,
          tabs: const [
            Tab(text: '支出'),
            Tab(text: '收入'),
          ],
        ),
      ),
      body: Column(
        children: [
          // 分类网格
          Expanded(
            child: GridView.builder(
              padding: const EdgeInsets.all(16),
              gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 4,
                mainAxisSpacing: 16,
                crossAxisSpacing: 16,
              ),
              itemCount: _currentCategories.length,
              itemBuilder: (context, index) {
                final category = _currentCategories[index];
                final isSelected = category.id == _selectedCategoryId;
                return _buildCategoryItem(category, isSelected);
              },
            ),
          ),
          // 底部编辑区域
          _buildBottomEditor(),
        ],
      ),
    );
  }

  /// 构建分类项
  Widget _buildCategoryItem(Category category, bool isSelected) {
    return InkWell(
      onTap: () => setState(() => _selectedCategoryId = category.id),
      child: Container(
        decoration: BoxDecoration(
          color: isSelected ? Theme.of(context).primaryColor.withOpacity(0.1) : null,
          border: Border.all(
            color: isSelected ? Theme.of(context).primaryColor : Colors.grey,
          ),
          borderRadius: BorderRadius.circular(8),
        ),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              category.icon,
              color: isSelected ? Theme.of(context).primaryColor : Colors.grey,
            ),
            const SizedBox(height: 4),
            Text(
              category.name,
              style: TextStyle(
                color: isSelected ? Theme.of(context).primaryColor : Colors.grey,
              ),
            ),
          ],
        ),
      ),
    );
  }

  /// 构建底部编辑区域
  Widget _buildBottomEditor() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.1),
            blurRadius: 8,
            offset: const Offset(0, -2),
          ),
        ],
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          // 备注和金额
          Row(
            children: [
              Expanded(
                child: TextField(
                  decoration: const InputDecoration(
                    hintText: '添加备注',
                    border: InputBorder.none,
                  ),
                  onChanged: (value) => setState(() => _note = value),
                ),
              ),
              Text(
                '¥${_amount.toStringAsFixed(2)}',
                style: const TextStyle(
                  fontSize: 24,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ],
          ),
          // 配置按钮
          Row(
            children: [
              TextButton.icon(
                onPressed: () {
                  // TODO: 实现账户选择
                },
                icon: const Icon(Icons.account_balance_wallet),
                label: const Text('默认账户'),
              ),
              TextButton.icon(
                onPressed: () async {
                  final date = await showDatePicker(
                    context: context,
                    initialDate: _selectedDate,
                    firstDate: DateTime(2000),
                    lastDate: DateTime.now(),
                  );
                  if (date != null) {
                    setState(() => _selectedDate = date);
                  }
                },
                icon: const Icon(Icons.calendar_today),
                label: Text(_selectedDate == DateTime.now() 
                    ? '今天' 
                    : '${_selectedDate.month}月${_selectedDate.day}日'),
              ),
              TextButton.icon(
                onPressed: () {
                  // TODO: 实现图片选择
                },
                icon: const Icon(Icons.photo),
                label: const Text('图片'),
              ),
            ],
          ),
          // 数字键盘
          _buildNumberKeyboard(),
        ],
      ),
    );
  }

  /// 构建数字键盘
  Widget _buildNumberKeyboard() {
    return GridView.count(
      shrinkWrap: true,
      crossAxisCount: 4,
      childAspectRatio: 2,
      children: [
        _buildKeyboardButton('7'),
        _buildKeyboardButton('8'),
        _buildKeyboardButton('9'),
        _buildKeyboardButton('删除', isFunction: true),
        _buildKeyboardButton('4'),
        _buildKeyboardButton('5'),
        _buildKeyboardButton('6'),
        _buildKeyboardButton('+'),
        _buildKeyboardButton('1'),
        _buildKeyboardButton('2'),
        _buildKeyboardButton('3'),
        _buildKeyboardButton('-'),
        _buildKeyboardButton('again'),
        _buildKeyboardButton('0'),
        _buildKeyboardButton('.'),
        _buildKeyboardButton('保存', isFunction: true),
      ],
    );
  }

  /// 构建键盘按钮
  Widget _buildKeyboardButton(String text, {bool isFunction = false}) {
    return TextButton(
      onPressed: () => _onKeyboardButtonPressed(text),
      child: Text(
        text,
        style: TextStyle(
          fontSize: 20,
          color: isFunction ? Theme.of(context).primaryColor : Colors.black,
        ),
      ),
    );
  }

  /// 处理键盘按钮点击
  void _onKeyboardButtonPressed(String value) {
    switch (value) {
      case '删除':
        setState(() {
          final amountStr = _amount.toStringAsFixed(2);
          if (amountStr.length > 1) {
            _amount = double.parse(amountStr.substring(0, amountStr.length - 1));
          } else {
            _amount = 0;
          }
        });
        break;
      case '保存':
        _saveRecord();
        break;
      case 'again':
        // TODO: 实现again功能
        break;
      case '+':
      case '-':
        // TODO: 实现加减功能
        break;
      case '.':
        // TODO: 实现小数点功能
        break;
      default:
        if (_amount == 0) {
          setState(() => _amount = double.parse(value));
        } else {
          setState(() => _amount = double.parse('$_amount$value'));
        }
    }
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }
}