import 'package:flutter/material.dart';

/// 多选框组
class VCheckBoxGroup<T, TValue> extends StatefulWidget {
  final List<T> source;
  final List<TValue>? values;
  final String Function(T data) labelGetter;
  final TValue Function(T data) valueGetter;
  final ValueChanged<List<TValue>>? onChanged;
  final double? itemSpace;

  const VCheckBoxGroup({
    super.key,
    required this.source,
    this.values,
    required this.labelGetter,
    required this.valueGetter,
    this.onChanged,
    this.itemSpace,
  });

  @override
  State<StatefulWidget> createState() => _VCheckBoxGroupState<T, TValue>();
}

class _VCheckBoxGroupState<T, TValue> extends State<VCheckBoxGroup<T, TValue>> {
  late List<TValue> _checkedValues;

  @override
  void initState() {
    _checkedValues = widget.values ?? [];
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    final children = <Widget>[];
    final length = widget.source.length;
    for (var i = 0; i < length; i++) {
      final e = widget.source[i];
      children.add(
        VCheckBox(
          label: widget.labelGetter(e),
          isChecked: false,
          onChanged: (value) {
            _onItemChanged(e, value);
          },
        ),
      );
      if (i < length - 1) {
        children.add(SizedBox(width: widget.itemSpace));
      }
    }
    // return Flow(
    //   delegate: FlowlayoutDelegate(),
    //   children: children,
    // );
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: children,
    );
  }

  void _onItemChanged(T data, bool isChecked) {
    final value = widget.valueGetter(data);
    if (isChecked) {
      if (_checkedValues.contains(value) == false) {
        _checkedValues.add(value);
      }
    } else {
      _checkedValues.remove(value);
    }
    widget.onChanged?.call(_checkedValues);
  }
}

/// 多选框
class VCheckBox extends StatefulWidget {
  /// 文本
  final String label;

  /// 是否默认选中
  final bool? isChecked;

  /// 选中状态变更
  final ValueChanged<bool>? onChanged;

  const VCheckBox({
    super.key,
    required this.label,
    this.isChecked,
    this.onChanged,
  });
  @override
  State<StatefulWidget> createState() => _VCheckBoxState();
}

class _VCheckBoxState extends State<VCheckBox> {
  bool _isChecked = false;

  @override
  void initState() {
    if (widget.isChecked != null) {
      _isChecked = widget.isChecked!;
    }
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Material(
      child: Ink(
        child: InkWell(
          onTap: () {
            setState(() {
              _isChecked = !_isChecked;
              widget.onChanged?.call(_isChecked);
            });
          },
          child: Container(
            padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
            alignment: Alignment.center,
            child: Row(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                _CheckStatusTag(isChecked: _isChecked),
                const SizedBox(width: 6),
                Text(
                  widget.label,
                  style: const TextStyle(color: Colors.black, fontSize: 16),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _CheckStatusTag extends StatelessWidget {
  final bool isChecked;

  const _CheckStatusTag({super.key, required this.isChecked});

  @override
  Widget build(BuildContext context) {
    final color = Theme.of(context).primaryColor;
    return Container(
      alignment: Alignment.center,
      width: 18,
      height: 18,
      decoration: BoxDecoration(
        color: isChecked ? color : Colors.white,
        border: Border.all(width: 1, color: color),
        borderRadius: BorderRadius.zero,
        // boxShadow: [],
      ),
      child: isChecked
          ? const Icon(Icons.check, size: 16, color: Colors.white)
          : null,
    );
  }
}