// widgets/ds/ds_menu.dart — 原型 .menu/.menu-item 下拉菜单（镜像 atoms.css + shell.js openMenu）。
// 定位规则照抄 openMenu：宽 = max(锚宽, minW=168)，左缘夹在视口内(留 8px)，
// 锚下 6px 展开、下方放不下且上方够高则向上翻。
import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';

import '../../core/theme/context_tokens.dart';
import '../../core/theme/app_dims.g.dart';

/// 菜单项：sel → 前导 ✓(primary) + 文字 primary fw600；icon → 前导 16px 图标；
/// 都没有 → 16px 占位（对齐 openMenu 的 lead 槽）。
class DsMenuItem<T> {
  final T value;
  final String label;
  final IconData? icon;
  final bool selected;
  const DsMenuItem({
    required this.value,
    required this.label,
    this.icon,
    this.selected = false,
  });
}

/// 单选菜单：点击项返回其 value 并关闭；点外部关闭返回 null。
Future<T?> showDsMenu<T>(
  BuildContext anchorContext, {
  required List<DsMenuItem<T>> items,
  double minWidth = 168,
}) {
  final rect = _anchorRect(anchorContext);
  return Navigator.of(anchorContext).push<T>(_DsMenuRoute<T>(
    anchorRect: rect,
    minWidth: minWidth,
    builder: (ctx) => _DsMenuPanel(
      children: [
        for (final it in items)
          _DsMenuItemTile(
            item: it,
            onTap: () => Navigator.of(ctx).pop(it.value),
          ),
      ],
    ),
  ));
}

/// 多选菜单（列设置 / 多选筛选）：点击项切换选中、菜单保持打开；点外部关闭。
/// [itemsBuilder] 每次切换后重建以刷新 ✓ 态；[onToggle] 通知外部改状态。
Future<void> showDsMultiMenu<T>(
  BuildContext anchorContext, {
  required List<DsMenuItem<T>> Function() itemsBuilder,
  required ValueChanged<T> onToggle,
  double minWidth = 168,
}) {
  final rect = _anchorRect(anchorContext);
  return Navigator.of(anchorContext).push<void>(_DsMenuRoute<void>(
    anchorRect: rect,
    minWidth: minWidth,
    builder: (ctx) => StatefulBuilder(
      builder: (ctx, setState) => _DsMenuPanel(
        children: [
          for (final it in itemsBuilder())
            _DsMenuItemTile(
              item: it,
              onTap: () {
                onToggle(it.value);
                setState(() {});
              },
            ),
        ],
      ),
    ),
  ));
}

Rect _anchorRect(BuildContext anchorContext) {
  // 锚点矩形必须和菜单路由同坐标系：路由推到 Navigator.of(anchorContext)，
  // 该导航器不一定占满屏幕（shell 分支导航器原点在侧栏右/顶栏下；
  // useRootNavigator:false 的抽屉同理），用全局坐标会整体漂移。
  final box = anchorContext.findRenderObject() as RenderBox;
  final navBox =
      Navigator.of(anchorContext).context.findRenderObject() as RenderBox?;
  final origin = box.localToGlobal(Offset.zero, ancestor: navBox);
  return origin & box.size;
}

class _DsMenuRoute<T> extends PopupRoute<T> {
  final Rect anchorRect;
  final double minWidth;
  final WidgetBuilder builder;
  _DsMenuRoute({
    required this.anchorRect,
    required this.minWidth,
    required this.builder,
  });

  @override
  Color? get barrierColor => Colors.transparent;
  @override
  bool get barrierDismissible => true;
  @override
  String? get barrierLabel => 'menu';
  @override
  Duration get transitionDuration => Duration.zero;

  @override
  Widget buildPage(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation) {
    return CustomSingleChildLayout(
      delegate: _DsMenuLayout(anchorRect, minWidth),
      child: builder(context),
    );
  }
}

class _DsMenuLayout extends SingleChildLayoutDelegate {
  final Rect anchor;
  final double minWidth;
  _DsMenuLayout(this.anchor, this.minWidth);

  @override
  BoxConstraints getConstraintsForChild(BoxConstraints constraints) {
    final maxW = math.max(minWidth, constraints.maxWidth - 16);
    return BoxConstraints(
      minWidth: math.min(math.max(anchor.width, minWidth), maxW),
      maxWidth: maxW,
      maxHeight: math.max(0, constraints.maxHeight - 16),
    );
  }

  @override
  Offset getPositionForChild(Size size, Size childSize) {
    final left = anchor.left
        .clamp(8.0, math.max(8.0, size.width - childSize.width - 8))
        .toDouble();
    final below = anchor.bottom + 6;
    final above = anchor.top - childSize.height - 6;
    final top =
        (below + childSize.height > size.height && above > 6) ? above : below;
    return Offset(left, top);
  }

  @override
  bool shouldRelayout(_DsMenuLayout old) =>
      old.anchor != anchor || old.minWidth != minWidth;
}

/// .menu：surface / border / r-md / sh-2(0 4px 14px shadow) / pad 6。
class _DsMenuPanel extends StatelessWidget {
  final List<Widget> children;
  const _DsMenuPanel({required this.children});

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    return Material(
      color: Colors.transparent,
      child: Container(
        padding: const EdgeInsets.all(6),
        decoration: BoxDecoration(
          color: t.surface,
          border: Border.all(color: t.border),
          borderRadius: BorderRadius.circular(AppDims.rMd),
          boxShadow: [
            BoxShadow(
                color: t.shadow, offset: const Offset(0, 4), blurRadius: 14),
          ],
        ),
        child: SingleChildScrollView(
          child: IntrinsicWidth(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: children,
            ),
          ),
        ),
      ),
    );
  }
}

/// .menu-item：gap9 / pad 8 10 / r-sm / fs-body，hover→bg；
/// sel → 前导 ✓ + primary fw600；icon 颜色随文字（.mi-ic 继承 currentColor）。
class _DsMenuItemTile extends StatelessWidget {
  final DsMenuItem<dynamic> item;
  final VoidCallback onTap;
  const _DsMenuItemTile({required this.item, required this.onTap});

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    final fg = item.selected ? t.primary : t.text;
    return InkWell(
      onTap: onTap,
      hoverColor: t.bg,
      borderRadius: BorderRadius.circular(AppDims.rSm),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            SizedBox(
              width: 16,
              height: 16,
              child: item.selected
                  ? Icon(LucideIcons.check, size: 16, color: t.primary)
                  : (item.icon != null
                      ? Icon(item.icon, size: 16, color: fg)
                      : null),
            ),
            const SizedBox(width: 9),
            Text(item.label,
                style: TextStyle(
                    fontSize: AppDims.fsBody,
                    color: fg,
                    fontWeight:
                        item.selected ? FontWeight.w600 : FontWeight.w400)),
          ],
        ),
      ),
    );
  }
}