// 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/app_tokens.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。
///
/// [searchHint] 非空 → 升级为「可搜索单选」下拉（镜像原型 openSearchMenu / .combo-pop，
/// 照 stock-out 客户筛选写法）：顶部持久搜索框 + 边打边过滤 + 命中高亮 + 底部结果统计，
/// 点选即返回并关闭。宽度锚定触发器宽（`max(触发器宽, 220)` 固定，对齐原型 openSearchMenu
/// `w = max(r.width, 220)`）、列表 264 封顶，供规格/系列等长名录单选筛选复用。
Future<T?> showDsMenu<T>(
  BuildContext anchorContext, {
  required List<DsMenuItem<T>> items,
  double minWidth = 168,
  String? searchHint,
}) {
  final rect = _anchorRect(anchorContext);
  return Navigator.of(anchorContext).push<T>(_DsMenuRoute<T>(
    anchorRect: rect,
    minWidth: searchHint != null ? math.max(minWidth, 220) : minWidth,
    search: searchHint != null,
    builder: (ctx) => searchHint != null
        ? _DsSearchSinglePanel<T>(
            items: items,
            hint: searchHint,
            onPick: (v) => Navigator.of(ctx).pop(v),
          )
        : _DsMenuPanel(
            children: [
              for (final it in items)
                _DsMenuItemTile(
                  item: it,
                  onTap: () => Navigator.of(ctx).pop(it.value),
                ),
            ],
          ),
  ));
}

/// 多选菜单（列设置）：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 bool search;
  final WidgetBuilder builder;
  _DsMenuRoute({
    required this.anchorRect,
    required this.minWidth,
    this.search = false,
    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, search),
      child: builder(context),
    );
  }
}

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

  @override
  BoxConstraints getConstraintsForChild(BoxConstraints constraints) {
    final avail = constraints.maxWidth - 16;
    final maxH = math.max(0.0, constraints.maxHeight - 16);
    if (search) {
      // 可搜索下拉：宽度锚定触发器宽（对齐原型 openSearchMenu `w = max(r.width, 220)`），
      // tight 固定，避免 Expanded 搜索框撑满视口。触发器宽 → 弹层宽；窄 pill → 220。
      final w = math.min(math.max(anchor.width, minWidth), avail);
      return BoxConstraints(minWidth: w, maxWidth: w, maxHeight: maxH);
    }
    return BoxConstraints(
      minWidth: math.min(math.max(anchor.width, minWidth), avail),
      maxWidth: avail,
      maxHeight: maxH,
    );
  }

  @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 ||
      old.search != search;
}

/// .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)),
          ],
        ),
      ),
    );
  }
}

/// 可搜索单选面板（镜像原型 .combo-pop + openSearchMenu，照 stock-out 客户筛选）：
/// 顶部 .cp-search 持久搜索框 → .cp-list 列表（命中子串高亮、选中项尾部 ✓、点选即返回并关闭）
/// → .cp-foot 结果统计（匹配 X 条 · 共 N 条）。供工具栏规格/系列等长名录单选筛选复用。
class _DsSearchSinglePanel<T> extends StatefulWidget {
  final List<DsMenuItem<T>> items;
  final ValueChanged<T> onPick;
  final String hint;
  const _DsSearchSinglePanel({
    required this.items,
    required this.onPick,
    required this.hint,
  });

  @override
  State<_DsSearchSinglePanel<T>> createState() =>
      _DsSearchSinglePanelState<T>();
}

class _DsSearchSinglePanelState<T> extends State<_DsSearchSinglePanel<T>> {
  final _ctrl = TextEditingController();
  final _focus = FocusNode();
  String _kw = '';

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

  @override
  void dispose() {
    _ctrl.dispose();
    _focus.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    final all = widget.items;
    final q = _kw.trim().toLowerCase();
    final hits =
        q.isEmpty ? all : all.where((it) => it.label.toLowerCase().contains(q)).toList();
    return Material(
      color: Colors.transparent,
      child: Container(
        clipBehavior: Clip.antiAlias,
        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: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // .cp-search
            Container(
              padding: const EdgeInsets.fromLTRB(11, 9, 11, 9),
              decoration: BoxDecoration(
                border: Border(bottom: BorderSide(color: t.borderSubtle)),
              ),
              child: Row(
                children: [
                  Icon(LucideIcons.search, size: 14, color: t.faint),
                  const SizedBox(width: 8),
                  Expanded(
                    child: TextField(
                      controller: _ctrl,
                      focusNode: _focus,
                      style: TextStyle(fontSize: AppDims.fsBody, color: t.text),
                      cursorColor: t.primary,
                      onChanged: (v) => setState(() => _kw = v),
                      decoration: InputDecoration(
                        isCollapsed: true,
                        contentPadding: EdgeInsets.zero,
                        border: InputBorder.none,
                        enabledBorder: InputBorder.none,
                        focusedBorder: InputBorder.none,
                        hintText: widget.hint,
                        hintStyle: TextStyle(
                            fontSize: AppDims.fsBody, color: t.faint),
                      ),
                    ),
                  ),
                ],
              ),
            ),
            // .cp-list（overflow auto，max-height:264 → 超出滚动、foot 常驻可见；空 → .cp-empty）
            ConstrainedBox(
              constraints: const BoxConstraints(maxHeight: 264),
              child: hits.isEmpty
                  ? Padding(
                      padding: const EdgeInsets.all(20),
                      child: Text('无匹配结果',
                          textAlign: TextAlign.center,
                          style: TextStyle(
                              fontSize: AppDims.fsSm, color: t.muted)),
                    )
                  : ListView.builder(
                      padding: const EdgeInsets.all(5),
                      shrinkWrap: true,
                      itemCount: hits.length,
                      itemBuilder: (c, i) => _item(t, hits[i]),
                    ),
            ),
            // .cp-foot
            Container(
              padding: const EdgeInsets.fromLTRB(12, 7, 12, 7),
              decoration: BoxDecoration(
                color: t.bg,
                border: Border(top: BorderSide(color: t.borderSubtle)),
              ),
              child: _foot(t, hits.length, all.length, q.isNotEmpty),
            ),
          ],
        ),
      ),
    );
  }

  // .cp-item：点选即回调 onPick（其内 Navigator.pop 关闭菜单）→ 单选。
  Widget _item(AppTokens t, DsMenuItem<T> it) {
    final fg = it.selected ? t.primary : t.text;
    return InkWell(
      onTap: () => widget.onPick(it.value),
      hoverColor: t.rowHover,
      borderRadius: BorderRadius.circular(AppDims.rSm),
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
        child: Row(
          children: [
            Expanded(child: _highlight(t, it.label, fg, it.selected)),
            if (it.selected) ...[
              const SizedBox(width: 9),
              Icon(LucideIcons.check, size: 15, color: t.primary),
            ],
          ],
        ),
      ),
    );
  }

  // 命中子串高亮（.hl：primary fw700）
  Widget _highlight(AppTokens t, String name, Color fg, bool sel) {
    final base = TextStyle(
        fontSize: AppDims.fsBody,
        color: fg,
        fontWeight: sel ? FontWeight.w600 : FontWeight.w400);
    final kw = _kw.trim();
    final i =
        kw.isEmpty ? -1 : name.toLowerCase().indexOf(kw.toLowerCase());
    if (i < 0) {
      return Text(name,
          maxLines: 1, overflow: TextOverflow.ellipsis, style: base);
    }
    return RichText(
      maxLines: 1,
      overflow: TextOverflow.ellipsis,
      text: TextSpan(style: base, children: [
        TextSpan(text: name.substring(0, i)),
        TextSpan(
            text: name.substring(i, i + kw.length),
            style: base.copyWith(
                color: t.primary, fontWeight: FontWeight.w700)),
        TextSpan(text: name.substring(i + kw.length)),
      ]),
    );
  }

  // .cp-foot：q 空 → 共 N 条；有关键字 → 匹配 X 条 · 共 N 条。数字 mono 加粗。
  Widget _foot(AppTokens t, int hits, int total, bool filtered) {
    final base = TextStyle(fontSize: AppDims.fsXs, color: t.muted);
    final b = base.copyWith(
        color: t.text,
        fontWeight: FontWeight.w600,
        fontFamily: 'JetBrainsMono');
    return RichText(
      text: TextSpan(style: base, children: [
        if (filtered) ...[
          const TextSpan(text: '匹配 '),
          TextSpan(text: '$hits', style: b),
          const TextSpan(text: ' 条 · 共 '),
          TextSpan(text: '$total', style: b),
          const TextSpan(text: ' 条'),
        ] else ...[
          const TextSpan(text: '共 '),
          TextSpan(text: '$total', style: b),
          const TextSpan(text: ' 条'),
        ],
      ]),
    );
  }
}