// sub_scaffold.dart — 通用「返回箭头 + 标题」子页脚手架(六处收敛,视觉零变化)。
//
// 收敛自 account_screens.dart/orders_page.dart 的私有 `_SubScaffold`,以及
// purchase_page.dart/payment_page.dart/invite_page.dart/notifications_page.dart
// 里结构相同的内联等价实现。逐像素沿用原实现(同 padding/字号/图标),纯收敛非重设计。
//
// embedded=true 时只返回内容(desktop 内容区下钻,返回/标题由外层 shell 顶栏提供);
// 否则整页 Scaffold + SafeArea + 返回箭头行(mobile/tablet 全屏 push)。
// wrapPageBody=true 时由本组件把 child 套进 PageBody(桌面内容页统一宽度容器);默认
// false——调用方若已自行用 PageBody 包裹 child(如购买页需要 wide 变体),避免重复包裹。
import 'package:flutter/material.dart';

import '../pangolin_theme.dart';
import 'page_body.dart';
import 'pangolin_icons.dart';

class SubScaffold extends StatelessWidget {
  const SubScaffold({
    super.key,
    required this.title,
    required this.child,
    this.onBack,
    this.embedded = false,
    this.wrapPageBody = false,
  });

  final String title;
  final Widget child;
  final VoidCallback? onBack;
  final bool embedded;
  final bool wrapPageBody;

  @override
  Widget build(BuildContext context) {
    final c = context.pangolin;
    final body = wrapPageBody ? PageBody(child: child) : child;
    if (embedded) return body;
    return Scaffold(
      backgroundColor: c.bg,
      body: SafeArea(
        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
            child: Row(children: [
              IconButton(
                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
              ),
              Text(title, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
            ]),
          ),
          Expanded(child: body),
        ]),
      ),
    );
  }
}