{{-- A pane: a content region with M3's margins, and its own top app bar if it has a title.

         <x-pane title="Settings" subtitle="Your account" width="narrow">
             <x-slot:actions><x-button icon="help" tooltip="Help" /></x-slot:actions>
             <x-slot:navigation><x-section-nav :items="$sections" /></x-slot:navigation>
             …
         </x-pane>

     M3 puts every piece of content in a pane and lets each carry its own top app bar
     (docs/reference/m3/foundations.md § Layout → Scaffold). The body is kept off the window's edge
     by M3's margin, 16px below medium (600px) and 24px from it
     (docs/reference/m3/foundations-supplement.md § Breakpoints); a pane inside something that
     already keeps that margin — the scaffold's content region, a canonical layout, another pane's
     body — draws none, so the margin is never doubled; on an `<x-surface>` it draws it again.

     `width` caps the pane and centres it: `narrow` (40rem, M3's 40–60 characters a line),
     `medium` (60rem), `wide` (80rem) or `full` (the default, all the room it has).

     The app bar is `<x-app-bar>`, drawn when there is a `title`, `actions`, a `leading` slot or
     `back`: `title` and `subtitle`, `heading` (`h1` by default; the second pane of a canonical
     layout passes `h2`), `sticky` (true: it holds to the top of the window for as long as the pane
     is on screen), the `actions` slot at its end. Its leading icon button is the `leading` slot,
     or `back`: a URL makes it a link back there, and `true` calls `back()` in the Alpine scope
     around it, which `<x-list-detail>` provides — and which it hides where both panes show, as M3
     shows a back button only in a single-pane list-detail. The back arrow mirrors in a
     right-to-left document.

     `navigation` is the pane's section navigation (`<x-section-nav>`, `<x-tabs>`), under the bar
     and above the body, with the body's margins; it is not the bar's leading button.

     It takes `as` (`div` by default: `section`, `article`, `main` …), `hide-below` and `hide-from`
     like every layout component, and the caller's `class` and `style` land on it untouched. Drawn
     by resources/css/layout/pane.css. --}}

@props([
    'as' => null,
    'title' => null,
    'subtitle' => null,
    'heading' => 'h1',
    'sticky' => true,
    'back' => null,
    'width' => null,
    'hideBelow' => null,
    'hideFrom' => null,
])

@php
    $layout = \NoNameWeb\LivewireMaterial\Support\Layout::class;
    $element = $layout::element($as);
    $backLink = is_string($back) && $back !== '' ? $back : null;
    $backAction = $back === true;
    $bar = filled($title) || isset($actions) || isset($leading) || $backLink !== null || $backAction;

    $attributes = $attributes->merge(array_filter([
        'data-md-pane' => true,
        'data-md-width' => $layout::choice($width, ['full', 'narrow', 'medium', 'wide']),
    ] + $layout::visibility($hideBelow, $hideFrom), fn ($value): bool => $value !== null));
@endphp

<{{ $element }} {{ $attributes }}>
    @if ($bar)
        <x-livewire-material::app-bar :title="$title" :subtitle="$subtitle" :heading="$heading" :sticky="$sticky" data-md-pane-bar>
            @if (isset($leading))
                <x-slot:navigation>{{ $leading }}</x-slot:navigation>
            @elseif ($backLink !== null || $backAction)
                <x-slot:navigation>
                    <span data-md-pane-back @if ($backAction) data-md-list-detail-back @endif>
                        @if ($backLink !== null)
                            <x-livewire-material::button icon="arrow_back" :tooltip="__('Back')" :link="$backLink" />
                        @else
                            <x-livewire-material::button icon="arrow_back" :tooltip="__('Back')" x-on:click="back()" />
                        @endif
                    </span>
                </x-slot:navigation>
            @endif

            @isset($actions)
                <x-slot:actions>{{ $actions }}</x-slot:actions>
            @endisset
        </x-livewire-material::app-bar>
    @endif

    @isset($navigation)
        <div data-md-pane-navigation>{{ $navigation }}</div>
    @endisset

    <div data-md-pane-body>{{ $slot }}</div>
</{{ $element }}>