nexarch/web/shl/components/Shell.tsx

"use client";

// Layout-Shell mit Navigation — SHL-01 Akzeptanzkriterium 1.
// Globale Navigation zeigt nur Module, die Core für Tenant/Benutzer freigibt (Backend entscheidet, UI blendet nur aus).
//
// UX-01: unter 768px klappt die Navigation hinter einem Hamburger-Button
// weg (Akzeptanzkriterium 1: Kernabläufe auf dem Telefon vollständig
// durchführbar — eine dauerhaft sichtbare, mehrzeilig umbrechende Leiste
// wäre das nicht), `max-width:100%`/`overflow-x:hidden` auf der Shell
// verhindert horizontales Scrollen (Akzeptanzkriterium 2), alle
// interaktiven Elemente sind mindestens 44×44px groß
// (Akzeptanzkriterium 3, WCAG-Empfehlung für Touch-Ziele).
//
// UX-05 Akzeptanzkriterium 2: sichtbare Fokusmarkierung global über
// :focus-visible statt je Komponente einzeln (Shell umschließt alle
// Modul-Inhalte).

import { useState } from "react";
import type { ReactNode } from "react";
import { useI18n } from "../i18n/i18n";
import { useTheme } from "../theme/ThemeProvider";
import { baseComponentStyles } from "../tokens/tokens";

export interface ModuleLink {
  key: string;
  label: string;
  href: string;
  active?: boolean;
}

export interface ShellProps {
  modules: ModuleLink[];
  tenantLabel: string;
  children: ReactNode;
}

const responsiveStyles = `
  .shl-shell { max-width: 100%; overflow-x: hidden; box-sizing: border-box; }
  .shl-shell *:focus-visible {
    outline: 3px solid var(--shl-color-focus-ring, #1D4ED8);
    outline-offset: 2px;
  }
  .shl-shell *, .shl-shell *::before, .shl-shell *::after { box-sizing: inherit; }
  .shl-shell-header {
    display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
    padding: 10px 20px;
    background: var(--shl-color-surface-raised, #fff);
    border-bottom: 1px solid var(--shl-color-border, #d7dbe0);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    position: sticky; top: 0; z-index: 10;
  }
  .shl-shell-header nav ul { display: flex; gap: 4px; list-style: none; margin: 0; padding: 0; flex-wrap: wrap; }
  .shl-shell-header nav a {
    min-height: 44px; display: inline-flex; align-items: center; justify-content: center; padding: 0 14px;
    border-radius: 8px; font-weight: 500; text-decoration: none;
    color: var(--shl-color-text-secondary, #4b5563);
    transition: background-color 0.15s ease, color 0.15s ease;
  }
  .shl-shell-header nav a:hover { background: var(--shl-color-accent-subtle, #eef3ff); }
  .shl-shell-header nav a[aria-current="page"] {
    background: var(--shl-color-accent-subtle, #eef3ff);
    color: var(--shl-color-accent, #1d4ed8);
    font-weight: 600;
  }
  .shl-shell-header button,
  .shl-nav-toggle {
    min-height: 44px; min-width: 44px; display: inline-flex; align-items: center; justify-content: center; padding: 0 12px;
    border-radius: 8px;
  }
  .shl-nav-toggle { display: none; background: none; border: 1px solid var(--shl-color-border, #d7dbe0); font-size: 1.25rem; }
  .shl-shell-context { display: flex; align-items: center; gap: 12px; }
  .shl-tenant-context {
    font-size: 0.85rem; font-weight: 500; color: var(--shl-color-text-secondary, #4b5563);
    padding: 4px 10px; border-radius: 999px; background: var(--shl-color-surface, #f5f6f8);
  }
  .shl-shell-context button {
    background: none; border: 1px solid var(--shl-color-border, #d7dbe0);
  }
  @media (max-width: 768px) {
    .shl-nav-toggle { display: inline-flex; }
    .shl-shell-header nav { display: none; width: 100%; order: 3; }
    .shl-shell-header nav.shl-nav-open { display: block; }
    .shl-shell-header nav ul { flex-direction: column; }
  }
`;

export function Shell({ modules, tenantLabel, children }: ShellProps) {
  const { scheme, toggle } = useTheme();
  const { t } = useI18n();
  const [navOpen, setNavOpen] = useState(false);

  return (
    <div className="shl-shell">
      <style>{responsiveStyles}</style>
      <style>{baseComponentStyles}</style>
      <a className="shl-skip-link" href="#shl-main-content">
        {t("shl.shell.skipToContent", "Zum Inhalt springen")}
      </a>
      <header className="shl-shell-header">
        <button
          type="button"
          className="shl-nav-toggle"
          data-testid="shl-nav-toggle"
          aria-expanded={navOpen}
          aria-controls="shl-module-nav"
          onClick={() => setNavOpen((open) => !open)}
          aria-label={t("shl.shell.toggleNav", "Navigation umschalten")}
        >
          ☰
        </button>
        <nav
          id="shl-module-nav"
          aria-label={t("shl.shell.moduleNav", "Modul-Navigation")}
          className={navOpen ? "shl-nav-open" : undefined}
        >
          <ul>
            {modules.map((mod) => (
              <li key={mod.key}>
                <a href={mod.href} aria-current={mod.active ? "page" : undefined} onClick={() => setNavOpen(false)}>
                  {mod.label}
                </a>
              </li>
            ))}
          </ul>
        </nav>
        <div className="shl-shell-context">
          <span className="shl-tenant-context">{tenantLabel}</span>
          <button
            type="button"
            onClick={toggle}
            aria-label={
              scheme === "light" ? t("shl.theme.toggleToDark") : t("shl.theme.toggleToLight")
            }
          >
            {scheme === "light" ? "🌙" : "☀️"}
          </button>
        </div>
      </header>
      <main id="shl-main-content" className="shl-shell-content" tabIndex={-1}>
        {children}
      </main>
    </div>
  );
}