---
import Wordmark from './Wordmark.astro';
import { localePath, t, type Lang } from '../i18n/ui';

interface Props { lang: Lang; tone?: 'paper' | 'night' }
const { lang, tone = 'paper' } = Astro.props;
const ui = t(lang);
const home = localePath(lang, '/');
const items = [
  { href: localePath(lang, '/cipherverifier'), label: ui.nav.product },
  { href: localePath(lang, '/insights'), label: ui.nav.insights },
  { href: localePath(lang, '/team'), label: ui.nav.team },
];
const contactHref = `${home}#contact`;
const path = Astro.url.pathname.replace(/\/$/, '') || '/';
const isCurrent = (href: string) => href.split('#')[0] === path && !href.includes('#');
---
<header class="header" data-header data-tone={tone} data-tone-init>
  <div class="container header__shell">
    <div class="header__bar hud-frame">
      <a class="header__home" href={home} aria-label={ui.nav.homeLabel}>
        <Wordmark inline class="header__logo header__logo--paper" />
        <Wordmark inline light class="header__logo header__logo--night" />
      </a>

      <nav class="header__nav hud-frame" aria-label="Primary" id="primary-nav">
        <ul class="header__list" role="list">
          {items.map((item) => {
            const current = isCurrent(item.href);
            return (
              <li><a class:list={[{ 'hud-corners': current }]} href={item.href} aria-current={current ? 'page' : undefined}>{item.label}</a></li>
            );
          })}
          <li class="header__contact-mobile"><a href={contactHref}>{ui.nav.contact}</a></li>
        </ul>
      </nav>

      <a class="header__contact" href={contactHref}>{ui.nav.contact}</a>

      <button class="header__toggle" type="button" aria-expanded="false" aria-controls="primary-nav" data-nav-toggle>
        <span data-label-open>{ui.nav.menu}</span>
        <span data-label-close hidden>{ui.nav.close}</span>
      </button>
    </div>
  </div>
</header>

<style>
  /* The header is a transparent sticky strip; the bar floats inside it with room on every side
     for the corner crosses. Only the bar takes pointer events, so the margin never blocks clicks. */
  .header {
    position: sticky;
    top: 0;
    z-index: 20;
    pointer-events: none;
  }
  .header__shell {
    padding-block: calc(var(--space-3) + var(--safe-top)) var(--space-3);
    transition:
      max-width var(--dur-slow) var(--ease),
      padding var(--dur-slow) var(--ease);
  }
  /* Once the page scrolls, the bar docks: full width, flush to the top, and as tall as the header
     so nothing below moves. Its outer crosses would sit off-screen (and the side ones would make
     the page scroll sideways), so they go, with the top and side borders; the bottom line stays. */
  .header[data-scrolled] .header__shell {
    max-width: 100%;
    padding: 0;
  }
  /* Docked, the glass also fills the status-bar strip, so scrolled content never shows behind the
     clock; the bar's contents stay below it. */
  .header[data-scrolled] .header__bar {
    min-height: var(--header-offset);
    padding-top: var(--safe-top);
    border-width: 0 0 var(--line);
  }
  .header[data-scrolled] .header__bar::after { content: none; }
  .header__bar {
    pointer-events: auto;
    isolation: isolate;
    display: flex;
    align-items: stretch;
    min-height: calc(var(--header-height) - 2 * var(--space-3));
    color: var(--ink-base);
    font-family: var(--font-mono);
    font-size: var(--step-micro);
    font-weight: var(--weight-medium);
    line-height: 1;
    letter-spacing: var(--track-caps);
    text-transform: uppercase;
    transition:
      color var(--dur) var(--ease),
      border-color var(--dur) var(--ease),
      min-height var(--dur-slow) var(--ease);
  }
  /* The glass sits on a pseudo-element rather than the bar itself: a backdrop-filter on the bar
     would make it a backdrop root, and the mobile panel inside it could then blur nothing. */
  .header__bar::before,
  .header__nav[data-open]::before {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: var(--glass-solid);
    transition: background-color var(--dur) var(--ease);
  }
  /* Until the script has settled the tone on load, it changes without a fade: the tone is a fact
     about where the page is, not a change the visitor made. */
  .header[data-tone-init],
  .header[data-tone-init] *,
  .header[data-tone-init] ::before,
  .header[data-tone-init] ::after { transition: none !important; }
  @supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
    .header__bar::before,
    .header__nav[data-open]::before {
      background: var(--glass);
      -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(1.4);
      backdrop-filter: blur(var(--glass-blur)) saturate(1.4);
    }
  }

  /* Over a night section the bar takes the night tone. */
  .header[data-tone='night'] { --hud-line: var(--hud-line-on-night); }
  .header[data-tone='night'] .header__bar { color: var(--ink-on-night); }
  .header[data-tone='night'] .header__bar::before,
  .header[data-tone='night'] .header__nav[data-open]::before { background: var(--glass-solid-on-night); }
  @supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
    .header[data-tone='night'] .header__bar::before,
    .header[data-tone='night'] .header__nav[data-open]::before { background: var(--glass-on-night); }
  }

  .header__home {
    display: flex;
    align-items: center;
    padding-inline: var(--space-4);
    text-decoration: none;
  }
  .header__home :global(.header__logo--night),
  .header[data-tone='night'] .header__home :global(.header__logo--paper) { display: none; }
  .header[data-tone='night'] .header__home :global(.header__logo--night) { display: block; }

  /* Cells: every item is a full-height cell, divided from its neighbour by one frame line. */
  .header__nav { margin-left: auto; display: flex; }
  /* On desktop the nav is just a run of cells inside the bar: no frame of its own. */
  .header__nav.hud-frame { border: 0; }
  .header__nav.hud-frame::after { content: none; }
  .header__list { display: flex; }
  .header__list li { display: flex; border-left: var(--line) solid var(--frame-color); }
  .header__list a,
  .header__contact,
  .header__toggle {
    display: flex;
    align-items: center;
    padding-inline: var(--space-4);
    text-decoration: none;
    transition: background-color var(--dur-fast) var(--ease);
  }
  .header__list a:hover,
  .header__toggle:hover { background: color-mix(in srgb, currentColor var(--tint-hover), transparent); }
  .header__list a[aria-current='page'] { background: color-mix(in srgb, currentColor var(--tint-active), transparent); }
  .header__contact {
    border-left: var(--line) solid var(--frame-color);
    background: var(--ink-base);
    color: var(--paper);
  }
  .header__contact:hover { background: var(--ink-muted-base); }
  .header[data-tone='night'] .header__contact { background: var(--paper); color: var(--night); }
  .header[data-tone='night'] .header__contact:hover { background: var(--paper-deep); }
  .header__list .header__contact-mobile { display: none; }
  .header__toggle {
    display: none;
    border-left: var(--line) solid var(--frame-color);
    text-transform: inherit;
    letter-spacing: inherit;
  }

  /* Focus ring drawn inside the cell, so it never collides with the frame lines. */
  .header__bar :focus-visible {
    outline-offset: calc(-1 * var(--space-1));
    border-radius: 0;
  }

  /* A panel left open across a resize to desktop must not paint a second glass layer. */
  @media (min-width: 48rem) {
    .header__nav[data-open]::before { content: none; }
  }

  @media (max-width: 47.99rem) {
    .header__contact { display: none; }
    .header__list .header__contact-mobile { display: flex; }
    .header__toggle { display: flex; margin-left: auto; }
    .header__nav {
      position: absolute;
      top: calc(100% + var(--space-3));
      left: calc(-1 * var(--line));
      right: calc(-1 * var(--line));
      display: none;
    }
    /* As the mobile panel it is a full .hud-frame: border and corner crosses. */
    .header__nav.hud-frame { border: var(--line) solid var(--frame-color); }
    .header__nav.hud-frame::after { content: ''; }
    .header__nav[data-open] { display: block; }
    /* Docked: the panel hangs straight off the bar's bottom line, edge to edge. */
    .header[data-scrolled] .header__nav {
      top: calc(100% + var(--line));
      border-width: 0 0 var(--line);
    }
    .header[data-scrolled] .header__nav.hud-frame::after { content: none; }
    .header__list { flex-direction: column; }
    .header__list li { border-left: 0; }
    .header__list li + li { border-top: var(--line) solid var(--frame-color); }
    .header__list a {
      flex: 1;
      padding-block: var(--space-4);
      font-size: var(--step-small);
    }
  }
</style>

<script>
  const header = document.querySelector<HTMLElement>('[data-header]');
  const toggle = header?.querySelector<HTMLButtonElement>('[data-nav-toggle]');
  const nav = header?.querySelector<HTMLElement>('#primary-nav');
  if (header && toggle && nav) {
    const open = toggle.querySelector<HTMLElement>('[data-label-open]')!;
    const close = toggle.querySelector<HTMLElement>('[data-label-close]')!;
    const set = (isOpen: boolean) => {
      toggle.setAttribute('aria-expanded', String(isOpen));
      if (isOpen) nav.setAttribute('data-open', ''); else nav.removeAttribute('data-open');
      open.hidden = isOpen;
      close.hidden = !isOpen;
    };
    toggle.addEventListener('click', () => set(toggle.getAttribute('aria-expanded') !== 'true'));
    document.addEventListener('keydown', (e) => { if (e.key === 'Escape') set(false); });
    nav.addEventListener('click', (e) => { if ((e.target as HTMLElement).closest('a')) set(false); });
  }

  /* Scrolled: a one-pixel marker at the very top of the document; once it leaves the viewport
     the page has scrolled. An IntersectionObserver, so nothing runs on scroll. */
  if (header && 'IntersectionObserver' in window) {
    const marker = document.createElement('div');
    marker.setAttribute('aria-hidden', 'true');
    marker.style.cssText = 'position:absolute;top:0;left:0;width:1px;height:1px;pointer-events:none;';
    document.body.prepend(marker);
    new IntersectionObserver(([entry]) => {
      header.toggleAttribute('data-scrolled', !entry.isIntersecting);
    }).observe(marker);
  }

  /* Tone: watch a one-pixel line through the middle of the bar and switch to night while a
     .night section crosses it. An IntersectionObserver, so nothing runs on scroll. */
  const sections = document.querySelectorAll<HTMLElement>('.night');
  // Transitions come back once the first tone is drawn (two frames, so it has been painted).
  const settle = () => requestAnimationFrame(() => requestAnimationFrame(() => header?.removeAttribute('data-tone-init')));
  if (header && sections.length && 'IntersectionObserver' in window) {
    const under = new Set<Element>();
    let observer: IntersectionObserver | undefined;
    const watch = () => {
      observer?.disconnect();
      under.clear();
      const mid = Math.round(header.offsetHeight / 2);
      observer = new IntersectionObserver((entries) => {
        for (const entry of entries) {
          if (entry.isIntersecting) under.add(entry.target); else under.delete(entry.target);
        }
        header.dataset.tone = under.size ? 'night' : 'paper';
        if (header.hasAttribute('data-tone-init')) settle();
      }, { rootMargin: `-${mid}px 0px -${window.innerHeight - mid - 1}px 0px` });
      sections.forEach((section) => observer!.observe(section));
    };
    watch();
    let resize: number | undefined;
    window.addEventListener('resize', () => {
      window.clearTimeout(resize);
      resize = window.setTimeout(watch, 150);
    });
  } else {
    settle();
  }
</script>