// hive-btn.js — <hive-btn>, a customized built-in `<button>` (`<button
// is="hive-btn">`) — the button primitive for modal.js's dialog buttons.
// Extending `HTMLButtonElement` keeps native button behaviour (click/
// keyboard activation, `:disabled`) for free.
//
// NOT shadow-DOM-encapsulated: a customized built-in can't host a shadow
// root — `attachShadow()` throws `NotSupportedError` unconditionally for
// any element that isn't an autonomous custom element or on the HTML
// spec's short fixed list (article/aside/div/span/etc., no `button`),
// and `is=`-upgraded built-ins are excluded regardless of tag. The prior
// version called `attachShadow()` here anyway — it shipped and passed
// review since nothing in CI exercises real browser DOM, then broke the
// very first live dialog open. Styled via a stylesheet adopted once on
// `document` instead, scoped with `[is="hive-btn"]` (hive-btn.css) — the
// light-DOM approach the rest of the app's `.btn` consumers already use.
// (`<hive-dialog>`/`<hive-toast>` in modal.js are unaffected — genuine
// autonomous custom elements, valid shadow hosts.)
//
// Customized built-ins aren't supported in Safari/WebKit — fine here
// since the project targets recent Firefox only.
//
// Usage: `el('button', { type: 'button', is: 'hive-btn', variant: 'danger' }, 'label')`.
// `variant` ∈ 'cancel' | 'confirm' | 'danger' | unset (neutral default).

import hiveBtnCss from './hive-btn.css';

// Adopted once, module-wide — every <hive-btn> instance shares the same
// document-level stylesheet rather than each instance re-adopting it.
let styleInstalled = false;
function ensureStyleInstalled() {
  if (styleInstalled) return;
  styleInstalled = true;
  const sheet = new CSSStyleSheet();
  sheet.replaceSync(hiveBtnCss);
  document.adoptedStyleSheets = [...document.adoptedStyleSheets, sheet];
}

class HiveBtn extends HTMLButtonElement {
  connectedCallback() {
    ensureStyleInstalled();
  }
}
customElements.define('hive-btn', HiveBtn, { extends: 'button' });