// hive-menu.js — <hive-menu>, the generic dropdown-menu shadow-DOM custom
// element behind any "click a trigger, get a positioned dropdown" UI
// (currently just <hive-agent-menu>'s per-agent "⋮" menu). Owns
// open/close state, trigger + dropdown positioning, singleton
// close-on-open coordination across every `<hive-menu>` instance in the
// app, and the document-level outside-click/Escape listeners. Doesn't
// know or care what's inside the trigger/dropdown — opaque DOM nodes the
// caller hands over via `._opts = { trigger, content }` before appending
// (same `._opts`-before-append convention `<hive-dialog>` uses).
//
// `trigger`/`content` are appended as *light-DOM* children, projected
// into the shadow template via named `<slot>`s rather than moved into
// the shadow root. Load-bearing: it keeps the caller's own class-scoped
// styling applying to the nodes it built — a `<style>` only styles
// elements within the same tree it's part of, and slotted content keeps
// the tree membership of wherever it's actually a light-DOM child, so
// re-parenting into this element's own shadow root would make the
// caller's classes go dark.
//
// `openInstances` tracks every open instance app-wide (a deliberate
// widening from the old per-agent-menu-only coordination) so
// `closeAll()` can close each via its own `.close()`. `closeAllMenus()`
// force-closes everything before tearing down DOM one might anchor off
// of (e.g. swarm.js before replacing the container tree).
//
// The document-level listeners below, registered once: shadow-DOM
// retargeting means `e.target` for a click inside a shadow tree gets
// retargeted past that instance's host, so `e.composedPath()` (includes
// slotted content) tests "did this land inside any open menu" — same
// reasoning as `<hive-dialog>`'s backdrop-click check.

import { el } from '../dom.js';
import { attachShadowCss } from '../shadow-css.js';
import hiveMenuCss from './hive-menu.css';

const openInstances = new Set();

function closeAll() {
  for (const inst of [...openInstances]) inst.close();
}

// Exported for any caller that needs to force-close every open menu —
// see module header.
export function closeAllMenus() {
  closeAll();
}

// Close on any click outside every currently-open instance.
document.addEventListener('click', (e) => {
  if (!openInstances.size) return;
  const path = e.composedPath();
  for (const inst of [...openInstances]) {
    if (!path.includes(inst)) inst.close();
  }
}, true);
// Close on Escape. stopImmediatePropagation so a caller's own
// selection-clear Escape handler (e.g. swarm.js's) doesn't also fire
// while a menu is open.
document.addEventListener('keydown', (e) => {
  if (e.key === 'Escape' && openInstances.size) {
    closeAll();
    e.stopImmediatePropagation();
  }
}, true);

class HiveMenu extends HTMLElement {
  connectedCallback() {
    const { trigger, content } = this._opts || {};
    const root = attachShadowCss(this, hiveMenuCss);

    // Project the caller's opaque nodes via named slots — see module
    // header for why this has to be slotting, not a shadow-root append.
    trigger.slot = 'trigger';
    content.slot = 'content';
    this.append(trigger, content);

    const dropdown = el('div', { class: 'menu-dropdown', hidden: true });
    dropdown.append(el('slot', { name: 'content' }));
    root.append(el('slot', { name: 'trigger' }), dropdown);

    this._trigger = trigger;
    this._dropdown = dropdown;

    trigger.addEventListener('click', (e) => {
      e.stopPropagation();
      const wasOpen = openInstances.has(this);
      closeAll();
      if (!wasOpen) this.open();
    });
  }

  disconnectedCallback() {
    // Guards against a stale entry if the element is removed from the DOM
    // (row re-render, tab switch) while its dropdown was still open.
    openInstances.delete(this);
  }

  open() {
    this._dropdown.hidden = false;
    this._trigger.setAttribute('aria-expanded', 'true');
    this.style.setProperty('--menu-btn-opacity', '1');
    openInstances.add(this);
  }

  close() {
    if (!openInstances.has(this)) return;
    this._dropdown.hidden = true;
    this._trigger.setAttribute('aria-expanded', 'false');
    this.style.removeProperty('--menu-btn-opacity');
    openInstances.delete(this);
  }
}
customElements.define('hive-menu', HiveMenu);