/**
 * <rstack-comment-bell> — Comment button with unresolved-count badge.
 *
 * Shows a chat-bubble icon in the header bar. Badge displays the count
 * of unresolved comment pins on the current canvas. Clicking dispatches
 * a `comment-pin-activate` event on `window` so canvas.html can enter
 * pin-placement mode.
 *
 * Data source: `window.__communitySync?.doc?.commentPins`
 * Listens for `comment-pins-changed` on `window` (re-dispatched by canvas).
 * Polls every 5s as fallback (sync may appear after component mounts).
 */

const POLL_INTERVAL = 5_000;

export class RStackCommentBell extends HTMLElement {
  #shadow: ShadowRoot;
  #count = 0;
  #pollTimer: ReturnType<typeof setInterval> | null = null;

  constructor() {
    super();
    this.#shadow = this.attachShadow({ mode: "open" });
  }

  connectedCallback() {
    this.#render();
    this.#refreshCount();
    this.#pollTimer = setInterval(() => this.#refreshCount(), POLL_INTERVAL);
    window.addEventListener("comment-pins-changed", this.#onPinsChanged);
  }

  disconnectedCallback() {
    if (this.#pollTimer) clearInterval(this.#pollTimer);
    window.removeEventListener("comment-pins-changed", this.#onPinsChanged);
  }

  #onPinsChanged = () => {
    this.#refreshCount();
  };

  #refreshCount() {
    const sync = (window as any).__communitySync;
    const pins = sync?.doc?.commentPins;
    if (!pins) {
      if (this.#count !== 0) {
        this.#count = 0;
        this.#render();
      }
      return;
    }
    const newCount = Object.values(pins).filter(
      (p: any) => !p.resolved
    ).length;
    if (newCount !== this.#count) {
      this.#count = newCount;
      this.#render();
    }
  }

  #render() {
    const badge =
      this.#count > 0
        ? `<span class="badge">${this.#count > 99 ? "99+" : this.#count}</span>`
        : "";

    this.#shadow.innerHTML = `
      <style>${STYLES}</style>
      <button class="comment-btn" aria-label="Leave Comment" title="Leave Comment (/)">
        <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
          <path d="M21 11.5a8.38 8.38 0 01-.9 3.8 8.5 8.5 0 01-7.6 4.7 8.38 8.38 0 01-3.8-.9L3 21l1.9-5.7a8.38 8.38 0 01-.9-3.8 8.5 8.5 0 014.7-7.6 8.38 8.38 0 013.8-.9h.5a8.48 8.48 0 018 8v.5z"/>
        </svg>
        ${badge}
      </button>
    `;

    this.#shadow
      .querySelector(".comment-btn")
      ?.addEventListener("click", (e) => {
        e.stopPropagation();
        window.dispatchEvent(new CustomEvent("comment-pin-activate"));
      });
  }

  static define(tag = "rstack-comment-bell") {
    if (!customElements.get(tag)) customElements.define(tag, RStackCommentBell);
  }
}

const STYLES = `
:host {
  display: inline-flex;
  align-items: center;
}

.comment-btn {
  position: relative;
  background: none;
  border: none;
  color: var(--rs-text-muted, #94a3b8);
  cursor: pointer;
  padding: 6px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s, background 0.15s;
}
.comment-btn:hover {
  color: var(--rs-text-primary, #e2e8f0);
  background: var(--rs-bg-hover, rgba(255,255,255,0.05));
}

.badge {
  position: absolute;
  top: 2px;
  right: 2px;
  min-width: 16px;
  height: 16px;
  border-radius: 8px;
  background: #ef4444;
  color: white;
  font-size: 10px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 4px;
  line-height: 1;
  pointer-events: none;
}

@media (max-width: 640px) {
  .comment-btn { display: none; }
}
`;