class WallPanelPanel extends HTMLElement {
  constructor() {
    super();
    this._hass = null;
    this._panel = null;
    this._narrow = false;
    this._pollTimer = null;
    this._activePanelUrl = '';
    this.attachShadow({ mode: 'open' });
  }

  set hass(hass) {
    this._hass = hass;
    this._render();
  }

  set panel(panel) {
    this._panel = panel;
    this._render();
  }

  set narrow(narrow) {
    this._narrow = Boolean(narrow);
    this._render();
  }

  connectedCallback() {
    this._render();
  }

  disconnectedCallback() {
    if (this._pollTimer) {
      window.clearInterval(this._pollTimer);
      this._pollTimer = null;
    }
  }

  _resolveUrl(rawUrl) {
    const value = String(rawUrl || '').trim();
    if (!value) {
      return '';
    }

    try {
      const url = new URL(value, window.location.href);
      if (!url.searchParams.has('embed')) {
        url.searchParams.set('embed', '1');
      }
      if (!url.searchParams.has('mode')) {
        url.searchParams.set('mode', 'ha');
      }
      return url.toString();
    } catch (error) {
      return value;
    }
  }

  _panelConfig() {
    const config = this._panel?.config || {};
    const customConfig = config._panel_custom || {};
    return customConfig.config || customConfig || config;
  }

  _configUrl() {
    const payload = this._panelConfig();
    const entryId = String(payload.entry_id || '').trim();
    if (!entryId) {
      return '';
    }
    return `/api/wall_panel/config/${encodeURIComponent(entryId)}`;
  }

  async _fetchPanelUrl() {
    const payload = this._panelConfig();
    const configUrl = this._configUrl();
    const syncToken = String(payload.sync_token || '').trim();
    if (!configUrl || !syncToken) {
      return '';
    }

    try {
      const response = await fetch(configUrl, {
        method: 'GET',
        headers: {
          'X-Wall-Panel-Token': syncToken,
          Accept: 'application/json',
        },
        credentials: 'same-origin',
        cache: 'no-store',
      });

      if (!response.ok) {
        return '';
      }

      const data = await response.json();
      const panelUrl = String(data?.panel?.panel_url || data?.panel_url || '').trim();
      return panelUrl;
    } catch (error) {
      return '';
    }
  }

  _renderMessage(title, body, extra = '') {
    if (!this.shadowRoot) {
      return;
    }

    this.shadowRoot.innerHTML = `
      <style>
        :host {
          display: block;
          width: 100%;
          height: 100%;
          min-height: 100vh;
          background: var(--primary-background-color, #0d0f14);
          color: var(--primary-text-color, #fff);
        }
        .wrap {
          position: relative;
          width: 100%;
          height: 100vh;
          overflow: hidden;
          background: var(--primary-background-color, #0d0f14);
        }
        .message {
          display: grid;
          place-items: center;
          height: 100%;
          padding: 24px;
          box-sizing: border-box;
          text-align: center;
          font-family: var(--primary-font-family, sans-serif);
          color: var(--secondary-text-color, #b3b8c2);
        }
        .message strong {
          display: block;
          color: var(--primary-text-color, #fff);
          margin-bottom: 8px;
          font-size: 1.1rem;
        }
        .message code {
          display: inline-block;
          margin-top: 10px;
          padding: 6px 10px;
          border-radius: 8px;
          background: rgba(255, 255, 255, 0.06);
          color: var(--primary-text-color, #fff);
          word-break: break-all;
        }
      </style>
      <div class="wrap">
        <div class="message">
          <div>
            <strong>${title}</strong>
            <div>${body}</div>
            ${extra}
          </div>
        </div>
      </div>
    `;
  }

  _renderIframe(panelUrl) {
    if (!this.shadowRoot) {
      return;
    }

    const wrap = this.shadowRoot.querySelector('.wrap');
    if (!wrap) {
      return;
    }

    const iframe = document.createElement('iframe');
    iframe.src = panelUrl;
    iframe.loading = 'eager';
    iframe.referrerPolicy = 'no-referrer';
    iframe.allow = 'autoplay; fullscreen; picture-in-picture';
    iframe.style.width = '100%';
    iframe.style.height = '100%';
    iframe.style.border = '0';
    iframe.style.display = 'block';
    iframe.style.background = 'transparent';
    wrap.replaceChildren(iframe);
    this._activePanelUrl = panelUrl;
  }

  async _tryAttachPanel() {
    const payload = this._panelConfig();
    const initialUrl = this._resolveUrl(
      payload.panel_url || payload.ingress_url || ''
    );

    if (initialUrl && initialUrl === this._activePanelUrl) {
      return;
    }

    if (initialUrl && !(window.location.protocol === 'https:' && initialUrl.startsWith('http://'))) {
      this._renderIframe(initialUrl);
      return;
    }

      const panelUrl = this._resolveUrl(await this._fetchPanelUrl());
    if (panelUrl && panelUrl === this._activePanelUrl) {
      return;
    }

    if (panelUrl && !(window.location.protocol === 'https:' && panelUrl.startsWith('http://'))) {
      this._renderIframe(panelUrl);
      return;
    }

    const configUrl = this._configUrl();
    this._renderMessage(
      'Waiting for Wall Panel',
      'The add-on will publish a secure HTTPS ingress URL here.',
      configUrl ? `<code>${configUrl}</code>` : ''
    );
  }

  _render() {
    if (!this.shadowRoot) {
      return;
    }

    if (this._pollTimer) {
      window.clearInterval(this._pollTimer);
      this._pollTimer = null;
    }

    this._tryAttachPanel();
    this._pollTimer = window.setInterval(() => {
      this._tryAttachPanel();
    }, 2000);
  }
}

if (!customElements.get('wall-panel-panel')) {
  customElements.define('wall-panel-panel', WallPanelPanel);
}