(function initHelpIconOverlayModule() {
  const CLOSE_HANDLERS = {
    '.sg-pulldown-demo': (root) => {
      root.querySelectorAll('.sg-pulldown-demo').forEach((demo) => {
        const trigger = demo.querySelector('.sg-pulldown-demo__trigger');
        demo.dataset.open = 'false';
        if (trigger) {
          trigger.setAttribute('aria-expanded', 'false');
        }
      });
    },
    '.sg-sandwich-menu-wrap': (root) => {
      root.querySelectorAll('.sg-sandwich-menu-wrap').forEach((wrap) => {
        const button = wrap.querySelector('.sg-sandwich-button');
        wrap.dataset.open = 'false';
        if (button) {
          button.setAttribute('aria-expanded', 'false');
        }
      });
    },
  };

  const getViewportWidth = () => {
    if (window.visualViewport && typeof window.visualViewport.width === 'number') {
      return window.visualViewport.width;
    }
    return window.innerWidth;
  };

  const getViewportHeight = () => {
    if (window.visualViewport && typeof window.visualViewport.height === 'number') {
      return window.visualViewport.height;
    }
    return window.innerHeight;
  };

  const getSafeInsetPx = () => {
    const rootStyles = getComputedStyle(document.documentElement);
    const spacingSmallRaw = rootStyles.getPropertyValue('--spacing-small').trim();
    const rootFontSize = parseFloat(rootStyles.fontSize) || 16;
    const spacingSmallValue = parseFloat(spacingSmallRaw);
    if (Number.isNaN(spacingSmallValue)) {
      return 0;
    }
    if (spacingSmallRaw.endsWith('rem')) {
      return spacingSmallValue * rootFontSize;
    }
    return spacingSmallValue;
  };

  const closeAllHelpIcons = (root) => {
    root.querySelectorAll('.sg-help-icon-wrap').forEach((wrap) => {
      const button = wrap.querySelector('.sg-help-icon');
      const panel = wrap.querySelector('.sg-help-icon-panel');
      wrap.dataset.open = 'false';
      if (panel) {
        panel.style.removeProperty('transform');
        panel.style.removeProperty('max-height');
        panel.style.removeProperty('overflow-y');
      }
      if (button) {
        button.setAttribute('aria-expanded', 'false');
      }
    });
  };

  const positionHelpPanel = (wrap, panel) => {
    wrap.dataset.align = 'left';
    wrap.dataset.vertical = 'bottom';
    panel.style.removeProperty('transform');
    panel.style.removeProperty('max-height');
    panel.style.removeProperty('overflow-y');

    const viewportWidth = getViewportWidth();
    const panelRect = panel.getBoundingClientRect();
    if (panelRect.right > viewportWidth) {
      wrap.dataset.align = 'right';
    }
    const alignedPanelRect = panel.getBoundingClientRect();
    if (alignedPanelRect.left < 0) {
      wrap.dataset.align = 'left';
    }

    const clampedRect = panel.getBoundingClientRect();
    const safeInset = getSafeInsetPx();
    let shiftX = 0;
    if (clampedRect.right > (viewportWidth - safeInset)) {
      shiftX -= clampedRect.right - (viewportWidth - safeInset);
    }
    if ((clampedRect.left + shiftX) < safeInset) {
      shiftX += safeInset - (clampedRect.left + shiftX);
    }
    if (shiftX !== 0) {
      panel.style.transform = `translateX(${shiftX}px)`;
    }

    const viewportHeight = getViewportHeight();
    const verticalSafeInset = getSafeInsetPx();
    const bottomRect = panel.getBoundingClientRect();
    if (bottomRect.bottom > (viewportHeight - verticalSafeInset)) {
      wrap.dataset.vertical = 'top';
      const topRect = panel.getBoundingClientRect();
      if (topRect.top < verticalSafeInset) {
        const wrapRect = wrap.getBoundingClientRect();
        const spaceAbove = Math.max(0, wrapRect.top - verticalSafeInset);
        const spaceBelow = Math.max(0, viewportHeight - verticalSafeInset - wrapRect.bottom);
        const useTop = spaceAbove >= spaceBelow;
        wrap.dataset.vertical = useTop ? 'top' : 'bottom';
        const availableHeight = Math.max(96, Math.floor((useTop ? spaceAbove : spaceBelow) - verticalSafeInset));
        panel.style.maxHeight = `${availableHeight}px`;
        panel.style.overflowY = 'auto';
      }
    }
  };

  window.sgInitHelpIconOverlays = (options = {}) => {
    const root = options.root || document;
    const closeOnOpenSelectors = options.closeOnOpenSelectors || [];
    const outsideClickIgnoreSelectors = options.outsideClickIgnoreSelectors || [];

    root.querySelectorAll('.sg-help-icon-wrap').forEach((wrap) => {
      if (wrap.dataset.helpIconInit === 'true') {
        return;
      }
      wrap.dataset.helpIconInit = 'true';

      const button = wrap.querySelector('.sg-help-icon');
      const panel = wrap.querySelector('.sg-help-icon-panel');
      if (!button || !panel) {
        return;
      }

      button.addEventListener('click', (event) => {
        event.stopPropagation();
        const nextState = wrap.dataset.open !== 'true';

        closeAllHelpIcons(root);
        closeOnOpenSelectors.forEach((selector) => {
          const handler = CLOSE_HANDLERS[selector];
          if (handler) {
            handler(root);
          }
        });

        if (!nextState) {
          return;
        }

        wrap.dataset.open = 'true';
        button.setAttribute('aria-expanded', 'true');
        positionHelpPanel(wrap, panel);
        window.requestAnimationFrame(() => {
          if (wrap.dataset.open === 'true') {
            positionHelpPanel(wrap, panel);
          }
        });
      });
    });

    const refreshOpenPanels = () => {
      root.querySelectorAll('.sg-help-icon-wrap[data-open="true"]').forEach((wrap) => {
        const panel = wrap.querySelector('.sg-help-icon-panel');
        if (panel) {
          positionHelpPanel(wrap, panel);
        }
      });
    };

    if (!window.sgHelpIconOverlayResizeBound) {
      window.addEventListener('resize', refreshOpenPanels);
      if (window.visualViewport && typeof window.visualViewport.addEventListener === 'function') {
        window.visualViewport.addEventListener('resize', refreshOpenPanels);
      }
      window.sgHelpIconOverlayResizeBound = true;
    }

    document.addEventListener('click', (event) => {
      const isInsideIgnoredZone = ['.sg-help-icon-wrap', ...outsideClickIgnoreSelectors]
        .some((selector) => event.target.closest(selector));
      if (isInsideIgnoredZone) {
        return;
      }
      closeAllHelpIcons(root);
    });
  };
})();