/**
 * Detects if the primary pointing device or environment is a touch device
 * (e.g. tablet, phone, POS touchscreen terminal).
 * Returns false on desktop devices with mice/trackpads even if they have touchscreens.
 */
export function isTouchDevice() {
  if (typeof window === 'undefined') return false;
  if (window.matchMedia) {
    if (window.matchMedia('(pointer: coarse)').matches) {
      return true;
    }
    if (window.matchMedia('(pointer: fine)').matches) {
      return false;
    }
  }
  return 'ontouchstart' in window || (navigator.maxTouchPoints > 0);
}

/**
 * Globally disables autofocus on touch devices to prevent virtual keyboard popups.
 * Physical taps on inputs still focus and open the keyboard normally.
 */
export function disableTouchAutofocus() {
  if (!isTouchDevice()) return;

  // 1. Intercept programmatic focus called during mount/render on autofocus elements
  const originalFocus = HTMLElement.prototype.focus;
  HTMLElement.prototype.focus = function (options) {
    if (this.hasAttribute?.('autofocus') || this.autofocus) {
      this.removeAttribute?.('autofocus');
      try {
        this.autofocus = false;
      } catch {
        // ignore
      }
      return;
    }

    const stack = new Error().stack || '';
    if (stack.includes('commitMount') || stack.includes('commitHostUpdate')) {
      return;
    }

    return originalFocus.call(this, options);
  };

  // 2. Prevent browser from honoring native autofocus attribute on dynamically inserted elements
  const originalSetAttribute = Element.prototype.setAttribute;
  Element.prototype.setAttribute = function (name, value) {
    if (typeof name === 'string' && name.toLowerCase() === 'autofocus') {
      return;
    }
    return originalSetAttribute.call(this, name, value);
  };
}