import { unref } from "vue";

export const useScroll = () => {
  /**
   * Scrolls to a target element within a scroll container.
   * The function is agnostic to whether the container is a QScrollArea or a native DOM element.
   *
   * @param {Ref<Component|HTMLElement>} targetRef - Ref to the target component or DOM element.
   * @param {Ref<Component|HTMLElement>} containerRef - Ref to the container (QScrollArea or a scrollable DOM element like body).
   * @param {Object} options - Scroll options.
   * @param {number} options.offset - Offset from the top in pixels (default: 50).
   * @param {number} options.duration - Animation duration for QScrollArea (default: 150). Note: duration is not supported for native scrolling.
   * @returns {boolean} - Whether the scroll was successful.
   */
  const scrollToComponent = (targetRef, containerRef, options = {}) => {
    const { offset = 150, duration = 150 } = options;

    const targetInstance = unref(targetRef);
    const containerInstance = unref(containerRef);

    const targetElement = targetInstance?.$el ?? targetInstance;

    const containerElement = containerInstance?.$el ?? containerInstance;

    if (!targetElement || !containerElement) {
      console.warn("useScroll: Target or container element not found");
      return false;
    }

    try {
      let currentElement = targetElement;
      let offsetTop = 0;

      while (currentElement && currentElement !== containerElement) {
        offsetTop += currentElement.offsetTop;
        if (
          containerElement.contains(currentElement.offsetParent) ||
          containerElement === document.body
        ) {
          currentElement = currentElement.offsetParent;
        } else {
          currentElement = null;
        }
      }

      if (
        containerElement !== document.body &&
        !containerElement.contains(targetElement)
      ) {
        console.warn("useScroll: Target is not a child of the container");
        return false;
      }

      const targetPosition = Math.max(0, offsetTop - offset);

      if (typeof containerInstance.setScrollPosition === "function") {
        containerInstance.setScrollPosition(
          "vertical",
          targetPosition,
          duration,
        );
      } else {
        const scrollable =
          containerElement === document.body ? window : containerElement;
        scrollable.scrollTo({
          top: targetPosition,
          behavior: "smooth",
        });
      }

      return true;
    } catch (error) {
      console.error("useScroll: Error while scrolling", error);
      return false;
    }
  };

  return {
    scrollToComponent,
  };
};