import { findScrollableParent } from "./findScrollableParent";
import { getScrollerBoundingClientRect } from "./getScrollerBoundingClientRect";

export function scrollElementIntoView(
   el: Element,
   vertical: boolean = true,
   horizontal: boolean = false,
   inflate: number = 0,
   scrollContainer: HTMLElement | null = null
): void {
   if (horizontal) {
      let parentEl = scrollContainer || findScrollableParent(el, true);
      if (parentEl) {
         let pr = getScrollerBoundingClientRect(parentEl);
         let er = el.getBoundingClientRect();
         let scrollbarWidth = parentEl.offsetWidth - parentEl.clientWidth;

         if (er.right + inflate > pr.right - scrollbarWidth)
            parentEl.scrollLeft = Math.max(0, parentEl.scrollLeft + er.right + inflate - pr.right + scrollbarWidth);

         if (er.left - inflate < pr.left)
            parentEl.scrollLeft = Math.max(0, parentEl.scrollLeft + er.left - inflate - pr.left);
      }
   }

   if (vertical) {
      let parentEl = scrollContainer || findScrollableParent(el);
      if (parentEl) {
         let pr = getScrollerBoundingClientRect(parentEl);
         let er = el.getBoundingClientRect();
         let scrollbarHeight = parentEl.offsetHeight - parentEl.clientHeight;

         if (er.bottom + inflate > pr.bottom - scrollbarHeight)
            parentEl.scrollTop = Math.max(0, parentEl.scrollTop + er.bottom + inflate - pr.bottom + scrollbarHeight);

         if (er.top - inflate < pr.top)
            parentEl.scrollTop = Math.max(0, parentEl.scrollTop + er.top - inflate - pr.top);
      }
   }
}