sorenabedi/artist-svelte

import type { voidFunction } from '../../types/global';
import type { scrollHook } from '../../types/hook';

export const slideEffectAction = (element: HTMLElement, scrollPosition: scrollHook): void => {
    if (scrollPosition.direction === 'up') {
        element.style.top = '';
    } else {
        element.style.top = `-${element.clientHeight + 30}px`;
    }
};
export const compactEffectAction = (
    element: HTMLElement
): {
    initCompactEffect: voidFunction<never>;
    updateCompactEffect: (scrollPosition: scrollHook) => void;
    destroyCompactEffect: voidFunction<never>;
} => {
    const observer = new IntersectionObserver(
        /* istanbul ignore next */ (entries) => {
            entries.forEach((entryElement) => {
                entryElement.target.classList.toggle(
                    'compact',
                    window.scrollY === 0 &&
                        entryElement.boundingClientRect.top === 0 &&
                        (entryElement.intersectionRatio === 1 ||
                            entryElement.boundingClientRect.y < entryElement.rootBounds.y)
                );
            });
        },
        {
            threshold: [1],
            rootMargin: `0px 0px  -${window.innerHeight - element.clientHeight - 10}px 0px`
        }
    );
    return {
        initCompactEffect: () => observer.observe(element),
        updateCompactEffect: (scrollPosition: scrollHook) => {
            if (scrollPosition.scrollY !== 0 && element.getBoundingClientRect().top === 0)
                element.classList.add('compact');
        },
        destroyCompactEffect: () => observer.disconnect()
    };
};

export const mergeEffectAction = (element: HTMLElement): void => {
    if (window.scrollY === 0) element.classList.remove('compact');
    if (element.getBoundingClientRect().top <= 0) element.classList.add('mergeToTop');
    if (element.getBoundingClientRect().top > 0) element.classList.remove('mergeToTop');
};