/**
 * brands.js
 *
 * Adds sticky functionality to the brands index.
 */
( function () {
	document.addEventListener( 'DOMContentLoaded', function () {
		const brandsAZ = document.getElementsByClassName( 'brands_index' );

		if ( ! brandsAZ.length ) {
			return;
		}

		const adminBar = document.body.classList.contains( 'admin-bar' )
				? 32
				: 0,
			brandsContainerHeight =
				document.getElementById( 'brands_a_z' ).scrollHeight,
			brandsAZHeight = brandsAZ[ 0 ].scrollHeight + 40;

		const stickyBrandsAZ = function () {
			if (
				window.innerWidth > 768 &&
				brandsAZ[ 0 ].getBoundingClientRect().top < 0
			) {
				brandsAZ[ 0 ].style.paddingTop =
					Math.min(
						Math.abs( brandsAZ[ 0 ].getBoundingClientRect().top ) +
							20 +
							adminBar,
						brandsContainerHeight - brandsAZHeight
					) + 'px';
			} else {
				brandsAZ[ 0 ].style.paddingTop = 0;
			}
		};

		stickyBrandsAZ();

		window.addEventListener( 'scroll', function () {
			stickyBrandsAZ();
		} );
	} );
} )();
