console.clear();

gsap.registerPlugin(Observer);

const scrollingText = gsap.utils.toArray('.rail h4');

const tl = horizontalLoop(scrollingText, {
 repeat: -1,
 paddingRight: 30,
});

Observer.create({
 onChangeY(self) {
 let factor = 2.5;
 if (self.deltaY < 0) {
 factor *= -1;
 } 
 gsap.timeline({
 defaults: {
 ease: "none",
 }
 })
 .to(tl, { timeScale: factor * 2.5, duration: 0.2, overwrite: true, })
 .to(tl, { timeScale: factor / 2.5, duration: 1 }, "+=0.3");
 }
});

/*
This helper function makes a group of elements animate along the x-axis in a seamless, responsive loop.

Features:
 - Uses xPercent so that even if the widths change (like if the window gets resized), it should still work in most cases.
 - When each item animates to the left or right enough, it will loop back to the other side
 - Optionally pass in a config object with values like "speed" (default: 1, which travels at roughly 100 pixels per second), paused (boolean), repeat, reversed, and paddingRight.
 - The returned timeline will have the following methods added to it:
 - next() - animates to the next element using a timeline.tweenTo() which it returns. You can pass in a vars object to control duration, easing, etc.
 - previous() - animates to the previous element using a timeline.tweenTo() which it returns. You can pass in a vars object to control duration, easing, etc.
 - toIndex() - pass in a zero-based index value of the element that it should animate to, and optionally pass in a vars object to control duration, easing, etc. Always goes in the shortest direction
 - current() - returns the current index (if an animation is in-progress, it reflects the final index)
 - times - an Array of the times on the timeline where each element hits the "starting" spot. There's also a label added accordingly, so "label1" is when the 2nd element reaches the start.
 */
function horizontalLoop(items, config) {
	items = gsap.utils.toArray(items);
	config = config || {};
	let tl = gsap.timeline({repeat: config.repeat, paused: config.paused, defaults: {ease: "none"}, onReverseComplete: () => tl.totalTime(tl.rawTime() + tl.duration() * 100)}),
		length = items.length,
		startX = items[0].offsetLeft,
		times = [],
		widths = [],
		xPercents = [],
		curIndex = 0,
		pixelsPerSecond = (config.speed || 1) * 100,
		snap = config.snap === false ? v => v : gsap.utils.snap(config.snap || 1), // some browsers shift by a pixel to accommodate flex layouts, so for example if width is 20% the first element's width might be 242px, and the next 243px, alternating back and forth. So we snap to 5 percentage points to make things look more natural
		totalWidth, curX, distanceToStart, distanceToLoop, item, i;
	gsap.set(items, { // convert "x" to "xPercent" to make things responsive, and populate the widths/xPercents Arrays to make lookups faster.
		xPercent: (i, el) => {
			let w = widths[i] = parseFloat(gsap.getProperty(el, "width", "px"));
			xPercents[i] = snap(parseFloat(gsap.getProperty(el, "x", "px")) / w * 100 + gsap.getProperty(el, "xPercent"));
			return xPercents[i];
		}
	});
	gsap.set(items, {x: 0});
	totalWidth = items[length-1].offsetLeft + xPercents[length-1] / 100 * widths[length-1] - startX + items[length-1].offsetWidth * gsap.getProperty(items[length-1], "scaleX") + (parseFloat(config.paddingRight) || 0);
	for (i = 0; i < length; i++) {
		item = items[i];
		curX = xPercents[i] / 100 * widths[i];
		distanceToStart = item.offsetLeft + curX - startX;
		distanceToLoop = distanceToStart + widths[i] * gsap.getProperty(item, "scaleX");
		tl.to(item, {xPercent: snap((curX - distanceToLoop) / widths[i] * 100), duration: distanceToLoop / pixelsPerSecond}, 0)
		 .fromTo(item, {xPercent: snap((curX - distanceToLoop + totalWidth) / widths[i] * 100)}, {xPercent: xPercents[i], duration: (curX - distanceToLoop + totalWidth - curX) / pixelsPerSecond, immediateRender: false}, distanceToLoop / pixelsPerSecond)
		 .add("label" + i, distanceToStart / pixelsPerSecond);
		times[i] = distanceToStart / pixelsPerSecond;
	}
	function toIndex(index, vars) {
		vars = vars || {};
		(Math.abs(index - curIndex) > length / 2) && (index += index > curIndex ? -length : length); // always go in the shortest direction
		let newIndex = gsap.utils.wrap(0, length, index),
			time = times[newIndex];
		if (time > tl.time() !== index > curIndex) { // if we're wrapping the timeline's playhead, make the proper adjustments
			vars.modifiers = {time: gsap.utils.wrap(0, tl.duration())};
			time += tl.duration() * (index > curIndex ? 1 : -1);
		}
		curIndex = newIndex;
		vars.overwrite = true;
		return tl.tweenTo(time, vars);
	}
	tl.next = vars => toIndex(curIndex+1, vars);
	tl.previous = vars => toIndex(curIndex-1, vars);
	tl.current = () => curIndex;
	tl.toIndex = (index, vars) => toIndex(index, vars);
	tl.times = times;
	tl.progress(1, true).progress(0, true); // pre-render for performance
	if (config.reversed) {
	 tl.vars.onReverseComplete();
	 tl.reverse();
	}
	return tl;
}